49 Cfr 393

[Code of Federal Regulations]

[Title 49, Volume 5]

[Revised as of October 1, 2005]

From the U.S. Government Printing Office via GPO Access

[CITE: 49CFR393]

[Page 361-449]

TITLE 49--TRANSPORTATION

DEPARTMENT OF TRANSPORTATION

PART 393_PARTS AND ACCESSORIES NECESSARY FOR SAFE OPERATION

Subpart A_General

Sec.

393.1 Scope of the rules of this part.

393.3 Additional equipment and accessories.

393.5 Definitions.

393.7 Matter incorporated by reference.

Subpart B_Lamps, Reflective Devices, and Electrical Wiring

393.9 Lamps operable, prohibition of obstructions of lamps and

reflectors.

393.11 Lamps and reflective devices.

393.13 Retroreflective sheeting and reflex reflectors, requirements for

semitrailers and trailers manufactured before December 1,

1993.

393.17 Lamps and reflectors--combinations in driveaway-towaway

operation.

393.19 Hazard warning signals.

393.20 [Reserved]

393.22 Combination of lighting devices and reflectors.

393.23 Power supply for lamps.

393.24 Requirements for head lamps, auxiliary driving lamps and front

fog lamps.

393.25 Requirements for lamps other than head lamps.

393.26 Requirements for reflex reflectors.

393.27 [Reserved]

393.28 Wiring systems.

393.29 [Reserved]

393.30 Battery installation.

393.31--393.33 [Reserved]

Subpart C_Brakes

393.40 Required brake systems.

393.41 Parking brake system.

393.42 Brakes required on all wheels.

393.43 Breakaway and emergency braking.

393.44 Front brake lines, protection.

393.45 Brake tubing and hoses; hose assemblies and end fittings.

393.46 [Reserved]

393.47 Brake actuators, slack adjusters, linings/pads and drums/rotors.

393.48 Brakes to be operative.

393.49 Single valve to operate all brakes.

393.50 Reservoirs required.

393.51 Warning signals, air pressure and vacuum gauges.

393.52 Brake performance.

393.53 Automatic brake adjusters and brake adjustment indicators.

393.55 Antilock brake systems.

Subpart D_Glazing and Window Construction

393.60 Glazing in specified openings.

393.61 Truck and truck tractor window construction.

393.62 Emergency exits for buses.

393.63 [Reserved]

Subpart E_Fuel Systems

393.65 All fuel systems.

393.67 Liquid fuel tanks.

393.68 Compressed natural gas fuel containers.

393.69 Liquefied petroleum gas systems.

Subpart F_Coupling Devices and Towing Methods

393.70 Coupling devices and towing methods, except for driveaway-towaway

operations.

393.71 Coupling devices and towing methods, driveaway-towaway

operations.

Subpart G_Miscellaneous Parts and Accessories

393.75 Tires.

393.76 Sleeper berths.

393.77 Heaters.

393.78 Windshield wiping and washing systems.

393.79 Windshield defrosting and defogging systems.

393.80 Rear-vision mirrors.

393.81 Horn.

393.82 Speedometer.

393.83 Exhaust systems.

393.84 Floors.

393.85 [Reserved]

393.86 Rear impact guards and rear end protection.

393.87 Warning flags on projecting loads.

393.88 Television receivers.

393.89 Buses, driveshaft protection.

393.90 Buses, standee line or bar.

393.91 Buses, aisle seats prohibited.

393.92 [Reserved]

393.93 Seats, seat belt assemblies, and seat belt assembly anchorages.

393.94 Interior noise levels in power units.

Subpart H_Emergency Equipment

393.95 Emergency equipment on all power units.

Subpart I_Protection Against Shifting and Falling Cargo

393.100 Which types of commercial motor vehicles are subject to the

cargo securement standards of this subpart, and what general

requirements apply?

393.102 What are the minimum performance criteria for cargo securement

devices and systems?

393.104 What standards must cargo securement devices and systems meet in

order

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to satisfy the requirements of this subpart?

393.106 What are the general requirements for securing articles of

cargo?

393.108 How is the working load limit of a tiedown determined?

393.110 What else do I have to do to determine the minimum number of

tiedowns?

393.112 Must a tiedown be adjustable?

393.114 What are the requirements for front end structures used as part

of a cargo securement system?

Specific Securement Requirements by Commodity Type

393.116 What are the rules for securing logs?

393.118 What are the rules for securing dressed lumber or similar

building products?

393.120 What are the rules for securing metal coils?

393.122 What are the rules for securing paper rolls?

393.124 What are the rules for securing concrete pipe?

393.126 What are the rules for securing intermodal containers?

393.128 What are the rules for securing automobiles, light trucks and

vans?

393.130 What are the rules for securing heavy vehicles, equipment and

machinery?

393.132 What are the rules for securing flattened or crushed vehicles?

393.134 What are the rules for securing roll-on/roll-off and hook lift

containers?

393.136 What are the rules for securing large boulders?

Subpart J_Frames, Cab and Body Components, Wheels, Steering, and

Suspension Systems

393.201 Frames.

393.203 Cab and body components.

393.205 Wheels.

393.207 Suspension systems.

393.209 Steering wheel systems.

Authority: 49 U.S.C. 322, 31136, and 31502; Section 1041(b) of Pub.

L. 102-240, 105 Stat. 1914, 1993 (1991); and 49 CFR 1.73.

Source: 33 FR 19735, Dec. 25, 1968, unless otherwise noted.

Editorial Note: Nomenclature changes to part 393 appear at 66 FR

49874, Oct. 1, 2001.

Subpart A_General

Source: 53 FR 49384, Dec. 7, 1988, unless otherwise noted.

Sec. 393.1 Scope of the rules in this part.

(a) The rules in this part establish minimum standards for

commercial motor vehicles as defined in Sec. 390.5 of this title. Only

motor vehicles (as defined in Sec. 390.5) and combinations of motor

vehicles which meet the definition of a commercial motor vehicle are

subject to the requirements of this part. All requirements that refer to

motor vehicles with a GVWR below 4,536 kg (10,001 pounds) are applicable

only when the motor vehicle or combination of motor vehicles meets the

definition of a commercial motor vehicle.

(b) Every employer and employee shall comply and be conversant with

the requirements and specifications of this part. No employer shall

operate a commercial motor vehicle, or cause or permit it to be

operated, unless it is equipped in accordance with the requirements and

specifications of this part.

[70 FR 48025, Aug. 15, 2005]

Sec. 393.3 Additional equipment and accessories.

Nothing contained in this subchapter shall be construed to prohibit

the use of additional equipment and accessories, not inconsistent with

or prohibited by this subchapter, provided such equipment and

accessories do not decrease the safety of operation of the motor

vehicles on which they are used.

Sec. 393.5 Definitions.

As used in this part, the following words and terms are construed to

mean:

Aggregate working load limit. The summation of the working load

limits or restraining capacity of all devices used to secure an article

of cargo on a vehicle.

Agricultural commodity trailer. A trailer that is designed to

transport bulk agricultural commodities in off-road harvesting sites and

to a processing plant or storage location, as evidenced by skeletal

construction that accommodates harvest containers, a maximum length of

28 feet, and an arrangement of air control lines and reservoirs that

minimizes damage in field operations.

Air brake system. A system, including an air-over-hydraulic brake

subsystem, that uses air as a medium for transmitting pressure or force

from the driver

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control to the service brake, but does not include a system that uses

compressed air or vacuum only to assist the driver in applying muscular

force to hydraulic or mechanical components.

Air-over-hydraulic brake subsystem. A subsystem of the air brake

system that uses compressed air to transmit a force from the driver

control to a hydraulic brake system to actuate the service brakes.

Anchor point. Part of the structure, fitting or attachment on a

vehicle or article of cargo to which a tiedown is attached.

Antilock Brake System or ABS means a portion of a service brake

system that automatically controls the degree of rotational wheel slip

during braking by:

(1) Sensing the rate of angular rotation of the wheels;

(2) Transmitting signals regarding the rate of wheel angular

rotation to one or more controlling devices which interpret those

signals and generate responsive controlling output signals; and

(3) Transmitting those controlling signals to one or more modulators

which adjust brake actuating forces in response to those signals.

Article of cargo. A unit of cargo, other than a liquid, gas, or

aggregate that lacks physical structure (e.g., grain, gravel, etc.)

including articles grouped together so that they can be handled as a

single unit or unitized by wrapping, strapping, banding or edge

protection device(s).

Auxiliary driving lamp. A lighting device mounted to provide

illumination forward of the vehicle which supplements the upper beam of

a standard headlighting system. It is not intended for use alone or with

the lower beam of a standard headlamp system.

Bell pipe concrete. Pipe whose flanged end is of larger diameter

than its barrel.

Blocking. A structure, device or another substantial article placed

against or around an article of cargo to prevent horizontal movement of

the article of cargo.

Boat trailer. A trailer designed with cradle-type mountings to

transport a boat and configured to permit launching of the boat from the

rear of the trailer.

Bracing. A structure, device, or another substantial article placed

against an article of cargo to prevent it from tipping, that may also

prevent it from shifting.

Brake. An energy conversion mechanism used to stop, or hold a

vehicle stationary.

Brake power assist unit. A device installed in a hydraulic brake

system that reduces the operator effort required to actuate the system,

but which if inoperative does not prevent the operator from braking the

vehicle by a continued application of muscular force on the service

brake control.

Brake power unit. A device installed in a brake system that provides

the energy required to actuate the brakes, either directly or indirectly

through an auxiliary device, with the operator action consisting only of

modulating the energy application level.

Brake tubing/hose. Metallic brake tubing, nonmetallic brake tubing

and brake hose are conduits or lines used in a brake system to transmit

or contain the medium (fluid or vacuum) used to apply the motor

vehicle's brakes.

Chassis. The load-supporting frame of a commercial motor vehicle,

exclusive of any appurtenances which might be added to accommodate

cargo.

Clearance Lamps. Lamps that provide light to the front or rear,

mounted on the permanent structure of the vehicle, such that they

indicate the overall width of the vehicle.

Container chassis trailer. A semitrailer of skeleton construction

limited to a bottom frame, one or more axles, specially built and fitted

with locking devices for the transport of intermodal cargo containers,

so that when the chassis and container are assembled, the units serve

the same function as an over the road trailer.

Converter dolly. A motor vehicle consisting of a chassis equipped

with one or more axles, a fifth wheel and/or equivalent mechanism, and

drawbar, the attachment of which converts a semitrailer to a full

trailer.

Curb weight. The weight of a motor vehicle with standard equipment,

maximum capacity of fuel, oil, and coolant; and, if so equipped, air

conditioning

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and additional weight of optional engine. Curb weight does not include

the driver.

Dunnage. All loose materials used to support and protect cargo.

Dunnage bag. An inflatable bag intended to fill otherwise empty

space between articles of cargo, or between articles of cargo and the

wall of the vehicle.

Edge protector. A device placed on the exposed edge of an article to

distribute tiedown forces over a larger area of cargo than the tiedown

itself, to protect the tie-down and/or cargo from damage, and to allow

the tiedown to slide freely when being tensioned.

Electric brake system. A system that uses electric current to

actuate the service brake.

Emergency brake. A mechanism designed to stop a motor vehicle after

a failure of the service brake system.

Emergency brake system. A mechanism designed to stop a vehicle after

a single failure occurs in the service brake system of a part designed

to contain compressed air or brake fluid or vacuum (except failure of a

common valve, manifold brake fluid housing or brake chamber housing).

Fifth wheel. A device mounted on a truck tractor or similar towing

vehicle (e.g., converter dolly) which interfaces with and couples to the

upper coupler assembly of a semitrailer.

Frame vehicle. A vehicle with skeletal structure fitted with one or

more bunk units for transporting logs. A bunk unit consists of U-shaped

front and rear bunks that together cradle logs. The bunks are welded,

gusseted or otherwise firmly fastened to the vehicle's main beams, and

are an integral part of the vehicle.

Friction mat. A device placed between the deck of a vehicle and

article of cargo, or between articles of cargo, intended to provide

greater friction than exists naturally between these surfaces.

Front fog lamp. A lighting device whose beam provides downward

illumination forward of the vehicle and close to the ground, and is to

be used only under conditions of rain, snow, dust, smoke or fog. A pair

of fog lamps may be used alone, with parking, tail, side, marker,

clearance and identification lamps, or with a lower beam headlamp at the

driver's discretion in accordance with state and local use law.

Fuel tank fitting. Any removable device affixed to an opening in the

fuel tank with the exception of the filler cap.

g. The acceleration due to gravity, 32.2 ft/sec\2\ (9.81 m/sec\2\).

Grommet. A device that serves as a support and protection to that

which passes through it.

Hazard warning signal. Lamps that flash simultaneously to the front

and rear, on both the right and left sides of a commercial motor

vehicle, to indicate to an approaching driver the presence of a

vehicular hazard.

Head lamps. Lamps used to provide general illumination ahead of a

motor vehicle.

Heater. Any device or assembly of devices or appliances used to heat

the interior of any motor vehicle. This includes a catalytic heater

which must meet the requirements of Sec. 177.834(l)(2) of this title

when Class 3 (flammable liquid) or Division 2.1 (flammable gas) is

transported.

Heavy hauler trailer. A trailer which has one or more of the

following characteristics, but which is not a container chassis trailer:

(1) Its brake lines are designed to adapt to separation or extension

of the vehicle frame; or

(2) Its body consists only of a platform whose primary cargo-

carrying surface is not more than 1,016 mm (40 inches) above the ground

in an unloaded condition, except that it may include sides that are

designed to be easily removable and a permanent ``front-end structure''

as that term is used in Sec. 393.106 of this title.

Hook-lift container. A specialized container, primarily used to

contain and transport materials in the waste, recycling, construction/

demolition and scrap industries, which is used in conjunction with

specialized vehicles, in which the container is loaded and unloaded onto

a tilt frame body by an articulating hook-arm.

Hydraulic brake system. A system that uses hydraulic fluid as a

medium for transmitting force from a service brake control to the

service brake, and

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that may incorporate a brake power assist unit, or a brake power unit.

Identification lamps. Lamps used to identify certain types of

commercial motor vehicles.

Integral securement system. A system on certain roll-on/roll-off

containers and hook-lift containers and their related transport vehicles

in which compatible front and rear hold down devices are mated to

provide securement of the complete vehicle and its articles of cargo.

Lamp. A device used to produce artificial light.

Length of a manufactured home. The largest exterior length in the

traveling mode, including any projections which contain interior space.

Length does not include bay windows, roof projections, overhangs, or

eaves under which there is no interior space, nor does it include

drawbars, couplings or hitches.

License plate lamp. A lamp used to illuminate the license plate on

the rear of a motor vehicle.

Longwood. All logs that are not shortwood, i.e., are over 4.9 m (16

feet) long. Such logs are usually described as long logs or treelength.

Low chassis vehicle. (1) A trailer or semitrailer manufactured on or

after January 26, 1998, having a chassis which extends behind the

rearmost point of the rearmost tires and which has a lower rear surface

that meets the guard width, height, and rear surface requirements of

Sec. 571.224 in effect on the date of manufacture, or a subsequent

edition.

(2) A motor vehicle, not described by paragraph (1) of this

definition, having a chassis which extends behind the rearmost point of

the rearmost tires and which has a lower rear surface that meets the

guard configuration requirements of Sec. 393.86(b)(1).

Manufactured home means a structure, transportable in one or more

sections, which in the traveling mode, is eight body feet or more in

width or forty body feet or more in length, or, when erected on site, is

three hundred twenty or more square feet, and which is built on a

permanent chassis and designed to be used as a dwelling with or without

a permanent foundation when connected to the required utilities, and

includes the plumbing, heating, air-conditioning, and electrical systems

contained therein. Calculations used to determine the number of square

feet in a structure will be based on the structure's exterior dimensions

measured at the largest horizontal projections when erected on site.

These dimensions will include all expandable rooms, cabinets, and other

projections containing interior space, but do not include bay windows.

This term includes all structures which meet the above requirements

except the size requirements and with respect to which the manufacturer

voluntarily files a certification pursuant to 24 CFR 3282.13 and

complies with the standards set forth in 24 CFR part 3280.

Multi-piece windshield. A windshield consisting of two or more

windshield glazing surface areas.

Parking brake system. A mechanism designed to prevent the movement

of a stationary motor vehicle.

Play. Any free movement of components.

Pulpwood trailer. A trailer or semitrailer that is designed

exclusively for harvesting logs or pulpwood and constructed with a

skeletal frame with no means for attachment of a solid bed, body, or

container.

Rail vehicle. A vehicle whose skeletal structure is fitted with

stakes at the front and rear to contain logs loaded crosswise.

Rear extremity. The rearmost point on a motor vehicle that falls

above a horizontal plane located 560 mm (22 inches) above the ground and

below a horizontal plane located 1,900 mm (75 inches) above the ground

when the motor vehicle is stopped on level ground; unloaded; its fuel

tanks are full; the tires (and air suspension, if so equipped) are

inflated in accordance with the manufacturer's recommendations; and the

motor vehicle's cargo doors, tailgate, or other permanent structures are

positioned as they normally are when the vehicle is in motion.

Nonstructural protrusions such as taillamps, rubber bumpers, hinges and

latches are excluded from the determination of the rearmost point.

Reflective material. A material conforming to Federal Specification

L-S-300, ``Sheeting and Tape, Reflective; Non-exposed Lens, Adhesive

Backing,''

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(September 7, 1965) meeting the performance standard in either Table 1

or Table 1A of SAE Standard J594f, ``Reflex Reflectors'' (January,

1977).

Reflex reflector. A device which is used on a vehicle to give an

indication to an approaching driver by reflected lighted from the lamps

on the approaching vehicle.

Saddle-mount. A device, designed and constructed as to be readily

demountable, used in driveaway-towaway operations to perform the

functions of a conventional fifth wheel:

(1) Upper-half. Upper-half of a ``saddle-mount'' means that part of

the device which is securely attached to the towed vehicle and maintains

a fixed position relative thereto, but does not include the ``king-

pin;''

(2) Lower-half. Lower-half of a ``saddle-mount'' means that part of

the device which is securely attached to the towing vehicle and

maintains a fixed position relative thereto but does not include the

``king-pin;'' and

(3) King-pin. King-pin means that device which is used to connect

the ``upper-half'' to the ``lower-half'' in such manner as to permit

relative movement in a horizontal plane between the towed and towing

vehicles.

Service brake system. A primary brake system used for slowing and

stopping a vehicle.

Shoring bar. A device placed transversely between the walls of a

vehicle and cargo to prevent cargo from tipping or shifting.

Shortwood. All logs typically up to 4.9 m (16 feet) long. Such logs

are often described as cut-up logs, cut-to-length logs, bolts or

pulpwood. Shortwood may be loaded lengthwise or crosswise, though that

loaded crosswise is usually no more than 2.6 m (102 inches) long.

Sided vehicle. A vehicle whose cargo compartment is enclosed on all

four sides by walls of sufficient strength to contain articles of cargo,

where the walls may include latched openings for loading and unloading,

and includes vans, dump bodies, and a sided intermodal container carried

by a vehicle.

Side extremity. The outermost point on a side of the motor vehicle

that is above a horizontal plane located 560 mm (22 inches) above the

ground, below a horizontal plane located 1,900 mm (75 inches) above the

ground, and between a transverse vertical plane tangent to the rear

extremity of the vehicle and a transverse vertical plane located 305 mm

(12 inches) forward of that plane when the vehicle is unloaded; its fuel

tanks are full; and the tires (and air suspension, if so equipped) are

inflated in accordance with the manufacturer's recommendations. Non-

structural protrusions such as taillights, hinges and latches are

excluded from the determination of the outermost point.

Side marker lamp (Intermediate). A lamp mounted on the side, on the

permanent structure of the motor vehicle that provides light to the side

to indicate the approximate middle of the vehicle, when the motor

vehicle is 9.14 meters (30 feet) or more in length.

Side Marker Lamps. Lamps mounted on the side, on the permanent

structure of the motor vehicle as near as practicable to the front and

rear of the vehicle, that provide light to the side to indicate the

overall length of the motor vehicle.

Special purpose vehicle. (1) A trailer or semitrailer manufactured

on or after January 26, 1998, having work-performing equipment that,

while the motor vehicle is in transit, resides in or moves through the

area that could be occupied by the horizontal member of the rear impact

guard, as defined by the guard width, height and rear surface

requirements of Sec. 571.224 (paragraphs S5.1.1 through S5.1.3), in

effect on the date of manufacture, or a subsequent edition.

(2) A motor vehicle, not described by paragraph (1) of this

definition, having work-performing equipment that, while the motor

vehicle is in transit, resides in or moves through the area that could

be occupied by the horizontal member of the rear impact guard, as

defined by the guard width, height and rear surface requirements of

Sec. 393.86(b)(1).

Split service brake system. A brake system consisting of two or more

subsystems actuated by a single control designed so that a leakage-type

failure of a pressure component in a single subsystem (except structural

failure of a housing that is common to two or more subsystems) shall not

impair the operation of any other subsystem.

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Steering wheel lash. The condition in which the steering wheel may

be turned through some part of a revolution without associated movement

of the front wheels.

Stop lamps. Lamps shown to the rear of a motor vehicle to indicate

that the service brake system is engaged.

Tail lamps. Lamps used to designate the rear of a motor vehicle.

Tiedown. A combination of securing devices which forms an assembly

that attaches articles of cargo to, or restrains articles of cargo on, a

vehicle or trailer, and is attached to anchor point(s).

Tow bar. A strut or column-like device temporarily attached between

the rear of a towing vehicle and the front of the vehicle being towed.

Tractor-pole trailer. A combination vehicle that carries logs

lengthwise so that they form the body of the vehicle. The logs are

supported by a bunk located on the rear of the tractor, and another bunk

on the skeletal trailer. The tractor bunk may rotate about a vertical

axis, and the trailer may have a fixed, scoping, or cabled reach, or

other mechanical freedom, to allow it to turn.

Trailer kingpin. A pin (with a flange on its lower end) which

extends vertically from the front of the underside of a semitrailer and

which locks into a fifth wheel.

Turn signals. Lamps used to indicate a change in direction by

emitting a flashing light on the side of a motor vehicle towards which a

turn will be made.

Upper coupler assembly. A structure consisting of an upper coupler

plate, king-pin and supporting framework which interfaces with and

couples to a fifth wheel.

Upper coupler plate. A plate structure through which the king-pin

neck and collar extend. The bottom surface of the plate contacts the

fifth wheel when coupled.

Vacuum brake system. A system that uses a vacuum and atmospheric

pressure for transmitting a force from the driver control to the service

brake, not including a system that uses vacuum only to assist the driver

in applying muscular force to hydraulic or mechanical components.

Void filler. Material used to fill a space between articles of cargo

and the structure of the vehicle that has sufficient strength to prevent

movement of the articles of cargo.

Well. The depression formed between two cylindrical articles of

cargo when they are laid with their eyes horizontal and parallel against

each other.

Wheels back vehicle. (1) A trailer or semitrailer manufactured on or

after January 26, 1998, whose rearmost axle is permanently fixed and is

located such that the rearmost surface of the tires (of the size

recommended by the vehicle manufacturer for the rear axle) is not more

than 305 mm (12 inches) forward of the transverse vertical plane tangent

to the rear extremity of the vehicle.

(2) A motor vehicle, not described by paragraph (1) of this

definition, whose rearmost axle is permanently fixed and is located such

that the rearmost surface of the tires (of the size recommended by the

vehicle manufacturer for the rear axle) is not more than 610 mm (24

inches) forward of the transverse vertical plane tangent to the rear

extremity of the vehicle.

Width of a manufactured home. The largest exterior width in the

traveling mode, including any projections which contain interior space.

Width does not include bay windows, roof projections, overhangs, or

eaves under which there is no interior space.

Windshield. The principal forward facing glazed surface provided for

forward vision in operating a motor vehicle.

Working load limit (WLL). The maximum load that may be applied to a

component of a cargo securement system during normal service, usually

assigned by the manufacturer of the component.

[53 FR 49384, Dec. 7, 1988, as amended at 63 FR 8339, Feb. 18, 1998; 63

FR 24465, May 4, 1998; 64 FR 47707, Sept. 1, 1999; 67 FR 61224, Sept.

27, 2002; 68 FR 56208, Sept. 30, 2003; 70 FR 48026, Aug. 15, 2005]

Sec. 393.7 Matter incorporated by reference.

(a) Incorporation by reference. Part 393 includes references to

certain matter or materials, as listed in paragraph (b) of this section.

The text of the materials is not included in the regulations

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contained in part 393. The materials are hereby made a part of the

regulations in part 393. The Director of the Federal Register has

approved the materials incorporated by reference in accordance with 5

U.S.C. 552(a) and 1 CFR part 51. For materials subject to change, only

the specific version approved by the Director of the Federal Register

and specified in the regulation are incorporated. Material is

incorporated as it exists on the date of the approval and a notice of

any change in these materials will be published in the Federal Register.

(b) Matter or materials referenced in part 393. The matter or

materials listed in this paragraph are incorporated by reference in the

corresponding sections noted.

(1) Auxiliary Upper Beam Lamps, Society of Automotive Engineers

(SAE) J581, July 2004, incorporation by reference approved for Sec.

393.24(b).

(2) Front Fog Lamp, SAE J583, August 2004, incorporation by

reference approved for Sec. 393.24(b).

(3) Stop Lamps for Use on Motor Vehicles Less Than 2032 mm in

Overall Width, SAE J586, March 2000, incorporation by reference approved

for Sec. 393.25(c).

(4) Stop Lamps and Front- and Rear-Turn Signal Lamps for Use on

Motor Vehicles 2032 mm or more in Overall Width, SAE J2261, January

2002, incorporated by reference approved for Sec. 393.25 (c).

(5) Tail Lamps (Rear Position Lamps) for Use on Motor Vehicles Less

Than 2032 mm in Overall Width, SAE J585, March 2000, incorporation by

reference approved for Sec. 393.25(c).

(6) Tail Lamps (Rear Position Lamps) for Use on Vehicles 2032 mm or

More in Overall Width, SAE J2040, March 2002, incorporation by reference

approved for Sec. 393.25(c).

(7) Turn Signal Lamps for Use on Motor Vehicles Less Than 2032 mm in

Overall Width, SAE J588, March 2000, incorporation by reference approved

for Sec. 393.25(c).

(8) Sidemarker Lamps for Use on Road Vehicles Less Than 2032 mm in

Overall Width, SAE J592, August 2000, incorporation by reference

approved for Sec. 393.25(c).

(9) Directional Flashing Optical Warning Devices for Authorized

Emergency, Maintenance, and Service Vehicles, SAE J595, January 2005,

incorporation by reference approved for Sec. 393.25(e).

(10) Optical Warning Devices for Authorized Emergency, Maintenance,

and Service Vehicles, SAE J845, May 1997, incorporation by reference

approved for Sec. 393.25(e).

(11) Gaseous Discharge Warning Lamp for Authorized Emergency,

Maintenance, and Service Vehicles, SAE J1318, May 1998, incorporation by

reference approved for Sec. 393.25(e).

(12) Reflex Reflectors, SAE J594, December 2003, incorporation by

reference approved for Sec. 393.26(c).

(13) Standard Specification for Retroreflective Sheeting for Traffic

Control, American Society of Testing and Materials, ASTM D 4956-04,

2004, incorporation by reference approved for Sec. 393.26(c).

(14) Automobile, Truck, Truck-Tractor, Trailer, and Motor Coach

Wiring, SAE J1292, October 1981, incorporated by reference approved for

Sec. 393.28.

(15) Long Stroke Air Brake Actuator Marking, SAE J1817, July 2001,

incorporation by reference approved for Sec. 393.47(e).

(16) American National Standard for Safety Glazing Materials for

Glazing Motor Vehicles and Motor Vehicle Equipment Operating on Land

Highways-Safety Standard, SAE Z26.1-1996, August 1997, incorporation by

reference approved for Sec. 393.62(d).

(17) Specification for Sound Level Meters, American National

Standards Institute, S1.4-1983, incorporation by reference approved for

Sec. 393.94(c).

(18) Standard Specification for Strapping, Flat Steel and Seals,

American Society for Testing and Materials (ASTM), D3953-97, February

1998, incorporation by reference approved for Sec. 393.104(e).

(19) Welded Steel Chain Specifications, National Association of

Chain Manufacturers, November 15, 1999, incorporation by reference

approved for Sec. 393.104(e).

(20) Recommended Standard Specification for Synthetic Web Tiedowns,

Web Sling and Tiedown Association,

[[Page 369]]

WSTDA-T1, 1998, incorporation by reference approved for Sec.

393.104(e).

(21) Wire Rope Users Manual, 2nd Edition, Wire Rope Technical Board

November 1985, incorporation by reference approved for Sec. 393.104(e).

(22) Cordage Institute rope standards approved for incorporation

into Sec. 393.104(e):

(i) PETRS-2, Polyester Fiber Rope, 3-Strand and 8-Strand

Constructions, January 1993;

(ii) PPRS-2, Polypropylene Fiber Rope, 3-Strand and 8-Strand

Constructions, August 1992;

(iii) CRS-1, Polyester/Polypropylene Composite Rope Specifications,

Three-Strand and Eight-Strand Standard Construction, May 1979;

(iv) NRS-1, Nylon Rope Specifications, Three-Strand and Eight-Strand

Standard Construction, May 1979; and

(v) C-1, Double Braided Nylon Rope Specifications DBN, January 1984.

(c) Availability. The materials incorporated by reference are

available as follows:

(1) Standards of the Underwriters Laboratories, Inc. Information and

copies may be obtained by writing to: Underwriters Laboratories, Inc.,

333 Pfingsten Road, Northbrook, Illinois 60062.

(2) Specifications of the American Society for Testing and

Materials. Information and copies may be obtained by writing to:

American Society for Testing and Materials, 100 Barr Harbor Drive, West

Conshohocken, Pennsylvania 19428-2959.

(3) Specifications of the National Association of Chain

Manufacturers. Information and copies may be obtained by writing to:

National Association of Chain Manufacturers, P.O. Box 22681, Lehigh

Valley, Pennsylvania 18002-2681.

(4) Specifications of the Web Sling and Tiedown Association.

Information and copies may be obtained by writing to: Web Sling and

Tiedown Association, Inc., 5024-R Campbell Boulevard, Baltimore,

Maryland 21236-5974.

(5) Manuals of the Wire Rope Technical Board. Information and copies

may be obtained by writing to: Wire Rope Technical Committee, P.O. Box

849, Stevensville, Maryland 21666.

(6) Standards of the Cordage Institute. Information and copies may

be obtained by writing to: Cordage Institute, 350 Lincoln Street,

<greek-i> 115, Hingham, Massachusetts 02043.

(7) Standards of the Society of Automotive Engineers (SAE).

Information and copies may be obtained by writing to: Society of

Automotive Engineers, Inc., 400 Commonwealth Drive, Warrendale,

Pennsylvania 15096.

(8) Standards of the American National Standards Institute (ANSI).

Information and copies may be obtained by writing to: American National

Standards Institute, 25 West 43rd Street, New York, New York 10036.

(9) [Reserved].

(10) All of the materials incorporated by reference are available

for inspection at:

(i) The Federal Motor Carrier Safety Administration, Office of Bus

and Truck Standards and Operations, 400 Seventh Street, SW., Washington,

DC 20590; and

(ii) The National Archives and Records Administration (NARA). For

information on the availability of this material at NARA, call 202-741-

6030, or go to: http://www.archives.gov/federal--register/code--of--

federal--regulations/ibr--locations.html.

[67 FR 61225, Sept. 27, 2002, as amended at 70 FR 48027, Aug. 15, 2005]

Subpart B_Lamps, Reflective Devices, and Electrical Wiring

Sec. 393.9 Lamps operable, prohibition of obstructions of lamps and

reflectors.

(a) All lamps required by this subpart shall be capable of being

operated at all times. This paragraph shall not be construed to require

that any auxiliary or additional lamp be capable of operating at all

times.

(b) Lamps and reflective devices/material required by this subpart

must not be obscured by the tailboard, or by any part of the load, or

its covering by dirt, or other added vehicle or work equipment, or

otherwise. Exception: The conspicuity treatments on the front end

protection devices may be obscured by part of the load being

transported.

[70 FR 48027, Aug. 15, 2005]

[[Page 370]]

Sec. 393.11 Lamps and reflective devices.

(a)(1) Lamps and reflex reflectors. Table 1 specifies the

requirements for lamps, reflective devices and associated equipment by

the type of commercial motor vehicle. The diagrams in this section

illustrate the position of the lamps, reflective devices and associated

equipment specified in Table 1. All commercial motor vehicles

manufactured on or after December 25, 1968, must, at a minimum, meet the

applicable requirements of 49 CFR 571.108 (FMVSS No. 108) in effect at

the time of manufacture of the vehicle. Commercial motor vehicles

manufactured before December 25, 1968, must, at a minimum, meet the

requirements of subpart B of part 393 in effect at the time of

manufacture.

(2) Exceptions: Pole trailers and trailer converter dollies must

meet the part 393 requirements for lamps, reflective devices and

electrical equipment in effect at the time of manufacture. Trailers

which are equipped with conspicuity material which meets the

requirements of Sec. 393.11(b) are not required to be equipped with the

reflex reflectors listed in Table 1 if--

(i) The conspicuity material is placed at the locations where reflex

reflectors are required by Table 1; and

(ii) The conspicuity material when installed on the motor vehicle

meets the visibility requirements for the reflex reflectors.

(b) Conspicuity Systems. Each trailer of 2,032 mm (80 inches) or

more overall width, and with a GVWR over 4,536 kg (10,000 pounds),

manufactured on or after December 1, 1993, except pole trailers and

trailers designed exclusively for living or office use, shall be

equipped with either retroreflective sheeting that meets the

requirements of FMVSS No. 108 (S5.7.1), reflex reflectors that meet the

requirements FMVSS No. 108 (S5.7.2), or a combination of retroreflective

sheeting and reflex reflectors that meet the requirements of FMVSS No.

108 (S5.7.3). The conspicuity system shall be installed and located as

specified in FMVSS No. 108 [S5.7.1.4 (for retroreflective sheeting),

S5.7.2.2 (for reflex reflectors), S5.7.3 (for a combination of sheeting

and reflectors)] and have certification and markings as required by

S5.7.1.5 (for retroreflective tape) and S5.7.2.3 (for reflex

reflectors).

(c) Prohibition on the use of amber stop lamps and tail lamps. No

commercial motor vehicle may be equipped with an amber stop lamp, a tail

lamp, or other lamp which is optically combined with an amber stop lamp

or tail lamp.

(d) Prohibition on the use of auxiliary lamps that supplement the

identification lamps. No commercial motor vehicle may be equipped with

lamps that are in a horizontal line with the required identification

lamps unless those lamps are required by this regulation.

[[Page 371]]

Table 1.--Required Lamps and Reflectors on Commercial Motor Vehicles

--------------------------------------------------------------------------------------------------------------------------------------------------------

Height above

the road

surface in

millimeters

(mm) (with

Item on the vehicle Quantity Color Location Position English units Vehicles for which the devices

in parenthesis) are required

measured from

the center of

the lamp at

curb weight

--------------------------------------------------------------------------------------------------------------------------------------------------------

Headlamps........................ 2 White.................. Front.......... On the front at Not less than A, B, C

the same 559 mm (22

height, with inches) nor

an equal more than

number at each 1,372 mm (54

side of the inches).

vertical

center line as

far apart as

practicable.

Turn signal (front). See 2 Amber.................. At or near the One on each Not less than A, B, C

footnotes <greek-i>2 and 12. front. side of the 381 mm (15

vertical inches) nor

centerline at more than

the same 2,108 mm (83

height and as inches).

far apart as

practicable.

Identification lamps (front). See 3 Amber.................. Front.......... As close as All three on B, C

footnote <greek-i>1. practicable to the same level

the top of the as close as

vehicle, at practicable to

the same the top of the

height, and as motor vehicle.

close as

practicable to

the vertical

centerline of

the vehicle

(or the

vertical

centerline of

the cab where

different from

the centerline

of the

vehicle) with

lamp centers

spaced not

less than 152

mm (6 inches)

or more than

305 mm (12

inches) apart.

Alternatively,

the front

lamps may be

located as

close as

practicable to

the top of the

cab.

Tail lamps. See footnotes <greek- 2 Red.................... Rear........... One lamp on Both on the A, B, C, D, E, F, G, H

i>5 and 11. each side of same level

the vertical between 381 mm

centerline at (15 inches)

the same and 1,829 mm

height and as (72 inches).

far apart as

practicable.

--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 372]]

Table 1.--Required Lamps and Reflectors on Commercial Motor Vehicles

--------------------------------------------------------------------------------------------------------------------------------------------------------

Height above

the road

surface in

millimeters

(mm) (with

Item on the vehicle Quantity Color Location Position English units Vehicles for which the devices

in parenthesis) are required

measured from

the center of

the lamp at

curb weight

--------------------------------------------------------------------------------------------------------------------------------------------------------

Stop lamps. See footnotes <greek- 2 Red.................... Rear........... One lamp on Both on the A, B, C, D, E, F, G

i>5 and 13. each side of same level

the vertical between 381 mm

centerline at (15 inches)

the same and 1,829 mm

height and as (72 inches).

far apart as

practicable.

Clearance lamps. See footnotes 2 Amber.................. One on each One on each Both on the B, C, D, G, H

<greek-i>8, 9, 10, 15 & 17. side of the side of the same level as

front of the vertical high as

vehicle. centerline to practicable.

indicate

overall width.

2 Red.................... One on each One on each Both on the B, D, G, H

side of the side of the same level as

rear of the vertical high as

vehicle. centerline to practicable.

indicate

overall width.

Reflex reflector, intermediate 2 Amber.................. One on each At or near the Between 381 mm A, B, D, F, G

(side). side. midpoint (15inches) and

between the 1,524 (60

front and rear inches).

side marker

lamps, if the

length of the

vehicle is

more than

9,144 mm (30

feet).

Reflex reflector (rear). See 2 Red.................... Rear........... One on each Both on the A, B, C, D, E, F, G

footnotes <greek-i>5, 6, and 8. side of the same level,

vertical between 381 mm

centerline, as (15 inches)

far apart as and 1,524 mm

practicable (60 inches).

and at the

same height.

Reflex reflector (rear side)..... 2 Red.................... One on each As far to the Both on the A, B, D, F, G

side (rear). rear as same level,

practicable. between 381 mm

(15 inches)

and 1,524 mm

(60 inches).

Reflex reflector (front side). 2 Amber.................. One on each As far to the Between 381 mm A, B, C, D, F, G

See footnote <greek-i>16. side (front). front as (15 inches)

practicable. and 1,524 mm

(60 inches).

License plate lamp (rear). See 1 White.................. At rear license No requirements A, B, C, D, F, G

footnote <greek-i>11. plate to

illuminate the

plate from the

top or sides.

Side marker lamp (front). See 2 Amber.................. One on each As far to the Not less than A, B, C, D, F

footnote <greek-i>16. side. front as 381 mm (15

practicable. inches).

[[Page 373]]

Side marker lamp intermediate.... 2 Amber.................. One on each At or near the Not less tan A, B, D, F, G

side. midpoint 381 mm (15

between the inches).

front and rear

side marker

lamps, if the

length of the

vehicle is

more than

9,144 mm (30

feet).

Side marker lamp (rear). See 2 Red.................... One on each As far to the Not less than A, B, D, F, G

footnotes <greek-i>4 and 8. side. rear as 381 mm (15

practicable. inches), and

on the rear of

trailers not

more than

1,524 mm (60

inches).

Turn signal (rear). See footnotes 2 Amber or red........... Rear........... One lamp on Both on the A, B, C, D, E, F, G

<greek-i>5 and 12. each side of same level,

the vertical between 381 mm

centerline as (15 inches)

far apart as and 2,108 mm

practicable. (83 inches).

Identification lamp (rear). See 3 Red.................... Rear........... One as close as All three on B, D, G

footnotes <greek-i>3, 7, and 15. practicable to the same level

the vertical as close as

centerline. practicable to

One on each the top of the

side with lamp vehicle.

centers spaced

not less than

152 mm (6

inches) or

more than 305

mm (12 inches)

apart.

Vehicular hazard warning signal 2 Amber.................. Front.......... One lamp on Both on the A, B, C

flasher lamps. See footnotes each side of same level,

<greek-i>5 and 12. the vertical between 381 mm

centerline, as (15 inches)

far apart as and 2,108 mm

practicable. (83 inches).

2 Amber or red........... Rear........... One lamp on Both on the A, B, C, D, E, F, G

each side of same level,

the vertical between 381 mm

centerline, as (15 inches)

far apart as and 2,108 mm

practicable. (83 inches).

Backup lamp. See footnote <greek- 1 or 2 White.................. Rear........... Rear........... No requirement. A, B, C

i>14.

Parking lamp..................... 2 Amber or white......... Front.......... One lamp on Both on the A

each side of same level,

the vertical between 381 mm

centerline, as (15 inches)

far apart as and 2,108 mm

practicable. (83 inches).

--------------------------------------------------------------------------------------------------------------------------------------------------------

Legend: Types of commercial motor vehicles shown in the last column of Table 1.

A. Buses and trucks less than 2,032 mm (80 inches) in overall width.

B. Buses and trucks 2,032 mm (80 inches) or more in overall width.

C. Truck tractors.

D. Semitrailers and full trailers 2,032 mm (80 inches) or more in overall width except converter dollies.

E. Converter dolly.

F. Semitrailers and full trailers less than 2,032 mm (80 inches) in overall width.

G. Pole trailers.

H. Projecting loads.

Note: Lamps and reflectors may be combined as permitted by Sec. 393.22 and S5.4 of 49 CFR 571.108, Equipment combinations.

Footnote--1 Identification lamps may be mounted on the vertical centerline of the cab where different from the centerline of the vehicle, except where

the cab is not more than 42 inches wide at the front roofline, then a single lamp at the center of the cab shall be deemed to comply with the

requirements for identification lamps. No part of the identification lamps or their mountings may extend below the top of the vehicle windshield.

[[Page 374]]

Footnote--2 Unless the turn signals on the front are so constructed (double-faced) and located as to be visible to passing drivers, two turn signals are

required on the rear of the truck tractor, one at each side as far apart as practicable.

Footnote--3 The identification lamps need not be visible or lighted if obscured by a vehicle in the same combination.

Footnote--4 Any semitrailer or full trailer manufactured on or after March 1, 1979, shall be equipped with rear side-marker lamps at a height of not

less than 381 mm (15 inches), and on the rear of trailers not more than 1,524 mm (60 inches) above the road surface, as measured from the center of

the lamp on the vehicle at curb weight.

Footnote--5 Each converter dolly, when towed singly by another vehicle and not as part of a full trailer, shall be equipped with one stop lamp, one tail

lamp, and two reflectors (one on each side of the vertical centerline, as far apart as practicable) on the rear. Each converter dolly shall be

equipped with rear turn signals and vehicular hazard warning signal flasher lamps when towed singly by another vehicle and not as part of a full

trailer, if the converter dolly obscures the turn signals at the rear of the towing vehicle.

Footnote--6 Pole trailers shall be equipped with two reflex reflectors on the rear, one on each side of the vertical centerline as far apart as

practicable, to indicate the extreme width of the trailer.

Footnote--7 Pole trailers, when towed by motor vehicles with rear identification lamps meeting the requirements of Sec. 393.11 and mounted at a height

greater than the load being transported on the pole trailer, are not required to have rear identification lamps.

Footnote--8 Pole trailers shall have on the rearmost support for the load: (1) two front clearance lamps, one on each side of the vehicle, both on the

same level and as high as practicable to indicate the overall width of the pole trailer; (2) two rear clearance lamps, one on each side of the

vehicle, both on the same level and as high as practicable to indicate the overall width of the pole trailer; (3) two rear side marker lamps, one on

each side of the vehicle, both on the same level, not less than 375 mm (15 inches) above the road surface; (4) two rear reflex reflectors, one on each

side, both on the same level, not less than 375 mm (15 inches) above the road surface to indicate maximum width of the pole trailer; and (5) one red

reflector on each side of the rearmost support for the load. Lamps and reflectors may be combined as allowed in Sec. 393.22.

Footnote--9 Any motor vehicle transporting a load which extends more than 102 mm (4 inches) beyond the overall width of the motor vehicle shall be

equipped with the following lamps in addition to other required lamps when operated during the hours when headlamps are required to be used.

(1) The foremost edge of that portion of the load which projects beyond the side of the vehicle shall be marked (at its outermost extremity) with an

amber lamp visible from the front and side.

(2) The rearmost edge of that portion of the load which projects beyond the side of the vehicle shall be marked (at its outermost extremity) with a red

lamp visible from the rear and side.

(3) If the projecting load does not measure more than 914 mm (3 feet) from front to rear, it shall be marked with an amber lamp visible from the front,

both sides, and rear, except that if the projection is located at or near the rear it shall be marked by a red lamp visible from front, side, and

rear.

Footnote--10 Projections beyond rear of motor vehicles. Motor vehicles transporting loads which extend more than 1,219 mm (4 feet) beyond the rear of

the motor vehicle, or which have tailboards or tailgates extending more than 1,219 mm (4 feet) beyond the body, shall have these projections marked as

follows when the vehicle is operated during the hours when headlamps are required to be used:

(1) On each side of the projecting load, one red side marker lamp, visible from the side, located so as to indicate maximum overhang.

(2) On the rear of the projecting load, two red lamps, visible from the rear, one at each side; and two red reflectors visible from the rear, one at

each side, located so as to indicate maximum width.

Footnote--11 To be illuminated when tractor headlamps are illuminated.

Footnote--12 Every bus, truck, and truck tractor shall be equipped with a signaling system that, in addition to signaling turning movements, shall have

a switch or combination of switches that will cause the two front turn signals and the two rear signals to flash simultaneously as a vehicular traffic

signal warning, required by Sec. 392-22(a). The system shall be capable of flashing simultaneously with the ignition of the vehicle on or off.

Footnote--13 To be actuated upon application of service brakes.

Footnote--14 Backup lamp required to operate when bus, truck, or truck tractor is in reverse.

Footnote--15

(1) For the purposes of Section 393.11, the term ``overall width'' refers to the nominal design dimension of the widest part of the vehicle, exclusive

of the signal lamps, marker lamps, outside rearview mirrors, flexible fender extensions, and mud flaps.

(2) Clearance lamps may be mounted at a location other than on the front and rear if necessary to indicate the overall width of a vehicle, or for

protection from damage during normal operation of the vehicle.

(3) On a trailer, the front clearance lamps may be mounted at a height below the extreme height if mounting at the extreme height results in the lamps

failing to mark the overall width of the trailer.

(4) On a truck tractor, clearance lamps mounted on the cab may be located to indicate the width of the cab, rather than the width of the vehicle.

(5) When the rear identification lamps are mounted at the extreme height of a vehicle, rear clearance lamps are not required to be located as close as

practicable to the top of the vehicle.

Footnote--16 A trailer subject to this part that is less than 1829 mm (6 feet) in overall length, including the trailer tongue, need not be equipped

with front side marker lamps and front side reflex reflectors.

Footnote--17 A boat trailer subject to this part whose overall width is 2032 mm (80 inches) or more need not be equipped with both front and rear

clearance lamps provided an amber (front) and red (rear) clearance lamp is located at or near the midpoint on each side so as to indicate its extreme

width.

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[70 FR 48027, Aug. 15, 2005]

[[Page 387]]

Sec. 393.13 Retroreflective sheeting and reflex reflectors,

requirements for semitrailers and trailers manufactured before

December 1, 1993.

(a) Applicability. All trailers and semitrailers manufactured prior

to December 1, 1993, which have an overall width of 2,032 mm (80 inches)

or more and a gross vehicle weight rating of 4,536 kg (10,001 pounds) or

more, except trailers that are manufactured exclusively for use as

offices or dwellings, pole trailers (as defined in Sec. 390.5 of this

subchapter), and trailers transported in a driveaway-towaway operation,

must be equipped with retroreflective sheeting or an array of reflex

reflectors that meet the requirements of this section. Motor carriers

operating trailers, other than container chassis (as defined in Sec.

393.5), have until June 1, 2001, to comply with the requirements of this

section. Motor carriers operating container chassis have until December

1, 2001, to comply with the requirements of this section.

(b) Retroreflective sheeting and reflex reflectors. Motor carriers

are encouraged to retrofit their trailers with a conspicuity system that

meets all of the requirements applicable to trailers manufactured on or

after December 1, 1993, including the use of retroreflective sheeting or

reflex reflectors in a red and white pattern (see Federal Motor Vehicle

Safety Standard No. 108 (49 CFR 571.108), S5.7, Conspicuity systems).

Motor carriers which do not retrofit their trailers to meet the

requirements of FMVSS No. 108, for example by using an alternative color

pattern, must comply with the remainder of this paragraph and with

paragraph (c) or (d) of this section. Retroreflective sheeting or reflex

reflectors in colors or color combinations other than red and white may

be used on the sides or lower rear area of the semitrailer or trailer

until June 1, 2009. The alternate color or color combination must be

uniform along the sides and lower rear area of the trailer. The

retroreflective sheeting or reflex reflectors on the upper rear area of

the trailer must be white and conform to the requirements of FMVSS No.

108 (S5.7). Red retroreflective sheeting or reflex reflectors shall not

be used along the sides of the trailer unless it is used as part of a

red and white pattern. Retroreflective sheeting shall have a width of at

least 50 mm (2 inches).

(c) Locations for retroreflective sheeting--(1) Sides.

Retroreflective sheeting shall be applied to each side of the trailer or

semitrailer. Each strip of retroreflective sheeting shall be positioned

as horizontally as practicable, beginning and ending as close to the

front and rear as practicable. The strip need not be continuous but the

sum of the length of all of the segments shall be at least half of the

length of the trailer and the spaces between the segments of the strip

shall be distributed as evenly as practicable. The centerline for each

strip of retroreflective sheeting shall be between 375 mm (15 inches)

and 1,525 mm (60 inches) above the road surface when measured with the

trailer empty or unladen, or as close as practicable to this area. If

necessary to clear rivet heads or other similar obstructions, 50 mm (2

inches) wide retroreflective sheeting may be separated into two 25 mm (1

inch) wide strips of the same length and color, separated by a space of

not more than 25 mm (1 inch).

(2) Lower rear area. The rear of each trailer and semitrailer must

be equipped with retroreflective sheeting. Each strip of retroreflective

sheeting shall be positioned as horizontally as practicable, extending

across the full width of the trailer, beginning and ending as close to

the extreme edges as practicable. The centerline for each of the strips

of retroreflective sheeting shall be between 375 mm (15 inches) and

1,525 mm (60 inches) above the road surface when measured with the

trailer empty or unladen, or as close as practicable to this area.

(3) Upper rear area. Two pairs of white strips of retroreflective

sheeting, each pair consisting of strips 300 mm (12 inches) long, must

be positioned horizontally and vertically on the right and left upper

corners of the rear of the body of each trailer and semitrailer, as

close as practicable to the top of the trailer and as far apart as

practicable. If the perimeter of the body, as viewed from the rear, is

not square or rectangular, the strips may be applied along the

perimeter, as close as practicable to the uppermost and outermost areas

[[Page 388]]

of the rear of the body on the left and right sides.

(d) Locations for reflex reflectors.--(1) Sides. Reflex reflectors

shall be applied to each side of the trailer or semitrailer. Each array

of reflex reflectors shall be positioned as horizontally as practicable,

beginning and ending as close to the front and rear as practicable. The

array need not be continuous but the sum of the length of all of the

array segments shall be at least half of the length of the trailer and

the spaces between the segments of the strip shall be distributed as

evenly as practicable. The centerline for each array of reflex

reflectors shall be between 375 mm (15 inches) and 1,525 mm (60 inches)

above the road surface when measured with the trailer empty or unladen,

or as close as practicable to this area. The center of each reflector

shall not be more than 100 mm (4 inches) from the center of each

adjacent reflector in the segment of the array. If reflex reflectors are

arranged in an alternating color pattern, the length of reflectors of

the first color shall be as close as practicable to the length of the

reflectors of the second color.

(2) Lower rear area. The rear of each trailer and semitrailer must

be equipped with reflex reflectors. Each array of reflex reflectors

shall be positioned as horizontally as practicable, extending across the

full width of the trailer, beginning and ending as close to the extreme

edges as practicable. The centerline for each array of reflex reflectors

shall be between 375 mm (15 inches) and 1,525 mm (60 inches) above the

road surface when measured with the trailer empty or unladen, or as

close as practicable to this area. The center of each reflector shall

not be more than 100 mm (4 inches) from the center of each adjacent

reflector in the segment of the array.

(3) Upper rear area. Two pairs of white reflex reflector arrays,

each pair at least 300 mm (12 inches) long, must be positioned

horizontally and vertically on the right and left upper corners of the

rear of the body of each trailer and semitrailer, as close as

practicable to the top of the trailer and as far apart as practicable.

If the perimeter of the body, as viewed from the rear, is not square or

rectangular, the arrays may be applied along the perimeter, as close as

practicable to the uppermost and outermost areas of the rear of the body

on the left and right sides. The center of each reflector shall not be

more than 100 mm (4 inches) from the center of each adjacent reflector

in the segment of the array.

[64 FR 15605, Mar. 31, 1999, as amended at 66 FR 30339, June 6, 2001]

Sec. 393.17 Lamps and reflectors--combinations in driveaway-towaway

operation.

A combination of motor vehicles engaged in driveaway-towaway

operation must be equipped with operative lamps and reflectors

conforming to the rules in this section.

(a) The towing vehicle must be equipped as follows:

(1) On the front, there must be at least two headlamps, an equal

number at each side, two turn signals, one at each side, and two

clearance lamps, one at each side.

(2) On each side, there must be at least one side-marker lamp,

located near the front of the vehicle.

(3) On the rear, there must be at least two tail lamps, one at each

side, and two stop lamps, one at each side.

(b) Except as provided in paragraph (c) of this section, the

rearmost towed vehicle of the combination (including the towed vehicle

or a tow-bar combination, the towed vehicle of a single saddle-mount

combination, and the rearmost towed vehicle of a double or triple

saddle-mount combination) or, in the case of a vehicle full-mounted on a

saddle-mount vehicle, either the full-mounted vehicle or the rearmost

saddle-mounted vehicle must be equipped as follows:

(1) On each side, there must be at least one side-marker lamp,

located near the rear of the vehicle.

(2) On the rear, there must be at least two tail lamps, two stop

lamps, two turn signals, two clearance lamps, and two reflectors, one of

each type at each side. In addition, if any vehicle in the combination

is 80 inches or more in overall width, there must be three

identification lamps on the rear.

(c) If the towed vehicle in a combination is a mobile structure

trailer, it must be equipped in accordance with

[[Page 389]]

the following lighting devices. For the purposes of this part, mobile

structure trailer means a trailer that has a roof and walls, is at least

10 feet wide, and can be used off road for dwelling or commercial

purposes.

(1) When the vehicle is operated in accordance with the terms of a

special permit prohibiting operation during the times when lighted lamps

are required under Sec. 392.30, it must have on the rear--

(i) Two stop lamps, one on each side of the vertical centerline, at

the same height, and as far apart as practicable;

(ii) Two tail lamps, one on each side of the vertical centerline, at

the same height, and as far apart as practicable;

(iii) Two red reflex reflectors, one on each side of the vertical

centerline, at the same height, and as far apart as practicable; and

(iv) Two turn signal lamps, one on each side of the vertical

centerline, at the same height, and as far apart as practicable.

(2) At all other times, the vehicle must be equipped as specified in

paragraph (b) of this section.

(d) An intermediate towed vehicle in a combination consisting of

more than two vehicles (including the first saddle-mounted vehicle of a

double saddle-mount combination and the first and second saddle-mount

vehicles of a triple saddle-mount combination) must have one side-marker

lamp on each side, located near the rear of the vehicle.

[[Page 390]]

[GRAPHIC] [TIFF OMITTED] TR15AU05.017

[[Page 391]]

[GRAPHIC] [TIFF OMITTED] TR15AU05.018

[[Page 392]]

[GRAPHIC] [TIFF OMITTED] TR15AU05.019

(49 U.S.C. 304, 1655; 49 CFR 1.48(b) and 301.60)

[40 FR 36126, Aug. 19, 1975, as amended at 47 FR 47837, Oct. 28, 1982;

70 FR 48044, Aug. 15, 2005]

Sec. 393.19 Hazard warning signals.

The hazard warning signal operating unit on each commercial motor

vehicle shall operate independently of the ignition or equivalent

switch, and when activated, cause all turn signals required by Sec.

393.11 to flash simultaneously.

[70 FR 48046, Aug. 15, 2005]

Sec. 393.20 [Reserved]

Sec. 393.22 Combination of lighting devices and reflectors.

(a) Permitted combinations. Except as provided in paragraph (b) of

this section, two or more lighting devices and reflectors (whether or

not required by the rules in this part) may be combined optically if--

(1) Each required lighting device and reflector conforms to the

applicable rules in this part; and

(2) Neither the mounting nor the use of a nonrequired lighting

device or reflector impairs the effectiveness of a required lighting

device or reflector or causes that device or reflector to be

inconsistent with the applicable rules in this part.

(b) Prohibited combinations. (1) A turn signal lamp must not be

combined optically with either a head lamp or other

[[Page 393]]

lighting device or combination of lighting devices that produces a

greater intensity of light than the turn signal lamp.

(2) A turn signal lamp must not be combined optically with a stop

lamp unless the stop lamp function is always deactivated when the turn

signal function is activated.

(3) A clearance lamp must not be combined optically with a tail lamp

or identification lamp.

[39 FR 26908, July 24, 1974]

Sec. 393.23 Power supply for lamps.

All required lamps must be powered by the electrical system of the

motor vehicle with the exception of battery powered lamps used on

projecting loads.

[70 FR 48046, Aug. 15, 2005]

Sec. 393.24 Requirements for head lamps, auxiliary driving lamps and

front fog lamps.

(a) Headlamps. Every bus, truck and truck tractor shall be equipped

with headlamps as required by Sec. 393.11(a). The headlamps shall

provide an upper and lower beam distribution of light, selectable at the

driver's will and be steady-burning. The headlamps shall be marked in

accordance with FMVSS No. 108. Auxiliary driving lamps and/or front fog

lamps may not be used to satisfy the requirements of this paragraph.

(b) Auxiliary driving lamps and front fog lamps. Commercial motor

vehicles may be equipped with auxiliary driving lamps and/or front fog

lamps for use in conjunction with, but not in lieu of the required

headlamps. Auxiliary driving lamps shall meet SAE Standard J581

Auxiliary Upper Beam Lamps, July 2004, and front fog lamps shall meet

SAE Standard J583 Front Fog Lamp, August 2004. (See Sec. 393.7 for

information on the incorporation by reference and availability of these

documents.)

(c) Mounting. Headlamps shall be mounted and aimable in accordance

with FMVSS No. 108. Auxiliary driving lamps and front fog lamps shall be

mounted so that the beams are aimable and the mounting shall prevent the

aim of the lighting device from being disturbed while the vehicle is

operating on public roads.

(d) Aiming. Headlamps, auxiliary driving lamps and front fog lamps

shall be aimed to meet the aiming specifications in FMVSS No. 108 (49

CFR 571.108), SAE J581, and SAE J583, respectively.

[70 FR 48046, Aug. 15, 2005]

Sec. 393.25 Requirements for lamps other than head lamps.

(a) Mounting. All lamps shall be securely mounted on a rigid part of

the vehicle. Temporary lamps must be securely mounted to the load and

are not required to be mounted to a permanent part of the vehicle.

(b) Visibility. Each lamp shall be located so that it meets the

visibility requirements specified by FMVSS No. 108 in effect at the time

of manufacture of the vehicle. Vehicles which were not subject to FMVSS

No. 108 at the time of manufacture shall have each lamp located so that

it meets the visibility requirements specified in the SAE standards

listed in paragraph (c) of this section. If motor vehicle equipment

(e.g., mirrors, snow plows, wrecker booms, backhoes, and winches)

prevents compliance with this paragraph by any required lamp, an

auxiliary lamp or device meeting the requirements of this paragraph

shall be provided. This shall not be construed to apply to lamps on one

unit which are obscured by another unit of a combination of vehicles.

(c) Specifications. All required lamps (except marker lamps on

projecting loads, lamps which are temporarily attached to vehicles

transported in driveaway-towaway operations, and lamps on converter

dollies and pole trailers) on vehicles manufactured on or after December

25, 1968, shall, at a minimum, meet the applicable requirements of FMVSS

No. 108 in effect on the date of manufacture of the vehicle. Marker

lamps on projecting loads, all lamps which are temporarily attached to

vehicles transported in driveaway-towaway operations, and all lamps on

converter dollies and pole trailers must meet the following applicable

SAE standards: J586--Stop Lamps for Use on Motor Vehicles Less Than 2032

mm in Overall Width, March 2000; J2261 Stop

[[Page 394]]

Lamps and Front- and Rear-Turn Signal Lamps for Use on Motor Vehicles

2032 mm or More in Overall Width, January 2002; J585--Tail Lamps (Rear

Position Lamps) for Use on Motor Vehicles Less Than 2032 mm in Overall

Width, March 2000; J588--Turn Signal Lamps for Use on Motor Vehicles

Less Than 2032 mm in Overall Width, March 2000; J2040--Tail Lamps (Rear

Position Lamps) for Use on Vehicles 2032 mm or More in Overall Width,

March 2002; J592--Sidemarker Lamps for Use on Road Vehicles Less Than

2032 mm in Overall Width, August 2000. (See Sec. 393.7 for information

on the incorporation by reference and availability of these documents.)

(d) (Reserved)

(e) Lamps to be steady-burning. All exterior lamps (both required

lamps and any additional lamps) shall be steady-burning with the

exception of turn signal lamps; hazard warning signal lamps; school bus

warning lamps; amber warning lamps or flashing warning lamps on tow

trucks and commercial motor vehicles transporting oversized loads; and

warning lamps on emergency and service vehicles authorized by State or

local authorities. Lamps combined into the same shell or housing with a

turn signal are not required to be steady burning while the turn signal

is in use. Amber warning lamps must meet SAE J845--Optical Warning

Devices for Authorized Emergency, Maintenance and Service Vehicles, May

1997. Amber flashing warning lamps must meet SAE J595--Directional

Flashing Optical Warning Devices for Authorized Emergency, Maintenance

and Service Vehicles, January 2005. Amber gaseous discharge warning

lamps must meet SAE J1318 Gaseous Discharge Warning Lamp for Authorized

Emergency, Maintenance, and Service Vehicles, May 1998. (See Sec.

393.7(b) for information on the incorporation by reference and

availability of these documents.)

(f) Stop lamp operation. The stop lamps on each vehicle shall be

activated upon application of the service brakes. The stop lamps are not

required to be activated when the emergency feature of the trailer

brakes is used or when the stop lamp is optically combined with the turn

signal and the turn signal is in use.

[70 FR 48047, Aug. 15, 2005]

Sec. 393.26 Requirements for reflectors.

(a) Mounting. Reflex reflectors shall be mounted at the locations

required by Sec. 393.11. In the case of motor vehicles so constructed

that requirement for a 381 mm (15-inch) minimum height above the road

surface is not practical, the reflectors shall be mounted as close as

practicable to the required mounting height range. All permanent reflex

reflectors shall be securely mounted on a rigid part of the vehicle.

Temporary reflectors on projecting loads must be securely mounted to the

load and are not required to be permanently mounted to a part of the

vehicle. Temporary reflex reflectors on vehicles transported in

driveaway-towaway operations must be firmly attached.

(b) Specifications. All required reflex reflectors (except reflex

reflectors on projecting loads, vehicles transported in a driveaway-

towaway operation, converter dollies and pole trailers) on vehicles

manufactured on or after December 25, 1968, shall meet the applicable

requirements of FMVSS No. 108 in effect on the date of manufacture of

the vehicle. Reflex reflectors on projecting loads, vehicles transported

in a driveaway-towaway operation, and all reflex reflectors on converter

dollies and pole trailers must conform to SAE J594--Reflex Reflectors,

December 2003.

(c) Substitute material for side reflex reflectors. Reflective

material conforming to ASTM D 4956-04, Standard Specification for

Retroreflective Sheeting for Traffic Control, may be used in lieu of

reflex reflectors if the material as used on the vehicle, meets the

performance standards in either Table I of SAE J594 or Table IA of SAE

J594--Reflex Reflectors, December 2003. (See Sec. 393.7(b) for

information on the incorporation by reference and availability of these

documents.)

(d) Use of additional retroreflective surfaces. Additional

retroreflective surfaces may be used in conjunction with, but not in

lieu of the reflex reflectors required in subpart B of part 393, and the

substitute material for side reflex reflectors allowed by paragraph (c)

of this section, provided:

[[Page 395]]

(1) Designs do not resemble traffic control signs, lights, or

devices, except that straight edge striping resembling a barricade

pattern may be used.

(2) Designs do not tend to distort the length and/or width of the

motor vehicle.

(3) Such surfaces shall be at least 3 inches from any required lamp

or reflector unless of the same color as such lamp or reflector.

(4) No red color shall be used on the front of any motor vehicle,

except for display of markings or placards required by Sec. 177.823 of

this title.

(5) Retroreflective license plates required by State or local

authorities may be used.

[33 FR 19735, Dec. 25, 1968, as amended at 35 FR 3167, Feb. 19, 1970; 53

FR 49397, Dec. 7, 1988; 70 FR 48047, Aug. 15, 2005]

Sec. 393.27 [Reserved]

Sec. 393.28 Wiring systems.

Electrical wiring shall be installed and maintained to conform to

SAE J1292--Automobile, Truck, Truck-Tractor, Trailer, and Motor Coach

Wiring, October 1981, except the jumper cable plug and receptacle need

not conform to SAE J560. The reference to SAE J1292 shall not be

construed to require circuit protection on trailers. (See Sec. 393.7(b)

for information on the incorporation by reference and availability of

this document.)

[70 FR 48047, Aug. 15, 2005]

Sec. 393.29 [Reserved]

Sec. 393.30 Battery installation.

Every storage battery on every vehicle, unless located in the engine

compartment, shall be covered by a fixed part of the motor vehicle or

protected by a removable cover or enclosure. Removable covers or

enclosures shall be substantial and shall be securely latched or

fastened. The storage battery compartment and adjacent metal parts which

might corrode by reason of battery leakage shall be painted or coated

with an acid-resisting paint or coating and shall have openings to

provide ample battery ventilation and drainage. Wherever the cable to

the starting motor passes through a metal compartment, the cable shall

be protected against grounding by an acid and waterproof insulating

bushing. Wherever a battery and a fuel tank are both placed under the

driver's seat, they shall be partitioned from each other, and each

compartment shall be provided with an independent cover, ventilation,

and drainage.

Sec. 393.31--393.33 [Reserved]

Subpart C_Brakes

Sec. 393.40 Required brake systems.

(a) Each commercial motor vehicle must have brakes adequate to stop

and hold the vehicle or combination of motor vehicles. Each commercial

motor vehicle must meet the applicable service, parking, and emergency

brake system requirements provided in this section.

(b) Service brakes. (1) Hydraulic brake systems. Motor vehicles

equipped with hydraulic brake systems and manufactured on or after

September 2, 1983, must, at a minimum, have a service brake system that

meets the requirements of FMVSS No. 105 in effect on the date of

manufacture. Motor vehicles which were not subject to FMVSS No. 105 on

the date of manufacture must have a service brake system that meets the

applicable requirements of Sec. Sec. 393.42, 393.48, 393.49, 393.51,

and 393.52 of this subpart.

(2) Air brake systems. Buses, trucks and truck-tractors equipped

with air brake systems and manufactured on or after March 1, 1975, and

trailers manufactured on or after January 1, 1975, must, at a minimum,

have a service brake system that meets the requirements of FMVSS No. 121

in effect on the date of manufacture. Motor vehicles which were not

subject to FMVSS No. 121 on the date of manufacture must have a service

brake system that meets the applicable requirements of Sec. Sec.

393.42, 393.48, 393.49, 393.51, and 393.52 of this subpart.

(3) Vacuum brake systems. Motor vehicles equipped with vacuum brake

systems must have a service brake system that meets the applicable

requirements of Sec. Sec. 393.42, 393.48, 393.49, 393.51, and 393.52 of

this subpart.

[[Page 396]]

(4) Electric brake systems. Motor vehicles equipped with electric

brake systems must have a service brake system that meets the applicable

requirements of Sec. Sec. 393.42, 393.48, 393.49 and 393.52 of this

subpart.

(c) Parking brakes. Each commercial motor vehicle must be equipped

with a parking brake system that meets the applicable requirements of

Sec. 393.41.

(d) Emergency brakes--partial failure of service brakes.

(1) Hydraulic brake systems. Motor vehicles manufactured on or after

September 2, 1983, and equipped with a split service brake system must,

at a minimum, meet the partial failure requirements of FMVSS No. 105 in

effect on the date of manufacture.

(2) Air brake systems. Buses, trucks and truck tractors manufactured

on or after March 1, 1975, and trailers manufactured on or after January

1, 1975, must be equipped with an emergency brake system which, at a

minumum, meets the requirements of FMVSS No. 121 in effect on the date

of manufacture.

(3) Vehicles not subject to FMVSS Nos. 105 and 121 on the date of

manufacture. Buses, trucks and truck tractors not subject to FMVSS Nos.

105 or 121 on the date of manufacture must meet the requirements of

Sec. 393.40(e). Trailers not subject to FMVSS No. 121 at the time of

manufacture must meet the requirements of Sec. 393.43.

(e) Emergency brakes, vehicles manufactured on or after July 1,

1973. (1) A bus, truck, truck tractor, or a combination of motor

vehicles manufactured on or after July 1, 1973, and not covered under

paragraphs (d)(1) or (d)(2) of this section, must have an emergency

brake system which consists of emergency features of the service brake

system or an emergency system separate from the service brake system.

The emergency brake system must meet the applicable requirements of

Sec. Sec. 393.43 and 393.52.

(2) A control by which the driver applies the emergency brake system

must be located so that the driver can operate it from the normal

seating position while restrained by any seat belts with which the

vehicle is equipped. The emergency brake control may be combined with

either the service brake control or the parking brake control. However,

all three controls may not be combined.

(f) Interconnected systems. (1) If the brake systems required by

Sec. 393.40(a) are interconnected in any way, they must be designed,

constructed, and maintained so that in the event of a failure of any

part of the operating mechanism of one or more of the systems (except

the service brake actuation pedal or valve), the motor vehicle will have

operative brakes and, for vehicles manufactured on or after July 1,

1973, be capable of meeting the requirements of Sec. 393.52(b).

(2) A motor vehicle to which the requirements of FMVSS No. 105

(S5.1.2), dealing with partial failure of the service brake, applied at

the time of manufacture meets the requirements of Sec. 393.40(f)(1) if

the motor vehicle is maintained in conformity with FMVSS No. 105 and the

motor vehicle is capable of meeting the requirements of Sec. 393.52(b),

except in the case of a structural failure of the brake master cylinder

body.

(3) A bus is considered to meet the requirements of Sec.

393.40(f)(1) if it meets the requirements of Sec. 393.44 and Sec.

393.52(b).

[70 FR 48048, Aug. 15, 2005]

Sec. 393.41 Parking brake system.

(a) Hydraulic-braked vehicles manufactured on or after September 2,

1983. Each truck and bus (other than a school bus) with a GVWR of 4,536

kg (10,000 pounds) or less which is subject to this part and school

buses with a GVWR greater than 4,536 kg (10,000 pounds) shall be

equipped with a parking brake system as required by FMVSS No. 571.105

(S5.2) in effect at the time of manufacture. The parking brake shall be

capable of holding the vehicle or combination of vehicles stationary

under any condition of loading in which it is found on a public road

(free of ice and snow). Hydraulic-braked vehicles which were not subject

to the parking brake requirements of FMVSS No. 571.105 (S5.2) must be

equipped with a parking brake system that meets the requirements of

paragraph (c) of this section.

(b) Air-braked power units manufactured on or after March 1, 1975,

and air-

[[Page 397]]

braked trailers manufactured on or after January 1, 1975.

Each air-braked bus, truck and truck tractor manufactured on and

after March 1, 1975, and each air-braked trailer except an agricultural

commodity trailer, converter dolly, heavy hauler trailer or pulpwood

trailer, shall be equipped with a parking brake system as required by

FMVSS No. 121 (S5.6) in effect at the time of manufacture. The parking

brake shall be capable of holding the vehicle or combination of vehicles

stationary under any condition of loading in which it is found on a

public road (free of ice and snow). An agricultural commodity trailer,

heavy hauler or pulpwood trailer shall carry sufficient chocking blocks

to prevent movement when parked.

(c) Vehicles not subject to FMVSS Nos. 105 and 121 on the date of

manufacture. (1) Each singly driven motor vehicle not subject to parking

brake requirements of FMVSS Nos. 105 or 121 at the time of manufacturer,

and every combination of motor vehicles must be equipped with a parking

brake system adequate to hold the vehicle or combination on any grade on

which it is operated, under any condition of loading in which it is

found on a public road (free of ice and snow).

(2) The parking brake system shall, at all times, be capable of

being applied by either the driver's muscular effort or by spring

action. If other energy is used to apply the parking brake, there must

be an accumulation of that energy isolated from any common source and

used exclusively for the operation of the parking brake.

Exception: This paragraph shall not be applicable to air-applied,

mechanically-held parking brake systems which meet the parking brake

requirements of FMVSS No. 121 (S5.6).

(3) The parking brake system shall be held in the applied position

by energy other than fluid pressure, air pressure, or electric energy.

The parking brake system shall not be capable of being released unless

adequate energy is available to immediately reapply the parking brake

with the required effectiveness.

[70 FR 48048, Aug. 15, 2005]

Sec. 393.42 Brakes required on all wheels.

(a) Every commercial motor vehicle shall be equipped with brakes

acting on all wheels.

(b) Exception. (1) Trucks or truck tractors having three or more

axles and manufactured before July 25, 1980, are not required to have

brakes on the front wheels. However, these vehicles must meet the

requirements of Sec. 393.52.

(2) Motor vehicles being towed in a driveaway-towaway operation are

not required to have operative brakes provided the combination of

vehicles meets the requirements of Sec. 393.52. This exception is not

applicable to:

(i) Any motor vehicle towed by means of a tow-bar when another motor

vehicle is full-mounted on the towed vehicle; and

(ii) Any combination of motor vehicles utilizing three or more

saddle-mounts.

(3) Any semitrailer or pole trailer (laden or unladen) with a gross

weight of 1,361 kg (3,000 pounds) or less which is subject to this part

is not required to be equipped with brakes if the axle weight of the

towed vehicle does not exceed 40 percent of the sum of the axle weights

of the towing vehicle.

(4) Any full trailer or four-wheel pole trailer (laden or unladen)

with a gross weight of 1,361 kg (3,000 pounds) or less which is subject

to this part is not required to be equipped with brakes if the sum of

the axle weights of the towed vehicle does not exceed 40 percent of the

sum of the axle weights of the towing vehicle.

(5) Brakes are not required on the steering axle of a three-axle

dolly which is steered by a co-driver.

(6) Loaded housemoving dollies, specialized trailers and dollies

used to transport industrial furnaces, reactors, and similar motor

vehicles are not required to be equipped with brakes, provided the speed

at which the combination of vehicles will be operated does not exceed 32

km/hour (20 mph) and brakes on the combination of vehicles are capable

of stopping the combination within 12.2 meters (40 feet) from the speed

at which the vehicle is being operated or 32 km/hour (20 mph), whichever

is less.

[[Page 398]]

[GRAPHIC] [TIFF OMITTED] TR15AU05.020

[52 FR 2803, Jan. 27, 1987, as amended at 53 FR 49398, Dec. 7, 1988; 54

FR 48617, Nov. 24, 1989; 59 FR 25574, May 17, 1994; 61 FR 1843, Jan. 24,

1996; 70 FR 48049, Aug. 15, 2005]

Sec. 393.43 Breakaway and emergency braking.

(a) Towing vehicle protection system. Every motor vehicle, if used

to tow a trailer equipped with brakes, shall be equipped with a means

for providing that in the case of a breakaway of the trailer, the

service brakes on the towing vehicle will be capable of stopping the

towing vehicle. For air braked towing units, the tractor protection

valve or similar device shall operate automatically when the air

pressure on the towing vehicle is between 138 kPa and 310 kPa (20 psi

and 45 psi).

(b) Emergency brake requirements, air brakes. Every truck or truck

tractor equipped with air brakes, when used for towing other vehicles

equipped with air brakes, shall be equipped with two means of activating

the emergency features of the trailer brakes. One of these means shall

operate automatically in the event of reduction of the towing vehicle

air supply to a fixed pressure which shall not be lower than 20 pounds

per square inch nor higher than 45 pounds per square inch. The other

means shall be a manually controlled device readily operable by a person

[[Page 399]]

seated in the driving seat. Its emergency position or method of

operation shall be clearly indicated. In no instance may the manual

means be so arranged as to permit its use to prevent operation of the

automatic means. The automatic and manual means required by this section

may be, but are not required to be, separate.

(c) Emergency brake requirements, vacuum brakes. Every truck tractor

and truck when used for towing other vehicles equipped with vacuum

brakes, shall have, in addition to the single control required by Sec.

393.49 to operate all brakes of the combination, a second manual control

device which can be used to operate the brakes on the towed vehicles in

emergencies. Such second control shall be independent of brake air,

hydraulic, and other pressure, and independent of other controls, unless

the braking system be so arranged that failure of the pressure on which

the second control depends will cause the towed vehicle brakes to be

applied automatically. The second control is not required by this rule

to provide modulated or graduated braking.

(d) Breakaway braking requirements for trailers. Every trailer

required to be equipped with brakes shall have brakes which apply

automatically and immediately upon breakaway from the towing vehicle.

With the exception of trailers having three or more axles, all brakes

with which the trailer is required to be equipped must be applied upon

breakaway from the towing vehicle. The brakes must remain in the applied

position for at least 15 minutes.

(e) Emergency valves. Air brake systems installed on towed vehicles

shall be so designed, by the use of ``no-bleed-back'' relay emergency

valves or equivalent devices, that the supply reservoir used to provide

air for brakes shall be safeguarded against backflow of air to the

towing vehicle upon reduction of the towing vehicle air pressure.

(f) Exception. The requirements of paragraphs (b), (c) and (d) of

this section shall not be applicable to commercial motor vehicles being

transported in driveaway-towaway operations.

[53 FR 49384, Dec. 7, 1988, as amended at 70 FR 48050, Aug. 15, 2005]

Sec. 393.44 Front brake lines, protection.

On every bus, if equipped with air brakes, the braking system shall

be so constructed that in the event any brake line to any of the front

wheels is broken, the driver can apply the brakes on the rear wheels

despite such breakage. The means used to apply the brakes may be located

forward of the driver's seat as long as it can be operated manually by

the driver when the driver is properly restrained by any seat belt

assembly provided for use. Every bus shall meet this requirement or

comply with the regulations in effect at the time of its manufacture.

[53 FR 49400, Dec. 7, 1988]

Sec. 393.45 Brake tubing and hoses; hose assemblies and end fittings.

(a) General construction requirements for tubing and hoses,

assemblies, and end fittings. All brake tubing and hoses, brake hose

assemblies, and brake hose end fittings must meet the applicable

requirements of FMVSS No. 106 (49 CFR 571.106).

(b) Brake tubing and hose installation. Brake tubing and hose must--

(1) Be long and flexible enough to accommodate without damage all

normal motions of the parts to which it is attached;

(2) Be secured against chaffing, kinking, or other mechanical

damage; and

(3) Be installed in a manner that prevents it from contacting the

vehicle's exhaust system or any other source of high temperatures.

(c) Nonmetallic brake tubing. Coiled nonmetallic brake tubing may be

used for connections between towed and towing motor vehicles or between

the frame of a towed vehicle and the unsprung subframe of an adjustable

axle of the motor vehicle if--

(1) The coiled tubing has a straight segment (pigtail) at each end

that is at least 51 mm (2 inches) in length and is encased in a spring

guard or similar device which prevents the tubing from kinking at the

fitting at which it is attached to the vehicle; and

(2) The spring guard or similar device has at least 51 mm (2 inches)

of closed coils or similar surface at its interface with the fitting and

extends at least 38

[[Page 400]]

mm (1\1/2\ inches) into the coiled segment of the tubing from its

straight segment.

(d) Brake tubing and hose connections. All connections for air,

vacuum, or hydraulic braking systems shall be installed so as to ensure

an attachment free of leaks, constrictions or other conditions which

would adversely affect the performance of the brake system.

[70 FR 48050, Aug. 15, 2005]

Sec. 393.46 [Reserved]

Sec. 393.47 Brake actuators, slack adjusters, linings/pads and drums/

rotors.

(a) General requirements. Brake components must be constructed,

installed and maintained to prevent excessive fading and grabbing. The

means of attachment and physical characteristics must provide for safe

and reliable stopping of the commercial motor vehicle.

(b) Brake chambers. The service brake chambers and spring brake

chambers on each end of an axle must be the same size.

(c) Slack adjusters. The effective length of the slack adjuster on

each end of an axle must be the same.

(d) Linings and pads. The thickness of the brake linings or pads

shall meet the applicable requirements of this paragraph--

(1) Steering axle brakes. The brake lining/pad thickness on the

steering axle of a truck, truck-tractor or bus shall not be less than

4.8 mm (\3/16\ inch) at the shoe center for a shoe with a continuous

strip of lining; less than 6.4 mm (\1/4\ inch) at the shoe center for a

shoe with two pads; or worn to the wear indicator if the lining is so

marked, for air drum brakes. The steering axle brake lining/pad

thickness shall not be less than 3.2 mm (\1/8\ inch) for air disc

brakes, or 1.6 mm (\1/16\ inch) or less for hydraulic disc, drum and

electric brakes.

(2) Non-steering axle brakes. An air braked commercial motor vehicle

shall not be operated with brake lining/pad thickness less than 6.4 mm

(\1/4\ inch) or to the wear indicator if the lining is so marked

(measured at the shoe center for drum brakes); or less than 3.2 mm (\1/

8\ inch) for disc brakes. Hydraulic or electric braked commercial motor

vehicles shall not be operated with a lining/pad thickness less than 1.6

mm (\1/16\ inch) (measured at the shoe center) for disc or drum brakes.

(e) Clamp and Roto-Chamber Brake Actuator Readjustment limits. The

pushrod travel for clamp and roto-chamber type actuators must be less

than 80 percent of the rated strokes listed in SAE J1817--Long Stroke

Air Brake Actuator Marking, July 2001 (See Sec. 393.7 (b) for

information on incorporation by reference and availability of this

document), or 80 percent of the rated stroke marked on the brake chamber

by the chamber manufacturer, or the readjustment limit marked on the

brake chamber by the chamber manufacturer. The pushrod travel for Type

16 and 20 long stroke clamp type brake actuators must be less than 51 mm

(2 inches) or 80 percent of the rated stroke marked on the brake chamber

by the chamber manufacturer, or the readjustment limit marked on the

brake chamber by the chamber manufacturer.

(f) Wedge Brake Adjustment. The movement of the scribe mark on the

lining shall not exceed 1.6 mm (\1/16\ inch).

(g) Drums and rotors. The thickness of the drums or rotors shall not

be less than the limits established by the brake drum or rotor

manufacturer.

[70 FR 48051, Aug. 15, 2005]

Sec. 393.48 Brakes to be operative.

(a) General rule. Except as provided in paragraphs (b) and (c) of

this section, all brakes with which a commercial motor vehicle is

equipped must be operable at all times.

(b) Devices to reduce or remove front-wheel braking effort. A

commercial motor vehicle may be equipped with a device to reduce the

front wheel braking effort (or in the case of a three-axle truck or

truck tractor manufactured before March 1, 1975, a device to remove the

front-wheel braking effort) if that device meets the applicable

requirements of paragraphs (b)(1) and (2) of this section.

(1) Manually operated devices. Manually operated devices to reduce

or remove front-wheel braking effort may only be used on buses, trucks,

and truck tractors manufactured before March 1, 1975. Such devices must

not be

[[Page 401]]

used unless the vehicle is being operated under adverse conditions such

as wet, snowy, or icy roads.

(2) Automatic devices. Automatic devices must not reduce the front-

wheel braking force by more than 50 percent of the braking force

available when the automatic device is disconnected (regardless of

whether or not an antilock system failure has occurred on any axle). The

device must not be operable by the driver except upon application of the

control that activates the braking system. The device must not be

operable when the brake control application pressure exceeds 85 psig

(for vehicles equipped with air brakes) or 85 percent of the maximum

system pressure (for vehicles which are not equipped with air brakes).

(c) Exception. Paragraph (a) of this section does not apply to--

(1) A towed vehicle with disabling damage as defined in Sec. 390.5;

(2) A vehicle which is towed in a driveaway-towaway operation and is

included in the exemption to the requirement for brakes on all wheels,

Sec. 393.42(b);

(3) Unladen converter dollies with a gross weight of 1,361 kg (3,000

lbs) or less, and manufactured prior to March 1, 1998;

(4) The steering axle of a three-axle dolly which is steered by a

co-driver;

(5) Loaded house moving dollies, specialized trailers and dollies

used to transport industrial furnaces, reactors, and similar motor

vehicles provided the speed at which the combination of vehicles will be

operated does not exceed 32 km/hour (20 mph) and brakes on the

combination of vehicles are capable of stopping the combination within

12.2 meters (40 feet) from the speed at which the vehicle is being

operated or 32 km/hour (20 mph), whichever is less.

(6) Raised lift axles. Brakes on lift axles need not be capable of

being operated while the lift axle is raised. However, brakes on lift

axles must be capable of being applied whenever the lift axle is lowered

and the tires contact the roadway.

[70 FR 48051, Aug. 15, 2005]

Sec. 393.49 Single valve to operate all brakes.

Every motor vehicle, the date of manufacture of which is subsequent

to June 30, 1953, which is equipped with power brakes, shall have the

braking system so arranged that one application valve shall when applied

operate all the service brakes on the motor vehicle or combination of

motor vehicles. This requirement shall not be construed to prohibit

motor vehicles from being equipped with an additional valve to be used

to operate the brakes on a trailer or trailers or as provided in Sec.

393.44. This section shall not be applicable to driveaway-towaway

operations unless the brakes on such operations are designed to be

operated by a single valve.

Sec. 393.50 Reservoirs required.

(a) Reservoir capacity for air-braked power units manufactured on or

after March 1, 1975, and air-braked trailers manufactured on or after

January 1, 1975. Buses, trucks, and truck-tractors manufactured on or

after March 1, 1975, and air-braked trailers manufactured on or after

January 1, 1975, must meet the reservoir requirements of FMVSS No. 121,

S5.1.2, in effect on the date of manufacture.

(b) Reservoir capacity for air-braked vehicles not subject to FMVSS

No. 121 on the date of manufacture and all vacuum braked vehicles. Each

motor vehicle using air or vacuum braking must have either reserve

capacity, or a reservoir, that would enable the driver to make a full

service brake application with the engine stopped without depleting the

air pressure or vacuum below 70 percent of that indicated by the air or

vacuum gauge immediately before the brake application is made. For the

purposes of this paragraph, a full service brake application means

depressing the brake pedal or treadle valve to the limit of its travel.

(c) Safeguarding of air and vacuum. Each service reservoir system on

a motor vehicle shall be protected against a loss of air pressure or

vacuum due to a failure or leakage in the system between the service

reservoir and the source of air pressure or vacuum, by check valves or

equivalent devices whose proper functioning can be

[[Page 402]]

checked without disconnecting any air or vacuum line, or fitting.

(d) Drain valves for air braked vehicles. Each reservoir must have a

condensate drain valve that can be manually operated. Automatic

condensate drain valves may be used provided (1) they may be operated

manually, or (2) a manual means of draining the reservoirs is retained.

[70 FR 48052, Aug. 15, 2005]

Sec. 393.51 Warning signals, air pressure and vacuum gauges.

(a) General Rule. Every bus, truck and truck tractor, except as

provided in paragraph (f), must be equipped with a signal that provides

a warning to the driver when a failure occurs in the vehicle's service

brake system. The warning signal must meet the applicable requirements

of paragraphs (b), (c), (d) or (e) of this section.

(b) Hydraulic brakes. Vehicles manufactured on or after September 1,

1975, must meet the brake system indicator lamp requirements of FMVSS

No. 571.105 (S5.3) applicable to the vehicle on the date of manufacture.

Vehicles manufactured on or after July 1, 1973 but before September 1,

1975, or to which FMVSS No. 571.105 was not applicable on the date of

manufacture, must have a warning signal which operates before or upon

application of the brakes in the event of a hydraulic-type complete

failure of a partial system. The signal must be either visible within

the driver's forward field of view or audible. The signal must be

continuous. (NOTE: FMVSS No. 105 was applicable to trucks and buses from

September 1, 1975 to October 12, 1976, and from September 1, 1983, to

the present. FMVSS No. 105 was not applicable to trucks and buses

manufactured between October 12, 1976, and September 1, 1983. Motor

carriers have the option of equipping those vehicles to meet either the

indicator lamp requirements of FMVSS No. 105, or the indicator lamp

requirements specified in this paragraph for vehicles which were not

subject to FMVSS No. 105 on the date of manufacture.)

(c) Air brakes. A commercial motor vehicle (regardless of the date

of manufacture) equipped with service brakes activated by compressed air

(air brakes) or a commercial motor vehicle towing a vehicle with service

brakes activated by compressed air (air brakes) must be equipped with a

pressure gauge and a warning signal. Trucks, truck tractors, and buses

manufactured on or after March 1, 1975, must, at a minimum, have a

pressure gauge and a warning signal which meets the requirements of

FMVSS No. 121 (S5.1.4 for the pressure gauge and S5.1.5 for the warning

signal) applicable to the vehicle on the date of manufacture of the

vehicle. Power units to which FMVSS No. 571.121 was not applicable on

the date of manufacture of the vehicle must be equipped with--

(1) A pressure gauge, visible to a person seated in the normal

driving position, which indicates the air pressure (in kilopascals (kPa)

or pounds per square inch (psi)) available for braking; and

(2) A warning signal that is audible or visible to a person in the

normal driving position and provides a continuous warning to the driver

whenever the air pressure in the service reservoir system is at 379 kPa

(55 psi) and below, or one-half of the compressor governor cutout

pressure, whichever is less.

(d) Vacuum brakes. A commercial motor vehicle (regardless of the

date it was manufactured) having service brakes activated by vacuum or a

vehicle towing a vehicle having service brakes activated by vacuum must

be equipped with--

(1) A vacuum gauge, visible to a person seated in the normal driving

position, which indicates the vacuum (in millimeters or inches of

mercury) available for braking; and

(2) A warning signal that is audible or visible to a person in the

normal driving position and provides a continuous warning to the driver

whenever the vacuum in the vehicle's supply reservoir is less than 203

mm (8 inches) of mercury.

(e) Hydraulic brakes applied or assisted by air or vacuum. Each

vehicle equipped with hydraulically activated service brakes which are

applied or assisted by compressed air or vacuum, and to which FMVSS No.

105 was not applicable on the date of manufacture, must be equipped with

a warning signal that

[[Page 403]]

conforms to paragraph (b) of this section for the hydraulic portion of

the system; paragraph (c) of this section for the air assist/air applied

portion; or paragraph (d) of this section for the vacuum assist/vacuum

applied portion. This paragraph shall not be construed as requiring air

pressure gauges or vacuum gauges, only warning signals.

(f) Exceptions. The rules in paragraphs (c), (d) and (e) of this

section do not apply to property carrying commercial motor vehicles

which have less than three axles and (1) were manufactured before July

1, 1973, and (2) have a manufacturer's gross vehicle weight rating less

than 4,536 kg (10,001 pounds).

[70 FR 48052, Aug. 15, 2005]

Sec. 393.52 Brake performance.

(a) Upon application of its service brakes, a motor vehicle or

combination of motor vehicles must under any condition of loading in

which it is found on a public highway, be capable of--

(1) Developing a braking force at least equal to the percentage of

its gross weight specified in the table in paragraph (d) of this

section;

(2) Decelerating to a stop from 20 miles per hour at not less than

the rate specified in the table in paragraph (d) of this section; and

(3) Stopping from 20 miles per hour in a distance, measured from the

point at which movement of the service brake pedal or control begins,

that is not greater than the distance specified in the table in

paragraph (d) of this section; or, for motor vehicles or motor vehicle

combinations that have a GVWR or GVW greater than 4,536 kg (10,000

pounds),

(4) Developing only the braking force specified in paragraph (a)(1)

of this section and the stopping distance specified in paragraph (a)(3)

of this section, if braking force is measured by a performance-based

brake tester which meets the requirements of functional specifications

for performance-based brake testers for commercial motor vehicles, where

braking force is the sum of the braking force at each wheel of the

vehicle or vehicle combination as a percentage of gross vehicle or

combination weight.

(b) Upon application of its emergency brake system and with no other

brake system applied, a motor vehicle or combination of motor vehicles

must, under any condition of loading in which it is found on a public

highway, be capable of stopping from 20 miles per hour in a distance,

measured from the point at which movement of the emergency brake control

begins, that is not greater than the distance specified in the table in

paragraph (d) of this section.

(c) Conformity to the stopping-distance requirements of paragraphs

(a) and (b) of this section shall be determined under the following

conditions:

(1) Any test must be made with the vehicle on a hard surface that is

substantially level, dry, smooth, and free of loose material.

(2) The vehicle must be in the center of a 12-foot-wide lane when

the test begins and must not deviate from that lane during the test.

(d) Vehicle brake performance table:

[[Page 404]]

----------------------------------------------------------------------------------------------------------------

Service brake systems Emergency brake

--------------------------------------------------- systems

----------------

Braking force Application and Application and

Type of motor vehicle as a percentage Deceleration in braking braking

of gross feet per second distance in distance in

vehicle or per second feet from feet from

combination initial speed initial speed

weight at 20 mph of 20 mph

----------------------------------------------------------------------------------------------------------------

A. Passenger-carrying vehicles:

(1) Vehicles with a seating capacity of 65.2 21 20 54

10 persons or less, including driver,

and built on a passenger car chassis...

(2) Vehicles with a seating capacity of 52.8 17 25 66

more than 10 persons, including driver,

and built on a passenger car chassis;

vehicles built on a truck or bus

chassis and having a manufacturer's

GVWR of 10,000 pounds or less..........

(3) All other passenger-carrying 43.5 14 35 85

vehicles...............................

B. Property-carrying vehicles:

(1) Single unit vehicles having a 52.8 17 25 66

manufacturer's GVWR of 10,000 pounds or

less...................................

(2) Single unit vehicles having a 43.5 14 35 85

manufacturer's GVWR of more than 10,000

pounds, except truck tractors.

Combinations of a 2-axle towing vehicle

and trailer having a GVWR of 3,000

pounds or less. All combinations of 2

or less vehicles in drive-away or tow-

away operation.........................

(3) All other property-carrying vehicles 43.5 14 40 90

and combinations of property-carrying

vehicles...............................

----------------------------------------------------------------------------------------------------------------

Notes: (a) There is a definite mathematical relationship between the figures in columns 2 and 3. If the

decelerations set forth in column 3 are divided by 32.2 feet per-second per-second, the figures in column 2

will be obtained. (For example, 21 divided by 32.2 equals 65.2 percent.) Column 2 is included in the

tabulation because certain brake testing devices utilize this factor.

(b) The decelerations specified in column 3 are an indication of the effectiveness of the basic brakes, and as

measured in practical brake testing are the maximum decelerations attained at some time during the stop. These

decelerations as measured in brake tests cannot be used to compute the values in column 4 because the

deceleration is not sustained at the same rate over the entire period of the stop. The deceleration increases

from zero to a maximum during a period of brake system application and brake-force buildup. Also, other

factors may cause the deceleration to decrease after reaching a maximum. The added distance that results

because maximum deceleration is not sustained is included in the figures in column 4 but is not indicated by

the usual brake-testing devices for checking deceleration.

(c) The distances in column 4 and the decelerations in column 3 are not directly related. ``Brake-system

application and braking distance in feet'' (column 4) is a definite measure of the overall effectiveness of

the braking system, being the distance traveled between the point at which the driver starts to move the

braking controls and the point at which the vehicle comes to rest. It includes distance traveled while the

brakes are being applied and distance traveled while the brakes are retarding the vehicle.

(d) The distance traveled during the period of brake-system application and brake-force buildup varies with

vehicle type, being negligible for many passenger cars and greatest for combinations of commercial vehicles.

This fact accounts for the variation from 20 to 40 feet in the values in column 4 for the various classes of

vehicles.

(e) The terms ``GVWR'' and ``GVW'' refer to the manufacturer's gross vehicle weight rating and the actual gross

vehicle weight, respectively.

[36 FR 20298, Oct. 20, 1971, as amended at 37 FR 5251, Mar. 11, 1972; 37

FR 11336, June 7, 1972; 68 FR 51777, Aug. 9, 2002]

[[Page 405]]

Sec. 393.53 Automatic brake adjusters and brake adjustment indicators.

(a) Automatic brake adjusters (hydraulic brake systems). Each

commercial motor vehicle manufactured on or after October 20, 1993, and

equipped with a hydraulic brake system, shall meet the automatic brake

adjustment system requirements of Federal Motor Vehicle Safety Standard

No. 105 (49 CFR 571.105, S5.1) applicable to the vehicle at the time it

was manufactured.

(b) Automatic brake adjusters (air brake systems). Each commercial

motor vehicle manufactured on or after October 20, 1994, and equipped

with an air brake system shall meet the automatic brake adjustment

system requirements of Federal Motor Vehicle Safety Standard No. 121 (49

CFR 571.121, S5.1.8) applicable to the vehicle at the time it was

manufactured.

(c) Brake adjustment indicator (air brake systems). On each

commercial motor vehicle manufactured on or after October 20, 1994, and

equipped with an air brake system which contains an external automatic

adjustment mechanism and an exposed pushrod, the condition of service

brake under-adjustment shall be displayed by a brake adjustment

indicator conforming to the requirements of Federal Motor Vehicle Safety

Standard No. 121 (49 CFR 571.121, S5.1.8) applicable to the vehicle at

the time it was manufactured.

[60 FR 46245, Sept. 6, 1995]

Sec. 393.55 Antilock brake systems.

(a) Hydraulic brake systems. Each truck and bus manufactured on or

after March 1, 1999 (except trucks and buses engaged in driveaway-

towaway operations), and equipped with a hydraulic brake system, shall

be equipped with an antilock brake system that meets the requirements of

Federal Motor Vehicle Safety Standard (FMVSS) No. 105 (49 CFR 571.105,

S5.5).

(b) ABS malfunction indicators for hydraulic braked vehicles. Each

hydraulic braked vehicle subject to the requirements of paragraph (a) of

this section shall be equipped with an ABS malfunction indicator system

that meets the requirements of FMVSS No. 105 (49 CFR 571.105, S5.3).

(c) Air brake systems. (1) Each truck tractor manufactured on or

after March 1, 1997 (except truck tractors engaged in driveaway-towaway

operations), shall be equipped with an antilock brake system that meets

the requirements of FMVSS No. 121 (49 CFR 571.121, S5.1.6.1(b)).

(2) Each air braked commercial motor vehicle other than a truck

tractor, manufactured on or after March 1, 1998 (except commercial motor

vehicles engaged in driveaway-towaway operations), shall be equipped

with an antilock brake system that meets the requirements of FMVSS No.

121 (49 CFR 571.121, S5.1.6.1(a) for trucks and buses, S5.2.3 for

semitrailers, converter dollies and full trailers).

(d) ABS malfunction circuits and signals for air braked vehicles.

(1) Each truck tractor manufactured on or after March 1, 1997, and each

single-unit air braked vehicle manufactured on or after March 1, 1998,

subject to the requirements of paragraph (c) of this section, shall be

equipped with an electrical circuit that is capable of signaling a

malfunction that affects the generation or transmission of response or

control signals to the vehicle's antilock brake system (49 CFR 571.121,

S5.1.6.2(a)).

(2) Each truck tractor manufactured on or after March 1, 2001, and

each single-unit vehicle that is equipped to tow another air-braked

vehicle, subject to the requirements of paragraph (c) of this section,

shall be equipped with an electrical circuit that is capable of

transmitting a malfunction signal from the antilock brake system(s) on

the towed vehicle(s) to the trailer ABS malfunction lamp in the cab of

the towing vehicle, and shall have the means for connection of the

electrical circuit to the towed vehicle. The ABS malfunction circuit and

signal shall meet the requirements of FMVSS No. 121 (49 CFR 571.121,

S5.1.6.2(b)).

(3) Each semitrailer, trailer converter dolly, and full trailer

manufactured on or after March 1, 2001, and subject to the requirements

of paragraph (c)(2) of this section, shall be equipped with an

electrical circuit that is capable of signaling a malfunction in the

trailer's antilock brake system,

[[Page 406]]

and shall have the means for connection of this ABS malfunction circuit

to the towing vehicle. In addition, each trailer manufactured on or

after March 1, 2001, subject to the requirements of paragraph (c)(2) of

this section, that is designed to tow another air-brake equipped trailer

shall be capable of transmitting a malfunction signal from the antilock

brake system(s) of the trailer(s) it tows to the vehicle in front of the

trailer. The ABS malfunction circuit and signal shall meet the

requirements of FMVSS No. 121 (49 CFR 571.121, S5.2.3.2).

(e) Exterior ABS malfunction indicator lamps for trailers. Each

trailer (including a trailer converter dolly) manufactured on or after

March 1, 1998 and before March 1, 2009, and subject to the requirements

of paragraph (c)(2) of this section, shall be equipped with an ABS

malfunction indicator lamp which meets the requirements of FMVSS No. 121

(49 CFR 571.121, S5.2.3.3).

[63 FR 24465, May 4, 1998]

Subpart D_Glazing and Window Construction

Sec. 393.60 Glazing in specified openings.

(a) Glazing material. Glazing material used in windshields, windows,

and doors on a motor vehicle manufactured on or after December 25, 1968,

shall at a minimum meet the requirements of Federal Motor Vehicle Safety

Standard (FMVSS) No. 205 in effect on the date of manufacture of the

motor vehicle. The glazing material shall be marked in accordance with

FMVSS No. 205 (49 CFR 571.205, S6).

(b) Windshields required. Each bus, truck and truck-tractor shall be

equipped with a windshield. Each windshield or portion of a multi-piece

windshield shall be mounted using the full periphery of the glazing

material.

(c) Windshield condition. With the exception of the conditions

listed in paragraphs (c)(1), (c)(2), and (c)(3) of this section, each

windshield shall be free of discoloration or damage in the area

extending upward from the height of the top of the steering wheel

(excluding a 51 mm (2 inch) border at the top of the windshield) and

extending from a 25 mm (1 inch) border at each side of the windshield or

windshield panel. Exceptions:

(1) Coloring or tinting which meets the requirements of paragraph

(d) of this section;

(2) Any crack that is not intersected by any other cracks;

(3) Any damaged area which can be covered by a disc 19 mm (\3/4\

inch) in diameter if not closer than 76 mm (3 inches) to any other

similarly damaged area.

(d) Coloring or tinting of windshields and windows. Coloring or

tinting of windshields and the windows to the immediate right and left

of the driver is allowed, provided the parallel luminous transmittance

through the colored or tinted glazing is not less than 70 percent of the

light at normal incidence in those portions of the windshield or windows

which are marked as having a parallel luminous transmittance of not less

than 70 percent. The transmittance restriction does not apply to other

windows on the commercial motor vehicle.

(e) Prohibition on obstructions to the driver's field of view--(1)

Devices mounted at the top of the windshield. Antennas, transponders,

and similar devices must not be mounted more than 152 mm (6 inches)

below the upper edge of the windshield. These devices must be located

outside the area swept by the windshield wipers, and outside the

driver's sight lines to the road and highway signs and signals.

(2) Decals and stickers mounted on the windshield. Commercial

Vehicle Safety Alliance (CVSA) inspection decals, and stickers and/or

decals required under Federal or State laws may be placed at the bottom

or sides of the windshield provided such decals or stickers do not

extend more than 115 mm (4\1/2\ inches) from the bottom of the

windshield and are located outside the area swept by the windshield

wipers, and outside the driver's sight lines to the road and highway

signs or signals.

[63 FR 1387, Jan. 9, 1998]

Sec. 393.61 Truck and truck tractor window construction.

Each truck and truck tractor (except trucks engaged in armored car

service) shall have at least one window on each side of the driver's

compartment. Each window must have a minimum area of

[[Page 407]]

1,290 cm\2\ (200 in\2\) formed by a rectangle 33 cm by 45 cm (13 inches

by 17\3/4\ inches). The maximum radius of the corner arcs shall not

exceed 152 mm (6 inches). The long axis of the rectangle shall not make

an angle of more than 45 degrees with the surface on which the unladen

vehicle stands. If the cab is designed with a folding door or doors or

with clear openings where doors or windows are customarily located, no

windows shall be required in those locations.

[70 FR 48052, Aug. 15, 2005]

Sec. 393.62 Emergency exits for buses.

(a) Buses manufactured on or after September 1, 1994. Each bus with

a GVWR of 4,536 kg (10,000 pounds) or less must meet the emergency exit

requirements of FMVSS No. 217 (S5.2.2.3) in effect on the date of

manufacture. Each bus with a GVWR of more than 4,536 kg (10,000 pounds)

must have emergency exits which meet the applicable emergency exit

requirements of FMVSS No. 217 (S5.2.2 or S5.2.3) in effect on the date

of manufacture.

(b) Buses manufactured on or after September 1, 1973, but before

September 1, 1994. (1) Each bus (including a school bus used in

interstate commerce for non-school bus operations) with a GVWR of more

than 4,536 kg (10,000 lbs) must meet the requirements of FMVSS No. 217,

S5.2.2 in effect on the date of manufacture.

(2) Each bus (including a school bus used in interstate commerce for

non-school bus operations) with a GVWR of 4,536 kg (10,000 lbs) or less

must meet the requirements of FMVSS No. 217, S5.2.2.3 in effect on the

date of manufacture.

(c) Buses manufactured before September 1, 1973. For each seated

passenger space provided, inclusive of the driver there shall be at

least 432 cm\2\ (67 square inches) of glazing if such glazing is not

contained in a push-out window; or, at least 432 cm\2\ (67 square

inches) of free opening resulting from opening of a push-out type

window. No area shall be included in this minimum prescribed area unless

it will provide an unobstructed opening of at least 1,290 cm\2\ (200

in\2\) formed by a rectangle 33 cm by 45 cm (13 inches by 17\3/4\

inches). The maximum radius of the corner arcs shall not exceed 152 mm

(6 inches). The long axis of the rectangle shall not make an angle of

more than 45 degrees with the surface on which the unladen vehicle

stands. The area shall be measured either by removal of the glazing if

not of the push-out type, or of the movable sash if of the push-out

type. The exit must comply with paragraph (d) of this section. Each side

of the bus must have at least 40 percent of emergency exit space

required by this paragraph.

(d) Laminated safety glass/push-out window requirements for buses

manufactured before September 1, 1973. Emergency exit space used to

satisfy the requirements of paragraph (c) of this section must have

laminated safety glass or push-out windows designed and maintained to

yield outward to provide a free opening.

(1) Safety glass. Laminated safety glass must meet Test No. 25,

Egress, of American National Standard for Safety Glazing Materials for

Glazing Motor Vehicles and Motor Vehicle Equipment Operating on Land

Highways--Safety Standards ANSI/SAE Z26.1/96, August 1997. (See Sec.

393.7 (b) for information on incorporation by reference and availability

of this document.)

(2) Push-out windows. Each push-out window shall be releasable by

operating no more than two mechanisms and allow manual release of the

exit by a single occupant. For mechanisms which require rotary or

straight (parallel to the undisturbed exit surface) motions to operate

the exit, no more than 89 Newtons (20 pounds) of force shall be required

to release the exit. For exits which require a straight motion

perpendicular to the undisturbed exit surface, no more than 267 Newtons

(60 pounds) shall be required to release the exit.

(e) Emergency exit identification. Each bus and each school bus used

in interstate commerce for non-school bus operations, manufactured on or

after September 1, 1973, shall meet the applicable emergency exit

identification or marking requirements of FMVSS No. 217, S5.5, in effect

on the date of manufacture. The emergency exits and doors on all buses

(including school buses used in interstate commerce for non-school bus

operations) must be marked ``Emergency Exit'' or ``Emergency

[[Page 408]]

Door'' followed by concise operating instructions describing each motion

necessary to unlatch or open the exit located within 152 mm (6 inches)

of the release mechanism.

(f) Exception for the transportation of prisoners. The requirements

of this section do not apply to buses used exclusively for the

transportation of prisoners.

[70 FR 48052, Aug. 15, 2005]

Sec. 393.63 [Reserved]

Subpart E_Fuel Systems

Authority: Sec. 204, Interstate Commerce Act, as amended, 49 U.S.C.

304; sec. 6, Department of Transportation Act, 49 U.S.C. 1655;

delegation of authority at 49 CFR 1.48 and 389.4.

Sec. 393.65 All fuel systems.

(a) Application of the rules in this section. The rules in this

section apply to systems for containing and supplying fuel for the

operation of motor vehicles or for the operation of auxiliary equipment

installed on, or used in connection with, motor vehicles.

(b) Location. Each fuel system must be located on the motor vehicle

so that--

(1) No part of the system extends beyond the widest part of the

vehicle;

(2) No part of a fuel tank is forward of the front axle of a power

unit;

(3) Fuel spilled vertically from a fuel tank while it is being

filled will not contact any part of the exhaust or electrical systems of

the vehicle, except the fuel level indicator assembly;

(4) Fill pipe openings are located outside the vehicle's passenger

compartment and its cargo compartment;

(5) A fuel line does not extend between a towed vehicle and the

vehicle that is towing it while the combination of vehicles is in

motion; and

(6) No part of the fuel system of a bus manufactured on or after

January 1, 1973, is located within or above the passenger compartment.

(c) Fuel tank installation. Each fuel tank must be securely attached

to the motor vehicle in a workmanlike manner.

(d) Gravity or syphon feed prohibited. A fuel system must not supply

fuel by gravity or syphon feed directly to the carburetor or injector.

(e) Selection control valve location. If a fuel system includes a

selection control valve which is operable by the driver to regulate the

flow of fuel from two or more fuel tanks, the valve must be installed so

that either--

(1) The driver may operate it while watching the roadway and without

leaving his/her driving position; or

(2) The driver must stop the vehicle and leave his/her seat in order

to operate the valve.

(f) Fuel lines. A fuel line which is not completely enclosed in a

protective housing must not extend more than 2 inches below the fuel

tank or its sump. Diesel fuel crossover, return, and withdrawal lines

which extend below the bottom of the tank or sump must be protected

against damage from impact. Every fuel line must be--

(1) Long enough and flexible enough to accommodate normal movements

of the parts to which it is attached without incurring damage; and

(2) Secured against chafing, kinking, or other causes of mechanical

damage.

(g) Excess flow valve. When pressure devices are used to force fuel

from a fuel tank, a device which prevents the flow of fuel from the fuel

tank if the fuel feed line is broken must be installed in the fuel

system.

[36 FR 15445, Aug. 14, 1971, as amended at 37 FR 4341, Mar. 2, 1972; 37

FR 28752, Dec. 29, 1972]

Sec. 393.67 Liquid fuel tanks.

(a) Application of the rules in this section. The rules in this

section apply to tanks containing or supplying fuel for the operation of

commercial motor vehicles or for the operation of auxiliary equipment

installed on, or used in connection with commercial motor vehicles.

(1) A liquid fuel tank manufactured on or after January 1, 1973, and

a side-mounted gasoline tank must conform to all rules in this section.

(2) A diesel fuel tank manufactured before January 1, 1973, and

mounted on a bus must conform to the rules in paragraphs (c)(7)(iii) and

(d)(2) of this section.

(3) A diesel fuel tank manufactured before January 1, 1973, and

mounted on

[[Page 409]]

a vehicle other than a bus must conform to the rules in paragraph

(c)(7)(iii) of this section.

(4) A gasoline tank, other than a side-mounted gasoline tank,

manufactured before January 1, 1973, and mounted on a bus must conform

to the rules in paragraphs (c) (1) through (10) and (d)(2) of this

section.

(5) A gasoline tank, other than a side-mounted gasoline tank,

manufactured before January 1, 1973, and mounted on a vehicle other than

a bus must conform to the rules in paragraphs (c) (1) through (10),

inclusive, of this section.

(6) Private motor carrier of passengers. Motor carriers engaged in

the private transportation of passengers may continue to operate a

commercial motor vehicle which was not subject to this section or 49 CFR

571.301 at the time of its manufacture, provided the fuel tank of such

vehicle is maintained to the original manufacturer's standards.

(7) Motor vehicles that meet the fuel system integrity requirements

of 49 CFR 571.301 are exempt from the requirements of this subpart, as

they apply to the vehicle's fueling system.

(b) Definitions. As used in this section--

(1) The term liquid fuel tank means a fuel tank designed to contain

a fuel that is liquid at normal atmospheric pressures and temperatures.

(2) A side-mounted fuel tank is a liquid fuel tank which--

(i) If mounted on a truck tractor, extends outboard of the vehicle

frame and outside of the plan view outline of the cab; or

(ii) If mounted on a truck, extends outboard of a line parallel to

the longitudinal centerline of the truck and tangent to the outboard

side of a front tire in a straight ahead position. In determining

whether a fuel tank on a truck or truck tractor is side-mounted, the

fill pipe is not considered a part of the tank.

(c) Construction of liquid fuel tanks--(1) Joints. Joints of a fuel

tank body must be closed by arc-, gas-, seam-, or spot-welding, by

brazing, by silver soldering, or by techniques which provide heat

resistance and mechanical securement at least equal to those

specifically named. Joints must not be closed solely by crimping or by

soldering with a lead-based or other soft solder.

(2) Fittings. The fuel tank body must have flanges or spuds suitable

for the installation of all fittings.

(3) Threads. The threads of all fittings must be Dryseal American

Standard Taper Pipe Thread or Dryseal SAE Short Taper Pipe Thread,

specified in Society of Automotive Engineers Standard J476, as contained

in the 1971 edition of the ``SAE Handbook,'' except that straight

(nontapered) threads may be used on fittings having integral flanges and

using gaskets for sealing. At least four full threads must be in

engagement in each fitting.

(4) Drains and bottom fittings. (i) Drains or other bottom fittings

must not extend more than three-fourths of an inch below the lowest part

of the fuel tank or sump.

(ii) Drains or other bottom fittings must be protected against

damage from impact.

(iii) If a fuel tank has drains the drain fittings must permit

substantially complete drainage of the tank.

(iv) Drains or other bottom fittings must be installed in a flange

or spud designed to accommodate it.

(5) Fuel withdrawal fittings. Except for diesel fuel tanks, the

fittings through which fuel is withdrawn from a fuel tank must be

located above the normal level of fuel in the tank when the tank is

full.

(6) [Reserved]

(7) Fill pipe. (i) Each fill pipe must be designed and constructed

to minimize the risk of fuel spillage during fueling operations and when

the vehicle is involved in a crash.

(ii) For diesel-fueled vehicles, the fill pipe and vents of a fuel

tank having a capacity of more than 94.75 L (25 gallons) of fuel must

permit filling the tank with fuel at a rate of at least 75.8 L/m (20

gallons per minute) without fuel spillage.

(iii) For gasoline- and methanol-fueled vehicles with a GVWR of

3,744 kg (8,500 pounds) or less, the vehicle must permit filling the

tank with fuel dispensed at the applicable fill rate required by the

regulations of the Environmental Protection Agency under 40 CFR 80.22.

[[Page 410]]

(iv) For gasoline- and methanol-fueled vehicles with a GVWR of

14,000 pounds (6,400 kg) or less, the vehicle must comply with the

applicable fuel-spitback prevention and onboard refueling vapor recovery

regulations of the Environmental Protection Agency under 40 CFR part 86.

(v) Each fill pipe must be fitted with a cap that can be fastened

securely over the opening in the fill pipe. Screw threads or a bayonet-

type point are methods of conforming to the requirements of paragraph

(c) of this section.

(8) Safety venting system. A liquid fuel tank with a capacity of

more than 25 gallons of fuel must have a venting system which, in the

event the tank is subjected to fire, will prevent internal tank pressure

from rupturing the tank's body, seams, or bottom opening (if any).

(9) Pressure resistance. The body and fittings of a liquid fuel tank

with a capacity of more than 25 gallons of fuel must be capable of

withstanding an internal hydrostatic pressure equal to 150 percent of

the maximum internal pressure reached in the tank during the safety

venting systems test specified in paragraph (d)(1) of this section.

(10) Air vent. Each fuel tank must be equipped with a nonspill air

vent (such as a ball check). The air vent may be combined with the fill-

pipe cap or safety vent, or it may be a separate unit installed on the

fuel tank.

(11) Markings. If the body of a fuel tank is readily visible when

the tank is installed on the vehicle, the tank must be plainly marked

with its liquid capacity. The tank must also be plainly marked with a

warning against filling it to more than 95 percent of its liquid

capacity.

(12) Overfill restriction. A liquid fuel tank manufactured on or

after January 1, 1973, must be designed and constructed so that--

(i) The tank cannot be filled, in a normal filling operation, with a

quantity of fuel that exceeds 95 percent of the tank's liquid capacity;

and

(ii) When the tank is filled, normal expansion of the fuel will not

cause fuel spillage.

(d) Liquid fuel tank tests. Each liquid fuel tank must be capable of

passing the tests specified in paragraphs (d)(1) and (2) of this

section. The specified tests are a measure of performance only.

Alternative procedures which assure that equipment meets the required

performance standards may be used. .

(1) Safety venting system test--(i) Procedure. Fill the tank three-

fourths full with fuel, seal the fuel feed outlet, and invert the tank.

When the fuel temperature is between 50 [deg]F. and 80 [deg]F., apply an

enveloping flame to the tank so that the temperature of the fuel rises

at a rate of not less than 6 [deg]F. and not more than 8 [deg]F. per

minute.

(ii) Required performance. The safety venting system required by

paragraph (c)(8) of this section must activate before the internal

pressure in the tank exceeds 50 pounds per square inch, gauge, and the

internal pressure must not thereafter exceed the pressure at which the

system activated by more than five pounds per square inch despite any

further increase in the temperature of the fuel.

(2) Leakage test--(i) Procedure. Fill the tank to capacity with fuel

having a temperature between 50 [deg]F. and 80 [deg]F. With the fill-

pipe cap installed, turn the tank through an angle of 150[deg] in any

direction about any axis from its normal position.

(ii) Required performance. Neither the tank nor any fitting may leak

more than a total of one ounce by weight of fuel per minute in any

position the tank assumes during the test.

(e) Side-mounted liquid fuel tank tests. Each side-mounted liquid

fuel tank must be capable of passing the tests specified in paragraphs

(e)(1) and (2) of this section and the test specified in paragraphs

(d)(1) and (2) of this section. The specified tests are a measure of

performance only. Alternative procedures which assure that equipment

meets the required performance criteria may be used.

(1) Drop test--(i) Procedure. Fill the tank with a quantity of water

having a weight equal to the weight of the maximum fuel load of the tank

and drop the tank 30 feet onto an unyielding surface so that it lands

squarely on one corner.

(ii) Required performance. Neither the tank nor any fitting may leak

more

[[Page 411]]

than a total of 1 ounce by weight of water per minute.

(2) Fill-pipe test--(i) Procedure. Fill the tank with a quantity of

water having a weight equal to the weight of the maximum fuel load of

the tank and drop the tank 10 feet onto an unyielding surface so that it

lands squarely on its fill-pipe.

(ii) Required performance. Neither the tank nor any fitting may leak

more than a total of 1 ounce by weight of water per minute.

(f) Certification and markings. Each liquid fuel tank shall be

legibly and permanently marked by the manufacturer with the following

minimum information:

(1) The month and year of manufacture,

(2) The manufacturer's name on tanks manufactured on and after July

1, 1989, and means of identifying the facility at which the tank was

manufactured, and

(3) A certificate that it conforms to the rules in this section

applicable to the tank. The certificate must be in the form set forth in

either of the following:

(i) If a tank conforms to all rules in this section pertaining to

side-mounted fuel tanks: ``Meets all FMCSA side-mounted tank

requirements.''

(ii) If a tank conforms to all rules in this section pertaining to

tanks which are not side-mounted fuel tanks: ``Meets all FMCSA

requirements for non-side-mounted fuel tanks.''

(iii) The form of certificate specified in paragraph (f)(3) (i) or

(ii) of this section may be used on a liquid fuel tank manufactured

before July 11, 1973, but it is not mandatory for liquid fuel tanks

manufactured before March 7, 1989. The form of certification

manufactured on or before March 7, 1989, must meet the requirements in

effect at the time of manufacture.

(4) Exception. The following previously exempted vehicles are not

required to carry the certification and marking specified in paragraphs

(f)(1) through (3) of this section:

(i) Ford vehicles with GVWR over 10,000 pounds identified as

follows: The vehicle identification numbers (VINs) contain A, K, L, M,

N, W, or X in the fourth position.

(ii) GM G-Vans (Chevrolet Express and GMC Savanna) and full-sized C/

K trucks (Chevrolet Silverado and GMC Sierra) with GVWR over 10,000

pounds identified as follows: The VINs contain either a ``J'' or a ``K''

in the fourth position. In addition, the seventh position of the VINs on

the G-Van will contain a ``1.''

[36 FR 15445, Aug. 14, 1971, as amended at 37 FR 4341, Mar. 2, 1972; 37

FR 28753, Dec. 29, 1972; 45 FR 46424, July 10, 1980; 53 FR 49400, Dec.

7, 1988; 59 FR 8753, Feb. 23, 1994; 69 FR 31305, June 3, 2004; 70 FR

48053, Aug. 15, 2005]

Sec. 393.68 Compressed natural gas fuel containers.

(a) Applicability. The rules in this section apply to compressed

natural gas (CNG) fuel containers used for supplying fuel for the

operation of commercial motor vehicles or for the operation of auxiliary

equipment installed on, or used in connection with commercial motor

vehicles.

(b) CNG containers manufactured on or after March 26, 1995. Any

motor vehicle manufactured on or after March 26, 1995, and equipped with

a CNG fuel tank must meet the CNG container requirements of FMVSS No.

304 (49 CFR 571.304) in effect at the time of manufacture of the

vehicle.

(c) Labeling. Each CNG fuel container shall be permanently labeled

in accordance with the requirements of FMVSS No. 304, S7.4.

[70 FR 48053, Aug. 15, 2005]

Sec. 393.69 Liquefied petroleum gas systems.

(a) A fuel system that uses liquefied petroleum gas as a fuel for

the operation of a motor vehicle or for the operation of auxiliary

equipment installed on, or used in connection with, a motor vehicle must

conform to the ``Standards for the Storage and Handling of Liquefied

Petroleum Gases'' of the National Fire Protection Association, Battery

March Park, Quincy, MA 02269, as follows:

(1) A fuel system installed before December 31, 1962, must conform

to the 1951 edition of the Standards.

(2) A fuel system installed on or after December 31, 1962, and

before January 1, 1973, must conform to Division IV of the June 1959

edition of the Standards.

[[Page 412]]

(3) A fuel system installed on or after January 1, 1973, and

providing fuel for propulsion of the motor vehicle must conform to

Division IV of the 1969 edition of the Standards.

(4) A fuel system installed on or after January 1, 1973, and

providing fuel for the operation of auxiliary equipment must conform to

Division VII of the 1969 edition of the Standards.

(b) When the rules in this section require a fuel system to conform

to a specific edition of the Standards, the fuel system may conform to

the applicable provisions in a later edition of the Standards specified

in this section.

(c) The tank of a fuel system must be marked to indicate that the

system conforms to the Standards.

[36 FR 15445, Aug. 14, 1971, as amended at 37 FR 4342, Mar. 2, 1972; 41

FR 53031, Dec. 3, 1976; 53 FR 49400, Dec. 7, 1988]

Subpart F_Coupling Devices and Towing Methods

Sec. 393.70 Coupling devices and towing methods, except for driveaway-

towaway operations.

(a) Tracking. When two or more vehicles are operated in combination,

the coupling devices connecting the vehicles shall be designed,

constructed, and installed, and the vehicles shall be designed and

constructed, so that when the combination is operated in a straight line

on a level, smooth, paved surface, the path of the towed vehicle will

not deviate more than 3 inches to either side of the path of the vehicle

that tows it.

(b) Fifth wheel assemblies--(1) Mounting--(i) Lower half. The lower

half of a fifth wheel mounted on a truck tractor or converter dolly must

be secured to the frame of that vehicle with properly designed brackets,

mounting plates or angles and properly tightened bolts of adequate size

and grade, or devices that provide equivalent security. The installation

shall not cause cracking, warping, or deformation of the frame. The

installation must include a device for positively preventing the lower

half of the fifth wheel from shifting on the frame to which it is

attached.

(ii) Upper half. The upper half of a fifth wheel must be fastened to

the motor vehicle with at least the same security required for the

installation of the lower half on a truck tractor or converter dolly.

(2) Locking. Every fifth wheel assembly must have a locking

mechanism. The locking mechanism, and any adapter used in conjunction

with it, must prevent separation of the upper and lower halves of the

fifth wheel assembly unless a positive manual release is activated. The

release may be located so that the driver can operate it from the cab.

If a motor vehicle has a fifth wheel designed and constructed to be

readily separable, the fifth wheel locking devices shall apply

automatically on coupling.

(3) Location. The lower half of a fifth wheel shall be located so

that, regardless of the condition of loading, the relationship between

the kingpin and the rear axle or axles of the towing motor vehicle will

properly distribute the gross weight of both the towed and towing

vehicles on the axles of those vehicles, will not unduly interfere with

the steering, braking, and other maneuvering of the towing vehicle, and

will not otherwise contribute to unsafe operation of the vehicles

comprising the combination. The upper half of a fifth wheel shall be

located so that the weight of the vehicles is properly distributed on

their axles and the combination of vehicles will operate safely during

normal operation.

(c) Towing of full trailers. A full trailer must be equipped with a

tow-bar and a means of attaching the tow-bar to the towing and towed

vehicles. The tow-bar and the means of attaching it must--

(1) Be structurally adequate for the weight being drawn;

(2) Be properly and securely mounted;

(3) Provide for adequate articulation at the connection without

excessive slack at that location; and

(4) Be provided with a locking device that prevents accidental

separation of the towed and towing vehicles. The mounting of the trailer

hitch (pintle hook or equivalent mechanism) on the towing vehicle must

include reinforcement or bracing of the frame sufficient to produce

strength and rigidity of the frame to prevent its undue distortion.

[[Page 413]]

(d) Safety devices in case of tow-bar failure or disconnection.

Every full trailer and every converter dolly used to convert a

semitrailer to a full trailer must be coupled to the frame, or an

extension of the frame, of the motor vehicle which tows it with one or

more safety devices to prevent the towed vehicle from breaking loose in

the event the tow-bar fails or becomes disconnected. The safety device

must meet the following requirements:

(1) The safety device must not be attached to the pintle hook or any

other device on the towing vehicle to which the tow-bar is attached.

However, if the pintle hook or other device was manufactured prior to

July 1, 1973, the safety device may be attached to the towing vehicle at

a place on a pintle hook forging or casting if that place is independent

of the pintle hook.

(2) The safety device must have no more slack than is necessary to

permit the vehicles to be turned properly.

(3) The safety device, and the means of attaching it to the

vehicles, must have an ultimate strength of not less than the gross

weight of the vehicle or vehicles being towed.

(4) The safety device must be connected to the towed and towing

vehicles and to the tow-bar in a manner which prevents the tow-bar from

dropping to the ground in the event it fails or becomes disconnected.

(5) Except as provided in paragraph (d)(6) of this section, if the

safety device consists of safety chains or cables, the towed vehicle

must be equipped with either two safety chains or cables or with a

bridle arrangement of a single chain or cable attached to its frame or

axle at two points as far apart as the configuration of the frame or

axle permits. The safety chains or cables shall be either two separate

pieces, each equipped with a hook or other means for attachment to the

towing vehicle, or a single piece leading along each side of the tow-bar

from the two points of attachment on the towed vehicle and arranged into

a bridle with a single means of attachment to be connected to the towing

vehicle. When a single length of cable is used, a thimble and twin-base

cable clamps shall be used to form the forward bridle eye. The hook or

other means of attachment to the towing vehicle shall be secured to the

chains or cables in a fixed position.

(6) If the towed vehicle is a converter dolly with a solid tongue

and without a hinged tow-bar or other swivel between the fifth wheel

mounting and the attachment point of the tongue eye or other hitch

device--

(i) Safety chains or cables, when used as the safety device for that

vehicle, may consist of either two chains or cables or a single chain or

cable used alone;

(ii) A single safety device, including a single chain or cable used

alone as the safety device, must be in line with the centerline of the

trailer tongue; and

(iii) The device may be attached to the converter dolly at any point

to the rear of the attachment point of the tongue eye or other hitch

device.

(7) Safety devices other than safety chains or cables must provide

strength, security of attachment, and directional stability equal to, or

greater than, safety chains or cables installed in accordance with

paragraphs (d) (5) and (6) of this section.

(8)(i) When two safety devices, including two safety chains or

cables, are used and are attached to the towing vehicle at separate

points, the points of attachment on the towing vehicle shall be located

equally distant from, and on opposite sides of, the longitudinal

centerline of the towing vehicle.

(ii) Where two chains or cables are attached to the same point on

the towing vehicle, and where a bridle or a single chain or cable is

used, the point of attachment must be on the longitudinal centerline or

within 152 mm (6 inches) to the right of the longitudinal centerline of

the towing vehicle.

(iii) A single safety device, other than a chain or cable, must also

be attached to the towing vehicle at a point on the longitudinal

centerline or within 152 mm (6 inches) to the right of the longitudinal

centerline of the towing vehicle.

[37 FR 21439, Oct. 11, 1972, as amended at 70 FR 48053, Aug. 15, 2005]

[[Page 414]]

Sec. 393.71 Coupling devices and towing methods, driveaway-towaway

operations.

(a) Number in combination. (1) No more than three saddle-mounts may

be used in any combination.

(2) No more than one tow-bar or ball-and-socket type coupling device

may be used in any combination.

(3) When motor vehicles are towed by means of triple saddle-mounts,

the towed vehicles shall have brakes acting on all wheels which are in

contact with the roadway.

(b) Carrying vehicles on towing vehicle. (1) When adequately and

securely attached by means equivalent in security to that provided in

paragraph (j)(2) of this section, a motor vehicle or motor vehicles may

be full-mounted on the structure of a towing vehicle engaged in any

driveaway-towaway operation.

(2) No motor vehicle or motor vehicles may be full-mounted on a

towing vehicle unless the relationship of such full-mounted vehicles to

the rear axle or axles results in proper distribution of the total gross

weight of the vehicles and does not unduly interfere with the steering,

braking, or maneuvering of the towing vehicle, or otherwise contribute

to the unsafe operation of the vehicles comprising the combination.

(3) Saddle-mounted vehicles must be arranged such that the gross

weight of the vehicles is properly distributed to prevent undue

interference with the steering, braking, or maneuvering of the

combination of vehicles.

(c) Carrying vehicles on towed vehicles. (1) When adequately and

securely attached by means equivalent in security to that provided in

paragraph (j)(2) of this section, a motor vehicle or motor vehicles may

be full-mounted on the structure of towed vehicles engaged in any

driveaway-towaway operation.

(2) No motor vehicle shall be full-mounted on a motor vehicle towed

by means of a tow-bar unless the towed vehicle is equipped with brakes

and is provided with means for effective application of brakes acting on

all wheels and is towed on its own wheels.

(3) No motor vehicle or motor vehicles shall be full-mounted on a

motor vehicle towed by means of a saddle-mount unless the center line of

the kingpin or equivalent means of attachment of such towed vehicle

shall be so located on the towing vehicle that the relationship to the

rear axle or axles results in proper distribution of the total gross

weight of the vehicles and does not unduly interfere with the steering,

braking, or maneuvering of the towing vehicle or otherwise contribute to

the unsafe operation of vehicles comprising the combination; and unless

a perpendicular to the ground from the center of gravity of the full-

mounted vehicles lies forward of the center line of the rear axle of the

saddle-mounted vehicle.

(4) If a motor vehicle towed by means of a double saddle-mount has

any vehicle full-mounted on it, such saddle-mounted vehicle shall at all

times while so loaded have effective brakes acting on those wheels which

are in contact with the roadway.

(d) Bumper tow-bars on heavy vehicles prohibited. Tow-bars of the

type which depend upon the bumpers as a means of transmitting forces

between the vehicles shall not be used to tow a motor vehicle weighing

more than 5,000 pounds.

(e) Front wheels of saddle-mounted vehicles restrained. A motor

vehicle towed by means of a saddle-mount shall have the motion of the

front wheels restrained if under any condition of turning of such wheels

they will project beyond the widest part of either the towed or towing

vehicle.

(f) Vehicles to be towed in forward position. Unless the steering

mechanism is adequately locked in a straight-forward position, all motor

vehicles towed by means of a saddle-mount shall be towed with the front

end mounted on the towing vehicle.

(g) Means required for towing. No motor vehicles or combination of

motor vehicles shall be towed in driveaway-towaway operations by means

other than a tow-bar, ball-and-socket type coupling device, saddle-mount

connections which meet the requirements of this section, or in the case

of a semi-trailer equipped with an upper coupler assembly, a fifth-wheel

meeting the requirements of Sec. 393.70.

(h) Requirements for tow-bars. Tow-bars shall comply with the

following requirements:

[[Page 415]]

(1) Tow-bars, structural adequacy and mounting. Every tow-bar shall

be structurally adequate and properly installed and maintained. To

insure that it is structurally adequate, it must, at least, meet the

requirements of the following table:

------------------------------------------------------------------------

Longitudinal strength in tension and

compression \2\

-------------------------------------

New tow-

bars Strength as

Gross weight of towed vehicle acquired a beam (in

(pounds) \1\ and used any

All tow- by a motor direction

bars carrier concentrated

after load at

Sept. 30, center) 2, 3

1948

------------------------------------------------------------------------

Pounds

-------------

Less than 5,000................... 3,000 6,500 3,000

5,000 and over.................... .......... .......... ............

Less than 10,000.................. 6,000 (\1\ ) (\1\ )

10,000 and over................... .......... .......... ............

Less than 15,000.................. 9,000 (\1\ ) (\1\ )

------------------------------------------------------------------------

\1\ The required strength of tow-bars for towed vehicles of 15,000

pounds and over gross weight and of new tow-bars acquired and used

after Sept. 30, 1948, for towed vehicles of 5,000 pounds and over

gross weight shall be computed by means of the following formulae:

Longitudinal strength=gross weight of towed vehicle x 1.3. Strength as

a beam=gross weight of towed vehicle x 0.6.

\2\ In testing, the whole unit shall be tested with all clamps, joints,

and pins so mounted and fastened as to approximate conditions of

actual operation.

\3\ This test shall be applicable only to tow-bars which are, in normal

operation, subjected to a bending movement such as tow-bars for house

trailers.

(2) Tow-bars, jointed. The tow-bar shall be so constructed as to

freely permit motion in both horizontal and vertical planes between the

towed and towing vehicles. The means used to provide the motion shall be

such as to prohibit the transmission of stresses under normal operation

between the towed and towing vehicles, except along the longitudinal

axis of the tongue or tongues.

(3) Tow-bar fastenings. The means used to transmit the stresses to

the chassis or frames of the towed and towing vehicles may be either

temporary structures or bumpers or other integral parts of the vehicles:

Provided, however, That the means used shall be so constructed,

installed, and maintained that when tested as an assembly, failure in

such members shall not occur when the weakest new tow-bar which is

permissible under paragraph (h)(1) of this section is subjected to the

tests given therein.

(4) Means of adjusting length. On tow-bars, adjustable as to length,

the means used to make such adjustment shall fit tightly and not result

in any slackness or permit the tow-bar to bend. With the tow-bar

supported rigidly at both ends and with a load of 50 pounds at the

center, the sag, measured at the center, in any direction shall not

exceed 0.25 inch under any condition of adjustment as to length.

(5) Method of clamping. Adequate means shall be provided for

securely fastening the tow-bar to the towed and towing vehicles.

(6) Tow-bar connection to steering mechanism. The tow-bar shall be

provided with suitable means of attachment to and actuation of the

steering mechanism, if any, of the towed vehicle. The attachment shall

provide for sufficient angularity of movement of the front wheels of the

towed vehicle so that it may follow substantially in the path of the

towing vehicle without cramping the tow-bar. The tow-bar shall be

provided with suitable joints to permit such movement.

(7) Tracking. The tow-bar shall be so designed, constructed,

maintained, and mounted as to cause the towed vehicle to follow

substantially in the path of the towing vehicle. Tow-bars of such design

on in our condition as to permit the towed vehicle to deviate more than

3 inches to either side of the path of a towing vehicle moving in a

straight line as measured from the center of the towing vehicle are

prohibited.

(8) Passenger car-trailer type couplings. Trailer couplings used for

driveaway-towaway operations of passenger car trailers shall conform to

Society of Automotive Engineers Standard No. J684c, ``Trailer Couplings

and Hitches--Automotive Type,'' July 1970. \1\

---------------------------------------------------------------------------

\1\ See footnote 1 to Sec. 393.24(c).

---------------------------------------------------------------------------

(9) Marking tow-bars. Every tow-bar acquired and used in driveaway-

towaway operations by a motor carrier shall be plainly marked with the

following certification of the manufacturer thereof (or words of

equivalent meaning):

This tow-bar complies with the requirements of the Federal Motor

Carrier Safety Administration for (maximum gross weight for which tow-

bar is manufactured) vehicles.

Allowable Maximum Gross Weight__________________________________________

Manufactured____________________________________________________________

(month and year)

by______________________________________________________________________

[[Page 416]]

(name of manufacturer)

Tow-bar certification manufactured before the effective date of this

regulation must meet requirements in effect at the time of manufacture.

(10) Safety devices in case of tow-bar failure or disconnection. (i)

The towed vehicle shall be connected to the towing vehicle by a safety

device to prevent the towed vehicle from breaking loose in the event the

tow-bar fails or becomes disconnected. When safety chains or cables are

used as the safety device for that vehicle, at least two safety chains

or cables meeting the requirements of paragraph (h)(10)(ii) of this

section shall be used. The tensile strength of the safety device and the

means of attachment to the vehicles shall be at least equivalent to the

corresponding longitudinal strength for tow-bars required in the table

of paragraph (h)(1) of this section. If safety chains or cables are used

as the safety device, the required strength shall be the combined

strength of the combination of chains and cables.

(ii) If chains or cables are used as the safety device, they shall

be crossed and attached to the vehicles near the points of bumper

attachments to the chassis of the vehicles. The length of chain used

shall be no more than necessary to permit free turning of the vehicles.

The chains shall be attached to the tow-bar at the point of crossing or

as close to that point as is practicable.

(iii) A safety device other than safety chains or cables must

provide strength, security of attachment, and directional stability

equal to, or greater than, that provided by safety chains or cables

installed in accordance with paragraph (h)(10)(ii) of this section. A

safety device other than safety chains or cables must be designed,

constructed, and installed so that, if the tow-bar fails or becomes

disconnected, the tow-bar will not drop to the ground.

(i) [Reserved]

(j) Requirements for upper-half of saddle-mounts. The upper-half of

any saddle-mount shall comply with the following requirements:

(1) Upper-half connection to towed vehicle. The upper-half shall be

securely attached to the frame or axle of the towed vehicle by means of

U-bolts or other means providing at least equivalent security.

(2) U-bolts or other attachments. U-bolts used to attach the upper

half to the towed vehicle shall be made of steel rod, free of defects,

so shaped as to avoid at any point a radius of less than 1 inch:

Provided, however, That a lesser radius may be utilized if the U-bolt is

so fabricated as not to cause more than 5 percent reduction in cross-

sectional area at points of curvature, in which latter event the minimum

radius shall be one-sixteenth inch. U-bolts shall have a diameter not

less than required by the following table:

Diameter of U-Bolts in Inches

------------------------------------------------------------------------

Double or triple saddle-mount

-----------------------------------

Weight in pounds of heaviest towed Middle Single

vehicle Front or Rear saddle-

mount front mount mount

mount \1\

------------------------------------------------------------------------

Up to 5,000......................... 0.625 0.5625 0.500 0.500

5,000 and over...................... 0.6875 0.625 0.5625 0.5625

------------------------------------------------------------------------

\1\ The total weight of all the vehicles being towed shall govern. If

other devices are used to accomplish the same purposes as U-bolts they

shall have at least equivalent strength of U-bolts made of mild steel.

Cast iron shall not be used for clamps or any other holding devices.

(3) U-bolts and points of support, location. The distance between

the most widely separated U-bolts shall not be less than 9 inches. The

distance between the widely separated points where the upper-half

supports the towed vehicle shall not be less than 9 inches, except that

saddle-mounts employing ball and socket joints shall employ a device

which clamps the axle of the towed vehicle throughout a length of not

less than 5 inches.

(4) Cradle-type upper-halves, specifications. Upper-halves of the

cradle-type using vertical members to restrain the towed vehicle from

relative movement in the direction of motion of the vehicles shall be

substantially constructed and adequate for the purpose. Such cradle-

mounts shall be equipped with at least one bolt or equivalent means to

provide against relative vertical movement between the upper-half and

the towed vehicle. Bolts, if used, shall be at least one-half inch in

diameter. Devices using equivalent means shall have at least equivalent

strength. The means used to provide against relative vertical motion

between the upper-half and the towed vehicle shall be such as not to

permit a relative motion of over

[[Page 417]]

one-half inch. The distance between the most widely separated points of

support between the upper-half and the towed vehicle shall be at least 9

inches.

(5) Lateral movement of towed vehicle. (i) Towed vehicles having a

straight axle or an axle having a drop of less than 3 inches, unless the

saddle-mount is constructed in accordance with paragraph (m)(2) of this

section, shall be securely fastened by means of chains or cables to the

upper-half so as to insure against relative lateral motion between the

towed vehicle and the upper-half. The chains or cables shall be at least

\3/16\-inch diameter and secured by bolts of at least equal diameter.

(ii) Towed vehicles with an axle with a drop of 3 inches or more, or

connected by a saddle-mount constructed in accordance with paragraph

(m)(2) of this section, need not be restrained by chains or cables

provided that the upper-half is so designed as to provide against such

relative motion.

(iii) Chains or cables shall not be required if the upper-half is so

designed as positively to provide against lateral movement of the axle.

(k) Requirements for lower half of saddle-mounts. The lower half of

any saddle-mount shall comply with the following requirements:

(1) U-bolts or other attachments. U-bolts used to attach the lower

half to the towing vehicle shall be made of steel rod, free of defects,

so shaped as to avoid at any point a radius of less than 1 inch:

Provided, however, That a lesser radius may be utilized if the U-bolt is

so fabricated as not to cause more than 5 percent reduction in cross-

sectional area at points of curvature, in which latter event the minimum

radius shall be one-sixteenth inch. U-bolts shall have a total cross-

sectional area not less than as required by the following table:

Total Cross-Sectional Area of U-Bolts in Square Inches

------------------------------------------------------------------------

Double or triple saddle-mount

-----------------------------------

Weight in pounds of heaviest towed Middle Single

vehicle Front or Rear saddle-

mount front mount mount

mount \1\

------------------------------------------------------------------------

Up to 5,000......................... 1.2 1.0 0.8 0.8

5,000 and over...................... 1.4 1.2 1.0 1.0

------------------------------------------------------------------------

\1\ The total weight of all the vehicles being towed shall govern. If

other devices are used to accomplish the same purposes as U-bolts they

shall have at least equivalent strength of U-bolts made of mild steel.

Cast iron shall not be used for clamps or any other holding devices.

(2) Shifting. Adequate provision shall be made by design and

installation to provide against relative movement between the lower-half

and the towing vehicle especially during periods of rapid acceleration

and deceleration. To insure against shifting, designs of the tripod type

shall be equipped with adequate and securely fastened hold-back chains

or similar devices.

(3) Swaying. (i) Adequate provision shall be made by design and

installation to provide against swaying or lateral movement of the towed

vehicle relative to the towing vehicle. To insure against swaying,

lower-halves designed with cross-members attached to but separable from

vertical members shall have such cross-members fastened to the vertical

members by at least two bolts on each side. Such bolts shall be of at

least equivalent cross-sectional area as those required for U-bolts for

the corresponding saddle-mount as given in the table in paragraph (k)(1)

of this section. The minimum distance between the most widely separated

points of support of the cross-member by the vertical member shall be

three inches as measured in a direction parallel to the longitudinal

axis of the towing vehicle.

(ii) The lower-half shall have a bearing surface on the frame of the

towing vehicle of such dimensions that the pressure exerted by the

lower-half upon the frame of the towing vehicle shall not exceed 200

pounds per square inch under any conditions of static loading. Hardwood

blocks or blocks of other suitable material, such as hard rubber,

aluminum or brakelining, if used between the lower half and the frame of

the towing vehicle shall be at least \1/2\ inch thick, 3 inches wide,

and a combined length of 6 inches.

[[Page 418]]

(iii) Under no condition shall the highest point of support of the

towed vehicle by the upper-half be more than 24 inches, measured

vertically, above the top of the frame of the towing vehicle, measured

at the point where the lower-half rests on the towing vehicle.

(4) Wood blocks. (i) Hardwood blocks of good quality may be used to

build up the height of the front end of the towed vehicle, provided that

the total height of such wood blocks shall not exceed 8 inches and not

over two separate pieces are placed upon each other to obtain such

height; however, hardwood blocks, not over 4 in number, to a total

height not to exceed 14 inches, may be used if the total cross-sectional

area of the U-bolts used to attach the lower-half of the towing vehicle

is at least 50 percent greater than that required by the table contained

in paragraph (k)(1) of this section, or, if other devices are used in

lieu of U-bolts, they shall provide for as great a resistance to bending

as is provided by the larger U-bolts above prescribed.

(ii) Hardwood blocks must be at least 4 inches in width and the

surfaces between blocks or block and lower-half or block and upper-half

shall be planed and so installed and maintained as to minimize any

tendency of the towed vehicle to sway or rock.

(5) Cross-member, general requirements. The cross-member, which is

that part of the lower-half used to distribute the weight of the towed

vehicle equally to each member of the frame of the towing vehicle, if

used, shall be structurally adequate and properly installed and

maintained adequately to perform this function.

(6) Cross-member, use of wood. No materials, other than suitable

metals, shall be used as the cross-member, and wood may not be used

structurally in any manner that will result in its being subject to

tensile stresses. Wood may be used in cross-members if supported

throughout its length by suitable metal cross-members.

(7) Lower half strength. The lower half shall be capable of

supporting the loads given in the following table. For the purpose of

test, the saddle-mount shall be mounted as normally operated and the

load applied through the upper half:

Minimum Test Load in Pounds

------------------------------------------------------------------------

Double or triple saddle-mount

-----------------------------------

Weight in pounds of heaviest towed Middle Single

vehicle Front or Rear saddle-

mount front mount mount

mount \1\

------------------------------------------------------------------------

Up to 5,000......................... 15,000 10,000 5,000 5,000

5,000 and over...................... 30,000 20,000 10,000 10,000

------------------------------------------------------------------------

\1\ The total weight of all the vehicles being towed shall govern.

(l) Requirements for kingpins of saddle-mounts. The kingpin of any

saddle-mount shall comply with the following requirements:

(1) Kingpin size. (i) Kingpins shall be constructed of steel

suitable for the purpose, free of defects, and having a diameter not

less than required by the following table:

Diameter of Solid Kingpin in Inches

----------------------------------------------------------------------------------------------------------------

Double or triple saddle-mount

-----------------------------------------------------------------------------

Front mount Middle or front Rear mount Single saddle-

Weight in pounds of heaviest towed -------------------- mount -------------------- mount \1\

vehicle -------------------- -----------------

Mild H.T.S.\2\ Mild Mild H.T.S.\2\ Mild

steel steel H.T.S.\2\ steel steel H.T.S.

----------------------------------------------------------------------------------------------------------------

Up to 5,000....................... 1.125 1.000 1.000 0.875 0.875 0.750 0.875 0.750

5,000 and over.................... 1.500 1.125 1.250 1.000 1.000 0.875 1.000 0.875

----------------------------------------------------------------------------------------------------------------

\1\ The total weight of all the vehicles being towed shall govern.

\2\ High-tensile steel is steel having a minimum ultimate strength of 65,000 pounds per square inch.

(ii) If a ball and socket joint is used in place of a kingpin, the

diameter of the neck of the ball shall be at least equal to the diameter

of the corresponding solid kingpin given in the above table. If hollow

kingpins are used, the metallic cross-sectional area shall be at least

equal to the cross-sectional area of the corresponding solid kingpin.

(2) Kingpin fit. If a kingpin bushing is not used, the king-pin

shall fit snugly

[[Page 419]]

into the upper and lower-halves but shall not bind. Those portions of

the upper or lower-halves in moving contact with the kingpin shall be

smoothly machined with no rough or sharp edges. The bearing surface thus

provided shall not be less in depth than the radius of the kingpin.

(3) Kingpin bushing on saddle-mounts. The kingpin of all new saddle-

mounts acquired and used shall be snugly enclosed in a bushing at least

along such length of the kingpin as may be in moving contact with either

the upper or lower-halves. The bearing surface thus provided shall not

be less in depth than the radius of the kingpin.

(4) Kingpin to restrain vertical motion. The kingpin shall be so

designed and installed as to restrain the upper-half from moving in a

vertical direction relative to the lower-half.

(m) Additional requirements for saddle-mounts. Saddle-mounts shall

comply with the following requirements:

(1) Bearing surface between upper and lower-halves. The upper and

lower-halves shall be so constructed and connected that the bearing

surface between the two halves shall not be less than 16 square inches

under any conditions of angularity between the towing and towed

vehicles: Provided, however, That saddle-mounts using a ball and socket

joint shall have a ball of such dimension that the static bearing load

shall not exceed 800 pounds per square inch, based on the projected

cross-sectional area of the ball: And further provided, That saddle-

mounts having the upper-half supported by ball, taper, or roller-

bearings shall not have such bearings loaded beyond the limits

prescribed for such bearings by the manufacturer thereof. The upper-half

shall rest evenly and smoothly upon the lower-half and the contact

surfaces shall be lubricated and maintained so that there shall be a

minimum of frictional resistance between the parts.

(2) Saddle-mounts, angularity. All saddle-mounts acquired and used

shall provide for angularity between the towing and towed vehicles due

to vertical curvatures of the highway. Such means shall not depend upon

either the looseness or deformation of the parts of either the saddle-

mount or the vehicles to provide for such angularity.

(3) Tracking. The saddle-mount shall be so designed, constructed,

maintained, and installed that the towed vehicle or vehicles will follow

substantially in the path of the towing vehicle without swerving. Towed

vehicles shall not deviate more than 3 inches to either side of the path

of the towing vehicle when moving in a straight line.

(4) Prevention of frame bending. Where necessary, provision shall be

made to prevent the bending of the frame of the towing vehicle by

insertion of suitable blocks inside the frame channel to prevent

kinking. The saddle-mount shall not be so located as to cause

deformation of the frame by reason of cantilever action.

(5) Extension of frame. No saddle-mount shall be located at a point

to the rear of the frame of a towing vehicle.

(6) Nuts, secured. All nuts used on bolts, U-bolts, king-pins, or in

any other part of the saddle-mount shall be secured against accidental

disconnection by means of cotter-keys, lock-washers, double nuts, safety

nuts, or equivalent means. Parts shall be so designed and installed that

nuts shall be fully engaged.

(7) Inspection of all parts. The saddle-mount shall be so designed

that it may be disassembled and each separate part inspected for worn,

bent, cracked, broken, or missing parts.

(8) Saddle-mounts, marking. Every new saddle-mount acquired and used

in driveaway-towaway operations by a motor carrier shall have the upper-

half and the lower-half separately marked with the following

certification of the manufacturer thereof (or words of equivalent

meaning).

This saddle-mount complies with the requirements of the Federal

Motor Carrier Safety Administration for vehicles up to 5,000 pounds (or

over 5,000 pounds):

Manufactured____________________________________________________________

(Month and year)

by______________________________________________________________________

(Name of manufacturer)

(n) Requirements for devices used to connect motor vehicles or parts

of motor vehicles together to form one vehicle--(1) Front axle

attachment. The front axle of

[[Page 420]]

one motor vehicle intended to be coupled with another vehicle as defined

in paragraph (g)(2)(ii) of this section shall be attached with U-bolts

meeting the requirements of paragraph (j)(2) of this section.

(2) Rear axle attachment. The rear axle of one vehicle shall be

coupled to the frame of the other vehicle by means of a connecting

device which when in place forms a rectangle. The device shall be

composed of two pieces, top and bottom. The device shall be made of 4-

inch by \1/2\-inch steel bar bent to shape and shall have the corners

reinforced with a plate at least 3 inches by \1/2\ inch by 8 inches

long. The device shall be bolted together with \3/4\-inch bolts and at

least three shall be used on each side. Wood may be used as spacers to

keep the frames apart and it shall be at least 4 inches square.

(Sec. 12, 80 Stat. 931; 49 U.S.C. 1651 note; section 6 of the Department

of Transportation Act, 49 U.S.C. 1655, and the delegations of authority

at 49 CFR 1.48 and 389.4)

[33 FR 19735, Dec. 25, 1968, as amended at 35 FR 10907, July 7, 1970; 37

FR 21440, Oct. 11, 1972; 53 FR 49400, Dec. 7, 1988; 70 FR 48054, Aug.

15, 2005]

Subpart G_Miscellaneous Parts and Accessories

Sec. 393.75 Tires.

(a) No motor vehicle shall be operated on any tire that (1) has body

ply or belt material exposed through the tread or sidewall, (2) has any

tread or sidewall separation, (3) is flat or has an audible leak, or (4)

has a cut to the extent that the ply or belt material is exposed.

(b) Any tire on the front wheels of a bus, truck, or truck tractor

shall have a tread groove pattern depth of at least \4/32\ of an inch

when measured at any point on a major tread groove. The measurements

shall not be made where tie bars, humps, or fillets are located.

(c) Except as provided in paragraph (b) of this section, tires shall

have a tread groove pattern depth of at least \2/32\ of an inch when

measured in a major tread groove. The measurement shall not be made

where tie bars, humps or fillets are located.

(d) No bus shall be operated with regrooved, recapped or retreaded

tires on the front wheels.

(e) A regrooved tire with a load-carrying capacity equal to or

greater than 2,232 kg (4,920 pounds) shall not be used on the front

wheels of any truck or truck tractor.

(f) Tire loading restrictions (except on manufactured homes). No

motor vehicle (except manufactured homes, which are governed by

paragraph (g) of this section) shall be operated with tires that carry a

weight greater than that marked on the sidewall of the tire or, in the

absence of such a marking, a weight greater than that specified for the

tires in any of the publications of any of the organizations listed in

Federal Motor Vehicle Safety Standard No. 119 (49 CFR 571.119, S5.1(b))

unless:

(1) The vehicle is being operated under the terms of a special

permit issued by the State; and

(2) The vehicle is being operated at a reduced speed to compensate

for the tire loading in excess of the manufacturer's rated capacity for

the tire. In no case shall the speed exceed 80 km/hr (50 mph).

(g)(1) Tire loading restrictions for manufactured homes built before

January 1, 2002. Manufactured homes that are labeled pursuant to 24 CFR

3282.362(c)(2)(i) before January 1, 2002, must not be transported on

tires that are loaded more than 18 percent over the load rating marked

on the sidewall of the tire or, in the absence of such a marking, more

than 18 percent over the load rating specified in any of the

publications of any of the organizations listed in FMVSS No. 119 (49 CFR

571.119, S5.1(b)). Manufactured homes labeled before January 1, 2002,

transported on tires overloaded by 9 percent or more must not be

operated at speeds exceeding 80 km/hr (50 mph).

(2) Tire loading restrictions for manufactured homes built on or

after January 1, 2002. Manufactured homes that are labeled pursuant to

24 CFR 3282.362(c)(2)(i) on or after January 1, 2002, must not be

transported on tires loaded beyond the load rating marked on the

sidewall of the tire or, in the absence of such a marking, the load

rating specified in any of the publications

[[Page 421]]

of any of the organizations listed in FMVSS No. 119 (49 CFR 571.119,

S5.1(b)).

(h) Tire inflation pressure. (1) No motor vehicle shall be operated

on a tire which has a cold inflation pressure less than that specified

for the load being carried.

(2) If the inflation pressure of the tire has been increased by heat

because of the recent operation of the vehicle, the cold inflation

pressure shall be estimated by subtracting the inflation buildup factor

shown in Table 1 from the measured inflation pressure.

Table 1--Inflation Pressure Measurement Correction for Heat

------------------------------------------------------------------------

Minimum inflation pressure buildup

---------------------------------------

Average speed of vehicle in the Tires with 1,814

previous hour kg (4,000 lbs.) Tires with over

maximum load 1,814 kg (4,000

rating or less lbs.) load rating

------------------------------------------------------------------------

66-88.5 km/hr (41-55 mph)....... 34.5 kPa (5 psi).. 103.4 kPa (15

psi).

------------------------------------------------------------------------

[34 FR 9344, June 13, 1969, as amended at 40 FR 44557, Sept. 29, 1975;

41 FR 36657, Aug. 31, 1976; 44 FR 25455, May 1, 1979; 44 FR 47938, Aug.

16, 1979; 53 FR 18057, May 19, 1988; 53 FR 49401, Dec. 7, 1988; 63 FR

8339, Feb. 18, 1998; 65 FR 70220, Nov. 21, 2000; 66 FR 67694, Dec. 31,

2001; 70 FR 48054, Aug. 15, 2005]

Sec. 393.76 Sleeper berths.

(a) Dimensions--(1) Size. A sleeper berth must be at least the

following size:

------------------------------------------------------------------------

Height

Length Width measured

measured on measured from

centerline on highest

Date of installation on motor of centerline point of

vehicle longitudinal of top of

axis transverse mattress

(inches) axis (inches)

(inches) \1\

------------------------------------------------------------------------

Before January 1, 1953............ 72 18 18

After December 31, 1952, and 75 21 21

before October 1, 1975...........

After September 30, 1975.......... 75 24 24

------------------------------------------------------------------------

\1\ In the case of a sleeper berth which utilizes an adjustable

mechanical suspension system, the required clearance can be measured

when the suspension system is adjusted to the height to which it would

settle when occupied by a driver.

(2) Shape. A sleeper berth installed on a motor vehicle on or after

January 1, 1953 must be of generally rectangular shape, except that the

horizontal corners and the roof corners may be rounded to radii not

exceeding 10\1/2\ inches.

(3) Access. A sleeper berth must be constructed so that an

occupant's ready entrance to, and exit from, the sleeper berth is not

unduly hindered.

(b) Location. (1) A sleeper berth must not be installed in or on a

semitrailer or a full trailer other than a house trailer.

(2) A sleeper berth located within the cargo space of a motor

vehicle must be securely compartmentalized from the remainder of the

cargo space. A sleeper berth installed on or after January 1, 1953 must

be located in the cab or immediately adjacent to the cab and must be

securely fixed with relation to the cab.

(c) Exit from the berth. (1) Except as provided in paragraph (c)(2)

of this section, there must be a direct and ready means of exit from a

sleeper berth into the driver's seat or compartment. If the sleeper

berth was installed on or after January 1, 1963, the exit must be a

doorway or opening at least 18 inches high and 36 inches wide. If the

sleeper berth was installed before January 1, 1963, the exit must have

sufficient area to contain an ellipse having a major axis of 24 inches

and a minor axis of 16 inches.

(2) A sleeper berth installed before January 1, 1953 must either:

(i) Conform to the requirements of paragraph (c)(1) of this section;

or

(ii) Have at least two exits, each of which is at least 18 inches

high and 21 inches wide, located at opposite ends of the vehicle and

useable by the occupant without the assistance of any other person.

(d) Communication with the driver. A sleeper berth which is not

located within the driver's compartment and has no direct entrance into

the driver's compartment must be equipped with a means of communication

between the occupant and the driver. The means of communication may

consist of a telephone, speaker tube, buzzer, pull cord, or other

mechanical or electrical device.

(e) Equipment. A sleeper berth must be properly equipped for

sleeping. Its equipment must include:

(1) Adequate bedclothing and blankets; and

(2) Either:

(i) Springs and a mattress; or

[[Page 422]]

(ii) An innerspring mattress; or

(iii) A cellular rubber or flexible foam mattress at least four

inches thick; or

(iv) A mattress filled with a fluid and of sufficient thickness when

filled to prevent ``bottoming-out'' when occupied while the vehicle is

in motion.

(f) Ventilation. A sleeper berth must have louvers or other means of

providing adequate ventilation. A sleeper berth must be reasonably tight

against dust and rain.

(g) Protection against exhaust and fuel leaks and exhaust heat. A

sleeper berth must be located so that leaks in the vehicle's exhaust

system or fuel system do not permit fuel, fuel system gases, or exhaust

gases to enter the sleeper berth. A sleeper berth must be located so

that it will not be overheated or damaged by reason of its proximity to

the vehicle's exhaust system.

(h) Occupant restraint. A motor vehicle manufactured on or after

July 1, 1971, and equipped with a sleeper berth must be equipped with a

means of preventing ejection of the occupant of the sleeper berth during

deceleration of the vehicle. The restraint system must be designed,

installed, and maintained to withstand a minimum total force of 6,000

pounds applied toward the front of the vehicle and parallel to the

longitudinal axis of the vehicle.

[39 FR 14711, Apr. 26, 1974; 39 FR 17233, May 14, 1974, as amended at 53

FR 49401, Dec. 7, 1988]

Sec. 393.77 Heaters.

On every motor vehicle, every heater shall comply with the following

requirements:

(a) Prohibited types of heaters. The installation or use of the

following types of heaters is prohibited:

(1) Exhaust heaters. Any type of exhaust heater in which the engine

exhaust gases are conducted into or through any space occupied by

persons or any heater which conducts engine compartment air into any

such space.

(2) Unenclosed flame heaters. Any type of heater employing a flame

which is not fully enclosed, except that such heaters are not prohibited

when used for heating the cargo of tank motor vehicles.

(3) Heaters permitting fuel leakage. Any type of heater from the

burner of which there could be spillage or leakage of fuel upon the

tilting or overturning of the vehicle in which it is mounted.

(4) Heaters permitting air contamination. Any heater taking air,

heated or to be heated, from the engine compartment or from direct

contact with any portion of the exhaust system; or any heater taking air

in ducts from the outside atmosphere to be conveyed through the engine

compartment, unless said ducts are so constructed and installed as to

prevent contamination of the air so conveyed by exhaust or engine

compartment gases.

(5) Solid fuel heaters except wood charcoal. Any stove or other

heater employing solid fuel except wood charcoal.

(6) Portable heaters. Portable heaters shall not be used in any

space occupied by persons except the cargo space of motor vehicles which

are being loaded or unloaded.

(b) Heater specifications. All heaters shall comply with the

following specifications:

(1) Heating elements, protection. Every heater shall be so located

or protected as to prevent contact therewith by occupants, unless the

surface temperature of the protecting grilles or of any exposed portions

of the heaters, inclusive of exhaust stacks, pipes, or conduits shall be

lower than would cause contact burns. Adequate protection shall be

afforded against igniting parts of the vehicle or burning occupants by

direct radiation. Wood charcoal heaters shall be enclosed within a metal

barrel, drum, or similar protective enclosure which enclosure shall be

provided with a securely fastened cover.

(2) Moving parts, guards. Effective guards shall be provided for the

protection of passengers or occupants against injury by fans, belts, or

any other moving parts.

(3) Heaters, secured. Every heater and every heater enclosure shall

be securely fastened to the vehicle in a substantial manner so as to

provide against relative motion within the vehicle during normal usage

or in the event the vehicle overturns. Every heater shall be so

designed, constructed, and mounted as to minimize the likelihood of

disassembly of any of

[[Page 423]]

its parts, including exhaust stacks, pipes, or conduits, upon overturn

of the vehicle in or on which it is mounted. Wood charcoal heaters shall

be secured against relative motion within the enclosure required by

paragraph (c)(1) of this section, and the enclosure shall be securely

fastened to the motor vehicle.

(4) Relative motion between fuel tank and heater. When either in

normal operation or in the event of overturn, there is or is likely to

be relative motion between the fuel tank for a heater and the heater, or

between either of such units and the fuel lines between them, a suitable

means shall be provided at the point of greatest relative motion so as

to allow this motion without causing failure of the fuel lines.

(5) Operating controls to be protected. On every bus designed to

transport more than 15 passengers, including the driver, means shall be

provided to prevent unauthorized persons from tampering with the

operating controls. Such means may include remote control by the driver;

installation of controls at inaccessible places; control of adjustments

by key or keys; enclosure of controls in a locked space, locking of

controls, or other means of accomplishing this purpose.

(6) Heater hoses. Hoses for all hot water and steam heater systems

shall be specifically designed and constructed for that purpose.

(7) Electrical apparatus. Every heater employing any electrical

apparatus shall be equipped with electrical conductors, switches,

connectors, and other electrical parts of ample current-carrying

capacity to provide against overheating; any electric motor employed in

any heater shall be of adequate size and so located that it will not be

overheated; electrical circuits shall be provided with fuses and/or

circuit breakers to provide against electrical overloading; and all

electrical conductors employed in or leading to any heater shall be

secured against dangling, chafing, and rubbing and shall have suitable

protection against any other condition likely to produce short or open

circuits.

Note: Electrical parts certified as proper for use by Underwriters'

Laboratories, Inc., shall be deemed to comply with the foregoing

requirements.

(8) Storage battery caps. If a separate storage battery is located

within the personnel or cargo space, such battery shall be securely

mounted and equipped with nonspill filler caps.

(9) Combustion heater exhaust construction. Every heater employing

the combustion of oil, gas, liquefied petroleum gas, or any other

combustible material shall be provided with substantial means of

conducting the products of combustion to the outside of the vehicle:

Provided, however, That this requirement shall not apply to heaters used

solely to heat the cargo space of motor vehicles where such motor

vehicles or heaters are equipped with means specifically designed and

maintained so that the carbon monoxide concentration will never exceed

0.2 percent in the cargo space. The exhaust pipe, stack, or conduit if

required shall be sufficiently substantial and so secured as to provide

reasonable assurance against leakage or discharge of products of

combustion within the vehicle and, if necessary, shall be so insulated

as to make unlikely the burning or charring of parts of the vehicle by

radiation or by direct contact. The place of discharge of the products

of combustion to the atmosphere and the means of discharge of such

products shall be such as to minimize the likelihood of their reentry

into the vehicle under all operating conditions.

(10) Combustion chamber construction. The design and construction of

any combustion-type heater except cargo space heaters permitted by the

proviso of paragraph (c)(9) of this section and unenclosed flame heaters

used for heating cargo of tank motor vehicles shall be such as to

provide against the leakage of products of combustion into air to be

heated and circulated. The material employed in combustion chambers

shall be such as to provide against leakage because of corrosion,

oxidation, or other deterioration. Joints between combustion chambers

and the air chambers with which they are in thermal and mechanical

contact shall be so designed and constructed as to prevent leakage

between the chambers and the materials employed in such joints shall

have melting points substantially higher than the maximum

[[Page 424]]

temperatures likely to be attained at the points of jointure.

(11) Heater fuel tank location. Every bus designed to transport more

than 15 passengers, including the driver, with heaters of the combustion

type shall have fuel tanks therefor located outside of and lower than

the passenger space. When necessary, suitable protection shall be

afforded by shielding or other means against the puncturing of any such

tank or its connections by flying stones or other objects.

(12) Heater, automatic fuel control. Gravity or siphon feed shall

not be permitted for heaters using liquid fuels. Heaters using liquid

fuels shall be equipped with automatic means for shutting off the fuel

or for reducing such flow of fuel to the smallest practicable magnitude,

in the event of overturn of the vehicle. Heaters using liquefied

petroleum gas as fuel shall have the fuel line equipped with automatic

means at the source of supply for shutting off the fuel in the event of

separation, breakage, or disconnection of any of the fuel lines between

the supply source and the heater.

(13) ``Tell-tale'' indicators. Heaters subject to paragraph (c)(14)

of this section and not provided with automatic controls shall be

provided with ``tell-tale'' means to indicate to the driver that the

heater is properly functioning. This requirement shall not apply to

heaters used solely for the cargo space in semitrailers or full

trailers.

(14) Shut-off control. Automatic means, or manual means if the

control is readily accessible to the driver without moving from the

driver's seat, shall be provided to shut off the fuel and electrical

supply in case of failure of the heater to function for any reason, or

in case the heater should function improperly or overheat. This

requirement shall not apply to wood charcoal heaters or to heaters used

solely to heat the contents of cargo tank motor vehicles, but wood

charcoal heaters must be provided with a controlled method of regulating

the flow of combustion air.

(15) Certification required. Every combustion-type heater, except

wood charcoal heaters, the date of manufacture of which is subsequent to

December 31, 1952, and every wood charcoal heater, the date of

manufacture of which is subsequent to September 1, 1953, shall be marked

plainly to indicate the type of service for which such heater is

designed and with a certification by the manufacturer that the heater

meets the applicable requirements for such use. For example, ``Meets

I.C.C. Bus Heater Requirements,'' Meets I.C.C. Flue-Vented Cargo Space

Heater Requirements,'' and after December 31, 1967, such certification

shall read ``Meets FMCSA Bus Heater Requirements,'' ``Meets FMCSA Flue-

Vented Cargo Space Heater Requirements,'' etc.

(i) Exception. The certification for a catalytic heater which is

used in transporting flammable liquid or gas shall be as prescribed

under Sec. 177.834(1) of this title.

[33 FR 19735, Dec. 25, 1968, as amended at 40 FR 51198, Nov. 4, 1975; 53

FR 49401, Dec. 7, 1988]

Sec. 393.78 Windshield wiping and washing systems.

(a) Vehicles manufactured on or after December 25, 1968. Each bus,

truck, and truck-tractor manufactured on or after December 25, 1968,

must have a windshield wiping system that meets the requirements of

FMVSS No. 104 (S4.1) in effect on the date of manufacture. Each of these

vehicles must have a windshield washing system that meets the

requirements of FMVSS No. 104 (S4.2.2) in effect on the date of

manufacture.

(b) Vehicles manufactured between June 30, 1953, and December 24,

1968. Each truck, truck-tractor, and bus manufactured between June 30,

1953, and December 24, 1968, shall be equipped with a power-driven

windshield wiping system with at least two wiper blades, one on each

side of the centerline of the windshield. Motor vehicles which depend

upon vacuum to operate the windshield wipers, shall have the wiper

system constructed and maintained such that the performance of the

wipers will not be adversely affected by a change in the intake manifold

pressure.

(c) Driveaway-towaway operations. Windshield wiping and washing

systems need not be in working condition while a commercial motor

vehicle is

[[Page 425]]

being towed in a driveaway-towaway operation.

[70 FR 48054, Aug. 15, 2005]

Sec. 393.79 Windshield defrosting and defogging systems.

(a) Vehicles manufactured on or after December 25, 1968. Each bus,

truck, and truck-tractor manufactured on or after December 25, 1968,

must have a windshield defrosting and defogging system that meets the

requirements of FMVSS No. 103 in effect on the date of manufacture.

(b) Vehicles manufactured before December 25, 1968. Each bus, truck,

and truck-tractor shall be equipped with a means for preventing the

accumulation of ice, snow, frost, or condensation that could obstruct

the driver's view through the windshield while the vehicle is being

driven.

[70 FR 48054, Aug. 15, 2005]

Sec. 393.80 Rear-vision mirrors.

(a) Every bus, truck, and truck tractor shall be equipped with two

rear-vision mirrors, one at each side, firmly attached to the outside of

the motor vehicle, and so located as to reflect to the driver a view of

the highway to the rear, along both sides of the vehicle. All such

regulated rear-vision mirrors and their replacements shall meet, as a

minimum, the requirements of FMVSS No. 111 (49 CFR 571.111) in force at

the time the vehicle was manufactured.

(b) Exceptions. (1) Mirrors installed on a vehicle manufactured

prior to January 1, 1981, may be continued in service, provided that if

the mirrors are replaced they shall be replaced with mirrors meeting, as

a minimum, the requirements of FMVSS No. 111 (49 CFR 571.111) in force

at the time the vehicle was manufactured.

(2) Only one outside mirror shall be required, which shall be on the

driver's side, on trucks which are so constructed that the driver has a

view to the rear by means of an interior mirror.

(3) In driveway-towaway operations, the driven vehicle shall have at

least one mirror furnishing a clear view to the rear.

[48 FR 57139, Dec. 28, 1983]

Sec. 393.81 Horn.

Every bus, truck, truck-tractor, and every driven motor vehicle in

drive away-towaway operations shall be equipped with a horn and

actuating elements which shall be in such condition as to give an

adequate and reliable warning signal.

Sec. 393.82 Speedometer.

Each bus, truck, and truck-tractor must be equipped with a

speedometer indicating vehicle speed in miles per hour and/or kilometers

per hour. The speedometer must be accurate to within plus or minus 8 km/

hr (5 mph) at a speed of 80 km/hr (50 mph).

[70 FR 48054, Aug. 15, 2005]

Sec. 393.83 Exhaust systems.

(a) Every motor vehicle having a device (other than as part of its

cargo) capable of expelling harmful combustion fumes shall have a system

to direct the discharge of such fumes. No part shall be located where

its location would likely result in burning, charring, or damaging the

electrical wiring, the fuel supply, or any combustible part of the motor

vehicle.

(b) No exhaust system shall discharge to the atmosphere at a

location immediately below the fuel tank or the fuel tank filler pipe.

(c) The exhaust system of a bus powered by a gasoline engine shall

discharge to the atmosphere at or within 6 inches forward of the

rearmost part of the bus.

(d) The exhaust system of a bus using fuels other than gasoline

shall discharge to the atmosphere either:

(1) At or within 15 inches forward of the rearmost part of the

vehicle; or

(2) To the rear of all doors or windows designed to be open, except

windows designed to be opened solely as emergency exits.

(e) The exhaust system of every truck and truck tractor shall

discharge to the atmosphere at a location to the rear of the cab or, if

the exhaust projects above the cab, at a location near the rear of the

cab.

(f) No part of the exhaust system shall be temporarily repaired with

wrap or patches.

[[Page 426]]

(g) No part of the exhaust system shall leak or discharge at a point

forward of or directly below the driver/sleeper compartment. The exhaust

outlet may discharge above the cab/sleeper roofline.

(h) The exhaust system must be securely fastened to the vehicle.

(i) Exhaust systems may use hangers which permit required movement

due to expansion and contraction caused by heat of the exhaust and

relative motion between engine and chassis of a vehicle.

[53 FR 49401, Dec. 7, 1988]

Sec. 393.84 Floors.

The flooring in all motor vehicles shall be substantially

constructed, free of unnecessary holes and openings, and shall be

maintained so as to minimize the entrance of fumes, exhaust gases, or

fire. Floors shall not be permeated with oil or other substances likely

to cause injury to persons using the floor as a traction surface.

[53 FR 49401, Dec. 7, 1988]

Sec. 393.85 [Reserved]

Sec. 393.86 Rear impact guards and rear end protection.

(a)(1) General requirements for trailers and semitrailers

manufactured on or after January 26, 1998. Each trailer and semitrailer

with a gross vehicle weight rating of 4,536 kg (10,000 pounds) or more,

and manufactured on or after January 26, 1998, must be equipped with a

rear impact guard that meets the requirements of Federal Motor Vehicle

Safety Standard No. 223 (49 CFR 571.223) in effect at the time the

vehicle was manufactured. When the rear impact guard is installed on the

trailer or semitrailer, the vehicle must, at a minimum, meet the

requirements of FMVSS No. 224 (49 CFR 571.224) in effect at the time the

vehicle was manufactured. The requirements of paragraph (a) of this

section do not apply to pole trailers (as defined in Sec. 390.5 of this

chapter); pulpwood trailers, low chassis vehicles, special purpose

vehicles, wheels back vehicles (as defined in Sec. 393.5); and trailers

towed in driveaway-towaway operations (as defined in Sec. 390.5).

(2) Impact guard width. The outermost surfaces of the horizontal

member of the guard must extend to within 100 mm (4 inches) of the side

extremities of the vehicle. The outermost surface of the horizontal

member shall not extend beyond the side extremity of the vehicle.

(3) Guard height. The vertical distance between the bottom edge of

the horizontal member of the guard and the ground shall not exceed 560

mm (22 inches) at any point across the full width of the member. Guards

with rounded corners may curve upward within 255 mm (10 inches) of the

longitudinal vertical planes that are tangent to the side extremities of

the vehicle.

(4) Guard rear surface. At any height 560 mm (22 inches) or more

above the ground, the rearmost surface of the horizontal member of the

guard must be within 305 mm (12 inches) of the rear extremity of the

vehicle. This paragraph shall not be construed to prohibit the rear

surface of the guard from extending beyond the rear extremity of the

vehicle. Guards with rounded corners may curve forward within 255 mm (10

inches) of the side extremity.

(5) Cross-sectional vertical height. The horizontal member of each

guard must have a cross sectional vertical height of at least 100 mm

(3.94 inches) at any point across the guard width.

(6) Certification and labeling requirements for rear impact

protection guards. Each rear impact guard used to satisfy the

requirements of paragraph (a)(1) of this section must be permanently

marked or labeled as required by FMVSS No. 223 (49 CFR 571.223, S5.3).

The label must be on the forward-facing surface of the horizontal member

of the guard, 305 mm (12 inches) inboard of the right end of the guard.

The certification label must contain the following information:

(i) The impact guard manufacturer's name and address;

(ii) The statement ``Manufactured in ----'' (inserting the month and

year that the guard was manufactured); and,

(iii) The letters ``DOT'', constituting a certification by the guard

manufacturer that the guard conforms to all requirements of FMVSS No.

223.

[[Page 427]]

(b)(1) Requirements for motor vehicles manufactured after December

31, 1952 (except trailers or semitrailers manufactured on or after

January 26, 1998). Each motor vehicle manufactured after December 31,

1952, (except truck tractors, pole trailers, pulpwood trailers, or

vehicles in driveaway-towaway operations) in which the vertical distance

between the rear bottom edge of the body (or the chassis assembly if the

chassis is the rearmost part of the vehicle) and the ground is greater

than 76.2 cm (30 inches) when the motor vehicle is empty, shall be

equipped with a rear impact guard(s). The rear impact guard(s) must be

installed and maintained in such a manner that:

(i) The vertical distance between the bottom of the guard(s) and the

ground does not exceed 76.2 cm (30 inches) when the motor vehicle is

empty;

(ii) The maximum lateral distance between the closest points between

guards, if more than one is used, does not exceed 61 cm (24 inches);

(iii) The outermost surfaces of the horizontal member of the guard

are no more than 45.7 cm (18 inches) from each side extremity of the

motor vehicle;

(iv) The impact guard(s) are no more than 61 cm (24 inches) forward

of the rear extremity of the motor vehicle.

(2) Construction and attachment. The rear impact guard(s) must be

substantially constructed and attached by means of bolts, welding, or

other comparable means.

(3) Vehicle components and structures that may be used to satisfy

the requirements of paragraph (b) of this section. Low chassis vehicles,

special purpose vehicles, or wheels back vehicles constructed and

maintained so that the body, chassis, or other parts of the vehicle

provide the rear end protection comparable to impact guard(s) conforming

to the requirements of paragraph (b)(1) of this section shall be

considered to be in compliance with those requirements.

[64 FR 47708, Sept. 1, 1999, as amended at 67 FR 61824, Oct. 2, 2002]

Sec. 393.87 Warning flags on projecting loads.

(a) Any commercial motor vehicle transporting a load which extends

beyond the sides by more than 102 mm (4 inches) or more than 1,219 mm (4

feet) beyond the rear must have the extremities of the load marked with

red or orange fluorescent warning flags. Each warning flag must be at

least 457 mm (18 inches) square.

(b) Position of flags. There must be a single flag at the extreme

rear if the projecting load is two feet wide or less. Two warning flags

are required if the projecting load is wider than two feet. Flags must

be located to indicate maximum width of loads which extend beyond the

sides and/or rear of the vehicle.

[70 FR 48054, Aug. 15, 2005]

Sec. 393.88 Television receivers.

Any motor vehicle equipped with a television viewer, screen or other

means of visually receiving a television broadcast shall have the viewer

or screen located in the motor vehicle at a point to the rear of the

back of the driver's seat if such viewer or screen is in the same

compartment as the driver and the viewer or screen shall be so located

as not to be visible to the driver, while he/she is driving the motor

vehicle. The operating controls for the television receiver shall be so

located that the driver cannot operate them without leaving the driver's

seat.

Sec. 393.89 Buses, driveshaft protection.

Any driveshaft extending lengthways under the floor of the passenger

compartment of a bus shall be protected by means of at least one guard

or bracket at that end of the shaft which is provided with a sliding

connection (spline or other such device) to prevent the whipping of the

shaft in the event of failure thereof or of any of its component parts.

A shaft contained within a torque tube shall not require any such

device.

[33 FR 19735, Dec. 25, 1968, as amended at 53 FR 49402, Dec. 7, 1988]

Sec. 393.90 Buses, standee line or bar.

Except as provided below, every bus, which is designed and

constructed so as to allow standees, shall be plainly marked with a line

of contrasting color at least 2 inches wide or equipped with some other

means so as to indicate to any person that he/she is prohibited

[[Page 428]]

from occupying a space forward of a perpendicular plane drawn through

the rear of the driver's seat and perpendicular to the longitudinal axis

of the bus. Every bus shall have clearly posted at or near the front, a

sign with letters at least one-half inch high stating that it is a

violation of the Federal Motor Carrier Safety Administration's

regulations for a bus to be operated with persons occupying the

prohibited area. The requirements of this section shall not apply to any

bus being transported in driveaway-towaway operation or to any level of

the bus other that the level in which the driver is located nor shall

they be construed to prohibit any seated person from occupying permanent

seats located in the prohibited area provided such seats are so located

that persons sitting therein will not interfere with the driver's safe

operation of the bus.

Sec. 393.91 Buses, aisle seats prohibited.

No bus shall be equipped with aisle seats unless such seats are so

designed and installed as to automatically fold and leave a clear aisle

when they are unoccupied. No bus shall be operated if any seat therein

is not securely fastened to the vehicle.

[53 FR 49402, Dec. 7, 1988]

Sec. 393.92 [Reserved]

Sec. 393.93 Seats, seat belt assemblies, and seat belt assembly

anchorages.

(a) Buses--(1) Buses manufactured on or after January 1, 1965, and

before July 1, 1971. After June 30, 1972, every bus manufactured on or

after January 1, 1965, and before July 1, 1971, must be equipped with a

Type 1 or Type 2 seat belt assembly that conforms to Federal Motor

Vehicle Safety Standard No. 209 \1\ (Sec. 571.209) installed at the

driver's seat and seat belt assembly anchorages that conform to the

location and geometric requirements of Federal Motor Vehicle Safety

Standard No. 210 \1\ (Sec. 571.210) for that seat belt assembly.

---------------------------------------------------------------------------

\1\ Individual copies of Federal Motor Vehicle Safety Standards may

be obtained from the National Highway Traffic Safety Administration.

Nassif Building, 400 Seventh Street SW., Washington, D.C. 20590.

---------------------------------------------------------------------------

(2) Buses manufactured on or after July 1, 1971. Every bus

manufactured on or after July 1, 1971, must conform to the requirements

of Federal Motor Vehicle Safety Standard No. 208 \1\ (Sec. 571.208)

(relating to installation of seat belt assemblies) and Federal Motor

Vehicle Safety Standard No. 210 \1\ (Sec. 571.210) (relating to

installation of seat belt assembly anchorages).

(3) Buses manufactured on or after January 1, 1972. Every bus

manufactured on or after January 1, 1972, must conform to the

requirements of Federal Motor Vehicle Safety Standard No. 207 \1\ (Sec.

571.207) (relating to seating systems).

(b) Trucks and truck tractors--(1) Trucks and truck tractors

manufactured on and after January 1, 1965, and before July 1, 1971.

Except as provided in paragraph (d) of this section, after June 30,

1972, every truck and truck tractor manufactured on or after January 1,

1965, and before July 1, 1971, must be equipped with a Type 1 or Type 2

seat belt assembly that conforms to Federal Motor Vehicle Safety

Standard No. 209 (Sec. 571.209) installed at the driver's seat and at

the right front outboard seat, if the vehicle has one, and seat belt

assembly anchorages that conform to the location and geometric

requirements of Federal Motor Vehicle Safety Standard No. 210 (Sec.

571.210) for each seat belt assembly that is required by this

subparagraph.

(2) Trucks and truck tractors manufactured on or after July 1, 1971.

Every truck and truck tractor manufactured on or after July 1, 1971,

except a truck or truck tractor being transported in driveaway-towaway

operation and having an incomplete vehicle seating and cab

configuration, must conform to the requirements of Federal Motor Vehicle

Safety Standard No. 208 \1\ (Sec. 571.208) (relating to installation of

seat belt assemblies) and Federal Motor Vehicle Safety Standard No. 210

\1\ (Sec. 571.210) (relating to installation of seat belt assembly

anchorages).

---------------------------------------------------------------------------

\1\ See footnote to Sec. 393.93(a).

---------------------------------------------------------------------------

(3) Trucks and truck tractors manufactured on or after January 1,

1972. Every truck and truck tractor manufactured on or after January 1,

1972, except a

[[Page 429]]

truck or truck tractor being transported in driveaway-towaway operation

and having an incomplete vehicle seating and cab configuration, must

conform to the requirements of Federal Motor Vehicle Safety Standard No.

207 \1\ (Sec. 571.207) (relating to seating systems).

(c) Effective date of standards. Whenever paragraph (a) or (b) of

this section requires conformity to a Federal Motor Vehicle Safety

Standard, the vehicle or equipment must conform to the version of the

Standard that is in effect on the date the vehicle is manufactured or on

the date the vehicle is modified to conform to the requirements of

paragraph (a) or (b) of this section, whichever is later.

(d) Trucks and truck tractors manufactured on or after January 1,

1965, and before July 1, 1971, and operated in the State of Hawaii, must

comply with the provisions of paragraph (b) of this section on and after

January 1, 1976.

[35 FR 16839, Oct. 30, 1970, as amended at 39 FR 32561, Sept. 9, 1974;

40 FR 32336, Aug. 1, 1975]

Sec. 393.94 Interior noise levels in power units.

(a) Applicability of this section. The interior noise level

requirements apply to all trucks, truck-tractors, and buses.

(b) General rule. The interior sound level at the driver's seating

position of a motor vehicle must not exceed 90 dB(A) when measured in

accordance with paragraph (c) of this section.

(c) Test procedure. (1) Park the vehicle at a location so that no

large reflecting surfaces, such as other vehicles, signboards,

buildings, or hills, are within 50 feet of the driver's seating

position.

(2) Close all vehicle doors, windows, and vents. Turn off all power-

operated accessories.

(3) Place the driver in his/her normal seated position at the

vehicle's controls. Evacuate all occupants except the driver and the

person conducting the test.

(4) The sound level meters used to determine compliance with the

requirements of this section must meet the American National Standards

Institute ``Specification for Sound Level Meters,'' ANSI S1.4--1983.

(See Sec. 393.7(b) for information on the incorporation by reference

and availability of this document.)

(5) Locate the microphone, oriented vertically upward, 6 inches to

the right of, in the same plane as, and directly in line with, the

driver's right ear.

(6) With the vehicle's transmission in neutral gear, accelerate its

engine to either its maximum governed engine speed, if it is equipped

with an engine governor, or its speed at its maximum rated horsepower,

if it is not equipped with an engine governor. Stabilize the engine at

that speed.

(7) Observe the A-weighted sound level reading on the meter for the

stabilized engine speed condition. Record that reading, if the reading

has not been influenced by extraneous noise sources such as motor

vehicles operating on adjacent roadways.

(8) Return the vehicle's engine speed to idle and repeat the

procedures specified in paragraphs (c) (6) and (7) of this section until

two maximum sound levels within 2 dB of each other are recorded.

Numerically average those two maximum sound level readings.

(9) The average obtained in accordance with paragraph (c)(8) of this

section is the vehicle's interior sound level at the driver's seating

position for the purpose of determining whether the vehicle conforms to

the rule in paragraph (b) of this section. How ever, a 2 dB tolerance

over the sound level limitation specified in that paragraph is permitted

to allow for variations in test conditions and variations in the

capabilities of meters.

(10) If the motor vehicle's engine radiator fan drive is equipped

with a clutch or similar device that automatically either reduces the

rotational speed of the fan or completely disengages the fan from its

power source in response to reduced engine cooling loads the vehicle may

be parked before testing with its engine running at high idle or any

other speed the operator may choose, for sufficient time but not more

than 10 minutes, to permit the engine radiator fan to automatically

disengage.

[38 FR 30881, Nov. 8, 1973, as amended at 40 FR 32336, Aug. 1, 1975; 41

FR 28268, July 9, 1976; 70 FR 48054, Aug. 15, 2005]

[[Page 430]]

Subpart H_Emergency Equipment

Sec. 393.95 Emergency equipment on all power units.

Each truck, truck tractor, and bus (except those towed in driveaway-

towaway operations) must be equipped as follows:

(a) Fire Extinguishers. (1) Minimum ratings: (i) A power unit that

is used to transport hazardous materials in a quantity that requires

placarding (See Sec. 177.823 of this title) must be equipped with a

fire extinguisher having an Underwriters' Laboratories rating of 10 B:C

or more.

(ii) A power unit that is not used to transport hazardous materials

must be equipped with either:

(A) A fire extinguisher having an Underwriters' Laboratories rating

of 5 B:C or more; or

(B) Two fire extinguishers, each of which has an Underwriters'

Laboratories rating of 4 B:C or more.

(2) Labeling and marking. Each fire extinguisher required by this

section must be labeled or marked by the manufacturer with its

Underwriters' Laboratories rating.

(3) Visual Indicators. The fire extinguisher must be designed,

constructed, and maintained to permit visual determination of whether it

is fully charged.

(4) Condition, location, and mounting. The fire extinguisher(s) must

be filled and located so that it is readily accessible for use. The

extinguisher(s) must be securely mounted to prevent sliding, rolling, or

vertical movement relative to the motor vehicle.

(5) Extinguishing agents. The fire extinguisher must use an

extinguishing agent that does not need protection from freezing.

Extinguishing agents must comply with the toxicity provisions of the

Environmental Protection Agency's Significant New Alternatives Policy

(SNAP) regulations under 40 CFR Part 82, Subpart G.

(b) Spare fuses. Power units for which fuses are needed to operate

any required parts and accessories must have at least one spare fuse for

each type/size of fuse needed for those parts and accessories.

(c)-(e) [Reserved]

(f) Warning devices for stopped vehicles. Except as provided in

paragraph (g) of this section, one of the following options must be

used:

(1) Three bidirectional emergency reflective triangles that conform

to the requirements of Federal Motor Vehicle Safety Standard No. 125,

Sec. 571.125 of this title; or

(2) At least 6 fusees or 3 liquid-burning flares. The vehicle must

have as many additional fusees or liquid-burning flares as are necessary

to satisfy the requirements of Sec. 392.22.

(3) Other warning devices may be used in addition to, but not in

lieu of, the required warning devices, provided those warning devices do

not decrease the effectiveness of the required warning devices.

(g) Restrictions on the use of flame-producing devices. Liquid-

burning flares, fusees, oil lanterns, or any signal produced by a flame

shall not be carried on any commercial motor vehicle transporting

Division 1.1, 1.2, 1.3 (explosives) hazardous materials; any cargo tank

motor vehicle used for the transportation of Division 2.1 (flammable

gas) or Class 3 (flammable liquid) hazardous materials whether loaded or

empty; or any commercial motor vehicle using compressed gas as a motor

fuel.

(h)--(i) [Reserved]

(j) Requirements for fusees and liquid-burning flares. Each fusee

shall be capable of burning for 30 minutes, and each liquid-burning

flare shall contain enough fuel to burn continuously for at least 60

minutes. Fusees and liquid-burning flares shall conform to the

requirements of Underwriters Laboratories, Inc., UL No. 912, Highway

Emergency Signals, Fourth Edition, July 30, 1979, (with an amendment

dated November 9, 1981). (See Sec. 393.7(c) for information on the

incorporation by reference and availability of this document.) Each

fusee and liquid-burning flare shall be marked with the UL symbol in

accordance with the requirements of UL 912.

(k) Requirements for red flags. Red flags shall be not less than 12

inches square, with standards adequate to

[[Page 431]]

maintain the flags in an upright position.

(49 U.S.C. 304, 1655; 49 CFR 1.48(b) and 301.60)

[33 FR 19735, Dec. 25, 1968, as amended at 35 FR 13019, Aug. 15, 1970;

35 FR 14619, Sept. 18, 1970; 37 FR 17176, Aug. 25, 1972; 40 FR 10685,

Mar. 7, 1975; 41 FR 53031, Dec. 3, 1976; 47 FR 47837, Oct. 28, 1982; 59

FR 34712, July 6, 1994; 67 FR 61225, Sept. 27, 2002; 70 FR 48054, Aug.

15, 2005]

Subpart I_Protection Against Shifting and Falling Cargo

Source: 67 FR 61225, Sept. 27, 2002, unless otherwise noted.

Sec. 393.100 Which types of commercial motor vehicles are subject to

the cargo securement standards of this subpart, and what

general requirements apply?

(a) Applicability. The rules in this subpart are applicable to

trucks, truck tractors, semitrailers, full trailers, and pole trailers.

(b) Prevention against loss of load. Each commercial motor vehicle

must, when transporting cargo on public roads, be loaded and equipped,

and the cargo secured, in accordance with this subpart to prevent the

cargo from leaking, spilling, blowing or falling from the motor vehicle.

(c) Prevention against shifting of load. Cargo must be contained,

immobilized or secured in accordance with this subpart to prevent

shifting upon or within the vehicle to such an extent that the vehicle's

stability or maneuverability is adversely affected.

Sec. 393.102 What are the minimum performance criteria for cargo

securement devices and systems?

(a) Performance criteria. Cargo securement devices and systems must

be capable of withstanding the following three forces, applied

separately:

(1) 0.8 g deceleration in the forward direction;

(2) 0.5 g acceleration in the rearward direction; and

(3) 0.5 g acceleration in a lateral direction.

(b) Performance criteria for devices to prevent vertical movement of

loads that are not contained within the structure of the vehicle.

Securement systems must provide a downward force equivalent to at least

20 percent of the weight of the article of cargo if the article is not

fully contained within the structure of the vehicle. If the article is

fully contained within the structure of the vehicle, it may be secured

in accordance with Sec. 393.106(b).

(c) Prohibition on exceeding working load limits. Cargo securement

devices and systems must be designed, installed, and maintained to

ensure that the maximum forces acting on the devices or systems do not

exceed the working load limit for the devices under the conditions

listed in paragraphs (a) and (b) of this section.

(d) Equivalent means of securement. Cargo that is immobilized, or

secured in accordance with the applicable requirements of Sec. Sec.

393.104 through 393.136, is considered as meeting the performance

criteria of this section.

Sec. 393.104 What standards must cargo securement devices and systems

meet in order to satisfy the requirements of this subpart?

(a) General. All devices and systems used to secure cargo to or

within a vehicle must be capable of meeting the requirements of Sec.

393.102.

(b) Prohibition on the use of damaged securement devices. All

vehicle structures, systems, parts, and components used to secure cargo

must be in proper working order when used to perform that function with

no damaged or weakened components that will adversely effect their

performance for cargo securement purposes, including reducing the

working load limit, and must not have any cracks or cuts.

(c) Vehicle structures and anchor points. Vehicle structures,

floors, walls, decks, tiedown anchor points, headerboards, bulkheads,

stakes, posts and associated mounting pockets used to contain or secure

articles of cargo must be strong enough to meet the performance criteria

of Sec. 393.102, with no damaged or weakened components that will

adversely effect their performance for cargo securement purposes,

including reducing the working load limit, and must not have any cracks

or cuts.

(d) Material for dunnage, chocks, cradles, shoring bars, blocking

and bracing. Material used as dunnage or dunnage

[[Page 432]]

bags, chocks, cradles, shoring bars, or used for blocking and bracing,

must not have damage or defects which would compromise the effectiveness

of the securement system.

(e) Manufacturing standards for tiedown assemblies. Tiedown

assemblies (including chains, wire rope, steel strapping, synthetic

webbing, and cordage) and other attachment or fastening devices used to

secure articles of cargo to, or in, commercial motor vehicles must

conform to the following applicable standards:

[[Page 433]]

----------------------------------------------------------------------------------------------------------------

An assembly component of . . . Must conform to . . .

----------------------------------------------------------------------------------------------------------------

(1) Steel strapping 1, 2................................... Standard Specification for Strapping, Flat Steel

and Seals, American Society for Testing and

Materials (ASTM) D3953-97, February 1998.\4\

(2) Chain.................................................. National Association of Chain Manufacturers' Welded

Steel Chain Specifications, November 15, 1999.\4\

(3) Webbing................................................ Web Sling and Tiedown Association's Recommended

Standard Specification for Synthetic Web Tiedowns,

WSTDA-T1, 1998.\4\

(4) Wire rope \3\.......................................... Wire Rope Technical Board's Wire Rope Users Manual,

2nd Edition, November 1985.\4\

(5) Cordage................................................ Cordage Institute rope standard:

(i) PETRS-2, Polyester Fiber Rope, three-Strand

and eight-Strand Constructions, January 1993;

\4\

(ii) PPRS-2, Polypropylene Fiber Rope, three-

Strand and eight-Strand Constructions, August

1992; \4\

(iii) CRS-1, Polyester/Polypropylene Composite

Rope Specifications, three-Strand and eight-

Strand Standard Construction, May 1979; \4\

(iv) NRS-1, Nylon Rope Specifications, three-

Strand and eight-Strand Standard Construction,

May 1979; \4\ and

(v) C-1, Double Braided Nylon Rope

Specifications DBN, January 1984.\4\

----------------------------------------------------------------------------------------------------------------

\1\ Steel strapping not marked by the manufacturer with a working load limit will be considered to have a

working load limit equal to one-fourth of the breaking strength listed in ASTM D3953-97.

\2\ Steel strapping 25.4 mm (1 inch) or wider must have at least two pairs of crimps in each seal and, when an

end-over-end lap joint is formed, must be sealed with at least two seals.

\3\ Wire rope which is not marked by the manufacturer with a working load limit shall be considered to have a

working load limit equal to one-fourth of the nominal strength listed in the manual.

\4\ See Sec. 393.7 for information on the incorporation by reference and availability of this document.

[[Page 434]]

(f) Use of tiedowns. (1) Tiedowns and securing devices must not

contain knots.

(2) If a tiedown is repaired, it must be repaired in accordance with

the applicable standards in paragraph (e) of this section, or the

manufacturer's instructions.

(3) Each tiedown must be attached and secured in a manner that

prevents it from becoming loose, unfastening, opening or releasing while

the vehicle is in transit.

(4) All tiedowns and other components of a cargo securement system

used to secure loads on a trailer equipped with rub rails, must be

located inboard of the rub rails whenever practicable.

(5) Edge protection must be used whenever a tiedown would be subject

to abrasion or cutting at the point where it touches an article of

cargo. The edge protection must resist abrasion, cutting and crushing.

Sec. 393.106 What are the general requirements for securing articles

of cargo?

(a) Applicability. The rules in this section are applicable to the

transportation of all types of articles of cargo, except commodities in

bulk that lack structure or fixed shape (e.g., liquids, gases, grain,

liquid concrete, sand, gravel, aggregates) and are transported in a

tank, hopper, box or similar device that forms part of the structure of

a commercial motor vehicle. The rules in this section apply to the cargo

types covered by the commodity-specific rules of Sec. 393.116 through

Sec. 393.136. The commodity-specific rules take precedence over the

general requirements of this section when additional requirements are

given for a commodity listed in those sections.

(b) General. Cargo must be firmly immobilized or secured on or

within a vehicle by structures of adequate strength, dunnage or dunnage

bags, shoring bars, tiedowns or a combination of these.

(c) Cargo placement and restraint. (1) Articles of cargo that are

likely to roll must be restrained by chocks, wedges, a cradle or other

equivalent means to prevent rolling. The means of preventing rolling

must not be capable of becoming unintentionally unfastened or loose

while the vehicle is in transit.

(2) Articles or cargo placed beside each other and secured by

transverse tiedowns must either:

(i) Be placed in direct contact with each other, or

(ii) Be prevented from shifting towards each other while in transit.

(d) Minimum strength of cargo securement devices and systems. The

aggregate working load limit of any securement system used to secure an

article or group of articles against movement must be at least one-half

times the weight of the article or group of articles. The aggregate

working load limit is the sum of:

(1) One-half of the working load limit of each associated connector

or attachment mechanism used to secure a part of the article of cargo to

the vehicle; and

(2) One-half of the working load limit for each end section of a

tiedown that is attached to an anchor point.

[67 FR 61225, Sept. 27, 2002, as amended at 68 FR 56208, Sept. 30, 2003]

Sec. 393.108 How is the working load limit of a tiedown determined?

(a) The working load limit (WLL) of a tiedown, associated connector

or attachment mechanism is the lowest working load limit of any of its

components (including tensioner), or the working load limit of the

anchor points to which it is attached, whichever is less.

(b) The working load limits of tiedowns may be determined by using

either the tiedown manufacturer's markings or by using the tables in

this section. The working load limits listed in the tables are to be

used when the tiedown material is not marked by the manufacturer with

the working load limit. Tiedown materials which are marked by the

manufacturer with working load limits that differ from the tables, shall

be considered to have a working load limit equal to the value for which

they are marked.

(c) Synthetic cordage (e.g., nylon, polypropylene, polyester) which

is not marked or labeled to enable identification of its composition or

working load limit shall be considered to have a

[[Page 435]]

working load limit equal to that for polypropylene fiber rope.

(d) Welded steel chain which is not marked or labeled to enable

identification of its grade or working load limit shall be considered to

have a working load limit equal to that for grade 30 proof coil chain.

(e)(1) Wire rope which is not marked by the manufacturer with a

working load limit shall be considered to have a working load limit

equal to one-fourth of the nominal strength listed in the Wire Rope

Users Manual.

(2) Wire which is not marked or labeled to enable identification of

its construction type shall be considered to have a working load limit

equal to that for 6 x 37, fiber core wire rope.

(f) Manila rope which is not marked by the manufacturer with a

working load limit shall be considered to have a working load limit

based on its diameter as provided in the tables of working load limits.

(g) Friction mats which are not marked or rated by the manufacturer

shall be considered to provide resistance to horizontal movement equal

to 50 percent of the weight placed on the mat.

Tables to Sec. 393.108

[Working Load Limits (WLL), Chain]

--------------------------------------------------------------------------------------------------------------------------------------------------------

WLL in kg (pounds)

-----------------------------------------------------------------------------------------

Size mm (inches) Grade 30 proof Grade 43 high Grade 70

coil test transport Grade 80 alloy Grade 100 alloy

--------------------------------------------------------------------------------------------------------------------------------------------------------

1. 7 (1/4).................................................... 580 (1,300) 1,180 (2,600) 1,430 (3,150) 1,570 (3,500) 1,950 (4,300)

2. 8 (5/16)................................................... 860 (1,900) 1,770 (3,900) 2,130 (4,700) 2,000 (4,500) 2,600 (5,700)

3. 10 (3/8)................................................... 1,200 (2,650) 2,450 (5,400) 2,990 (6,600) 3,200 (7,100) 4,000 (8,800)

4. 11 (7/16).................................................. 1,680 (3,700) 3,270 (7,200) 3,970 (8,750)

5. 13 (1/2)................................................... 2,030 (4,500) 4,170 (9,200) 5,130 (11,300) 5,400 (12,000) 6,800 (15,000)

6. 16 (5/8)................................................... 3,130 (6,900) 5,910 (13,000) 7,170 (15,800) 8,200 (18,100) 10,300 (22,600)

Chain Mark Examples:

Example 1................................................. 3 4 7 8 10

Example 2................................................. 30 43 70 80 100

Example 3................................................. 300 430 700 800 1000

--------------------------------------------------------------------------------------------------------------------------------------------------------

Synthetic Webbing

------------------------------------------------------------------------

Width mm (inches) WLL kg (pounds)

------------------------------------------------------------------------

45 (1\3/4\)........................................... 790 (1,750)

50 (2)................................................ 910 (2,000)

75 (3)................................................ 1,360 (3,000)

100 (4)............................................... 1,810 (4,000)

------------------------------------------------------------------------

Wire Rope (6 x 37, Fiber Core)

------------------------------------------------------------------------

Diameter mm (inches) WLL kg (pounds)

------------------------------------------------------------------------

7 (1/4)............................................... 640 (1,400)

8 (5/16).............................................. 950 (2,100)

10 (3/8).............................................. 1,360 (3,000)

11 (7/16)............................................. 1,860 (4,100)

13 (1/2).............................................. 2,400 (5,300)

16 (5/8).............................................. 3,770 (8,300)

20 (3/4).............................................. 4,940 (10,900)

22 (7/8).............................................. 7,300 (16,100)

25 (1)................................................ 9,480 (20,900)

------------------------------------------------------------------------

Manila Rope

------------------------------------------------------------------------

Diameter mm (inches) WLL kg (pounds)

------------------------------------------------------------------------

10 (3/8).............................................. 90 (205)

11 (7/16)............................................. 120 (265)

13 (1/2).............................................. 150 (315)

16 (5/8).............................................. 210 (465)

20 (3/4).............................................. 290 (640)

25 (1)................................................ 480 (1,050)

------------------------------------------------------------------------

Polypropylene Fiber Rope WLL (3-Strand and 8-Strand Constructions)

------------------------------------------------------------------------

Diameter mm (inches) WLL kg (pounds)

------------------------------------------------------------------------

10 (3/8).............................................. 180 (400)

11 (7/16)............................................. 240 (525)

13 (1/2).............................................. 280 (625)

16 (5/8).............................................. 420 (925)

20 (3/4).............................................. 580 (1,275)

25 (1)................................................ 950 (2,100)

------------------------------------------------------------------------

Polyester Fiber Rope WLL (3-Strand and 8-Strand Constructions)

------------------------------------------------------------------------

Diameter mm (inches) WLL kg (pounds)

------------------------------------------------------------------------

10 (3/8).............................................. 250 (555)

11 (7/16)............................................. 340 (750)

13 (1/2).............................................. 440 (960)

16 (5/8).............................................. 680 (1,500)

20 (3/4).............................................. 850 (1,880)

25 (1)................................................ 1,500 (3,300)

------------------------------------------------------------------------

Nylon Rope

------------------------------------------------------------------------

Diameter mm (inches) WLL kg (pounds)

------------------------------------------------------------------------

10 (3/8).............................................. 130 (278)

11 (7/16)............................................. 190 (410)

13 (1/2).............................................. 240 (525)

16 (5/8).............................................. 420 (935)

20 (3/4).............................................. 640 (1,420)

[[Page 436]]

25 (1)................................................ 1,140 (2,520)

------------------------------------------------------------------------

Double Braided Nylon Rope

------------------------------------------------------------------------

Diameter mm (inches) WLL kg (pounds)

------------------------------------------------------------------------

10 (3/8).............................................. 150 (336)

11 (7/16)............................................. 230 (502)

13 (1/2).............................................. 300 (655)

16 (5/8).............................................. 510 (1,130)

20 (3/4).............................................. 830 (1,840)

25 (1)................................................ 1,470 (3,250)

------------------------------------------------------------------------

Steel Strapping

------------------------------------------------------------------------

Width x thickness mm (inches) WLL kg (pounds)

------------------------------------------------------------------------

31.7 x .74 (1 1/4 x 0.029)............................ 540 (1,190)

31.7 x .79 (1\1/4\ x 0.031)........................... 540 (1,190)

31.7 x .89 (1\1/4\ x 0.035)........................... 540 (1,190)

31.7 x 1.12 (1\1/4\ x 0.044).......................... 770 (1,690)

31.7 x 1.27 (1\1/4\ x 0.05)........................... 770 (1,690)

31.7 x 1.5 (1\1/4\ x 0.057)........................... 870 (1,925)

50.8 x 1.12 (2 x 0.044)............................... 1,200 (2,650)

50.8 x 1.27 (2 x 0.05)................................ 1,200 (2,650)

------------------------------------------------------------------------

Sec. 393.110 What else do I have to do to determine the minimum number

of tiedowns?

(a) In addition to the requirements of Sec. 393.106, the minimum

number of tiedowns required to secure an article or group of articles

against movement depends on the length of the article(s) being secured,

and the requirements of paragraphs (b) and (c) of this section.

(b) When an article is not blocked or positioned to prevent movement

in the forward direction by a headerboard, bulkhead, other cargo that is

positioned to prevent movement, or other appropriate blocking devices,

it must be secured by at least:

(1) One tiedown for articles 5 feet (1.52 meters) or less in length,

and 1,100 pounds (500 kg) or less in weight;

(2) Two tiedowns if the article is:

(i) 5 feet (1.52 meters) or less in length and more than 1,100

pounds (500 kg) in weight; or

(ii) Longer than 5 feet (1.52 meters) but less than or equal to 10

feet (3.04 meters) in length, irrespective of the weight.

(3) Two tiedowns if the article is longer than 10 feet (3.04

meters), and one additional tiedown for every 10 feet (3.04 meters) of

article length, or fraction thereof, beyond the first 10 feet (3.04

meters) of length.

(c) If an individual article is required to be blocked, braced or

immobilized to prevent movement in the forward direction by a

headerboard, bulkhead, other articles which are adequately secured or by

an appropriate blocking or immobilization method, it must be secured by

at least one tiedown for every 3.04 meters (10 feet) or article length,

or fraction thereof.

(d) Special rule for special purpose vehicles. The rules in this

section do not apply to a vehicle transporting one or more articles of

cargo such as, but not limited to, machinery or fabricated structural

items (e.g., steel or concrete beams, crane booms, girders, and trusses,

etc.) which, because of their design, size, shape, or weight, must be

fastened by special methods. However, any article of cargo carried on

that vehicle must be securely and adequately fastened to the vehicle.

Sec. 393.112 Must a tiedown be adjustable?

Each tiedown, or its associated connectors, or its attachment

mechanisms must be designed, constructed, and maintained so the driver

of an in-transit commercial motor vehicle can tighten them. However,

this requirement does not apply to the use of steel strapping.

Sec. 393.114 What are the requirements for front end structures used

as part of a cargo securement system?

(a) Applicability. The rules in this section are applicable to

commercial motor vehicles transporting articles of cargo that are in

contact with the front end structure of the vehicle. The front end

structure on these cargo-carrying vehicles must meet the performance

requirements of this section.

(b) Height and width. (1) The front end structure must extend either

to a height of 4 feet above the floor of the vehicle or to a height at

which it blocks forward movement of any item of article of cargo being

carried on the vehicle, whichever is lower.

(2) The front end structure must have a width which is at least

equal to the width of the vehicle or which blocks forward movement of

any article of cargo being transported on the vehicle, whichever is

narrower.

[[Page 437]]

(c) Strength. The front end structure must be capable of

withstanding the following horizontal forward static load:

(1) For a front end structure less than 6 feet in height, a

horizontal forward static load equal to one-half (0.5) of the weight of

the articles of cargo being transported on the vehicle uniformly

distributed over the entire portion of the front end structure that is

within 4 feet above the vehicle's floor or that is at or below a height

above the vehicle's floor at which it blocks forward movement of any

article of the vehicle's cargo, whichever is less; or

(2) For a front end structure 6 feet in height or higher, a

horizontal forward static load equal to four-tenths (0.4) of the weight

of the articles of cargo being transported on the vehicle uniformly

distributed over the entire front end structure.

(d) Penetration resistance. The front end structure must be

designed, constructed, and maintained so that it is capable of resisting

penetration by any article of cargo that contacts it when the vehicle

decelerates at a rate of 20 feet per second, per second. The front end

structure must have no aperture large enough to permit any article of

cargo in contact with the structure to pass through it.

(e) Substitute devices. The requirements of this section may be met

by the use of devices performing the same functions as a front end

structure, if the devices are at least as strong as, and provide

protection against shifting articles of cargo at least equal to, a front

end structure which conforms to those requirements.

Specific Securement Requirements by Commodity Type

Sec. 393.116 What are the rules for securing logs?

(a) Applicability. The rules in this section are applicable to the

transportation of logs with the following exceptions:

(1) Logs that are unitized by banding or other comparable means may

be transported in accordance with the general cargo securement rules of

Sec. Sec. 393.100 through 393.114.

(2) Loads that consist of no more than four processed logs may be

transported in accordance with the general cargo securement rules of

Sec. Sec. 393.100 through 393.114.

(3) Firewood, stumps, log debris and other such short logs must be

transported in a vehicle or container enclosed on both sides, front, and

rear and of adequate strength to contain them. Longer logs may also be

so loaded.

(b) Components of a securement system. (1) Logs must be transported

on a vehicle designed and built, or adapted, for the transportation of

logs. Any such vehicle must be fitted with bunks, bolsters, stakes or

standards, or other equivalent means, that cradle the logs and prevent

them from rolling.

(2) All vehicle components involved in securement of logs must be

designed and built to withstand all anticipated operational forces

without failure, accidental release or permanent deformation. Stakes or

standards that are not permanently attached to the vehicle must be

secured in a manner that prevents unintentional separation from the

vehicle in transit.

(3) Tiedowns must be used in combination with the stabilization

provided by bunks, stakes and bolsters to secure the load.

(c) Use of securement system. (1) Logs must be solidly packed, and

the outer bottom logs must be in contact with and resting solidly

against the bunks, bolsters, stakes or standards.

(2) Each outside log on the side of a stack of logs must touch at

least two stakes, bunks, bolsters, or standards. If one end does not

actually touch a stake, it must rest on other logs in a stable manner

and must extend beyond the stake, bunk, bolster or standard.

(3) The center of the highest outside log on each side or end must

be below the top of each stake, bunk or standard.

(4) Each log that is not held in place by contact with other logs or

the stakes, bunks, or standards must be held in place by a tiedown.

Additional tiedowns or securement devices must be used when the

condition of the wood results in such low friction between logs that

they are likely to slip upon each other.

[[Page 438]]

(d) Securement of shortwood logs loaded crosswise on frame, rail and

flatbed vehicles. In addition to the requirements of paragraphs (b) and

(c) of this section, each stack of logs loaded crosswise must meet the

following rules:

(1) In no case may the end of a log in the lower tier extend more

than one-third of the log's total length beyond the nearest supporting

structure on the vehicle.

(2) When only one stack of shortwood is loaded crosswise, it must be

secured with at least two tiedowns. The tiedowns must attach to the

vehicle frame at the front and rear of the load, and must cross the load

in this direction.

(3) When two tiedowns are used, they must be positioned at

approximately one-third and two-thirds of the length of the logs.

(4) A vehicle that is more than 10 meters (33 feet) long must be

equipped with center stakes, or comparable devices, to divide it into

sections approximately equal in length. Where a vehicle is so divided,

each tiedown must secure the highest log on each side of the center

stake, and must be fastened below these logs. It may be fixed at each

end and tensioned from the middle, or fixed in the middle and tensioned

from each end, or it may pass through a pulley or equivalent device in

the middle and be tensioned from one end.

(5) Any structure or stake that is subjected to an upward force when

the tiedowns are tensioned must be anchored to resist that force.

(6) If two stacks of shortwood are loaded side-by-side, in addition

to meeting the requirements of paragraphs (d)(1) through (d)(5) of this

section, they must be loaded so that:

(i) There is no space between the two stacks of logs;

(ii) The outside of each stack is raised at least 2.5 cm (1 in)

within 10 cm (4 in) of the end of the logs or the side of the vehicle;

(iii) The highest log is no more than 2.44 m (8 ft) above the deck;

and

(iv) At least one tiedown is used lengthwise across each stack of

logs.

(e) Securement of logs loaded lengthwise on flatbed and frame

vehicles. In addition to meeting the requirements of paragraphs (b) and

(c) of this section, each stack of shortwood loaded lengthwise on a

frame vehicle or on a flatbed must be secured to the vehicle by at least

two tiedowns.

(f) Securement of logs transported on pole trailers. (1) The load

must be secured by at least one tiedown at each bunk, or alternatively,

by at least two tiedowns used as wrappers that encircle the entire load

at locations along the load that provide effective securement.

(2) The front and rear wrappers must be at least 3.04 meters (10

feet) apart.

(3) Large diameter single and double log loads must be immobilized

with chock blocks or other equivalent means to prevent shifting.

(4) Large diameter logs that rise above bunks must be secured to the

underlying load with at least two additional wrappers.

Sec. 393.118 What are the rules for securing dressed lumber or similar

building products?

(a) Applicability. The rules in this section apply to the

transportation of bundles of dressed lumber, packaged lumber, building

products such as plywood, gypsum board or other materials of similar

shape. Lumber or building products which are not bundled or packaged

must be treated as loose items and transported in accordance with

Sec. Sec. 393.100 through 393.114 of this subpart. For the purpose of

this section, ``bundle'' refers to packages of lumber, building

materials or similar products which are unitized for securement as a

single article of cargo.

(b) Positioning of bundles. Bundles must be placed side by side in

direct contact with each other, or a means must be provided to prevent

bundles from shifting towards each other.

(c) Securement of bundles transported using no more than one tier.

Bundles carried on one tier must be secured in accordance with the

general provisions of Sec. Sec. 393.100 through 393.114.

(d) Securement of bundles transported using more than one tier.

Bundles carried in more than one tier must be either:

(1) Blocked against lateral movement by stakes on the sides of the

vehicle and secured by tiedowns laid out over

[[Page 439]]

the top tier, as outlined in the general provisions of Sec. Sec.

393.100 through 393.114; or

(2) Restrained from lateral movement by blocking or high friction

devices between tiers and secured by tiedowns laid out over the top

tier, as outlined in the general provisions of Sec. Sec. 393.100

through 393.114; or

(3) Placed directly on top of other bundles or on spacers and

secured in accordance with the following:

(i) The length of spacers between bundles must provide support to

all pieces in the bottom row of the bundle.

(ii) The width of individual spacers must be equal to or greater

than the height.

(iii) If spacers are comprised of layers of material, the layers

must be unitized or fastened together in a manner which ensures that the

spacer performs as a single piece of material.

(iv) The arrangement of the tiedowns for the bundles must be:

(A) Secured by tiedowns over the top tier of bundles, in accordance

with the general provisions of Sec. Sec. 393.100 through 393.114 with a

minimum of two tiedowns for bundles longer than 1.52 meters (5 ft); and

(B) Secured by tiedowns in accordance with the general provisions of

Sec. Sec. 393.100 through 393.114 over the second tier or over a middle

tier of a maximum height of 1.85 meters (6 ft) above the trailer deck,

whichever is greater, for each stack of bundles composed of more than

two tiers; or

(4) Secured by tiedowns over each tier of bundles, in accordance

with Sec. Sec. 393.100 through 393.114 using a minimum of two tiedowns

over each of the top bundles longer than 1.52 meters (5 ft), in all

circumstances.

Sec. 393.120 What are the rules for securing metal coils?

(a) Applicability. The rules in this section apply to the

transportation of one or more metal coils which, individually or grouped

together, weigh 2268 kg (5000 pounds) or more. Shipments of metal coils

that weigh less than 2268 kg (5000 pounds) may be secured in accordance

with the provisions of Sec. Sec. 393.100 through 393.114.

(b) Securement of coils transported with eyes vertical on a flatbed

vehicle, in a sided vehicle or intermodal container with anchor points--

(1) An individual coil. Each coil must be secured by tiedowns arranged

in a manner to prevent the coils from tipping in the forward, rearward,

and lateral directions. The restraint system must include the following:

(i) At least one tiedown attached diagonally from the left side of

the vehicle or intermodal container (near the forwardmost part of the

coil), across the eye of the coil, to the right side of the vehicle or

intermodal container (near the rearmost part of the coil);

(ii) At least one tiedown attached diagonally from the right side of

the vehicle or intermodal container (near the forwardmost part of the

coil), across the eye of the coil, to the left side of the vehicle or

intermodal container (near the rearmost part of the coil);

(iii) At least one tiedown attached transversely over the eye of the

coil; and

(iv) Either blocking and bracing, friction mats or tiedowns must be

used to prevent longitudinal movement in the forward direction.

(2) Coils grouped in rows. When coils are grouped and loaded side by

side in a transverse or longitudinal row, the each row of coils must be

secured by the following:

(i) At least one tiedown attached to the front of the row of coils,

restraining against forward motion, and whenever practicable, making an

angle no more than 45 degrees with the floor of the vehicle or

intermodal container when viewed from the side of the vehicle or

container;

(ii) At least one tiedown attached to the rear of the row of coils,

restraining against rearward motion, and whenever practicable, making an

angle no more than 45 degrees with the floor of the vehicle or

intermodal container when viewed from the side of the vehicle or

container;

(iii) At least one tiedown over the top of each coil or transverse

row of coils, restraining against vertical motion. Tiedowns going over

the top of a coil(s) must be as close as practicable to the eye of the

coil and positioned to prevent the tiedown from slipping or becoming

unintentionally unfastened while the vehicle is in transit; and

[[Page 440]]

(iv) Tiedowns must be arranged to prevent shifting or tipping in the

forward, rearward and lateral directions.

(c) Securement of coils transported with eyes crosswise on a flatbed

vehicle, in a sided vehicle or intermodal container with anchor points--

(1) An individual coil. Each coil must be secured by the following:

(i) A means (e.g., timbers, chocks or wedges, a cradle, etc.) to

prevent the coil from rolling. The means of preventing rolling must

support the coil off the deck, and must not be capable of becoming

unintentionally unfastened or loose while the vehicle is in transit. If

timbers, chocks or wedges are used, they must be held in place by coil

bunks or similar devices to prevent them from coming loose. The use of

nailed blocking or cleats as the sole means to secure timbers, chocks or

wedges, or a nailed wood cradle, is prohibited;

(ii) At least one tiedown through its eye, restricting against

forward motion, and whenever practicable, making an angle no more than

45 degrees with the floor of the vehicle or intermodal container when

viewed from the side of the vehicle or container; and

(iii) At least one tiedown through its eye, restricting against

rearward motion, and whenever practicable, making an angle no more than

45 degrees with the floor of the vehicle or intermodal container when

viewed from the side of the vehicle or container.

(2) Prohibition on crossing of tiedowns when coils are transported

with eyes crosswise. Attaching tiedowns diagonally through the eye of a

coil to form an X-pattern when viewed from above the vehicle is

prohibited.

(d) Securement of coils transported with eyes lengthwise on a

flatbed vehicle, in a sided vehicle or intermodal container with anchor

points--(1) An individual coil-option 1. Each coil must be secured by:

(i) A means (e.g., timbers, chocks or wedges, a cradle, etc.) to

prevent the coil from rolling. The means of preventing rolling must

support the coil off the deck, and must not be capable of becoming

unintentionally unfastened or loose while the vehicle is in transit. If

timbers, chocks or wedges are used, they must be held in place by coil

bunks or similar devices to prevent them from coming loose. The use of

nailed blocking or cleats as the sole means to secure timbers, chocks or

wedges, or a nailed wood cradle, is prohibited;

(ii) At least one tiedown attached diagonally through its eye from

the left side of the vehicle or intermodal container (near the forward-

most part of the coil), to the right side of the vehicle or intermodal

container (near the rearmost part of the coil), making an angle no more

than 45 degrees, whenever practicable, with the floor of the vehicle or

intermodal container when viewed from the side of the vehicle or

container;

(iii) At least one tiedown attached diagonally through its eye, from

the right side of the vehicle or intermodal container (near the forward-

most part of the coil), to the left side of the vehicle or intermodal

container (near the rearmost part of the coil), making an angle no more

than 45 degrees, whenever practicable, with the floor of the vehicle or

intermodal container when viewed from the side of the vehicle or

container;

(iv) At least one tiedown attached transversely over the top of the

coil; and

(v) Either blocking, or friction mats to prevent longitudinal

movement.

(2) An individual coil--option 2. Each coil must be secured by:

(i) A means (e.g., timbers, chocks or wedges, a cradle, etc.) to

prevent the coil from rolling. The means of preventing rolling must

support the coil off the deck, and must not be capable of becoming

unintentionally unfastened or loose while the vehicle is in transit. If

timbers, chocks or wedges are used, they must be held in place by coil

bunks or similar devices to prevent them from coming loose. The use of

nailed blocking or cleats as the sole means to secure timbers, chocks or

wedges, or a nailed wood cradle, is prohibited;

(ii) At least one tiedown attached straight through its eye from the

left side of the vehicle or intermodal container (near the forward-most

part of the coil), to the left side of the vehicle or intermodal

container (near the rearmost part of the coil), and, whenever

practicable, making an angle no more

[[Page 441]]

than 45 degrees with the floor of the vehicle or intermodal container

when viewed from the side of the vehicle or container;

(iii) At least one tiedown attached straight through its eye, from

the right side of the vehicle or intermodal container (near the forward-

most part of the coil), to the right side of the vehicle or intermodal

container (near the rearmost part of the coil), and whenever

practicable, making an angle no more than 45 degrees with the floor of

the vehicle or intermodal container when viewed from the side of the

vehicle or container;

(iv) At least one tiedown attached transversely over the top of the

coil; and

(v) Either blocking or friction mats to prevent longitudinal

movement.

(3) An individual coil--option 3. Each coil must be secured by:

(i) A means (e.g., timbers, chocks or wedges, a cradle, etc.) to

prevent the coil from rolling. The means of preventing rolling must

support the coil off the deck, and must not be capable of becoming

unintentionally unfastened or loose while the vehicle is in transit. If

timbers, chocks or wedges are used, they must be held in place by coil

bunks or similar devices to prevent them from coming loose. The use of

nailed blocking or cleats as the sole means to secure timbers, chocks or

wedges, or a nailed wood cradle, is prohibited;

(ii) At least one tiedown over the top of the coil, located near the

forward-most part of the coil;

(iii) At least one tiedown over the top of the coil located near the

rearmost part of the coil; and

(iv) Either blocking or friction mats to prevent longitudinal

movement.he forward direction.

(4) Rows of coils. Each transverse row of coils having approximately

equal outside diameters must be secured with:

(i) A means (e.g., timbers, chocks or wedges, a cradle, etc.) to

prevent each coil in the row of coils from rolling. The means of

preventing rolling must support each coil off the deck, and must not be

capable of becoming unintentionally unfastened or loose while the

vehicle is in transit. If timbers, chocks or wedges are used, they must

be held in place by coil bunks or similar devices to prevent them from

coming loose. The use of nailed blocking or cleats as the sole means to

secure timbers, chocks or wedges, or a nailed wood cradle, is

prohibited;

(ii) At least one tiedown over the top of each coil or transverse

row, located near the forward-most part of the coil;

(iii) At least one tiedown over the top of each coil or transverse

row, located near the rearmost part of the coil; and

(iv) Either blocking, bracing or friction mats to prevent

longitudinal movement.

(e) Securement of coils transported in a sided vehicle without

anchor points or an intermodal container without anchor points. Metal

coils transported in a vehicle with sides without anchor points or an

intermodal container without anchor points must be loaded in a manner to

prevent shifting and tipping. The coils may also be secured using a

system of blocking and bracing, friction mats, tiedowns, or a

combination of these to prevent any horizontal movement and tipping.

Sec. 393.122 What are the rules for securing paper rolls?

(a) Applicability. The rules in this section apply to shipments of

paper rolls which, individually or together, weigh 2268 kg (5000 lb) or

more. Shipments of paper rolls that weigh less than 2268 kg (5000 lb),

and paper rolls that are unitized on a pallet, may either be secured in

accordance with the rules in this section or the requirements of

Sec. Sec. 393.100 through 393.114.

(b) Securement of paper rolls transported with eyes vertical in a

sided vehicle. (1) Paper rolls must be placed tightly against the walls

of the vehicle, other paper rolls, or other cargo, to prevent movement

during transit.

(2) If there are not enough paper rolls in the shipment to reach the

walls of the vehicle, lateral movement must be prevented by filling the

void, blocking, bracing, tiedowns or friction mats. The paper rolls may

also be banded together.

(3) When any void behind a group of paper rolls, including that at

the rear of the vehicle, exceeds the diameter of the paper rolls,

rearward movement

[[Page 442]]

must be prevented by friction mats, blocking, bracing, tiedowns, or

banding to other rolls.

(4)(i) If a paper roll is not prevented from tipping or falling

sideways or rearwards by vehicle structure or other cargo, and its width

is more than 2 times its diameter, it must be prevented from tipping or

falling by banding it to other rolls, bracing, or tiedowns.

(ii) If the forwardmost roll(s) in a group of paper rolls is not

prevented from tipping or falling forwards by vehicle structure or other

cargo and it is restrained against forward movement by friction mat(s)

alone, and its width is more than 1.75 times its diameter, it must be

prevented from tipping or falling forwards by banding it to other rolls,

bracing, or tiedowns.

(iii) Otherwise, when a paper roll or the forwardmost roll in groups

of rolls that are not prevented from tipping or falling forwards by

vehicle structure or other cargo and its width exceeds 1.25 times its

diameter it must be prevented from tipping or falling by banding it to

other rolls, bracing or tiedowns.

(5) If paper rolls are banded together, the rolls must be placed

tightly against each other to form a stable group. The bands must be

applied tightly, and must be secured so that they cannot fall off the

rolls or to the deck.

(6) A friction mat used to provide the principal securement for a

paper roll must protrude from beneath the roll in the direction in which

it is providing that securement.

(c) Securement of split loads of paper rolls transported with eyes

vertical in a sided vehicle. (1) If a paper roll in a split load is not

prevented from forward movement by vehicle structure or other cargo, it

must be prevented from forward movement by filling the open space, or by

blocking, bracing, tiedowns, friction mats, or some combination of

these.

(2) A friction mat used to provide the principal securement for a

paper roll must protrude from beneath the roll in the direction in which

it is providing that securement.

(d) Securement of stacked loads of paper rolls transported with eyes

vertical in a sided vehicle. (1) Paper rolls must not be loaded on a

layer of paper rolls beneath unless the lower layer extends to the front

of the vehicle.

(2) Paper rolls in the second and subsequent layers must be

prevented from forward, rearward or lateral movement by means as allowed

for the bottom layer, or by use of a blocking roll from a lower layer.

(3) The blocking roll must be at least 38 mm (1.5 in) taller than

other rolls, or must be raised at least 38 mm (1.5 in) using dunnage.

(4) A roll in the rearmost row of any layer must not be raised using

dunnage.

(e) Securement of paper rolls transported with eyes crosswise in a

sided vehicle. (1) The paper rolls must be prevented from rolling or

shifting longitudinally by contact with vehicle structure or other

cargo, by chocks, wedges or blocking and bracing of adequate size, or by

tiedowns.

(2) Chocks, wedges or blocking must be held securely in place by

some means in addition to friction, so they cannot become

unintentionally unfastened or loose while the vehicle is in transit.

(3) The rearmost roll must not be secured using the rear doors of

the vehicle or intermodal container, or by blocking held in place by

those doors.

(4) If there is more than a total of 203 mm (8 in) of space between

the ends of a paper roll, or a row of rolls, and the walls of the

vehicle, void fillers, blocking, bracing, friction mats, or tiedowns

must be used to prevent the roll from shifting towards either wall.

(f) Securement of stacked loads of paper rolls transported with eyes

crosswise in a sided vehicle. (1) Rolls must not be loaded in a second

layer unless the bottom layer extends to the front of the vehicle.

(2) Rolls must not be loaded in a third or higher layer unless all

wells in the layer beneath are filled.

(3) The foremost roll in each upper layer, or any roll with an empty

well in front of it, must be secured against forward movement by:

(i) Banding it to other rolls, or

(ii) Blocking against an adequately secured eye-vertical blocking

roll resting on the floor of the vehicle which is

[[Page 443]]

at least 1.5 times taller than the diameter of the roll being blocked,

or

(iii) Placing it in a well formed by two rolls on the lower row

whose diameter is equal to or greater than that of the roll on the upper

row.

(4) The rearmost roll in each upper layer must be secured by banding

it to other rolls if it is located in either of the last two wells

formed by the rearmost rolls in the layer below.

(5) Rolls must be secured against lateral movement by the same means

allowed for the bottom layer when there is more than a total of 203 mm

(8 in) of space between the ends of a paper roll, or a row of rolls, and

the walls of the vehicle.

(g) Securement of paper rolls transported with the eyes lengthwise

in a sided vehicle.

(1) Each roll must be prevented from forward movement by contact

with vehicle structure, other cargo, blocking or tiedowns.

(2) Each roll must be prevented from rearward movement by contact

with other cargo, blocking, friction mats or tiedowns.

(3) The paper rolls must be prevented from rolling or shifting

laterally by contact with the wall of the vehicle or other cargo, or by

chocks, wedges or blocking of adequate size.

(4) Chocks, wedges or blocking must be held securely in place by

some means in addition to friction, so they cannot become

unintentionally unfastened or loose while the vehicle is in transit.

(h) Securement of stacked loads of paper rolls transported with the

eyes lengthwise in a sided vehicle. (1) Rolls must not be loaded in a

higher layer if another roll will fit in the layer beneath.

(2) An upper layer must be formed by placing paper rolls in the

wells formed by the rolls beneath.

(3) A roll in an upper layer must be secured against forward and

rearward movement by any of the means allowed for the bottom layer, by

use of a blocking roll, or by banding to other rolls.

(i) Securement of paper rolls transported on a flatbed vehicle or in

a curtain-sided vehicle--(1) Paper rolls with eyes vertical or with eyes

lengthwise.

(i) The paper rolls must be loaded and secured as described for a

sided vehicle, and the entire load must be secured by tiedowns in

accordance with the requirements of Sec. Sec. 393.100 through 393.114.

(ii) Stacked loads of paper rolls with eyes vertical are prohibited.

(2) Paper rolls with eyes crosswise. (i) The paper rolls must be

prevented from rolling or shifting longitudinally by contact with

vehicle structure or other cargo, by chocks, wedges or blocking and

bracing of adequate size, or by tiedowns.

(ii) Chocks, wedges or blocking must be held securely in place by

some means in addition to friction so that they cannot become

unintentionally unfastened or loose while the vehicle is in transit.

(iii) Tiedowns must be used in accordance with the requirements of

Sec. Sec. 393.100 through 393.114 to prevent lateral movement.

Sec. 393.124 What are the rules for securing concrete pipe?

(a) Applicability. (1) The rules in this section apply to the

transportation of concrete pipe on flatbed trailers and vehicles, and

lowboy trailers.

(2) Concrete pipe bundled tightly together into a single rigid

article that has no tendency to roll, and concrete pipe loaded in a

sided vehicle or container must be secured in accordance with the

provisions of Sec. Sec. Sec. 393.100 through 393.114.

(b) General specifications for tiedowns. (1) The aggregate working

load limit of all tiedowns on any group of pipes must not be less than

half the total weight of all the pipes in the group.

(2) A transverse tiedown through a pipe on an upper tier or over

longitudinal tiedowns is considered to secure all those pipes beneath on

which that tiedown causes pressure.

(c) Blocking. (1) Blocking may be one or more pieces placed

symmetrically about the center of a pipe.

(2) One piece must extend at least half the distance from the center

to each end of the pipe, and two pieces must be placed on the opposite

side, one at each end of the pipe.

(3) Blocking must be placed firmly against the pipe, and must be

secured

[[Page 444]]

to prevent it moving out from under the pipe.

(4) Timber blocking must have minimum dimensions of at least 10 x 15

cm (4 x 6 in).

(d) Arranging the load--(1) Pipe of different diameter. If pipe of

more than one diameter are loaded on a vehicle, groups must be formed

that consist of pipe of only one size, and each group must be separately

secured.

(2) Arranging a bottom tier. The bottom tier must be arranged to

cover the full length of the vehicle, or as a partial tier in one group

or two groups.

(3) Arranging an upper tier. Pipe must be placed only in the wells

formed by adjacent pipes in the tier beneath. A third or higher tier

must not be started unless all wells in the tier beneath are filled.

(4) Arranging the top tier. The top tier must be arranged as a

complete tier, a partial tier in one group, or a partial tier in two

groups.

(5) Arranging bell pipe. (i) Bell pipe must be loaded on at least

two longitudinal spacers of sufficient height to ensure that the bell is

clear of the deck.

(ii) Bell pipe loaded in one tier must have the bells alternating on

opposite sides of the vehicle.

(iii) The ends of consecutive pipe must be staggered, if possible,

within the allowable width, otherwise they must be aligned.

(iv) Bell pipe loaded in more than one tier must have the bells of

the bottom tier all on the same side of the vehicle.

(v) Pipe in every upper tier must be loaded with bells on the

opposite side of the vehicle to the bells of the tier below.

(vi) If the second tier is not complete, pipe in the bottom tier

which do not support a pipe above must have their bells alternating on

opposite sides of the vehicle.

(a) Securing pipe with an inside diameter up to 1,143 mm (45 in). In

addition to the requirements of paragraphs (b), (c) and (d) of this

section, the following rules must be satisfied:

(1) Stabilizing the bottom tier. (i) The bottom tier must be

immobilized longitudinally at each end by blocking, vehicle end

structure, stakes, a locked pipe unloader, or other equivalent means.

(ii) Other pipe in the bottom tier may also be held in place by

blocks and/or wedges; and

(iii) Every pipe in the bottom tier must also be held firmly in

contact with the adjacent pipe by tiedowns though the front and rear

pipes:

(A) At least one tiedown through the front pipe of the bottom tier

must run aft at an angle not more than 45 degrees with the horizontal,

whenever practicable.

(B) At least one tiedown through the rear pipe of the bottom tier

must run forward at an angle not more than 45 degrees with the

horizontal, whenever practicable.

(2) Use of tiedowns. (i) Each pipe may be secured individually with

tiedowns through the pipe.

(ii) If each pipe is not secured individually with a tiedown, then:

(A) Either one 1/2-inch diameter chain or wire rope, or two 3/8-inch

diameter chain or wire rope, must be placed longitudinally over the

group of pipes;

(B) One transverse tiedown must be used for every 3.04 m (10 ft) of

load length. The transverse tiedowns may be placed through a pipe, or

over both longitudinal tiedowns between two pipes on the top tier.

(C) If the first pipe of a group in the top tier is not placed in

the first well formed by pipes at the front of the tier beneath, it must

be secured by an additional tiedown that runs rearward at an angle not

more than 45 degrees to the horizontal, whenever practicable. This

tiedown must pass either through the front pipe of the upper tier, or

outside it and over both longitudinal tiedowns; and

(D) If the last pipe of a group in the top tier is not placed in the

last well formed by pipes at the rear of the tier beneath, it must be

secured by an additional tiedown that runs forward at an angle not more

than 45 degrees to the horizontal, whenever practicable. This tiedown

must pass either through the rear pipe of the upper tier or outside it

and over both longitudinal tiedowns.

(f) Securing large pipe, with an inside diameter over 1143 mm (45

in). In addition to the requirements of paragraphs (b), (c) and (d) of

this section, the following rules must be satisfied:

[[Page 445]]

(1) The front pipe and the rear pipe must be immobilized by

blocking, wedges, vehicle end structure, stakes, locked pipe unloader,

or other equivalent means.

(2) Each pipe must be secured by tiedowns through the pipe:

(i) At least one tiedown through each pipe in the front half of the

load, which includes the middle one if there is an odd number, and must

run rearward at an angle not more than 45 degrees with the horizontal,

whenever practicable.

(ii) At least one tiedown through each pipe in the rear half of the

load, and must run forward at an angle not more than 45 degrees with the

horizontal, whenever practicable, to hold each pipe firmly in contact

with adjacent pipe; and

(iii) If the front or rear pipe is not also in contact with vehicle

end structure, stakes, a locked pipe unloader, or other equivalent

means, at least two tiedowns positioned as described in paragraphs

(f)(2)(i) and (ii) of this section, must be used through that pipe.

(3) If only one pipe is transported, or if several pipes are

transported without contact between other pipes, the requirements in

this paragraph apply to each pipe as a single front and rear article.

Sec. 393.126 What are the rules for securing intermodal containers?

(a) Applicability. The rules in this section apply to the

transportation of intermodal containers. Cargo contained within an

intermodal container must be secured in accordance with the provisions

of Sec. Sec. 393.100 through 393.114 or, if applicable, the commodity

specific rules of this part.

(b) Securement of intermodal containers transported on container

chassis vehicle(s). (1) Each intermodal container must be secured to the

container chassis with securement devices or integral locking devices

that cannot unintentionally become unfastened while the vehicle is in

transit.

(2) The securement devices must restrain the container from moving

more than 1.27 cm (1/2 in) forward, more than 1.27 cm (1/2 in) aft, more

than 1.27 cm (1/2 in) to the right, more than 1.27 cm (1/2 in) to the

left, or more than 2.54 cm (1 in) vertically.

(3) The front and rear of the container must be secured

independently.

(c) Securement of loaded intermodal containers transported on

vehicles other than container chassis vehicle(s). (1) All lower corners

of the intermodal container must rest upon the vehicle, or the corners

must be supported by a structure capable of bearing the weight of the

container and that support structure must be independently secured to

the motor vehicle.

(2) Each container must be secured to the vehicle by:

(i) Chains, wire ropes or integral devices which are fixed to all

lower corners; or

(ii) Crossed chains which are fixed to all upper corners; and,

(3) The front and rear of the container must be secured

independently. Each chain, wire rope, or integral locking device must be

attached to the container in a manner that prevents it from being

unintentionally unfastened while the vehicle is in transit.

(d) Securement of empty intermodal containers transported on

vehicles other than container chassis vehicle(s). Empty intermodal

containers transported on vehicles other than container chassis vehicles

do not have to have all lower corners of the intermodal container

resting upon the vehicle, or have all lower corners supported by a

structure capable of bearing the weight of the empty container,

provided:

(1) The empty intermodal container is balanced and positioned on the

vehicle in a manner such that the container is stable before the

addition of tiedowns or other securement equipment; and,

(2) The amount of overhang for the empty container on the trailer

does not exceed five feet on either the front or rear of the trailer;

(3) The empty intermodal container must not interfere with the

vehicle's maneuverability; and,

(4) The empty intermodal container is secured to prevent lateral,

longitudinal, or vertical shifting.

Sec. 393.128 What are the rules for securing automobiles, light trucks

and vans?

(a) Applicability. The rules in this section apply to the

transportation of

[[Page 446]]

automobiles, light trucks, and vans which individually weigh 4,536 kg.

(10,000 lb) or less. Vehicles which individually are heavier than 4,536

kg (10,000 lb) must be secured in accordance with the provisions of

Sec. 393.130 of this part.

(b) Securement of automobiles, light trucks, and vans.

(1) Automobiles, light trucks, and vans must be restrained at both

the front and rear to prevent lateral, forward, rearward, and vertical

movement using a minimum of two tiedowns.

(2) Tiedowns that are designed to be affixed to the structure of the

automobile, light truck, or van must use the mounting points on those

vehicles that have been specifically designed for that purpose.

(3) Tiedowns that are designed to fit over or around the wheels of

an automobile, light truck, or van must provide restraint in the

lateral, longitudinal and vertical directions.

(4) Edge protectors are not required for synthetic webbing at points

where the webbing comes in contact with the tires.

Sec. 393.130 What are the rules for securing heavy vehicles, equipment

and machinery?

(a) Applicability. The rules in this section apply to the

transportation of heavy vehicles, equipment and machinery which operate

on wheels or tracks, such as front end loaders, bulldozers, tractors,

and power shovels and which individually weigh 4,536 kg (10,000 lb.) or

more. Vehicles, equipment and machinery which is lighter than 4,536 kg

(10,000 lb.) may also be secured in accordance with the provisions of

this section, with Sec. 393.128, or in accordance with the provisions

of Sec. Sec. 393.100 through 393.114.

(b) Preparation of equipment being transported. (1) Accessory

equipment, such as hydraulic shovels, must be completely lowered and

secured to the vehicle.

(2) Articulated vehicles shall be restrained in a manner that

prevents articulation while in transit.

(c) Securement of heavy vehicles, equipment or machinery with

crawler tracks or wheels. (1) In addition to the requirements of

paragraph (b) of this section, heavy equipment or machinery with crawler

tracks or wheels must be restrained against movement in the lateral,

forward, rearward, and vertical direction using a minimum of four

tiedowns.

(2) Each of the tiedowns must be affixed as close as practicable to

the front and rear of the vehicle, or mounting points on the vehicle

that have been specifically designed for that purpose.

Sec. 393.132 What are the rules for securing flattened or crushed

vehicles?

(a) Applicability. The rules in this section apply to the

transportation of vehicles such as automobiles, light trucks, and vans

that have been flattened or crushed.

(b) Prohibition on the use of synthetic webbing. The use of

synthetic webbing to secure flattened or crushed vehicles is prohibited.

(c) Securement of flattened or crushed vehicles. Flattened or

crushed vehicles must be transported on vehicles which have:

(1) Containment walls or comparable means on four sides which extend

to the full height of the load and which block against movement of the

cargo in the forward, rearward and lateral directions; or

(2)(i) Containment walls or comparable means on three sides which

extend to the full height of the load and which block against movement

of the cargo in the forward, rearward and the lateral direction for

which there is no containment wall or comparable means, and

(ii) A minimum of two tiedowns are required per vehicle stack; or

(3)(i) Containment walls on two sides which extend to the full

height of the load and which block against movement of the cargo in the

forward and rearward directions, and

(ii) A minimum of three tiedowns are required per vehicle stack; or

(4) A minimum of four tiedowns per vehicle stack.

(5) In addition to the requirements of paragraphs (c)(2), (3), and

(4), the following rules must be satisfied:

(i) Vehicles used to transport flattened or crushed vehicles must be

equipped with a means to prevent loose

[[Page 447]]

parts from falling from all four sides of the vehicle which extends to

the full height of the cargo.

(ii) The means used to contain loose parts may consist of structural

walls, sides or sideboards, or suitable covering material, alone or in

combinations.

(iii) The use of synthetic material for containment of loose parts

is permitted.

Sec. 393.134 What are the rules for securing roll-on/roll-off or hook

lift containers?

(a) Applicability. The rules in this section apply to the

transportation of roll-on/roll-off or hook lift containers.

(b) Securement of a roll-on/roll-off and hook lift container. Each

roll-on/roll-off and hook lift container carried on a vehicle which is

not equipped with an integral securement system must be:

(1) Blocked against forward movement by the lifting device, stops, a

combination of both or other suitable restraint mechanism;

(2) Secured to the front of the vehicle by the lifting device or

other suitable restraint against lateral and vertical movement;

(3) Secured to the rear of the vehicle with at least one of the

following mechanisms:

(i) One tiedown attached to both the vehicle chassis and the

container chassis;

(ii) Two tiedowns installed lengthwise, each securing one side of

the container to one of the vehicle's side rails; or

(iii) Two hooks, or an equivalent mechanism, securing both sides of

the container to the vehicle chassis at least as effectively as the

tiedowns in the two previous items.

(4) The mechanisms used to secure the rear end of a roll-on/roll off

or hook lift container must be installed no more than two meters (6 ft 7

in) from the rear of the container.

(5) In the event that one or more of the front stops or lifting

devices are missing, damaged or not compatible, additional manually

installed tiedowns must be used to secure the container to the vehicle,

providing the same level of securement as the missing, damaged or

incompatible components.

Sec. 393.136 What are the rules for securing large boulders?

(a) Applicability. (1) The rules in this section are applicable to

the transportation of any large piece of natural, irregularly shaped

rock weighing in excess of 5,000 kg (11,000 lb.) or with a volume in

excess of 2 cubic-meters on an open vehicle, or in a vehicle whose sides

are not designed and rated to contain such cargo.

(2) Pieces of rock weighing more than 100 kg (220 lb.), but less

than 5,000 kg (11,000 lb.) must be secured, either in accordance with

this section, or in accordance with the provisions of Sec. Sec. 393.100

through 393.114, including:

(i) Rock contained within a vehicle which is designed to carry such

cargo; or

(ii) Secured individually by tiedowns, provided each piece can be

stabilized and adequately secured.

(3) Rock which has been formed or cut to a shape and which provides

a stable base for securement must also be secured, either in accordance

with the provisions of this section, or in accordance with the

provisions of Sec. Sec. 393.100 through 393.114.

(b) General requirements for the positioning of boulders on the

vehicle. (1) Each boulder must be placed with its flattest and/or

largest side down.

(2) Each boulder must be supported on at least two pieces of hard

wood blocking at least 10 cm x 10 cm (4 inches x 4 inches) side

dimensions extending the full width of the boulder.

(3) Hardwood blocking pieces must be placed as symmetrically as

possible under the boulder and should support at least three-fourths of

the length of the boulder.

(4) If the flattest side of a boulder is rounded or partially

rounded, so that the boulder may roll, it must be placed in a crib made

of hardwood timber fixed to the deck of the vehicle so that the boulder

rests on both the deck and the timber, with at least three well-

separated points of contact that prevent its tendency to roll in any

direction.

(5) If a boulder is tapered, the narrowest end must point towards

the front of the vehicle.

[[Page 448]]

(c) General tiedown requirements. (1) Only chain may be used as

tiedowns to secure large boulders.

(2) Tiedowns which are in direct contact with the boulder should,

where possible, be located in valleys or notches across the top of the

boulder, and must be arranged to prevent sliding across the rock

surface.

(d) Securement of a cubic shaped boulder. In addition to the

requirements of paragraphs (b) and (c) of this section, the following

rules must be satisfied:

(1) Each boulder must be secured individually with at least two

chain tiedowns placed transversely across the vehicle.

(2) The aggregate working load limit of the tiedowns must be at

least half the weight of the boulder.

(3) The tiedowns must be placed as closely as possible to the wood

blocking used to support the boulder.

(e) Securement of a non-cubic shaped boulder--with a stable base. In

addition to the requirements of paragraphs (b) and (c) of this section,

the following rules must be satisfied:

(1) The boulder must be secured individually with at least two chain

tiedowns forming an ``X'' pattern over the boulder.

(2) The aggregate working load limit of the tiedowns must be at

least half the weight of the boulder.

(3) The tiedowns must pass over the center of the boulder and must

be attached to each other at the intersection by a shackle or other

connecting device.

(f) Securement of a non-cubic shaped boulder--with an unstable base.

In addition to the requirements of paragraphs (b) and (c) of this

section, each boulder must be secured by a combination of chain tiedowns

as follows:

(1) One chain must surround the top of the boulder (at a point

between one-half and two-thirds of its height). The working load limit

of the chain must be at least half the weight of the boulder.

(2) Four chains must be attached to the surrounding chain and the

vehicle to form a blocking mechanism which prevents any horizontal

movement. Each chain must have a working load limit of at least one-

fourth the weight of the boulder. Whenever practicable, the angle of the

chains must not exceed 45 degrees from the horizontal.

Subpart J_Frames, Cab and Body Components, Wheels, Steering, and

Suspension Systems

Source: 53 FR 49402, Dec. 7, 1988, unless otherwise noted.

Sec. 393.201 Frames.

(a) The frame or chassis of each commercial motor vehicle shall not

be cracked, loose, sagging or broken.

(b) Bolts or brackets securing the cab or the body of the vehicle to

the frame must not be loose, broken, or missing.

(c) The frame rail flanges between the axles shall not be bent, cut

or notched, except as specified by the manufacturer.

(d) Parts and accessories shall not be welded to the frame or

chassis of a commercial motor vehicle except in accordance with the

vehicle manufacturer's recommendations. Any welded repair of the frame

must also be in accordance with the vehicle manufacturer's

recommendations.

(e) No holes shall be drilled in the top or bottom rail flanges,

except as specified by the manufacturer.

[53 FR 49402, Dec. 7, 1988, as amended at 70 FR 48055, Aug. 15, 2005]

Sec. 393.203 Cab and body components.

(a) The cab compartment doors or door parts used as an entrance or

exist shall not be missing or broken. Doors shall not sag so that they

cannot be properly opened or closed. No door shall be wired shut or

otherwise secured in the closed position so that it cannot be readily

opened. Exception: When the vehicle is loaded with pipe or bar stock

that blocks the door and the cab has a roof exit.

(b) Bolts or brackets securing the cab or the body of the vehicle to

the frame shall not be loose, broken, or missing.

(c) The hood must be securely fastened.

(d) All seats must be securely mounted.

(e) The front bumper must not be missing, loosely attached, or

protruding beyond the confines of the vehicle so as to create a hazard.

[[Page 449]]

Sec. 393.205 Wheels.

(a) Wheels and rims shall not be cracked or broken.

(b) Stud or bolt holes on the wheels shall shall not be elongated

(out of round).

(c) Nuts or bolts shall not be missing or loose.

Sec. 393.207 Suspension systems.

(a) Axles. No axle positioning part shall be cracked, broken, loose

or missing. All axles must be in proper alignment.

(b) Adjustable axles. Adjustable axle assemblies shall not have

locking pins missing or disengaged.

(c) Leaf springs. No leaf spring shall be cracked, broken, or

missing nor shifted out of position.

(d) Coil springs. No coil spring shall be cracked or broken.

(e) Torsion bar. No torsion bar or torsion bar suspension shall be

cracked or broken.

(f) Air suspensions. The air pressure regulator valve shall not

allow air into the suspension system until at least 55 psi is in the

braking system. The vehicle shall be level (not tilting to the left or

right). Air leakage shall not be greater than 3 psi in a 5-minute time

period when the vehicle's air pressure gauge shows normal operating

pressure.

(g) Air suspension exhaust controls. The air suspension exhaust

controls must not have the capability to exhaust air from the suspension

system of one axle of a two-axle air suspension trailer unless the

controls are either located on the trailer, or the power unit and

trailer combination are not capable of traveling at a speed greater than

10 miles per hour while the air is exhausted from the suspension system.

This paragraph shall not be construed to prohibit--

(1) Devices that could exhaust air from both axle systems

simultaneously; or

(2) Lift axles on multi-axle units.

[53 FR 49402, Dec. 7, 1988, as amended at 70 FR 48055, Aug. 15, 2005]

Sec. 393.209 Steering wheel systems.

(a) The steering wheel shall be secured and must not have any spokes

cracked through or missing.

(b) Steering wheel lash. (1) The steering wheel lash shall not

exceed the following parameters:

------------------------------------------------------------------------

Manual steering Power steering

Steering wheel diameter system system

------------------------------------------------------------------------

406 mm or less (16 inches or 51 mm (2 inches).... 108 mm (4\1/4\

less). inches).

457 mm (18 inches).......... 57 mm (2\1/4\ 121 mm (4\3/4\

inches). inches).

483 mm (19 inches).......... 60 mm (2\3/8\ 127 mm (5 inches).

inches).

508 mm (20 inches).......... 64 mm (2\1/2\ 133 mm (5\1/4\

inches). inches).

533 mm (21 inches).......... 67 mm (2\5/8\ 140 mm (5\1/2\

inches). inches).

559 mm (22 inches).......... 70 mm (2\3/4\ 146 mm (5\3/4\

inches). inches).

------------------------------------------------------------------------

(2) For steering wheel diameters not listed in paragraph (b)(1) of

this section the steering wheel lash shall not exceed 14 degrees angular

rotation for manual steering systems, and 30 degrees angular rotation

for power steering systems.

(c) Steering column. The steering column must be securely fastened.

(d) Steering system. Universal joints and ball-and-socket joints

shall not be worn, faulty or repaired by welding. The steering gear box

shall not have loose or missing mounting bolts or cracks in the gear box

or mounting brackets. The pitman arm on the steering gear output shaft

shall not be loose. Steering wheels shall turn freely through the limit

of travel in both directions.

(e) Power steering systems. All components of the power system must

be in operating condition. No parts shall be loose or broken. Belts

shall not be frayed, cracked or slipping. The system shall not leak. The

power steering system shall have sufficient fluid in the reservoir.

[53 FR 49402, Dec. 7, 1988, as amended at 70 FR 48055, Aug. 15, 2005]

PART 394 [RESERVED]

[[Page 450]]