Current through Register Vol. XLI, No. 21, May 23, 2024
Section 56-23-3 - Underground Use3.1. Underground use of in by and out by diesel-powered equipment, including mobile equipment, stationary equipment and equipment of all horsepower ratings, may only be approved, operated and maintained as provided in this rule, except for emergency fire-fighting equipment to be used specifically for that purpose.3.2. All diesel-powered equipment shall be attended while in operation with the engine running in underground mines. For purposes of this rule, "attended" shall mean a diesel equipment operator is within sight or sound of the diesel-powered equipment.3.3. In by and out by diesel-powered equipment may be used in underground mines if the in by or out by diesel-powered equipment uses an engine approved or certified by MSHA, as applicable, for in by or out by use that, when tested at the maximum fuel-air ratio, does not require an MSHA Part 7 approval plate ventilation rate exceeding 75 c.f.m. per rated horsepower. Should MSHA promulgate new regulations that change the MSHA part 7 approval plate ventilation rate, the cfm requirement per rated horsepower will be revised either up or down on a direct ratio basis upon the recommendation of the director.