DEPARTMENT OF LABOR
MINE SAFETY AND HEALTH ADMINISTRATION
COAL MINE SAFETY AND HEALTH
REPORT OF INVESTIGATION
Surface Coal Mine
Fatal Machinery Accident
Occurred: September 19, 2000
Died: September 25, 2000
Jim Bridger Mine
Bridger Coal Company
Rock Springs, Sweetwater County, Wyoming
I.D. 48-00677
Accident Investigators
Fred L. Marietti
Coal Mine Safety and Health Inspector (Electrical)
Phillip R. Gibson, Jr.
Coal Mine Safety and Health Inspector (Health)
Ronald Medina
Technical Support, Mechanical Engineer
John Turner
Educational Field Services, Specialist
Originating Office
Mine Safety and Health Administration
District 9
P.O. Box 25367
Denver, Colorado 80225-0367
John A. Kuzar, District Manager
Report Release Date: March 12, 2001
Revised Date: March 22, 2001
THIS REPORT WAS REVISED TO ADDRESS THE FOLLOWING CONCERNS:
1. The sketch on page 1 was revised to correctly show that the hook that slipped and struck the victim was attached to the front-center bogie instead of the rear-center bogie. The sketch was also revised to show that the chain that broke was attached to the rear-center bogie. References to these bogie locations were corrected on pages 2, 4, 5, 7, and 11.
2. Item 3, Citation No. 7636506 in ENFORCEMENT ACTIONS, was removed from the report as Howard D. McCoy's lack of task training on the overhead crane and his operation of the crane prior to the accident were deemed not to have contributed to the cause of the accident. This citation was issued under a Spot Inspection.
3. Item 4, Citation No. 7636507 in ENFORCEMENT ACTIONS, was not issued. Mitigating information and documents obtained during the closeout with company and union officials on March 15, 2001, indicated that Kevin Fletcher and Don Bakula had received task training in Mechanical Journeyman Duties, as required by 30 CFR 48.27(c).
4. The OVERVIEW and CONCLUSION were revised to remove the statements that task training deficiencies contributed to the cause of the accident.
5. Item 12 in the DISCUSSION, was removed as it was redundant.
6. Items 13, 14, and 15 in the DISCUSSION were renumbered as Items 12, 13, and 14, respectively.
7. Item 15 in the DISCUSSION was added to the report to address the mine operator's revised track changing procedures, dated November 2, 2000.
8. The Description of the Accident, Conclusion, and Enforcement Actions in the Accident Investigation Data sheets (Appendix C) were revised to reflect the above changes.
9. Minor grammatical and clarifying changes were made.
OVERVIEW
On Monday, September 25, 2000, at approximately 9:30 p.m., Kevin J. Fletcher, age 33, heavy equipment mechanic, died of injuries sustained in a machinery accident that occurred at the Main Shop on September 19, 2000, at approximately 8:00 p.m. The accident occurred as Fletcher and Don D. Bakula, a heavy equipment mechanic, were removing the old track and installing a replacement track on the right side of a Caterpillar D11N bulldozer (No. 544). Bakula was also injured in the accident.
The old track had been disconnected at the master link and attached to the new track using a chain. While the bulldozer was hydraulically raised several inches off the ground using the blade and ripper, machine power was used to turn the final drive sprocket and thereby pull the replacement track onto the undercarriage roller frame. A forklift was used to pull the old track away from the bulldozer as it fed off. During this process, the master link (alligator) caught against one of the bogies causing the chain between the two tracks to break. To gain access to the broken chain, the bulldozer was raised higher using the blade and ripper. This allowed the bogie idlers above the track to drop down and prevent the removal of the broken chain. The 15-ton overhead shop crane and a four-chain sling were then used to lift the two center bogie idlers. One leg of the sling was hooked to the front-center bogie idler, one to the rear-center bogie idler, and the other two legs of the sling were unused. Hydraulic cylinder drift (leakage in the blade and ripper hydraulic circuits) allowed the bulldozer to slowly settle toward the ground and transfer the weight of the bulldozer to the chains supporting the bogie idlers. The chain hooked to the front-center bogie slipped off and struck the victim in the forehead, causing fatal injuries. Bakula, who was attempting to remove the broken chain connecting the two tracks, sustained an injury when the bogie dropped and pinched his right arm. In addition, the chain attached to the rear-center bogie broke shortly afterwards, but did not hit anyone.
The cause of the accident was the failure to securely block the bulldozer in its raised position prior to working under the machine to remove the broken chain, and the failure to install metal straps to secure the bogie idlers, as recommended by the manufacturer. The failure to consider the occurrence of cylinder drift, which allowed the bulldozer to settle and transfer weight to the chains/hooks supporting the bogies, also contributed to the accident.
GENERAL INFORMATION
The Jim Bridger Mine is a sub-bituminous surface coal mine located 35 miles northeast of Rock Springs, Sweetwater County, Wyoming. Mining operations began in May 1974. The mine is currently owned by Pacific Minerals Inc., Salt Lake City, Utah, in partnership with Idaho Energy Resources, Boise, Idaho.
There are five seams of coal mined within the Deadman Coal Zone of the Jim Bridger Coal Field. The seams are designated D5 through D1 from top to bottom. Coal seam thicknesses and quality vary throughout the coal field. Thicknesses range from 2 to 15 feet in areas of more than one seam. Where the coal seams form a single seam, it is a maximum thickness of 32 feet. Partings between the seams vary from a few inches to 50 feet thick. The mine has one active pit approximately 18 miles in length. Overburden is blasted, then removed with either a Page, Model 757 dragline equipped with a 62-cubic yard capacity bucket or one of two Marion, Model 8200 draglines each equipped with a 79-cubic yard capacity bucket.
Once the overburden has been removed, the coal is drilled and blasted, then loaded with either Caterpillar, Model 994 and 992; Dart, Model 600; or Hitachi, Model 2500 loading machines. Model 777 and 789 Caterpillar end dump trucks are used to transport the coal to one of three "nearpit" hoppers where it is crushed to one to six inches in size. An overland belt conveyor system transports the coal to the nearby Jim Bridger Power Plant.
Operating two 12-hour shifts, 7 days per week, the mine employs a work force of 360 persons and produces an average of 27,060 tons per day.
The last regular Mine Safety and Health Administration (MSHA) inspection prior to the accident was completed on May 11, 2000. The Non-Fatal Days Lost (NFDL) incidence rate (not including office workers) for the mine is 1.12. The surface mine NFDL rate for the nation is 2.37.
The principal officers at the mine at the time of the accident were:
Pat Akers .......... General Manager William L. Wilson .......... Shop Supervisor Patrick L. James .......... Safety Manager
DESCRIPTION OF THE ACCIDENT
On Tuesday, September 19, 2000, the graveyard shift employees began work at 7:00 p.m. William "Lynn" Wilson, shop supervisor, asked for volunteers to change the track on the No. 544 Caterpillar bulldozer. During the day shift, the bulldozer had been brought to the shop to have the right track replaced because of a "hot pin" connecting one track pad to another. Kevin J. Fletcher (victim) and Don D. Bakula (injured), heavy equipment mechanics, volunteered to change the track. Howard D. McCoy, mine service operator, assisted Fletcher and Bakula by operating the bulldozer during the track replacement work.
The new track, a "loaner" from an equipment supplier, was laid out on the shop floor behind the bulldozer. The track with the "hot pin" was taken apart at the back of the bull gear. The two tracks were then connected together with a 3/8-inch chain. The bulldozer was lifted several inches off the ground by the blade and ripper, and McCoy ran it in first gear, reverse to pull the replacement track onto the roller frame. Bakula used a forklift attached to the old track to pull it away from the bulldozer as it fed off the machine. During this process, the master link (alligator) caught against one of the bogies causing the chain between the two tracks to break.
Fletcher and Bakula asked McCoy to raise the bulldozer higher using the ripper and blade. Because the bogies were secured only on one end, the loose ends fell down on top of the track on the floor when the bulldozer was raised. Fletcher moved the overhead 15-ton crane into position at the right side of the bulldozer to lift the bogies off the track. He attached a chain sling and hook arrangement to the two center bogies and hooked it to the overhead crane. The sling arrangement consisted of four chains and four hooks, and when used together, was rated at a 33,800 pound capacity. Fletcher instructed McCoy to raise the bogies to a near-horizontal position with the overhead crane. The weight of one bogie was about 1,725 pounds.
Fletcher and Bakula laid on the shop floor, reaching under the bogies to remove the chain, broken when the two tracks separated. With the power off on the bulldozer, the loss of hydraulic pressure allowed the weight of the bulldozer to settle on the hooks attached to the bogies. At approximately 8:00 p.m., the hook on the front-center bogie slipped off, flew back and struck Fletcher in the forehead. The force of the blow knocked him backwards. When the hook slipped off the bogie, it allowed the bogie to settle on the right forearm of Bakula. Bakula called to McCoy to start the bulldozer and lift it off his forearm, which McCoy did.
While Fletcher was being given first aid and Bakula was determining the extent of his injuries, the weight of the bulldozer settled onto the hook attached to the rear-center bogie. The hook attached to that particular chain was pulled up under the bogie. As the bulldozer settled toward the floor, a link in the chain for the hook broke and flew across the shop. No one was struck by this chain link.
Bakula received first aid treatment and was transported to a hospital in Rock Springs, Wyoming. He was examined and released with a bruised forearm. Fletcher received first aid treatment and was transported by ambulance to a hospital in Rock Springs, Wyoming. His injuries were such that he was airlifted to a hospital in Salt Lake City, Utah. He died in the hospital at approximately 9:30 p.m. on September 25, 2000.
INVESTIGATION OF THE ACCIDENT
MSHA's investigation of the accident started on September 20, 2000, as a non-fatal injury accident. MSHA and the Wyoming State Inspector of Mines cooperated to conduct a joint investigation. Management personnel from Bridger Coal Company and Interwest Mining Company along with representatives of miners from the Western Energy Workers' union were recognized as parties to the investigation and allowed to participate. A list of those persons who participated in the investigation is contained in Appendix A.
During the initial non-fatal injury accident investigation, the lead investigator for MSHA was Phillip R. Gibson, Jr, a Coal Mine Safety and Health Inspector (Health) from Craig, Colorado. Fred L. Marietti, a Coal Mine Safety and Health Inspector (Electrical) from Price, Utah, was assigned as the lead investigator after the accident resulted in Fletcher's death. Ronald Medina, mechanical engineer with MSHA's Technical Support from the Approval and Certification Center in Triadelphia, West Virginia assisted in the investigation. John Turner, specialist with MSHA's Education Field Services from Castle Dale, Utah, reviewed the training and assisted in the investigation.
Interviews were conducted at the mine site on September 20 and 28, 2000. A list of those persons interviewed is contained in Appendix B. Interviews were taped recorded and transcribed by the State Inspector of Mines office. Investigative work at the mine concluded on October 2, 2000.
DISCUSSION
1. The machinery and equipment involved in the accident were a Caterpillar, Model D11N bulldozer (No. 544), serial number 4HK00363; an overhead 15-ton crane; and a four-hook cluster arrangement of which only two hooks were used to support two bogies of the bulldozer. The four-chain assembly was rated to support 33,800 pounds. Its main use was the loading and unloading of the bulldozer tracks. The track for the bulldozer weighed 14,250 pounds. The bulldozer was equipped with a blade and a ripper. The operating weight of the machine was approximately 212,000 pounds. It was equipped with an eight cylinder, model 3508 Caterpillar engine, rated at 817 Gross Horsepower.
2. At the time of the accident, bulldozer No. 544 was in the shop to have a track replaced because of a "hot pin." The procedure, as used at the mine, called for the old track to be broken behind the bull gear and the new track fastened to the old track either by a chain, or nylon straps, or bolted together. The mechanics chose to use a chain to make the connection between the two tracks.
3. At the point of connection of the new track to the old track there was a link referred to as an "alligator." This link overlapped the link of the old track. As the two tracks were being pulled along by the power of the bulldozer's engine and bull gear, the alligator master link caught against one of the bogies causing the chain between the two tracks to break.
4. To free the broken chain, the bulldozer was raised higher by applying down pressure to the cylinders of the ripper and the push blade. As the bulldozer was raised, the free ends of the bogies dropped down and caught on the lower track. The overhead crane was moved into position along side the bulldozer so that the four-chain cluster could be attached to the bogies. Each bogie weighed about 1,725 pounds. By attaching two of the chains and hooks to the bogies, the bogies could be raised to a horizontal position. With the bogies in place, Fletcher and Bakula could lie on the shop floor, reach under the raised bogies, and remove and reconnect the broken chain.
5. At the time of the accident, Fletcher and Bakula were on the shop floor trying to remove the broken chain from the track being removed. With the power off the raised bulldozer and by virtue of the weight of the bulldozer, hydraulic pressure to the cylinders of the ripper and the push blade leaked off. The weight of the bulldozer transferred to the hooks and chains supporting the two bogies. The hook at the free end of the front-center bogie slipped off and struck the victim in the forehead.
6. The procedure in removing and installing tracks on bulldozers had been performed numerous times at this mine without incident. Already this current year, tracks on bulldozers were broken and reattached 62 times. The two mechanics had changed 16 tracks this year. The procedure included using a three-person team. One person operated the forklift that brought the new track to the shop and lay it out behind the track being replaced. The forklift was used to pull off the old track while the new track was being pulled on by the bulldozer. The second person was in the cab of the bulldozer to operate it in pulling the old track off and the new track on. The bulldozer was operated in reverse, first gear. The third person stood on the shop floor so that he could see, and be seen by the operators of the two pieces of equipment. Reportedly, this was the first occasion when the overhead crane was used to support the weight of the bogies after a connecting chain had been broken.
7. DESCRIPTION OF TRACK AND UNDERCARRIAGE ASSEMBLY: The undercarriage design of the D11N tractor utilized an elevated drive sprocket on each side of the machine that provided power to turn the tracks. Each track was guided by front and rear idler pulleys, and eight bottom rollers. When viewed from the side, the track formed a roughly triangular shape with the two idlers at the base and the elevated drive sprocket at the top.
The front and rear track idler pulleys, rollers, and the structure supporting them constitute the roller frame. The track revolves around the roller frame when power is delivered to it by the elevated drive sprocket. Each of the two roller frames was attached to the tractor at two points. At the rear of the machine, each roller frame was attached to the dozer by a pivot shaft. Toward the front, each roller frame was attached to an equalizer bar that was perpendicular to the tracks. The equalizer bar was pinned at its midpoint to a frame cross member of the tractor and pivoted at this point. This pivot point was midway between the tracks. Each end of the equalizer bar was connected to the corresponding roller frame with a ball joint connection. The tractor frame was supported at three points, and the roller frames oscillated to allow the tracks to maintain ground contact on uneven surfaces.
Four bogies on the bottom portion of each roller frame guided the track. Each bogie consisted of two rollers, a track guide, and the structure holding it together. Each bogie could oscillate up and down at a pinned connection where it was attached to the roller frame. This allowed the track to conform to uneven terrain.
The roller frame could be lengthened or shortened to adjust track tension. This was accomplished by adding or releasing grease at the track adjusting piston that connected the rear segment of the roller frame to the front segment.
Note: this grease is under high hydraulic pressure.
The track consisted of a series of track links and pins with a track shoe fastened to each link by four bolts. Each track pin connected two links together and was encased in a lubricated bushing. Power was delivered to the track where the track pin bushings engaged in the elevated drive sprocket.
The two end links of the track had mating sawtooth surfaces that, when bolted together, formed the master link. The master track shoe was bolted to this link. The two end links are often referred to as alligators.
8. SUMMARY OF THE TRACK REPLACEMENT METHOD USED AT THE TIME OF THE ACCIDENT: The reported method used to replace the track at the time of the accident consisted of the steps listed below. During the interviews, the track replacement procedure was described verbally.
A. Loosen the tension on the track by relieving pressure from the track adjuster piston.9. SUMMARY OF THE TRACK REPLACEMENT METHOD DESCRIBED IN THE CATERPILLAR SERVICE MANUAL FOR THE D11N TRACTOR: The track replacement method described in the Caterpillar Service Manual for the dozer differs from the method used at Bridger Coal. The Caterpillar procedure describes a track replacement method with the assumption that a bulldozer blade is not installed on the tractor. The initial steps of both methods, for disconnecting the master link of the track being replaced, are similar. The methods differ, however, after the master link is separated. The Caterpillar manual calls for Caterpillar bogie straps to be used to hold the bogies up. The bogies must be supported because each bogie is free to swing down from its pivot point when the tractor's roller frame is lifted up from the track.
B. Raise the tractor off the ground using the dozer blade and ripper. Using machine power, move the track until the master link is aligned with the centerline of the rear idler.
C. Lower the tractor to the ground and support the lower section of the master link.
D. Unbolt the master link, remove the master track shoe, separate the master link, and place the lower section of the master link on the ground.
E. Attach the replacement track to the track being removed using a chain.
F. Attach the track being removed to a forklift positioned behind the tractor.
G. Raise the tractor off the ground several inches using the blade and ripper.
H. Place the tractor in first gear, in the reverse direction, and allow machine power to turn the drive sprocket and thereby pull the replacement track onto the roller frame. The forklift operator pulls the original track away from the tractor as it feeds off. A third person observes and directs the tractor and forklift operators with hand signals to coordinate the process. (It was during this process, that the chain between the two tracks broke.) The accident occurred while the mechanics were attempting to remove the broken chain. It was reported that the 3/8 inch chain connecting the two tracks broke when the master link (alligator) caught against one of the bogies as the track was being pulled onto the machine.
I. Run the replacement track onto the tractor until the leading edge rests on the rear idler, and then lower the tractor to the ground.
J. Support the end of the track being removed, disconnect the chain between the two tracks, and remove the original track with the forklift.
K. Lift the lower section of the replacement track's master link upward using an overhead crane, align the master link, and install the four master link bolts to close the loop at the master link and reinstall the master shoe.
L. Tighten the track by adding grease to the track adjuster.
The bogie straps are made of metal and are fastened to the bogies and roller frame to suspend the bogie assemblies. The early version of the Caterpillar Service Manual's Power Train Disassembly & Assembly Instructions, SENR 3287-01 described the use of four Caterpillar part #FT1997 straps. These straps were to be fastened to tapped holes in the bogies and roller frame. Each strap supported one bogie. However, in 1997 the procedure to secure the bogies described in SENR 3287-01 was superceded by Caterpillar. The revised procedure, described in SENR 3287-02, specifies the use of one Caterpillar part #105-3351 strap and two Caterpillar part #105-3349 straps to suspend the bogies. The #105-3351 strap supports the two center bogies, and the two #105-3349 straps support the front and rear bogies.
After the step of securing the bogies, the Caterpillar procedure states "Lift the side of the machine and remove the track." The replacement track is then positioned under the roller frame and the bogie straps are removed. At this point, the trailing end of the track is resting under the roller frame and the rest of the track is laid out in front of the tractor. The machine is subsequently lowered onto the track. The front portion of the track is then pulled up and over the front idler, and back toward the drive sprocket until the sprocket segments engage with the track bushings. To provide the pulling force, the manual states that one end of a cable is to be attached to the leading edge of the track and the other end to a wheel loader or similar machine. When the two ends of the track are brought into close proximity, the tractor is then started and the drive sprocket is turned in the reverse direction to pull the ends of the track completely together, and the master link is bolted together.
10. TRACK DESCRIPTION: Both the replacement track and the original track were 28 inches wide. The grousers (i.e. cleats) were 2 inches high on the original track and 1� inches high on the replacement track. The replacement track was a used track with worn grousers. The weight of a single track was approximately 14,250 pounds, as stated in the Caterpillar Service Manual.
11. CYLINDER DRIFT TESTS: Since the dozer was being supported solely by the blade and ripper hydraulics, tests were conducted to determine if the blade and ripper hydraulic circuits had any leakage that may have contributed to the accident. The tractor was elevated approximately 1 to 1� feet using the dozer blade and ripper to duplicate the way it had reportedly been elevated at the time of the accident. The rate at which the tractor drifted toward the ground was determined. Movement was measured from the center of the trunnion where the dozer blade arm was connected to the roller frame. The center point of the trunnion was approximately 80 inches from the rear of the roller frame. The tractor settled at a rate of approximately 0.43 in/min, and after five minutes had settled 2 5/32 inches. The chain that slipped and struck the victim was reportedly attached to the front-center bogie in the same general area where the drift was measured. The temperature of the fluid during the testing was approximately 65 degrees F, which was the ambient temperature in the shop. It was reported that the hydraulic fluid temperature at the time of the accident was similar. The dozer blade and ripper controls were in the hold position during the tests.
A second test was conducted in which the dozer blade was raised approximately one foot above the ground and the rate at which the blade drifted downward was determined. Movement was measured at the bottom edge of the blade. The bottom edge of the blade drifted downward 3 inches in five minutes. The ripper lift cylinder was also tested and it drifted downward at a rate of 1/8 inch in five minutes. The dozer blade and ripper controls were in the hold position during these tests.
The cylinder drift tests showed that the method the mine used to support the bogies at the time of the accident did not allow for cylinder drift. During the track replacement process, cylinder drift transferred the weight of the dozer from the blade and ripper to the chains, this overloaded the chains, causing one of the chain hooks to slip and strike the victim.
Cylinder drift tests are specified in Form No. SENR3289-01 found in the Service Manual for the D11N Tractor. According to Caterpillar personnel at its Peoria headquarters, the purpose of these cylinder drift tests is to determine if there is excessive hydraulic leakage that would prevent proper control of the blade and ripper implements during normal use. The drift rate is not intended to specify a safe period of time for working under a machine when it is raised with the blade and ripper.
12. Supporting the bogies with a chain connected to an overhead crane did not allow for cylinder drift. During the track replacement process, cylinder drift transferred the weight of the dozer from the blade and ripper to the chains. This overloaded the chains, causing one of the chain hooks to slip and strike the victim. Reportedly, in the normal Bridger track replacement procedure, it is not necessary to support the bogies. It only became necessary to support them because the chain connecting the replacement track to the original track broke. This led to a series of events to remove the broken chain which included improperly supporting the bogies. A factor in the hook slipping was that the hook was not wide enough to go over the bogie structure and securely attach to the bogie.
13. Cylinder drift also affects the normal Bridger track replacement procedure. The Bridger procedure involves raising the tractor off the ground several inches using the blade and ripper, and placing the tractor in first gear in the reverse direction, to allow machine power to turn the drive sprocket and thereby pull the replacement track onto the roller frame. Since the tractor will settle toward the ground due to cylinder drift, the tractor operator may have to periodically actuate the blade and ripper hydraulic controls to compensate. The frequency of compensating adjustments depends on the fluid temperature and the condition of the hydraulic components in the circuit.
14. During the investigation it was determined that the mine had a copy of the D11N Service Manual containing the Caterpillar track change procedure.
15. The mine operator developed revised track changing procedures, dated November 2, 2000, which require the bogies to be properly secured utilizing approved bogie straps and which prohibit personnel from being under the tractor when it is supported by hydraulics.
CONCLUSION
The cause of the accident was the failure to securely block the bulldozer in its raised position prior to working under the machine to remove the broken chain, and the failure to install metal straps to secure the bogie idlers, as recommended by the manufacturer. The failure to consider the occurrence of cylinder drift, which allowed the bulldozer to settle and transfer weight to the chains/hooks supporting the bogies, also contributed to the accident.
ENFORCEMENT ACTIONS
1. Section 103(k) Order No. 7618165 dated September 20, 2000, was issued to the operator to ensure the safety of all persons until an investigation could be completed and the mine deemed safe.
2. Section 104(a) Citation No. 7618166, S&S with moderate negligence, was issued to the operator for a violation of 30 CFR 77.405(b) on September 25, 2000. The citation stated, "Work was being performed under a raised bulldozer, company no. 544, in the main shop. The raised bulldozer was not securely blocked in position. Consequently, movement of the dozer resulted in an accident in which two miners were injured. While attempting to guide a new track by pulling it with the old track onto the bulldozer, the new track became stuck. A chain being used to hold the two tracks together broke. In the attempt to free the broken chain and reconnect it to the two tracks, the hydraulic pressure used to lift the bulldozer into a raised position leaked off. Two chains of a four-chain cluster fastened to the bogies (idlers) of the track began taking weight as the bulldozer settled on the hooks of the chains. One hook pulled free and struck a miner in the forehead. The force of the blow knocked him backwards. The bulldozer continued to settle and caught the right arm of a second miner. The second miner shouted to the bulldozer operator to start the engine and lift the bulldozer off his arm. The accident occurred about 8:00 p.m. on 9-19-2000."
This citation was issued during the initial Nonfatal Injury Accident Investigation (AFB, Event No. 4272323) but will be included in the Fatal Accident Investigation (AFA, Event No. 4269066) as a violation contributing to the cause of the accident.
Related Fatal Alert Bulletin:
FAB00C29
APPENDIX A
List of persons participating in the investigation:
BRIDGER COAL COMPANY OFFICIALS
Pat Akers .......... General ManagerINTERWEST MINING COMPANY OFFICIALS
Patrick James .......... Safety Manager
Scott Palmer .......... Maintenance Superintendent
Frank Toman .......... General Maintenance Foreman
Randy Foster .......... Shop Planner
William L. Wilson .......... Shop Supervisor
Jerry Bruner .......... Shop Supervisor
Kean Johnson .......... Safety Training Coordinator
Steve Martin .......... Safety Training Coordinator
Randy Tatton .......... Safety DirectorBRIDGER COAL COMPANY EMPLOYEES
John Enloe .......... Heavy Equipment MechanicWESTERN ENERGY WORKERS - UNION LOCAL S1978
John Powell .......... Heavy Equipment Mechanic
Ron McClimans .......... Heavy Equipment Mechanic
William Rosette .......... Miner's RepresentativeSTATE OF WYOMING
Stan Masters .......... Miner's Representative
Donald G. Stauffenberg .......... State Inspector of MinesMINE SAFETY AND HEALTH ADMINISTRATION
Hector Castillion .......... Deputy Mine Inspector
Rudolph King .......... Deputy Mine Inspector
Fred L. Marietti .......... Coal Mine Safety & Health Inspector (Electrical)APPENDIX B
Phillip R. Gibson, Jr. Coal Mine Safety & Health
Inspector (Health)
Ronald Medina .......... Mechanical Engineer, Technical Support
John Turner .......... Educational Field Services, Specialist
Persons who were interviewed as part of the investigation: Bridger Coal Company
Scott Palmer .......... Maintenance Superintendent
William L. Wilson .......... Shop Supervisor
Jim Cole .......... Heavy Equipment Mechanic
Don D. Bakula .......... Heavy Equipment Mechanic (Injured)
Gary Lyle .......... Welder
Jim High .......... Journeyman Mechanic
Larry G. Hedgecock .......... Heavy Equipment Mechanic
Howard D. McCoy .......... Mine Service Operator