In a final investigation report, MSHA said 32-year-old lube truck operator Rhett Lee Mosley was killed at Rex Coal’s Rex Strip No. 1 on the complex’s Lowsplint coal seam pit access roadway just after midnight November 23.

The worker, who had six years of industry experience, lost control of his DM-690-SX Mack tandem axle lube truck while descending the roadway.

“The truck encountered the outer roadway barrier near the bottom of the roadway, traveled approximately 77 more feet and overturned on its left side, onto back dumped spoil material,” investigators said.

“Mosley apparently either jumped or was thrown from the truck and was found lying under the service bed of the truck.”

After reviewing the truck and the roadway where the event occurred, MSHA said the accident was caused by the operator’s failure to ensure the truck was maintained in safe operating condition.

“Defects affecting safety were not corrected before the truck was put in service [and] brake system defects on the truck rendered the service brakes inadequate and insufficient to maintain control of the truck on the observed 22 per cent slope,” federal investigators said.

“The mine operator failed to ensure that the seat belt system in the truck was properly installed, and the victim was wearing a properly installed, functional seat belt.”

MSHA ordered corrective actions addressing the root causes of the incident, including the implementation and enforcement of a written procedure for regular mobile equipment examinations, maintenance, and repairs of braking systems for each machine at the mine. Should defects be found, workers are to report items to the foreman and correct the condition before placing the unit back into service.

Mine management has also been instructed to train and instruct drivers not to operate any equipment without wearing a seat belt. Finally, the mine must establish a written procedure to assure adequate pre-operational checks for mobile equipment.

As a result of its investigation, MSHA issued three 104(a) citations to Rex Coal for violations of 30 CFR, 77.1607(b) for failure to control; 30 CFR, 77.1605(b) for ineffective or compromised braking systems; and 30 CFR, 77.1606(a) for inadequate pre-operational examinations.

Rex Strip No. 1 mine in Harlan County is a multi-seam contour surface mine which produces mostly from the Highsplint and Lowsplint coal seams at a rate of about 500 tons daily.