(a) Heavy-duty diesel-powered equipment includes-
(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:
(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 Sec. 75.1101-23.
053-4 Wyo. Code R. § 75.1908