DEPARTMENT OF LABOR
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
Greenville, Greenville County, South Carolina
October 3, 1995
D. B. Craig
Supervisory Mine Inspector
Mine Safety and Health Inspector
Mine Safety and Health Administration
135 Gemini Circle, Suite 212
Birmingham, Alabama 35209
Timothy Edward Cox, haulage truck driver, age 20, was fatally injured at about 3:20 p.m. on October 3, 1995, when the truck he was operating went through a berm and fell approximately 65 feet to the bench below. The victim had a total of three months mining experience, all at this mine.
The MSHA district office in Birmingham, Alabama, was notified of the accident by a telephone call from Bobby E. Rider, divisional manager of personnel and safety, southeast division, at 3:45 p.m., October 3, 1995. An investigation was started on October 4, 1995.
The Lakeside Quarry, a multiple bench granite operation, owned and operated by Vulcan Materials Company, was located at 202 Brown Road in the city of Greenville, Greenville County, South Carolina. The mine was an open pit quarry operation with a crushing and finishing plant. The principal operating official was Louis Lester Callahan, III, quarry superintendent. The mine worked two, 11-hour shifts a day, 5 days a week, and one, 10-hour shift on Saturdays and Sundays. A total of 35 persons was employed.
Granite was drilled, blasted, crushed, sized and stockpiled. The finished product was used in concrete, asphalt and for other purposes in the construction industry.
The last regular inspection of this operation was conducted on August 23, 1995.
PHYSICAL FACTORS INVOLVED
The accident occurred at the 850 foot bench of the quarry. On one side of the bench was a wall from which material was blasted. On the other side was a highwall which dropped 65 feet to the bench below. The width of the bench where the accident occurred, was approximately 65 feet. A haulage road that went from the 850 foot level to the crusher was 16-1/2 feet wide and 10 feet back from the edge of the highwall where the truck went over. A berm averaging 4 to 5 feet in height had been constructed between the road and the edge of the highwall.
The truck was a 1974 model 201 Euclid R-50 off-road haulage truck, serial number 65059, equipped with a 635 HP Cummins 4-cycle, V-12 diesel engine and an Allison 6-speed Torqmatic transmission. The rear axle fifth member was equipped with a no-spin differential.
The steering axle brakes were air operated, shoe/drum actuated, by a type 30 brake chamber at each wheel. The rear drum brakes were air over hydraulic operated, shoe/drum comprised of two wheel actuator assemblies at each brake drum. The truck was 33 feet long and weighed 87,700 lbs.
Maintenance records revealed the right rear brakes were relined on May 25, 1995, and two new wheel cylinders and two new wedges were installed on the left rear brake. A new parking brake lining was installed on August 10, 1995. A rebuilt transmission was installed on August 10, 1995.
An examination of the truck after the accident revealed torque
tubes in the truck's frame had pre-existing broken welds. The
throttle linkage had severe wear spots in several areas where it
had been rubbing against other truck components. The right rear
brake drum was worn beyond its recommended wear limits and the
right rear brake shoes were incorrectly sized.
DESCRIPTION OF THE ACCIDENT
On the day of the accident, Timothy Edward Cox (victim), reported for work at 7:00 a.m., his regular starting time and was assigned the task of hauling rock.
Cox obtained the Euclid R-50 truck and began hauling rock as instructed. Work continued without incident until the victim's truck hit a front-end loader when the accelerator seemed to get stuck as the victim backed his truck to be loaded. However, Cox continued to use the truck and at 2:55 p.m. went to the 850 foot level to get another load.
Due to the narrow area on the bench, it was necessary for Cox to drive past the loading area and then back the truck off the road at a 45 degree angle to be loaded.
After loading was completed, Cox was to have pulled the truck forward, toward the highwall then back the truck, positioning it so that he could turn the truck back onto the road to go to the crusher.
After Cox's truck was loaded, he pulled the truck forward, backed up, and began moving forward again. Witnesses said they heard the truck's engine revving, getting louder and louder. The truck "jumped" several times and Cox was observed turning the steering wheel and trying to operate the gear shift, the brake light came on but it did not stop. The truck went through the berm, over the highwall and fell 65 feet before landing on the bench below. The truck hit on its left front bumper, fell onto the truck bed and remained upside down.
James Nations, utilityman, saw the truck drive off the highwall. He drove to the bench where the truck had driven through the berm and radioed Louis Callahan, quarry superintendent, for help.
When Nations arrived at the truck, he found the cab crushed with Cox inside and the engine still running. Upon impact, the bed became separated from the frame and slid against the cab causing it to collapse towards the front of the truck and the steering wheel column had folded. Nations attempted to kill the engine, but could not pull the emergency air shut off handle. He then went around to the other side of the truck and manually released the engine air shut-off dampers.
Mine personnel attending to Cox were unable to detect a pulse.
Attempts to free him from the cab were suspended when the
emergency medical service crew arrived at the site. The victim
was pronounced dead at the scene by the Greenville County
coroner. He died as a result of crushing injuries sustained in
The direct cause of the accident was the inability to control the vehicle before it went over the highwall. This was due to the accelerator linkage sticking, which caused the engine to "rev" at high rpm and took away the ability of the no-slip differential to release and allow the truck to be steered to the right.
Contributing to the accident were improperly maintained and
defective primary brakes on the vehicle.
Citation No. 4522605 was issued on January 3, 1996, under the provisions of 104(a) for violation of Standard 56.14100(b):
An employee was fatally injured on October 3, 1995, when the Euclid R50 model 201 haul truck, serial No. 65059, company No. 4262, he was operating went over a highwall. Wear on the truck's throttle linkage and also on adjacent components along the throttle linkage route indicated the linkage had been rubbing on the truck frame. This would cause the throttle to stick. The truck had experienced the engine revving up, when traveling across uneven terrain, without having the accelerator activated by the truck operator.
Citation No. 4522606 was issued on January 3, 1996, under the provisions of 104(d)(1) for violation of Standard 56.14101(a)(3):
An employee was fatally injured on October 3, 1995, when the haul truck he was operating went over a highwall. The right rear brakes on the Euclid R50 model 201 haul truck, serial No. 65059, company No. 4262, were not functionally proper. Incorrectly sized brake linings were installed on May 25, 1995, evidenced by the lining size being mismatched with the brake drum diameter. The brake linings still showed some of their original mill markings which indicates the right rear brake assembly was not maintained properly. The old brake drum was reinstalled in lieu of being replaced even though it had numerous open heat cracks and showed excessive wear of 3/16 inches beyond the manufacturer's recommended maximum limit. The brake activators, plungers, rollers, wedges and cylinders were found to have considerable damage and had not been replaced when the earlier repairs were made.
This is an unwarrantable failure.
Respectfully submitted by:
/s/ D. B. Craig
Supervisory Mine Inspector
/s/ Darrell Brennan
Mine Safety and Health Inspector
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