UNITED STATES
DEPARTMENT OF LABOR

Abstract: Employee #1, a truck mechanic, was lying on his back under a full-size GMC van adjusting its parking brake cables. The van had all four wheels off the ground and was supported by two 15 in. tall jack stands under the front axle and one tier of wood blocking on each side of the differential at the rear axle. An Allis-Chalmers lift truck, chassis serial #39233, model #479601, converted into a tractor tug was parked in front of the van. At the same time, a coworker was working on the tug engine, adjusting the governor down from 2,800 to 3,000 rpm at full throttle to the desired 1,800 rpm. The shift lever on the tug was accidentally bumped into reverse and the tug surged backward, crashing into the van. The force of the impact caused the van to move 32 in. backward, dislodging the right front axle jack stand and the wood blocks at the rear axle. The rear portion of the van chassis with the differential housing dropped down, pinning Employee #1's chest against the concrete floor. He was killed. The coworker adjusting the tug later stated that he had straddled the right side of the tractor cab with his right leg and had his right foot depressing the throttle treadle, while reaching forward into the engine area to adjust the governor. The coworker's body position during this job function placed his right knee next to the vertical transmission shift lever and it could readily have bumped the lever into the reverse position. The coworker had set the parking brake on the tug but the torque overrode the brake, resulting in a 32 in. long tire skid mark on the floor.