|U.S. Department of
Mine Safety and Health Administration|
1100 Wilson Boulevard
Arlington, Virginia 22209-3939
|EFFECTIVE DATE: April 19, 2012|| EXPIRATION DATE: 03/31/2014|
(Reissue of PIL I10-V-01)
PROCEDURE INSTRUCTION LETTER NO. I12-V-07
FROM: KEVIN G. STRICKLIN
Coal Mine Safety and Health
SUBJECT: Supplemental Roof Support Materials
This Procedure Instruction Letter (PIL) provides instructions to Mine Safety and Health Administration (MSHA) personnel responsible for enforcing the requirements of Title 30 Code of Federal Regulations (30 C.F.R.) § 75.214, and reviewing and evaluating new and revised roof control plans for underground coal mines to insure the plans are suitable to the prevailing mining conditions.
This PIL will assist MSHA enforcement personnel in determining the location, type, and quantity of supplemental roof support required at a particular mine and whether the supplemental roof support materials should be identified in the mine's roof control plan.
30 C.F.R. § 75.214, Supplemental support materials, equipment, and tools provides that:
(a) A supply of supplemental roof support materials and the tools and equipment necessary to install the materials shall be available at a readily accessible location on each working section or within four crosscuts of each working section.
(b) The quantity of support materials and tools and equipment maintained in accordance with this section shall be sufficient to support the roof if adverse roof conditions are encountered, or in the event of an accident involving a fall.
Mines using traditional roof bolting systems typically maintain wooden props/posts, cribs, cap pieces, wedges and crossbars with the tools necessary for installation on the section for use as supplemental roof support. In these situations, it is normally not necessary to address supplemental support material in the roof control plan as the identification of those materials and the quantity necessary at the mine is apparent to the inspector and miners.
Other mines may use more complex and sophisticated roof support systems including cable bolt systems, resin grouted roof bolts and trusses, tensioned bolting systems and conventional point anchor bolts, steel friction props, machined wooden cribbing and cementatious cribbing. The distinction between required support components and supplemental support components may become blurred and lead to confusion on the part of the inspectors and miners. Where these conditions exist, the District Manager will examine the mine's roof control plan to determine whether the plan should clearly identify which components are present to meet the supplementary requirements of 30 C.F.R. § 75.214. For both initial plan approval as well as the semi-annual review, District Managers, as part of the approval process, will determine whether additional supplemental support is necessary, whether additional support requirements should be added to the roof control plan, and whether the supplemental support materials and equipment required under 30 C.F.R. § 75.214, should be identified in the roof control plan. This review will assure that the plan is suitable to the geological conditions and the mining systems used at the mine, and assure that additional measures are available to protect persons if unusual hazards are encountered. In addition, during the plan review, the District Manager will take into consideration any falls of the roof, rib, or face and the adequacy of the support systems used at the mine.
Supplemental roof support materials and the tools and equipment necessary to install them should be regularly examined during mandatory inspections to assure that supplies have not been used, lost, or misplaced. These materials must be available in sufficient quantity and in a readily accessible location to support the roof if adverse roof conditions are encountered or a roof fall accident occurs.
This PIL provides directions for inspectors to assure that the standard is being applied properly and uniformly.
The Federal Mine Safety and Health Act of 1977, 30 C.F.R. § 75.214(a) and (b), 75.220(a)(1), 75.221(a)(5), 75.222(a), and 75.223(d).
The PIL may be viewed on the World Wide Web by accessing the MSHA home page (www.msha.gov) and choosing "Compliance Info" and "Procedure Instruction Letter."
Issuing Office and Contact Person
Coal Mine Safety and Health, Safety Division
Johnny P. Calhoun, (202) 693-9507
MSHA Coal and All-volume Program Policy Manual Holders
Underground Coal Mine Operators