MINE SAFETY AND HEALTH ADMINISTRATION
Metal and Nonmetal Mine Safety and Health
Accident Investigation Report
Surface Nonmetal Mine
Fatal Powered Haulage Accident
Vulcan Materials Company
Calera, Shelby County, Alabama
I.D. No. 01-00050
March 15, 1999
Supervisory Mine Safety and Health Inspector
Frederick B. Moore
Mine Safety and Health Inspector
George H. Gardner, P.E.
Dennis L. Ferlich
Mine Safety and Health Administration
135 Gemini Circle, Suite 212
Birmingham, Alabama 35209
Homer L. Clay, truck driver, age 61, was fatally injured at about 11:20 a.m. on March 15, 1999, when he backed a haulage truck over a highwall while dumping waste rock. Clay had a total of 40 years mining experience as an equipment operator, all with this company, the past two years at this operation. He had received training in accordance with 30 CFR, Part 48.
MSHA was notified at 11:50 a.m. on the day of the accident by a telephone call from the manager of safety and health for the mining company. An investigation was started the same day.
The Calera Quarry, a crushed stone operation, owned and operated by Vulcan Materials Company, was located adjacent to State Highway 84 at Calera, Shelby County, Alabama. The principal operating official was K. Tommy Thompson, superintendent. The mine was normally operated two, 12-hour shifts a day, six days a week. Total employment was 56 persons.
Limestone was drilled and blasted from multiple benches in the quarry, then hauled by truck to the plant where it was crushed, screened, sized and stockpiled. The finished product was sold for use in concrete, asphalt, and other purposes in the construction industry.
The last regular inspection of this operation was completed on January 13, 1999. Another inspection was conducted at the conclusion of this investigation.
PHYSICAL FACTORS INVOLVED
The accident occurred at the highwall of an inactive pit which was approximately 270 feet deep and contained about 130 feet of water. Waste material had been dumped into the pit over a period of time and had accumulated to approximately 10 feet below the water surface at the location where the truck went over the highwall. On the day of, and for about a month prior to the accident, waste material was being excavated in order to expand the railroad loadout facility. This material was hauled approximately 500 feet to the dump. Routinely, the truck driver dumped back from the edge of the highwall. The dump site was nearly level with a slight upgrade. A berm consisting of fine clay material had been constructed at the perimeter of the highwall. The berm measured approximately 35 feet long and 38 inches high. An 18-foot section of the berm had been removed or flattened at the dump site.
The truck involved in the accident was an 85-ton Caterpillar, model 777B and weighed approximately 290,000 pounds when loaded. The truck, powered by an eight-cylinder Caterpillar Model 3508 diesel engine, had an automatic transmission with seven forward gears and one reverse gear. Steering was all hydraulic with no mechanical connections. The braking system was air-over-hydraulic with the rear brakes being completely enclosed oil-cooled multi-disc brakes. The front braking system was dry-caliper disc brakes. Outside tire dimensions measured 16 feet at the front and 17 feet at the rear.
Tire marks at the accident site went a distance of about 20 feet at the point where the truck went over the edge. These marks may have been skid marks caused by application of the rear brakes, or they may have been caused by the acceleration of the truck being greater than the rotational speed of the wheels in reverse gear as it went over the edge. Tire tracks in the berm near the accident site indicated that the truck had backed to the edge of the highwall and partially through the berm.
Although the truck had not been recovered from the pit and could not be examined to conclusively rule out potential equipment problems, based on an examination of the maintenance records, examination of the accident site, and statements from witnesses, it is suspected that the condition of the equipment was not a contributing factor to the accident.
The weather on the day of the accident was clear. Significant rainfall had occurred two days earlier.
DESCRIPTION OF ACCIDENT
On the day of the accident, Homer Clay (victim) reported for work at 6:00 a.m., his normal starting time. He hauled material from the pit to the primary crusher until about 7:00 a.m. when the excavator operator arrived to load waste material. Clay then began hauling material from the waste pile to the abandoned pit. Clay hauled and dumped two loads at the berm. At about 8:10 a.m., he asked James Wells, front-end-loader operator, to "fix the berm" so that he could back the truck close enough to dump over the edge of the highwall. Wells pushed the material over the edge, removing or flattening a section of the berm. Clay dumped 22 more loads of material without incident. Lack of residual waste material at the dump site, indicated that Clay had backed the truck close enough to the edge of the highwall to dump all the loads over the edge.
At about 11:20 a.m., Clay backed the truck to dump a load and it traveled over the edge of the highwall. The truck slid down a steep slope for approximately 20 feet before losing contact with the ground. It fell an additional 15 feet, struck the top of a rock ledge, flipped over, and came to rest upside down, mostly submerged in the flooded pit.
The local 911 emergency assistance number was called and paramedics arrived a short time later. A dive team was called in to recover the body.
The direct causes of the accident were failure to maintain berms, bumper blocks or other impeding devices to eliminate the hazard of over traveling the dump site and failure to examine conditions as warranted.
Order number 7750011was issued on March 15, 1999, under the provisions of Section 103(k) of the Mine Act:
A fatal accident occurred at this operation at about 1120 hours on March 15, 1999, when a haulage truck driver backed his truck through a berm and over the highwall into an abandoned quarry. This order is issued to assure the safety of persons at this operation until the mine or affected areas can be returned to normal operations as determined by an authorized representative of the Secretary. The mine operator shall obtain approval from an authorized representative for all actions to recover persons, equipment, and/or restore operations in the affected areas.Citation number 7788889 was issued on April 1, 1999, under the provisions of Section 104(a) for violation of 30 CFR 56.9301:
A haulage truck driver was fatally injured at this operation on March 15, 1999, when he backed an 85-ton truck over the edge of a 140-foot highwall. Berms, bumper blocks, or other similar impeding devices were not maintained at the dumping location to eliminate the hazard of overtravel and overturning.This citation was terminated on April 1, 1999, after the dump location had been adequately bermed to prevent overtravel of haulage vehicles.
Citation number 7788890 was issued on April 1, 1999, under the provisions of Section 104(a) for violation of 30 CFR 56.9304(a):
A haulage truck driver was fatally injured at this operation on March 15, 1999, when he backed an 85-ton truck over the edge of a 140-foot highwall. Records indicated that an inspection of the dumping location had been conducted prior to the start of the shift. From the beginning of the shift until the accident, at least 24 loads of waste material were dumped at the site. Apparently, the front-end loader had removed or flattened the berm to allow the truck to dump over the edge. No follow-up inspections were made to visually examine the change in conditions that occurred at the dumping location.This citation was terminated on April 1, 1999. All plant management personnel and hourly employees associated with load, haul, dumping activities have received specific training pertaining to safe dumping procedures and berm maintenance. This training included the need to monitor changing conditions at dump sites and haulage locations.
APPENDIXES 1. List of Persons Present During the Investigation.
Related Fatal Alert Bulletin:
Vulcan Materials Company
Richard L. Seago ............... corporate safety managerState of Alabama Department of Mines and Minerals
Cynthia K. Kirby ............... division manager of safety and health
Michael Heenan ............... attorney
K. Tommy Thompson ............... plant manager
Renfro Smith ............... foreman and witness
James T. Lawley ............... superintendent
James Wells ............... loader operator
Michael Snipes ............... utility worker
Jerry Scharf ............... chief of mine safetyMine Safety and Health Administration
Rickie Evans ............... mine inspector
Mitchell Adams ............... supervisory mine inspector
Frederick B. Moore ...............mine safety and health inspector
George H. Gardner ............... civil engineer
Dennis L. Ferlich ............... mechanical engineer