The first incident occurred when a bulldozer overturned on an embankment, rolling onto a bench below, according to federal officials; low temperatures and frozen ground were cited. In the second episode, a bulldozer was completely covered after breaking into a raw coal stockpile above the feeder; the operator was freed after being trapped several hours.

In their report, MSHA officials stressed the importance of noting hazardous conditions before equipment operation and design limitations are noted. Operations, notably, should clear out slopes of large rocks or stumps where track-mounted equipment will operated, the MSHA said.

Roll-over-protection (ROPS), officials added, should be installed with seatbelts worn at all times. Operations, meanwhile, should install adequate lighting on mobile equipment operating at night or during challenging weather; pre-operational checks for mobile equipment and hazards reports to management should be mandatory.

The agency said crews should maintain two-way radio communications between mobile equipment operators and all personnel in the vicinity at all times. MSHA officials also encouraged enclosed cabs to use rollover protection in stockpile areas.

Communication should be maintained at all times, the MSHA added, between the feeder control room and the bulldozer operator. Operations should also place two 60-minute oxygen generating SCSRs in the bulldozer, overhead and inspect them during pre-operational checks and train operators in their use.

MSHA also advocated for the installation of an independent light source as well as a 40-psi cab window glass, or chemically treat it with a proper window support system. Finally, they noted, mines should provide remote-controlled stop devices in cabs that can shut off reclaim feeders and belt conveyors and mark feeder areas of coal stockpiles with a suspended marker near each feeder’s center.