Roof Control Plan for Underground Coal Mines
OMB 1219-0004
August, 2015
Supporting Statement
Roof Control Plan for Underground Coal Mines
OMB 30 CFR
Control Citations Title
1219-0004 75.215 Longwall mining systems
75.220(a)(1) Roof control plan
75.221(a) Roof control plan information
75.222(a) Roof control plan-approval
75.223(a), (b), & (d) Evaluation and revision of roof control plan
General Instructions
A Supporting Statement, including the text of the notice to the public required by 5 CFR 1320.5(a)(i)(iv) and its actual or estimated date of publication in the Federal Register, must accompany each request for approval of a collection of information. The Supporting Statement must be prepared in the format described below, and must contain the information specified in Section A below. If an item is not applicable, provide a brief explanation. When the question “Does this ICR contain surveys, censuses or employ statistical methods” is checked "Yes", Section B of the Supporting Statement must be completed. OMB reserves the right to require the submission of additional information with respect to any request for approval.
Specific Instructions
A. JUSTIFICATION
1. Explain the circumstances that make the collection of information necessary. Identify any legal or administrative requirements that necessitate the collection. Attach a copy of the appropriate section of each statute and regulation mandating or authorizing the collection of information.
Section 103(h) of the Federal Mine Safety and Health Act of 1977 (Mine Act), 30 U.S.C. 813(h), authorizes MSHA to collect information necessary to carry out its duty in protecting the safety and health of miners. Further, Section 101 (a) of the Mine Act, 30 U.S.C. 811, authorizes the Secretary to develop, promulgate, and revise as may be appropriate, improved mandatory health or safety standards for the protection of life and prevention of injuries in coal or other mines.
Section 302(a) of the Mine Act, 30 U.S.C. 862, requires that a roof control plan and revisions thereof suitable to the roof conditions and mining system of each coal mine be first approved by the Secretary of Labor (Secretary) before implementation by the operator. The plan must show the type of support and spacing approved by the Secretary, and the plan must be reviewed at least every six months by the Secretary.
30 CFR 75.220(a)(1) requires each mine operator to develop and follow a roof control plan, approved by the District Manager, that is suitable to the prevailing geological conditions and the mining system to be used at the mine. The standard also requires that additional measures are to be taken to protect persons if unusual hazards are encountered.
30 CFR 75.221(a) requires specific information be submitted and approved in the roof control plan to include the following: (1) the name and address of the company; (2) the name, address, mine identification number and location of the mine; (3) the name and title of the company official responsible for the plan; (4) a description of the mine strata; (5) a description and drawings of the sequence of installation and spacing of supports for each method of mining used; (6) the maximum distance that an ATRS system is to be set beyond the last row of permanent support (if applicable); (7) specifications and installation procedures for liners or arches (if applicable); (8) drawings indicating the planned width of openings, size of pillars, method of pillar recovery, and the sequence of mining pillars; (9) a list of all support materials required to be used in the roof, face and rib control system; (10) the intervals at which test holes will be drilled when mechanically anchored tensioned roof bolts are used; (11) a description of the methods to be used for the protection of persons from falling material at drift openings and when mining approaches within 150 feet of an outcrop; and (12) a description of the roof and rib support for location of refuge alternatives. Under 30 CFR 75.215, the roof control plan for each longwall mining section is required to specify the methods that will be used to maintain a safe travelway out of the section through the tailgate side of the longwall and the procedures that will be followed if a ground failure prevents travel out of the section through the tailgate side of the longwall.
Roof control plans, and revisions to those plans, are evaluated by Mine Safety and Health Administration (MSHA) specialists in accordance with the criteria set forth in 30 CFR 75.222. The District Manager may require additional measures in plans and may approve roof control plans that do not conform to the applicable criteria in this section, provided that effective control of the roof, face, and ribs can be maintained.
30 CFR 75.223(a) requires a mine operator to propose revisions to the roof control plan when conditions indicate that the plan is not suitable for controlling the roof, face, ribs, or coal or rock bursts, or when accident and injury experience at the mine indicates the plan is inadequate. This section also requires the accident and injury experience at each mine to be reviewed at least every six months. Under section 75.223(b) operators are also required to plot on a mine map each unplanned roof or rib fall and coal or rock burst that occurs in the active workings when certain criteria are met. Section 75.223(d) requires MSHA to review the plan every 6 months. This review requires MSHA to take into consideration any falls of the roof, face and ribs and the adequacy of the support systems used at the time.
2. Indicate how, by whom, and for what purpose the information is to be used. Except for a new collection, indicate the actual use the agency has made of the information received from the current collection.
Roof Control plans provide the means to instruct miners in the proper use and placement of roof supports. The plan also provides a reference for mine supervisors to ensure that the mine is in compliance with the MSHA regulations relating to roof control. Roof control plans are evaluated by MSHA personnel to ensure that mine operators have complied with the regulatory provisions outlined in 30 CFR 75.202 through 75.223. MSHA inspectors also refer to the plans when they are conducting safety and health inspections at the mines.
Approved roof control plans from the different MSHA coal mine safety and health districts are reviewed by MSHA roof control specialists to determine compliance with the regulations and to evaluate the roof and rib support methods used to provide a safe working environment. As roof control questions arise, the review of different roof control plans can provide solutions to problems that have been successfully addressed by other districts. The sharing of roof control plans within the agency also allows inspectors to communicate the latest mining technology to the nation’s mine operators and miners. It allows operators and miners to take advantage of MSHA’s technical ground support group that conducts studies on mining and support methods and evaluates their effectiveness. The success of this program is evidenced by the fact that Technical Support has evaluated numerous hazardous ground conditions at the nation’s mining operations and suggested prudent methods of support based on scientific and proven ground control methods.
3. Describe whether, and to what extent, the collection of information involves the use of automated, electronic, mechanical, or other technological collection techniques or other forms of information technology, e.g., permitting electronic submission of responses, and the basis for the decision for adopting this means of collection. Also describe any consideration of using information technology to reduce burden.
No improved information technology has been identified that would reduce the existing burden. Mine operators may submit the required information electronically.
4. Describe efforts to identify duplication. Show specifically why any similar information already available cannot be used or modified for use for the purposes described in Item 2 above.
Roof control plans are developed to address the unique roof conditions and mining methods at each mine. There is no similar or duplicate information that could be used.
5. If the collection of information impacts small businesses or other small entities, describe any methods used to minimize burden.
This information collection does not have a significant impact on small businesses or other small entities. However, MSHA has made available on our website explicit criteria and guidance for assessing the quality of and potential safety risks associated with proposed roof plans. Checklists and a new Roof Control Plan Approval and Review Procedures handbook are located at: http://www.msha.gov/READROOM/HANDBOOK/PH13-V-4.pdf.
6. Describe the consequence to Federal program or policy activities if the collection is not conducted or is conducted less frequently, as well as any technical or legal obstacles to reducing burden.
Roof control plans must be submitted by a mine operator when a new mine opens and when revisions are necessary. Revisions of an existing plan are necessary either due to conditions that indicate the plan is not suitable for controlling roof conditions (i.e., the roof, face, ribs, or coal or rock bursts) or accident and injury experience at the mine indicates the plan is inadequate. MSHA reviews the plans every 6 months to ensure that the roof control methods are adequate for the conditions and mining methods used at the mine. Without an approved plan, MSHA would not be able to determine whether miners were being exposed to hazardous roof conditions that could jeopardize their safety.
7. Explain any special circumstances that would cause an information collection to be conducted in a manner:
* requiring respondents to report information to the agency more often than quarterly;
* requiring respondents to prepare a written response to a collection of information in fewer than 30 days after receipt of it;
* requiring respondents to submit more than an original and two copies of any document;
* requiring respondents to retain records, other than health, medical, government contract, grant-in-aid, or tax records, for more than three years;
* in connection with a statistical survey, that is not designed to produce valid and reliable results that can be generalized to the universe of study;
* requiring the use of a statistical data classification that has not been reviewed and approved by OMB;
* that includes a pledge of confidentiality that is not supported by authority established in statute or regulation, that is not supported by disclosure and data security policies that are consistent with the pledge, or which unnecessarily impedes sharing of data with other agencies for compatible confidential use; or
* requiring respondents to submit proprietary trade secrets, or other confidential information unless the agency can demonstrate that it has instituted procedures to protect the information's confidentiality to the extent permitted by law.
This collection of information is consistent with the guidelines found in 5 CFR 1320.5. While there is no specific provision requiring that roof control plans be maintained for more than three years, there must be an approved plan in effect for the entire time the mine is in operation. Without an approved plan, MSHA would not be able to determine whether miners were being exposed to hazardous roof conditions that could jeopardize their safety.
8. If applicable, provide a copy and identify the date and page number of publication in the Federal Register of the agency's notice, required by 5 CFR 1320.8(d), soliciting comments on the information collection prior to submission to OMB. Summarize public comments received in response to that notice and describe actions taken by the agency in response to these comments. Specifically address comments received on cost and hour burden.
Describe efforts to consult with persons outside the agency to obtain their views on the availability of data, frequency of collection, the clarity of instructions and recordkeeping, disclosure, or reporting format (if any), and on the data elements to be recorded, disclosed, or reported.
Consultation with representatives of those from whom information is to be obtained or those who must compile records should occur at least once every 3 years - even if the collection of information activity is the same as in prior periods. There may be circumstances that may preclude consultation in a specific situation. These circumstances should be explained.
In accordance with 5 CFR 1320.8 (d), MSHA published the proposed information collection requirements in the Federal Register on December 1, 2014 (79 FR 71129), notifying the public that these information collection requirements are being reviewed in accordance with the Paperwork Reduction Act of 1995, and giving interested persons 60 days to submit comments. No comments were received.
9. Explain any decision to provide any payment or gift to respondents, other than remuneration of contractors or grantees.
MSHA does not provide payment or gifts to respondents.
10. Describe any assurance of confidentiality provided to respondents and the basis for the assurance in statute, regulation, or agency policy.
There is no assurance of confidentiality provided to respondents.
11. Provide additional justification for any questions of a sensitive nature, such as sexual behavior and attitudes, religious beliefs, and other matters that are commonly considered private. This justification should include the reasons why the agency considers the questions necessary, the specific uses to be made of the information, the explanation to be given to persons from whom the information is requested, and any steps to be taken to obtain their consent.
There are no questions of a sensitive nature.
12. Provide estimates of the hour burden of the collection of information. The statement should:
* Indicate the number of respondents, frequency of response, annual hour burden, and an explanation of how the burden was estimated. Unless directed to do so, agencies should not conduct special surveys to obtain information on which to base hour burden estimates. Consultation with a sample (fewer than 10) of potential respondents is desirable. If the hour burden on respondents is expected to vary widely because of differences in activity, size, or complexity, show the range of estimated hour burden, and explain the reasons for the variance. Generally, estimates should not include burden hours for customary and usual business practices.
* If this request for approval covers more than one form, provide separate hour burden estimates for each form and aggregate the hour burdens.
* Provide estimates of annualized cost to respondents for the hour burdens for collections of information, identifying and using appropriate wage rate categories. The cost of contracting out or paying outside parties for information collection activities should not be included here. Instead, this cost should be included under ‘Annual Cost to Federal Government’.
30 CFR 75.220 requires that each underground coal mine operator develop a roof control plan. 30 CFR 75.221(a) lists 12 items of information required to be included in each roof control plan, ranging from name, address, mine identification number, and location of the mine to a typical columnar section of the mine strata which identifies the type of strata and shows the thickness of each stratum up to and including the main roof above the coal bed for distance of at least 10 feet below the coal bed. Also, mine operators are required under 30 CFR 75.215, to specify the methods in the roof control plan that will be used to maintain a safe travelway out of the longwall mining section through the tailgate side of the longwall and the procedures that will be followed if a ground failure prevents travel out of the section through the tailgate side of the longwall.
Some of the required information may be retrieved by the operator fairly easily although other information may require more research time, especially when developing a new plan.
Revisions to plans, because they are based on an existing plan, do not require as much time. Revisions may be required as a response to an existing problem, or when instituting new technology, or as a cost savings to the mine operator. Again, some revisions may be more complex than others.
MSHA employees with experience preparing roof control plans while employed by industry have helped the Agency substantiate the time required to produce roof control plans.
According to MSHA records, there are 494 underground coal mines, all of which are required to develop and submit roof control plans. In 2013, new roof control plans were submitted for 305 of those mines. While roof control plans vary according to the size and complexity of each individual mine, MSHA estimates that it takes approximately 12 hours for a mine operator to prepare a new roof control plan. The Supervisor wage rate of $99.60 was used for these burden calculations {U.S. Coal Mines Salaries, Wages, and Benefits - 2012 Survey Results, InfoMine USA, Inc., 2012 (http://costs.infomine.com/laborcompensationreports/); adjusted to 2013 using the Bureau of Labor Statistics’ Employment Cost Index (http://www.bls.gov/ect/) for the “Goods-producing: natural resources, construction, and maintenance” industries}.
305 new plans x 12 hours/plan = 3,660 hours
3,660 hours x $99.60 per hour = $364,536
In addition, MSHA estimates that each mine operator may need to submit plan revisions. An operator may submit more than one revision if conditions require it. In 2013, MSHA received 1,054 plan revisions. MSHA estimates that it takes a mine operator approximately 4 hours to draft a plan revision.
1,054 revisions x 4 hours/revision = 4,216 hours
4,216 hours x $99.60 per hour = $419,914
Underground coal mine operators are also required to plot each unplanned roof fall, rib fall, and coal rock burst on a mine map when such incidents meet the criteria specified in 30 CFR 75.223(b). MSHA estimates that it takes 5 minutes (0.08 hours) to plot a roof fall or a coal or rock burst on a map. There were approximately 606 unplanned roof falls and coal or rock bursts which met such specified criteria and that occurred in underground coal mines in 2013.
606 roof falls/coal/rock bursts x 0.08 hours = 48 hours
48 hours x $99.60 per hour = $4,781
Total Burden Hours = 7,924 hours
Total Burden Hour Cost = $789,231
Estimated Annualized Burden Hours and Costs |
||||||||
Type of Respondent |
Standard/ Collection Activity |
No. of Respon-dents |
No. of Respon-ses per Respon-dent |
Total No. of Responses (rounded to whole numbers) |
Avg. Burden per Response (in hours)
|
Total Annual Burden (in hours/ rounded to whole numbers) |
Avg. Hourly Wage Rate* |
Total Annual Respondent Cost |
Business or other for-profit |
30 CFR 75.220, 75.221(a), and 75.215/ Plans |
305 |
1 |
305 |
12 hours |
3,660 hours |
$99.60 |
$364,536 |
Business or other for-profit |
30 CFR 75.220, 75.221(a), and 75.215, 75.222 and 75.223(a)/ Plan Revisions |
494 |
2.1336 |
1,054 |
4 hours |
4,216 hours |
$99.60 |
$419,914 |
Business or other for-profit |
30 CFR 75.223(b)/ Plots of unplanned roof falls, rib falls, and coal rock bursts |
494 |
1.2267 |
606 |
.08 hours |
48 hours |
$99.60 |
$4,781 |
Total |
|
494 |
|
1,965 |
|
7,924 hours |
|
$789,231 |
13. Provide an estimate for the total annual cost burden to respondents or record keepers resulting from the collection of information. (Do not include the cost of any hour burden already reflected on the burden worksheet).
* The cost estimate should be split into two components: (a) a total capital and start-up cost component (annualized over its expected useful life) and (b) a total operation and maintenance and purchase of services component. The estimates should take into account costs associated with generating, maintaining, and disclosing or providing the information. Include descriptions of methods used to estimate major cost factors including system and technology acquisition, expected useful life of capital equipment, the discount rate(s), and the time period over which costs will be incurred. Capital and start-up costs include, among other items, preparations for collecting information such as purchasing computers and software; monitoring, sampling, drilling and testing equipment; and record storage facilities.
* If cost estimates are expected to vary widely, agencies should present ranges of cost burdens and explain the reasons for the variance. The cost of purchasing or contracting out information collections services should be a part of this cost burden estimate. In developing cost burden estimates, agencies may consult with a sample of respondents (fewer than 10), utilize the 60-day pre-OMB submission public comment process and use existing economic or regulatory impact analysis associated with the rulemaking containing the information collection, as appropriate.
* Generally, estimates should not include purchases of equipment or services, or portions thereof, made: (1) prior to October 1, 1995, (2) to achieve regulatory compliance with requirements not associated with the information collection, (3) for reasons other than to provide information or keep records for the government, or (4) as part of customary and usual business or private practices.
Operation and Maintenance: MSHA estimates that the average copying and mailing cost for a new roof control plan or a plan revision is $5.00.
305 Plans ($1,525) + 1,054 Plans ($5,270)
1,359 new and revised plans x $5.00 = $6,795
Total Annual Cost Burden = $6,795
14. Provide estimates of annualized costs to the Federal government. Also, provide a description of the method used to estimate cost, which should include quantification of hours, operational expenses (such as equipment, overhead, printing, and support staff), and any other expense that would not have been incurred without this collection of information. Agencies may also aggregate cost estimates from Items 12, 13, and 14 in a single table.
MSHA estimates that it takes approximately 16 hours to review and approve a new roof control plan. A salary (including benefits) of $50.64 per hour for an MSHA roof control specialist, Grade 12, was used for these calculations {September 2013 OPM FedScope (http://www.fedscope.opm.gov/) employment data cube, Mine Safety and Health Inspection Series, GS-12; FY 2014 budget submission for benefit loading factor, FY 2013 enacted budget}.
305 new plans x 16 hours/plan = 4,880 hours
4,880 hours x $50.64 = $247,123
In 2013, MSHA received 1,054 roof control plan revisions. MSHA estimates that it takes approximately 4 hours to review a plan revision.
1,054 revisions x 4 hours/plan = 4,216 hours
4,216 hours x $50.64 per hour = $213,498
15. Explain the reasons for any program changes or adjustments reported on the burden worksheet.
Respondents: The number of underground coal mines requiring roof control plans decreased 55 from 549 to 494.
Responses: The number of new roof control plans decreased from 382 to 305; the number of plan revisions decreased from 1,255 to 1,054; and the number of unplanned roof falls and coal or rock bursts decreased from 1,514 to 606. This is an overall reduction in the number of responses of 1,186 (3,151-1,965).
Itemized Changes in Annual Burden Hours |
||||||
Regulation/ Data collection Activity |
Program Change (hours currently on OMB Inventory) |
Program Change (New) |
Difference |
Adjustment (hours currently on OMB Inventory) |
Adjustment (New) |
Difference |
30 CFR 75.220, 75.221(a), and 75.215/ Plans |
|
|
|
9,168 |
3,660 |
-5,508 |
30 CFR 75.220, 75.221(a), and 75.215, 75.222 and 75.223(a)/ Plan Revisions |
|
|
|
6,275 |
4,216 |
-2,059 |
30 CFR 75.223(b)/ Plots of unplanned roof falls, rib falls, and coal rock bursts |
|
|
|
121 |
48 |
-73
|
Total(s) |
|
|
|
15,564 |
7,924 |
-7,640 |
Burden Hours: The total number of burden hours decreased by 7,640 hours, from 15,564 hours to 7,924 hours.
As part of a burden reduction initiative, MSHA considered making the forms available in a fillable/fileable format; however, that proved impracticable. Instead, most of the decrease in hours resulted from the development of checklists and a new Roof Control Plan Approval and Review Procedures handbook that the agency has also made available to respondents on the Internet. While primarily intended for MSHA staff, these documents also provide operators with information that they may use to formulate roof control plans and addendums. This increased transparency has reduced the number of hours necessary to develop roof control plans and addendums. MSHA saved 4,714 of the difference of 7,640 burden because the increased transparency effort resulted in individual response times going down (24 hours to 12 hours response for 30 CFR 75.220, 75.221(a), and 75.215/ Plans) (and 5 hours to 4 hours response for 30 CFR 75.220, 75.221(a), and 75.215, 75.222 and 75.223(a)/ Plan Revisions). While the agency did enhance its compliance assistance materials by making the internal documents available to the public, it is important to note that the information collection requirements remain unchanged. Fewer respondents accounted for 2,926 hours of the burden reduction.
Itemized Changes in Annual Cost |
||||||
Regulation/ Data collection Activity |
Program Change (cost currently on OMB Inventory) |
Program Change (New) |
Difference |
Adjustment (cost currently on OMB Inventory) |
Adjustment (New) |
Difference |
30 CFR 75.220, 75.221(a), and 75.215/ Plans |
|
|
|
$1,910 |
$1,525 |
-$385 |
30 CFR 75.220, 75.221(a), and 75.215, 75.222 and 75.223(a)/ Plan Revisions |
|
|
|
$6,275 |
$5,270 |
-$1,005 |
30 CFR 75.223(b)/ Plots of unplanned roof falls, rib falls, and coal rock bursts |
|
|
|
0 |
0 |
0
|
Total(s) |
|
|
|
$8,185 |
$6,795 |
-$1,390 |
Burden Costs: Costs for this submission decreased by $1,390 (from $8,185 to $6,795) due to a decrease in the number of plans and revisions submitted.
16. For collections of information whose results will be published, outline plans for tabulation and publication. Address any complex analytical techniques that will be used. Provide the time schedule for the entire project, including beginning and ending dates of the collection of information, completion of report, publication dates, and other actions.
The results of this information collection will not be published.
17. If seeking approval to not display the expiration date for OMB approval of the information collection, explain the reasons that display would be inappropriate.
There is no form associated with this collection; therefore this question does not apply for this collection.
18. Explain each exception to the topics of the certification statement identified in “Certification for Paperwork Reduction Act Submissions.”
There are no certification exceptions identified with this information collection.
B. Collections of Information Employing Statistical Methods.
There is no statistical methodology involved in this collection.
ROOF SUPPORT
SEC. 302. (a) Each operator shall undertake to carry out on a continuing basis a program to improve the roof control system of each coal mine and the means and measures to accomplish such system. The roof and ribs of all active underground roadways, travelways, and working places shall be supported or otherwise controlled adequately to protect persons from falls of the roof or ribs. A roof control plan and revisions thereof suitable to the roof conditions and mining system of each coal mine and approved by the Secretary shall be adopted and set out in printed form within sixty days after the operative date of this title. The plan shall show the type of support and spacing approved by the Secretary. Such plan shall be reviewed periodically, at least every six months by the Secretary, taking into consideration any falls of roof or ribs or inadequacy of support of roof or ribs. No person shall proceed beyond the last permanent support unless adequate temporary support is provided or unless such temporary support is not required under the approved roof control plan and the absence of such support will not pose a hazard to the miners. A copy of the plan shall be furnished the Secretary or his authorized representative and shall be available to the miners and their representatives.
INSPECTIONS, INVESTIGATIONS, AND RECORDKEEPING
SEC. 103. (a) Authorized representatives of the Secretary or the Secretary of Health, Education, and Welfare shall make frequent inspections and investigations in coal or other mines each year for the purpose of (1) obtaining, utilizing, and disseminating information relating to health and safety conditions, the causes of accidents, and the causes of diseases and physical impairments originating in such mines, (2) gathering information with respect to mandatory health or safety standards, (3) determining whether an imminent danger exists, and (4) determining whether there is compliance with the mandatory health or safety standards or with any citation, order, or decision issued under this title or other requirements of this Act. In carrying out the requirements of this subsection, no advance notice of an inspection shall be provided to any person, except that in carrying out the requirements of clauses (1) and (2) of this subsection, the Secretary of Health, Education, and Welfare may give advance notice of inspections. In carrying out the requirements of clauses (3) and (4) of this subsection, the Secretary shall make inspections of each underground coal or other mine in its entirety at least four times a year, and of each surface coal or other mine in its entirety at least two times a year. The Secretary shall develop guidelines for additional inspections of mines based on criteria including, but not limited to, the hazards found in mines subject to this Act, and his experience under this Act and other health and safety laws. For the purpose of making any inspection or investigation under this Act, the Secretary, or the Secretary of Health, Education, and Welfare, with respect to fulfilling his responsibilities under this Act, or any authorized representative of the Secretary or the Secretary of Health, Education, and Welfare, shall have a right of entry to, upon, or through any coal or other mine. …
(h) In addition to such records as are specifically required by this Act, every operator of a coal or other mine shall establish and maintain such records, make such reports, and provide such information, as the Secretary or the Secretary of Health, Education, and Welfare may reasonably require from time to time to enable him to perform his functions under this Act. The Secretary or the Secretary of Health, Education, and Welfare is authorized to compile, analyze, and publish, either in summary or detailed form, such reports or information so obtained. Except to the extent otherwise specifically provided by this Act, all records, information, reports, findings, citations, notices, orders, or decisions required or issued pursuant to or under this Act may be published from time to time, may be released to any interested person, and shall be made available for public inspection.
* * * * *
30 CFR PART 75 Subpart C – Roof Support
Section 75.215 Longwall mining systems.
For
each longwall mining section, the roof control plan shall
specify--
(a) The methods that will be used to maintain a
safe travelway out of the section through the tailgate side of the
longwall; and
(b) The procedures that will be followed if
a ground failure prevents travel out of the section through the
tailgate side of the longwall.
Section 75.220 Roof control plan.
(a)(1)
Each mine operator shall develop and follow a roof control plan,
approved by the District Manager, that is suitable to the prevailing
geological conditions, and the mining system to be used at the mine.
Additional measures shall be taken to protect persons if unusual
hazards are encountered.
(2) The proposed roof control
plan and any revisions to the plan shall be submitted, in writing, to
the District Manager. When revisions to a roof control plan are
proposed, only the revised pages need to be submitted unless
otherwise specified by the District Manager.
(b)(1) The
mine operator will be notified in writing of the approval or denial
of approval of a proposed roof control plan or proposed
revision.
(2) When approval of a proposed plan or revision
is denied, the deficiencies of the plan or revision and recommended
changes will be specified and the mine operator will be afforded an
opportunity to discuss the deficiencies and changes with the District
Manager.
(3) Before new support materials, devices or
systems other than roof bolts and accessories, are used as the only
means of roof support, the District Manager may require that their
effectiveness be demonstrated by experimental installations.
(c)
No proposed roof control plan or revision to a roof control plan
shall be implemented before it is approved.
(d) Before
implementing an approved revision to a roof control plan, all persons
who are affected by the revision shall be instructed in its
provisions.
(e) The approved roof control plan and any
revisions shall be available to the miners and representative of
miners at the mine.
Section 75.221 Roof control plan information.
(a)
The following information shall be included in each roof control
plan:
(1) The name and address of the company.
(2)
The name, address, mine identification number and location of the
mine.
(3) The name and title of the company official
responsible for the plan.
(4) A typical columnar section
of the mine strata which shall--
(a)(4)(i) Show the name
and the thickness of the coalbed to be mined and any persistent
partings;
(a)(4)(ii) Identify the type and show the
thickness of each stratum up to and including the main roof above the
coalbed and for distance of at least 10 feet below the coalbed;
and
(a)(4)(iii) Indicate the maximum cover over the area
to be mined.
(5) A description and drawings of the
sequence of installation and spacing of supports for each method of
mining used.
(6) When an ATRS system is used, the maximum
distance that an ATRS system is to be set beyond the last row of
permanent support.
(7) When tunnel liners or arches are to
be used for roof support, specifications and installation procedures
for the liners or arches.
(8) Drawings indicating the
planned width of openings, size of pillars, method of pillar
recovery, and the sequence of mining pillars.
(9) A list
of all support materials required to be used in the roof, face and
rib control system, including, if roof bolts are to be
installed--
(a)(9)(i) The length, diameter, grade and type
of anchorage unit to be used;
(a)(9)(ii) The drill hole
size to be used; and
(a)(9)(iii) The installed torque or
tension range for tensioned roof bolts.
(10) When
mechanically anchored tensioned roof bolts are used, the intervals at
which test holes will be drilled.
(11) A description of
the method of protecting persons--
(a)(11)(i) From falling
material at drift openings; and
(a)(11)(ii) When mining
approaches within 150 feet of an outcrop.
(a)(12) A
description of the roof and rib support necessary for the refuge
alternatives.
(b)
Each drawing submitted with a roof control plan shall contain a
legend explaining all symbols used and shall specify the scale of the
drawing which shall not be less than 5 feet to the inch or more than
20 feet to the inch.
(c) All roof control plan
information, including drawings, shall be submitted on 8 1/2 by 11
inch paper, or paper folded to this size.
Section 75.222 Roof control plan-approval.
(a)
This section sets forth the criteria that shall be considered on a
mine-by-mine basis in the formulation and approval of roof control
plans and revisions. Additional measures may be required in plans by
the District Manager. Roof control plans that do not conform to the
applicable criteria in this section may be approved by the District
Manager, provided that effective control of the roof, face and ribs
can be maintained.
(b) Roof
Bolting. (1) Roof bolts should
be installed on centers not exceeding 5 feet lengthwise and
crosswise, except as specified in Section75.205.
(2)
When tensioned roof bolts are used as a means of roof support, the
torque or tension range should be capable of supporting roof bolt
loads of at least 50 percent of either the yield point of the bolt or
anchorage capacity of the strata, whichever is less.
(3)
Any opening that is more than 20 feet wide should be supported by a
combination of roof bolts and conventional supports.
(4)
In any opening more than 20 feet wide--
(b)(4)(i)
Posts should be installed to limit each roadway to 16 feet wide where
straight and 18 feet wide where curved; and
(b)(4)(ii)
A row of posts should be set for each 5 feet of space between the
roadway posts and the ribs.
(5) Openings should not be
more than 30 feet wide.
(c) Installation
of roof support using mining machines with integral roof bolters.
(1) Before an intersection or pillar split is started, roof bolts
should be installed on at least 5-foot centers where the work is
performed.
(2) Where the roof is supported by only two
roof bolts crosswise, openings should not be more than 16 feet
wide.
(d) Pillar
recovery. (1) During
development, any dimension of a pillar should be at least 20
feet.
(2) Pillar splits and lifts should not be more than
20 feet wide.
(3) Breaker posts should be installed on not
more than 4-foot centers.
(4) Roadside-radius (turn)
posts, or equivalent support, should be installed on not more than
4-foot centers leading into each pillar split or lift.
(5)
Before full pillar recovery is started in areas where roof bolts are
used as the only means of roof support and openings are more than 16
feet wide, at least one row of posts should be installed to limit the
roadway width to 16 feet. These posts should be--
(d)(5)(i)
Extended from the entrance to the split through the intersection
outby the pillar in which the split or lift is being made;
and
(d)(5)(ii)
Spaced on not more than 5-foot centers.
(e) Unsupported
openings at intersections.
Openings that create an intersection should be permanently supported
or at least one row of temporary supports should be installed on not
more than 5-foot centers across the opening before any other work or
travel in the intersection.
(f) ATRS
systems in working sections where the mining height is below 30
inches. In working sections
where the mining height is below 30 inches, an ATRS system should be
used to the extent practicable during the installation of roof bolts
with roof bolting machines and continuous-mining machines with
integral roof bolters.
(g) Longwall
mining systems. (1) Systematic
supplemental support should be installed throughout--
(g)(1)(i)
The tailgate entry of the first longwall panel prior to any mining;
and
(g)(1)(ii)
In the proposed tailgate entry of each subsequent panel in advance of
the frontal abutment stresses of the panel being mined.
(2)
When a ground failure prevents travel out of the section through the
tailgate side of the longwall section, the roof control plan should
address--
(g)(2)(i)
Notification of miners that the travelway is blocked;
(g)(2)(ii)
Re-instruction of miners regarding escapeways and escape procedures
in the event of an emergency;
(g)(2)(iii)
Re-instruction of miners on the availability and use of
self-contained self-rescue devices;
(g)(2)(iv)
Monitoring and evaluation of the air entering the longwall
section;
(g)(2)(v)
Location and effectiveness of the two-way communication systems;
and
(g)(2)(vi)
A means of transportation from the section to the main line.
(3)
The plan provisions addressed by paragraph (g)(2) of this section
should remain in effect until a travelway is reestablished on the
tailgate side of a longwall section.
Section 75.223 Evaluation and revision of roof control plan.
(a)
Revisions of the roof control plan shall be proposed by the
operator--
(1) When conditions indicate that the plan is
not suitable for controlling the roof, face, ribs, or coal or rock
bursts; or
(2) When accident and injury experience at the
mine indicates the plan is inadequate. The accident and injury
experience at each mine shall be reviewed at least every six
months.
(b) Each unplanned roof fall and rib fall and coal
or rock burst that occurs in the active workings shall be plotted on
a mine map if it--
(1) Is above the anchorage zone where
roof bolts are used;
(2) Impairs ventilation;
(3)
Impedes passage of persons;
(4) Causes miners to be
withdrawn from the area affected; or
(5) Disrupts regular
mining activities for more than one hour.
(c) The mine map
on which roof falls are plotted shall be available at the mine site
for inspection by authorized representatives of the Secretary and
representatives of miners at the mine.
(d) The roof
control plan for each mine shall be reviewed every six months by an
authorized representative of the Secretary. This review shall take
into consideration any falls of the roof, face and ribs and the
adequacy of the support systems used at the time.
File Type | application/vnd.openxmlformats-officedocument.wordprocessingml.document |
File Modified | 0000-00-00 |
File Created | 2021-01-25 |