MINE SAFETY AND HEALTH ADMINISTRATION
Report of Investigation
Surface Nonmetal Mine
(Sand and Gravel)
Fatal Machinery Accident
January 10, 2000
Lucherk's Gravel Co.
Lucherk's Gravel Co.
Ledbetter, Fayette County, Texas
ID No. 41-04125
Accident Investigators
Arthur L. Ellis
Supervisory Mine Safety and Health Inspector
Wyatt Andrews
Health and Safety Inspector
Ronald Medina
Mechanical Engineer
Originating Office
Mine Safety and Health Administration
South Central District
1100 Commerce Street, Room 4-C-50
Dallas, Texas 75242-0499
Doyle D. Fink
District Manager
OVERVIEW
David D. Cain, truck driver, age 44, was fatally injured at about 1:00 p.m., on January 10, 2000, when he was crushed against the drive shaft of a shaker screen. Cain had been performing maintenance while standing in the elevated bucket of a front-end loader.
Cain had a total of ten weeks mining experience as a truck driver, all at this operation. He had not received training in accordance with 30 CFR, Part 48.
GENERAL INFORMATION
Lucherk's Gravel Co., a sand and gravel mine, owned and operated by Lucherk's Gravel Co., was located at Ledbetter, Fayette County, Texas. The principal operating official was Chester Lucherk, owner. The mine was normally operated one, 8- hour shift a day, five days a week. Total employment was two persons.
Sand and gravel was extracted from a single bench using a dozer to push the raw material into stockpiles. A front-end loader fed the raw material into a portable plant where it was screened and stockpiled. The finished products were sold primarily as construction aggregate and road topping.
A regular inspection of this mine commenced on February 2, 2000 following this investigation. The Mine Safety and Health Administration had not been notified of the mine's existence until the accident was reported.
DESCRIPTION OF ACCIDENT
On the day of the accident, David Cain (victim) reported for work at 7:00 a.m., his normal starting time. The plant was not being operated that day due to recent rains. Cain performed clean-up work in the shop then he and Chester Lucherk, owner, left to pick up cement beams. At about 12:30 p.m, they returned to the mine site and unloaded the beams.
Cain and Lurcherk then proceeded to the portable screen plant to begin greasing the drive bearings. At about 1:00 p.m, Cain climbed into the bucket of the front-end loader and Lucherk positioned the machine. After greasing the bearings on the north side, Lucherk drove the loader to the south side of the plant with Cain in the bucket. Lucherk positioned the loader below the drive unit and began to raise the bucket into position. On the ascent, Cain motioned for him to stop, placing him in front of the clutch shaft. Lucherk then reached down with his right hand to pull up on the accelerator, which had stuck in the high idle position. As he did, his shoulder struck the bucket dump control lever causing the bucket to suddenly roll down pinning Cain against the protruding drive shaft. Lucherk, believing Cain had been injured, lowered the bucket to the ground and exited the loader to find Cain standing beside the bucket. Lucherk immediately called the office and summoned emergency medical personnel. He drove Cain in his vehicle to meet the ambulance. Cain was transported to a local medical center where he was pronounced dead at 3:25 p.m. Death was attributed to hemorrhage shock.
INVESTIGATION OF THE ACCIDENT
MSHA was notified of the accident on January 13, by an anonymous telephone call to mine safety and health inspector Larry Parks. An investigation was started the same day. MSHA's accident investigation team traveled to the mine, made a physical inspection of the accident site, interviewed a number of persons, and reviewed work procedures being performed at the time of the accident. An order was issued pursuant to Section 103(k) of the Mine Act to ensure the safety of miners. The miners did not request, nor have, representation during the investigation.
DISCUSSION
The accident occurred at the Marco power screen plant located in the pit. The plant was not in operation at the time of the accident. It consisted of a hopper, a conveyor belt, and a screen separator. Sand and gravel was loaded into the hopper and gravity fed onto the conveyor belt. The material was discharged onto a screen where gravel was separated into two sizes. Power was supplied by a single diesel engine through a series of chain and v-belt drives.
The drive shaft being lubricated was identified as the clutch shaft and was located next to the head pulley of the conveyor belt, about 8 feet 6 inches above material pile. The protruding drive shaft that injured the victim was located below the one being lubricated, and was about 5 feet 5 inches above the material pile.
The front-end loader involved in the accident was a 1993 Fiatallis articulating wheel loader, Model FR180. The loader was powered by a six-cylinder 8.3 liter, diesel engine. The transmission had four forward and four reverse speeds. The loader was equipped with a 4 yard standard bucket, 117 inches long, 50 inches wide, and 44 inches deep.
A boom/bucket inhibitor control was located on the control panel. When this lever was turned clockwise to the "on" position, it deactivated the bucket control joystick. With the inhibitor control on, the bucket remained stationary in any preset position even if the bucket control joystick was operated. To allow bucket movement, the inhibitor control was turned counterclockwise. This feature was tested and functioned properly as designed. This inhibitor control was not "on" at the time of the accident.
The accelerator linkage consisted of a foot pedal assembly, an accelerator cable, and the engine governor assembly linkage. The accelerator linkage was found to be defective. When the accelerator pedal was fully depressed it would stick in this position and cause the engine governor to remain in the full throttle position even after releasing the accelerator pedal. The accelerator linkage could be moved back to the low idle position by pulling the accelerator pedal back. The accelerator would also stick in the low idle position if the accelerator pedal was depressed and then suddenly released, as would happen if the operator's foot slipped off the accelerator pedal. When stuck in the low idle position, a breakaway force of 20 pounds was needed to initiate movement of the accelerator pedal. In between the two extremes, the accelerator linkage moved freely. Examination of the accelerator cable found a defective end link as well as dirt and corrosion buildup on the cable. The accelerator cable was removed and lubricated, and the cable end link was straightened. Testing performed after reinstallation showed the accelerator linkage to operate smoothly without binding. The engine governor linkage was tested and found to operate properly. Management had been aware of this defect for several weeks and had not attempted repair.
The accident occurred during routine maintenance of the screen plant. It was a practice at this operation to work from the elevated bucket of the front- end loader.
CONCLUSION
The root cause of the accident was the company's practice of allowing personnel to perform maintenance from the elevated bucket of a front-end loader. Management's failure to provide training on safe work practices and their failure to promptly repair the defective accelerator linkage were contributing factors.
ENFORCEMENT ACTIONS
Order No. 7887714 was issued on January 13, 2000 under provisions of Section 103(k) of the Mine Act:
A fatal accident occurred at this operation on January 10, 2000, when an employee was crushed between the screen/conveyor frame of the plant and the front-end loader bucket where he was standing. This order is issued to ensure 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 Secretary to return the affected areas of the mine to normal operations.This order was terminated on January 15, 2000. Conditions that contributed to the accident have been corrected and normal mining operations can resume.
Citation Number 4460262 was issued on February 28, 2000 under the provision of Section 104(d) of the Mine Act, for violation of 30 CFR Part 56.14211b:
On January 10, 2000 an employee was fatally injured at this operation when he was crushed between the loader bucket and the metal framework of the shaker screen v-belt drive unit. The front-end loader bucket was being used to work out of in a raised position and had not been blocked to prevent accidental lowering. The mine operator engaged in aggravated conduct constituting more than ordinary negligence when he knowingly participated in this activity. This violation is an unwarrantable failure to comply with a mandatory standard.This citation was terminated on February 28, when all employees were instructed that persons would not work from loader buckets. A portable ladder adequate to safely service the elevated drive was provided.
Citation Number 4460263 was issued on February 28, 2000 under the provision of Section 104(d) of the Mine Act, for violation of 30 CFR Part 56.14100b:
On January 10, 2000 an employee was fatally injured at this operation when he was crushed between the loader bucket and the metal framework of the shaker screen v-belt drive unit. The accelerator pedal on the Fiatallis FR180 front-end loader was defective in that it would stick in the accelerated mode when full throttle was applied. The mine operator engaged in aggravated conduct constituting more than ordinary negligence when he knowingly operated the front-end loader in this condition. This violation is an unwarrantable failure to comply with a mandatory standard.This citation was terminated on February 28, 2000. The accelerator linkage was repaired and operated properly.
The mine operator implemented a program for pre-inspection of mobile equipment that assures timely repairs are made.
Related Fatal Alert Bulletin:
FAB00M01
APPENDIX A
Persons
participating in the investigation
Lucherk's Gravel Co.
Chester R. Lucherk, owner/operatorFayette County Sheriffs Department
Kenny Lurcherk, owners son
Randy L. Noviskie, Deputy SheriffMine Safety & Health Administration
Arthur L. Ellis supervisory mine safety and health inspectorAPPENDIX B
Wyatt Andrews, mine safety & health inspector
Larry D. Parks, mine safety & health inspector
Ronald Medina, Mechanical engineer
Persons Interviewed
Lucherk Gravel Co.
Chester R. Lucherk, owner/operator
Washington County EMS
Rhett Draehn, EMT-P
David Zieders, EMT-I