Inspection Detail

Inspection: 111956173 - American Rock & Asphalt Inc

Inspection Information - Office: Sacramento Mining & Tunneling District Office

Investigation Summary

At approximately 6:00 a.m. on December 27, 1991, Employee #1 and a coworker were preparing to haul quarry rock from the upper loading area down to the unloading site at the #1 crusher. They were driving two-axle, 50 ton-capacity Euclid haul trucks with a four gear automatic transmission. Employee #1, a full time employee, was filling in for another driver. According to Employee #1, he had hauled 16 to 18 loads without any mishaps before taking a lunch break at 11:30 a.m. At approximately 12:15 p.m., Employee #1 was taking a full load of material (more than 50 tons) down to the #1 crusher site. When he left the loading area the truck was in first gear. According to Employee #1, he stopped his truck at the top of the steeper part of the upper haul road to view the road conditions. It had been raining slightly and his supervisor had told him that if the rain worsened or the road got too slippery he was to stop work and go home. While stopped on the road, Employee #1's truck suddenly started to slide down the haul road. Employee #1 attempted to turn left to drive either into the high berm and/or up grade into the recycle area. He was unable to maneuver or stop as the loaded truck gained momentum on the slick steep surface. The truck slid straight across the haul road, through a 4 ft berm, and over and down a very steep embankment. The truck landed on the lower part of the haul road, about 117 ft below, skidded another 56 ft, and then rolled over on its side. Employee #1 was able to release himself from his seat belt and get out of the truck by himself. His supervisor arrived within minutes and took him to the main office. About 15 minutes later paramedics arrived and drove him to Seton Hospital in Daly City, CA. Employee #1 was hospitalized for one week. Employee #1 stated he had worked on and off for about eight months at this mine. He had received training and instruction in the handling of the 50 ton Euclid truck prior to being hired as a full-time truck driver. Employee #1 also stated that the load he was bringing down prior to the accident would probably have been his last trip until conditions improved The other truck driver, who had just preceded Employee #1, and who had ceased from any further loading and hauling, had called Employee #1 on the radio and told him to stand by until the haul road was rocked because of the very slippery conditions. Employee #1 stated that he heard him but unfortunately it was too late as he was already skidding and unable to reply. Subsequent investigation by the vehicle servicing company indicated that the brake lining looked good and the brakes were in a locked position against the drum. The tire tread was very good.

Keywords: FRACTURE, CONSTRUCTION, STEEP GRADE, TRUCK, SLIPPERY SURFACE, ARM, LOST CONTROL, OVERTURN, TRUCK DRIVER