30 C.F.R. § 75.1908 Nonpermissible diesel-powered equipment; categories.
Title 30 - Mineral Resources
(a) Heavy-duty diesel-powered equipment includes— (1) Equipment that cuts or moves rock or coal; (2) Equipment that performs drilling or bolting functions; (3) Equipment that moves longwall components; (4) Self-propelled diesel fuel transportation units and self-propelled lube units; or (5) Machines used to transport portable diesel fuel transportation units or portable lube units. (b) Light-duty diesel-powered equipment is any diesel-powered equipment that does not meet the criteria of paragraph (a). (c) For the purposes of this subpart, the following equipment is considered attended: (1) Any machine or device operated by a miner; or (2) Any machine or device that is mounted in the direct line of sight of a job site located within 500 feet of such machine or device, which job site is occupied by a miner. (d) Diesel-powered ambulances and fire fighting equipment are a special category of equipment that may be used underground only in accordance with the mine fire fighting and evacuation plan under §75.1502. [61 FR 55527, Oct. 25, 1996; 70 FR 36347, June 23, 2005]
Title 30: Mineral Resources
PART 75—MANDATORY SAFETY STANDARDS—UNDERGROUND COAL MINES
Subpart T—Diesel-Powered Equipment
§ 75.1908 Nonpermissible diesel-powered equipment; categories.

