DEPARTMENT OF LABOR
MINE SAFETY AND HEALTH ADMINISTRATION
REPORT OF INVESTIGATION
(SURFACE COAL MINE)
FATAL POWERED HAULAGE ACCIDENT
Surface Mine No. 2 (I.D. No. 46-08377)
Fola Coal Company, LLC
Bickmore, Clay County, West Virginia
January 20, 1999
Coal Mine Safety and Health Inspector
George Gardner, P.E.
Mine Waste and Geotechnical Engineering Division
Pittsburgh Safety and Health Technology Center
Mechanical Engineer, Mechanical Safety Division
Approval and Certification Center
Originating Office - Mine Safety and Health Administration
100 Bluestone Road, Mount Hope, West Virginia 25880
Edwin P. Brady, District Manager
Release Date: April 27, 1999
The Surface Mine No. 2 is operated by Fola Coal Company, LLC. The mine is located near Bickmore, Clay County, West Virginia. The mine consists of five active strip pits and a preparation plant. When the accident occurred, coal was being mined from the Coalberg seam which averages 60-inches to 96-inches in thickness. The mine provides employment for 291 employees and operates two 12-hour shifts per day, six days per week and produces 10,900 tons of clean coal daily and 3.5 million tons yearly. The mine entered operational status in August 1993, and performs several methods of surface mining. Overburden is drilled with highwall drills, blasted using explosives, and removed with a shovel, excavators, bulldozers, endloaders, and various sizes of trucks. Coal is loaded into trucks using front-end loaders and is transported to the preparation plant for processing.
The principal officers are: Gary Patterson, president; Keith Bartley, vice president; Donald Sult, manager; Kenneth Gilliland, superintendent; James Stout, mine foreman; and Bruce Hamrick, safety director.
The last Mine Safety and Health Administration (MSHA) regular inspection (AAA) was completed September 21, 1998, and a AAA inspection was ongoing at the time the accident occurred.
DESCRIPTION OF THE ACCIDENT
On Wednesday, January 20, 1999, the day-shift foreman, Jim Stout, and superintendent, Kenneth Gilliland, began their shift at approximately 5:15 a.m., and performed their preshift examination at the C, D, and E dump areas. At 6:00 a.m., Stout issued the day-shift crew their instructions to resume mining operations at the No. 2 ridge, No. 3 area. The crew's assignment was the loading of overburden that had previously been drilled and blasted. Upon their arrival at the work site, the crew conducted a pre-operational inspection of their equipment. Ronald Kelly and Terry Hoover, rock-truck operators, were given instructions to mine overburden materials and dump at site C. The two rock trucks in use were a Caterpillar 150-ton model 785 and a Caterpillar 100-ton model 777D. James Stout, foreman, and Kenneth Gilliland, superintendent, stated that the preshift examination and several other examinations of this dump site showed it was dry, with no visible cracking. In addition, Timothy Gregory, an environmental technician, had taken water samples at the base and saw nothing wrong. Michael Brunsma, engineer, was at the top of the fill ground at 1:00 to 1:30 p.m., and also saw nothing wrong.
At approximately 3:00 p.m., the two trucks had been directed to the C and D dumping areas to continue dumping operations. After being loaded, the trucks were traveling approximately 500-600 feet from the cut, backing perpendicularly to the edge, end dumping waste material directly over the berm at the top of the spoil. According to interviews, this was the normal dumping practice at this mine. The Caterpillar model 785 truck had dumped two loads in this area and the Caterpillar model 777D truck had dumped one load and was in the process of dumping the second load. Kelly was operating the Caterpillar 785 rock truck and Hoover was operating the Caterpillar 777D rock truck at the time of the accident.
At approximately 3:30 p.m., Hoover began dumping his second load of overburden material, and had raised the truck bed one extension. James Tinnel and Roger Dye, maintenance workers driving into the C and D dump areas via the main haul road, were approximately 50 feet from Hoover's location when they observed the rock truck positioned at the edge of the spoil embankment in the process of dumping. Both Dye and Tinnel observed the truck as it creeled to the right and a large portion of material underneath the truck collapsed. They immediately summoned help by CB radio. The truck rolled backwards over the steep embankment. The rock truck traveled approximately 570 feet and came to rest at the bottom of the valley fill area with Terry Hoover, victim, still inside the cab.
Tinnel, an EMT, exited his vehicle and traveled over the embankment to the location of the victim's truck. He observed the victim sitting in the driver's seat with his seat belt fastened and the engine running. Tinnel climbed into the operator's compartment and checked for vital signs. Receiving no response, he began administering first-aid.
The Clay County Ambulance Service was summoned to the accident site at approximately 3:55 p.m. Upon their arrival at 4:22 p.m., the Clay County Coroner, Mary Beets, pronounced Hoover dead. Hoover was then transported to the Chief Medical Examiner's Office in Charleston, West Virginia. The cause of death was established as being due to craniocerebral injuries.
INVESTIGATION OF ACCIDENT
The Mine Safety and Health Administration (MSHA) was notified of the accident by Bruce Hamrick, safety director, at 4:30 p.m., Wednesday, January 20, 1999. Representatives of the Mine Safety and Health Administration and the West Virginia Office of Miners' Health, Safety and Training jointly conducted the preliminary investigation. A 103(k) closure order was issued to ensure the safety of all persons until the investigation could be completed.
Photographs, audio/video recordings, and an engineering survey of the area and accident scene were made. The actual recovery of the vehicle was delayed due to weather conditions and the unavailability of proper recovery equipment. The 103(k) order was subsequently modified to allow the vehicle to be removed to a safe location.
The Mine Safety and Health Administration (MSHA) and West Virginia Office of Miners' Health, Safety and Training continued the investigation, assisted by Fola Coal Company officials and mine personnel on Thursday, January 21, 1999. Interviews were conducted on January 21, 1999, in the conference room at the offices of Fola Coal Company. Statements were received from persons considered to have knowledge of the facts surrounding the accident. The on-site portion of the investigation was completed on January 29, 1999, and the 103(k) order was terminated.
The examination of records indicated that all training and required examinations were conducted in accordance with 30 CFR Part 48 and 77.1713(a). The victim had received annual refresher training on September 12, 1998. Previously he had received new task training on the bulldozer, front-end loader, rock truck and grader on March 6, 1996.
- The weather at the time of the accident was clear and dry, with temperatures in the lower fifties. There had been a freeze and thaw followed by rain within the 48 hours prior to the accident.
- The overburden materials hauled to the C and D dump areas consisted predominately of
blocky shot rock to smaller mixed rock in a matrix of fine soil.
- The Caterpillar model 777D Off-Highway Truck (OHT), serial number 3PR00967, was a
relatively new OHT which was delivered on January 14, 1999, and had been in service for
approximately 100 hrs. This machine is a single-axle rear dump equipped with the standard 78.6 cubic yard dump body and a Rollover Protection Structure (ROPS). According to the
manufacturer, the Maximum Gross Machine Weight (MGMW) is 355,000 lbs. and the total
empty weight is approximately 142,000 lbs. When loaded, approximately 67% of the weight is
on the rear wheels.
- This Caterpillar model 777D is equipped with four braking systems: service, parking,
retarder, and secondary. All four of the braking systems utilize the same disc packs of the rear brakes.
- The truck is equipped with an electronically controlled seven-speed wet clutch
automatic transmission. The control circuit is equipped with a transmission neutralizer switch that triggers the second generation Electronic Programmable Transmission Control (EPTC II) to automatically shift the transmission from reverse to neutral when an attempt is made to raise the dump body while the transmission is in reverse. Tests performed on the EPTC II circuit indicated that the system would neutralize the transmission's rotary spool selector if the transmission was in reverse when the dump body was being raised by the operator.
- The dump body or bed was in a partially raised position and the canopy extension over the operator's station was bent where it contacted the rear of the ROPS during the rollover. This impeded the bed's return to the normal position.
- No visible cracks or deformation were observed in the beams or welds of the ROPS' main structure. However, the machine sustained severe damage to most of the secondary structures of the operator's cab.
- A lap belt was in use by the operator at the time of the accident. Visual inspection of the seat belt system, including mounting hardware, revealed no noticeable damage due to the accident.
- The positions of the truck's retarder control lever, the parking brake toggle switch, and the gear selector at the time of the accident could not be established. Recovery personnel stated that they may have been moved in order to extricate the operator from the machine.
- The Caterpillar Monitoring System (CMS) was examined. This system monitors machine
status and allows the operator to access stored events through a display on the dash within the operator's compartment. An evaluation of the system display revealed that the machine was in service 101.1 hours and that a service code was stored within the CMS. The CMS was damaged during the accident and prevented the use of the switches to "scroll" through the CMS modes.
- To further analyze the truck's operating system, Caterpillar Electronic Technician (ET) system hardware and software was provided by an authorized Caterpillar representative from Walker Machinery located in Belle, West Virginia. The ET system for this application allows access to data stored in the transmission and engine control modules to aid in diagnostics of these two systems. No malfunctions were found that could be contributory to the accident.
- Tests of the brake systems revealed that there were no problems.
- The TPMS system and the position of the dump body indicate that the machine was in the
process of dumping the second of two hauls of 0.1 miles when the accident occurred. Physical evidence and data accessed by the ET indicated that the machine's transmission was responding to the EPTC II's desire to upshift when the wiring harness was torn apart as the rear suspension wishbone was broken.
- The truck came to rest approximately 340 feet (vertical distance) below at the bottom of the slope.
- Prior to the accident, the spoil material in this dump area had apparently been accumulating part way down the natural slope, with the thickest material near the top and only a small amount of spoil reaching the valley bottom.
- At some time prior to the accident, the spoil slope became unstable, resulting in a failure of the spoil and a large slide before the failure under the truck wheels. The conclusion that the large slide preceded the accident was drawn for two reasons: 1) None of the personnel on the scene at the time of the accident recalled any evidence of a large slide, such as witnessing any movement of the berm, or the dust or noise that would likely accompany a slide of this size. 2) There was clear evidence of two distinct failure arcs. The smaller arc was approximately the width of the truck and occurred directly under the back wheels at the dump point. The larger arc defined the initial failure. While the larger failure appears to have occurred initially, it is not possible to ascertain precisely when this failure occurred. The truck operator, from his position in the truck, could not have seen this initial failure.
- The larger slide area extended down approximately 100 feet from the top of the dump and
approximately 150 feet laterally. The bottom of the slide appeared to occur along the surficial
soils on the original ground surface.
- Following the slide, the spoil material remained at a very steep slope at the back of the slide mass. During the accident investigation, the slope was found to be inclined at an average of 50 degrees with respect to the horizontal for the top 105 feet. Locally, it was even steeper. For approximately 237 feet vertically between the bottom of the slide area and the base of the mountain, the spoil material had reposed to an angle of approximately 31 degrees, which was nearly approximate to the pre-mining slope in this area. The slope remained in this over-steepened condition (steeper than the natural angle of repose) due to moisture and the presence of significant fine material in the spoil. The slope was still in the process of sliding during the accident investigation. The slope failure may also have extended into part of the berm. The accident investigation revealed that the berm ranged from approximately 2 to 4 feet high along the dump area, and was very steep on the outer slope side. This is less than the mid-axle height of the truck (51.5 inches).
- The failure created a situation where the loaded trucks were backing close to the edge of a very steep slope. When loaded, the truck has approximately 67% of its weight distributed to the rear wheels. Raising the dump bed distributes additional weight to the rear wheels. When the loaded haul truck backed to the edge of an already over-steepened slope and began to dump, this additional weight triggered a second, smaller, localized slope failure under the rear tires of the truck causing the truck to roll and proceed down the slope. This localized slip was approximately 17.5 feet wide and 4-5 feet back from the edge.
It is the consensus of the accident investigation team members that the unconsolidated, randomly dumped earth failed to support the weight of the loaded Caterpillar model 777D rock truck and collapsed. The collapse caused the truck to fall into the valley, which resulted in fatal injuries to the driver.
A 103(k) order No. 7160517 was issued to the operator, stating in part, to preserve the scene of the accident and protect the miners until the investigation could be completed.
A 104(a) citation No. 7160523, Section 77.1608(b), Title 30 CFR, was issued, stating in part, that the dump site C area, middle dump, collapsed causing the 777D rock truck to roll to the bottom of the valley fill causing fatal injuries to the victim.
Coal Mine Safety and Health Inspector
Richard J. Kline
Assistant District Manager
Edwin P. Brady
Related Fatal Alert Bulletin: