|U.S. Department of
Mine Safety and Health Administration|
1100 Wilson Boulevard
Arlington, Virginia 22209-3939
|EFFECTIVE DATE: June 20, 2013|
PROGRAM POLICY LETTER NO. P13-V-05
FROM: KEVIN G. STRICKLIN
Coal Mine Safety and Health
SUBJECT: Application of Title 30, Code of Federal Regulations (C.F.R.)
§ 75.523-2 to Mobile Bridge Carriers Connected to Continuous
Miners That Form Component Part of Self-Propelled Electric
This Program Policy Letter (PPL) is intended for Coal Mine Safety and Health enforcement personnel, equipment manufacturers, underground coal mine operators, and independent contractors working at underground coal mines.
This PPL is issued to clarify 30 C.F.R. § 75.523-2, De-energization of self-propelled electric face equipment; performance requirements. The de-energization performance requirements of this section apply to all mobile bridge carriers (MBCs) that are mechanically or electrically connected to continuous miners (CMs) when they are component parts of a continuous mining and haulage system.
In 1999, as a result of an accident involving an MBC and a CM, the Mine Safety and Health Administration (MSHA) issued a citation pursuant to 30 C.F.R. § 75.523-2(c). Subsequently, a Federal Mine Safety and Health Review Commission administrative law judge (ALJ) issued a decision in the case of Secretary of Labor v. Rosebud Mining Company, 22 E.M.S.H.R.C.525(2000). The ALJ found that MSHA's enforcement policy regarding 30 C.F.R. § 75.523-2 was unclear. He reasoned that because the standard does not explicitly require that the panic bar on the MBC be able to de-energize the continuous miner, or define both pieces of equipment as different components of a single system of "self-propelled electric face equipment," and because MSHA's previous policy did not clarify the issue, "a reasonable operator familiar with the [mining] industry and the protective purposes of the standard" would not recognize that 30 C.F.R. § 75.523-2 was applicable in the manner interpreted by MSHA Id. at 534.
Furthermore, the ALJ noted that MSHA's most recent statement on de-energization devices appeared to "take a position counter to that advocated in this case" because it seemed to state that a continuous miner was not included in an "entire system." Id. at 533.
This policy letter clarifies the Agency's application of 30 C.F.R. § 75.523-2 to MBCs that are mechanically or electrically connected to CMs; MSHA considers the MBCs and the CMs to be part of a single system of electric face equipment.
When MBCs and CMs are mechanically or electrically connected to each other, they are components forming a continuous haulage system of self-propelled electric face equipment. Even though the components may be trammed independently, an emergency stop switch must be installed on each machine and wired to simultaneously de-energize the tramming motors of all components (MBC and CM) when any emergency stop switch in either machine is activated. A hazardous condition can occur when the machines are mechanically or electrically connected to each other, but trammed independently, and the emergency stop switch of any machine fails to de-energize the tramming motors of all components in the event of an emergency.
MBCs and CMs that do not have an emergency stop switch on all components that meet all the requirements of 30 C.F.R. § 75.523-2 are not in compliance with 30 C.F.R. § 75.523-2.
Section 75.523-2(a) provides that de-energization of the tramming motors of self-propelled electric face equipment shall be provided by:
- Mechanical actuation of an existing pushbutton emergency stopswitch;
- Mechanical actuation of an existing lever emergency stopswitch; or
- The addition of a separate electromechanical switch assembly. Section 75.523-2(b) states that "[t]he existing emergency stopswitch or additional switch assembly shall be actuated by a bar or lever which shall extend a sufficient distance in each direction to permit quick deenergization of the tramming motors of self-propelled electric face equipment from all locations from which the equipment can be operated."
Section 75.523-2(c) states that "[m]ovement of not more than 2 inches of the actuating bar or lever resulting from the application of not more than 15 pounds of force upon contact with any portion of the equipment operator's body at any point along the length of the actuating bar or lever shall cause de-energization of the tramming motors of the self-propelled electric face equipment."
A violation of 30 C.F.R. § 75.523-2 exists and a citation shall be issued whenever an emergency panic bar installed on an MBC connected to a CM does not meet the performance requirements of 30 C.F.R. § 75.523-2 (a), (b), and (c).
The interpretation set forth above is consistent with the language of 30 C.F.R. §§ 75.523-2 (a), (b), and (c) in that the MBCs and CMs that are connected form two or more components of one unit of self-propelled electric face equipment. Emergency de-energization of the tramming motors of all components is necessary to further the safety objectives of 30 C.F.R. §§ 75.523-2 (a), (b), and (c). The purpose of this standard is to prevent miners from being endangered by the unexpected movement and/or electrification of any component of the system of self-propelled electric face equipment.
The standard is intended to provide that electric face equipment be de-energized quickly in the event of an emergency, thereby preventing equipment operators from being pinned, squeezed, or crushed against the roof, ribs or other mining equipment which could possibly result in a serious or fatal injury.
In setting an abatement time for any violation described above, an inspector or other authorized agency representative should, at a minimum, consider the hazard(s) to miners and the reasonable time required to correct the condition.
Federal Mine Safety and Health Act of 1977, as amended, 30 U.S.C. § 801 et seq.; 30 C.F.R. § 75.523-2.
This policy letter should be filed behind the tab marked "Program Policy Letters" at the back of Volume V of the Program Policy Manual.
This program policy letter may be viewed on the World Wide Web by accessing the MSHA home page (www.msha.gov) under MSHA’s Major Laws, Regulations and Policies, choose “Compliance Information (PIBs, PILs, the PPM, and More” and select “Program Policy Letters.”
Issuing Office and Contact Person
Coal Mine Safety and Health, Safety Division
Rodney Adamson, (202) 693-9549
Program Policy Holders
Underground Coal Mine Operators
Underground Independent Contractors
Special Interest Groups