Skip to content
UNITED STATES
DEPARTMENT OF LABOR
MINE SAFETY AND HEALTH ADMINISTRATION
Metal and Nonmetal Mine Safety and Health

Report of Investigation

Underground Metal Mine
(Platinum)

Fatal Powered Haulage Accident

June 14, 2001

Thyssen Mining Construction of Canada Ltd. (NEV)
Regina, Saskatchewan, Canada
at
Stillwater Mine
Stillwater Mining Company
Nye, Stillwater County, Montana
ID No. 24-01490

Accident Investigators

Joseph O. Steichen
Mine Safety and Health Inspector

Rodney Gust
Mine Safety and Health Inspector

Phillip L. McCabe
Mechanical Engineer

F. Terry Marshall, Jr.
Mechanical Engineer

Emmett M. Sullivan
Mine Safety and Health Specialist

Originating Office
Mine Safety and Health Administration
Rocky Mountain District
P.O. Box 25367, DFC
Denver, CO 80225-0367
Irvin T. Hooker, District Manager


OVERVIEW

John F. Winninghoff, miner, age 56, was fatally injured on June 14, 2001, when he was struck by the bucket of a load-haul-dump (LHD) unit while he was kneeling to connect two air hoses.

The accident occurred because the loader operator failed to maintain a safe operating speed consistent with conditions of roadway, grade, clearance, visibility and traffic. There was heavy foot and mobile equipment traffic in the area.

Winninghoff had a total of 35 years mining experience as an underground miner. He had worked at this operation for 27 weeks. He had received training in accordance with 30 CFR, Part 48.

GENERAL INFORMATION

Stillwater Mine, a multi-level underground platinum mine, owned and operated by Stillwater Mining Company, was located near Nye, Stillwater County, Montana. The principal operating official was Ronald W. Clayton, vice-president of operations. The mine worked two, 10-hour shifts, 7 days a week. Total employment was 1,362; of this number 1,069 worked underground.

Ore was extracted using the ramp-and-fill mining method. Sub-level stoping was also done along with mechanized captive cut-and-fill stoping. Mine access drifts were driven at different elevations. Approximately 60 percent of the ore was transported to the mill via the 1,950-foot vertical shaft. Ore was also transported to the mill by trucks and a rail system which extended about 3 miles. The smelter and base metals refinery were located at a company-owned facility in Columbus, Montana.

The victim was employed by Thyssen Mining Construction of Canada Ltd., located in Regina, Saskatchewan, who was contracted to develop an underground area of the mine for future production. The principal operating official was Andy Saltis, project manager. This contractor employed 34 persons underground working two, 10-hour shifts, 7 days a week.

The last regular inspection of the operation was completed on May 4, 2001. Another regular inspection was conducted at the conclusion of this investigation.

DESCRIPTION OF THE ACCIDENT

On the day of the accident, John Winninghoff (victim) reported for work about 6:30 a.m. Winninghoff, along with six other crew members, were directed by Ruben Gamez, shift supervisor, to report to the 5300 west footwall lateral to haul blasted rock and install roof bolts. Upon arrival at the work area, Winninghoff started to install pipe hangers while Randy Cloud and Byron Schinmann, miners, began removing the blasted rock with the LHD. Raymond Rodriguez, truck driver, and Justin Vogt, equipment operator, were hauling rock, and Adam Zambrano and Joe Vigil were installing a fan silencer. About 1:00 p.m., Cloud and Winninghoff were setting up the bolting deck at the face. Cloud instructed Vogt to use the LHD to transport some split-set bolt plates and resin from the storage area. Cloud remained at the bolting deck while Winninghoff knelt on the ground connecting two air hoses about 50 feet away from the work area. As Vogt returned with the bolt plates and resin, the bucket of the LHD struck Winninghoff.

The miners immediately provided emergency medical assistance until the victim was transported out of the mine. Winninghoff was airlifted to a hospital in Billings, Montana, where he was pronounced dead at 5:07 p.m., by the deputy county coroner. Death was attributed to multiple crushing injuries.

INVESTIGATION OF THE ACCIDENT

MSHA was notified at 4:42 p.m., on the day of the accident by a telephone call from Steve Wood, corporate safety manager, to Irvin T. Hooker, district manager. An investigation was started the same day. An order was issued pursuant to Section 103(k) of the Mine Act to ensure the safety of miners. MSHA's investigation team traveled to the mine, made a physical inspection of the accident site and equipment involved, interviewed persons and reviewed documents relative to the job being performed by the victim. The miners did not request nor have representation during the investigation.

DISCUSSION

  • The load-haul-dump (LHD) was a Wagner Model ST-3.5, Serial Number DA04P0177, equipped with a 3.5 cubic yard bucket. The LHD was 6 feet 8 inches wide and 27 feet 9 inches long measuring from the lip of the bucket. The machine illumination consisted of four, 24 volt, 60 watts, sealed beam headlights. The LHD was equipped with four, Goodyear smooth tread SMD, D/L-5C, type 65, L-55, 17.5 rubber tires.


  • The LHD was equipped with a 3.5 cubic yard bucket designed to scoop, lift and carry ore or rock. It was powered by a four cylinder, two-cycle DDE series, supercharged, Detroit diesel engine, rated at 180 horsepower. It was equipped with a Clark 28000 series, 3 speed modulated shift automatic transmission, with three gears forward and 3 gears reverse. The scoop tram was four wheel drive with articulated steering. Internal wet disc brakes were provided on all four wheels.


  • The LHD operator's compartment had a single seat without a seatbelt and was suitable for one occupant only. There was no falling object protection provided for the machine operator. Three control levers and one joystick control were located on the front console in the operator's compartment. The control lever to the far left was the transmission select lever for forward, neutral and reverse. The next lever to the right was the transmission speed selector with first, second and third gear selections. The third gear selection was disabled by a weld bead placed across the selector gate which prevented the lever from going into third gear. The next lever to the right was the steering lever.


  • The victim was wearing personal protective equipment consisting of a hardhat, rubber steel-toed boots and safety glasses. Hearing protection was found near the victim. The victim's clothing was dark-colored. A yellow raincoat and pants were found nearby. The victim was wearing 12 square inches of reflective material, consisting of two, 1 inch by 6 inch white reflective strips located in a criss-cross fashion on his back.


  • The entryway where the accident occurred was measured to be about 12 feet wide and 13 feet high and generally level.


  • A tram-through test of the brakes was conducted. The service brakes were applied with the gear selector in first gear forward with full throttle and the machine did not move. The emergency/park brake was applied with the gear selector in first gear forward with full engine throttle and the machine did not move. The operation and steering capability of the scoop tram were checked by operating the machine in a nearly level area in first and second gears, forward and reverse. The bucket operation was checked by operating the raise/lower, dump/roll-back, and push-plate functions. No defects were visually observed during the operation of the machine or bucket. The articulated steering system was visually examined for wear and hydraulic leakage. Minor wear was observed.


  • A test was performed to quantify the visibility afforded by the machine when operated in a bucket forward direction. The front bucket was raised and rolled back slightly to simulate the reported position of the bucket at the time of the accident. The top of the bucket was approximately 63 inches off the ground, the front bucket lip was about 22 inches off the ground and the bottom rear section of the bucket was about 7 inches off the ground. The bucket position had been changed after the accident but the bucket was repositioned similar to the position specified by testimony of the machine operator at the time of the accident. The forward lights were turned on. The LHD was placed with the bucket facing forward near the rib where the accident occurred. A subject was kneeling at the site of the accident to simulate the victim's position at the time of the accident. The machine operator moved the LHD in reverse until the kneeling subject's head became visible. The visibility tests showed the operator of the LHD was unable to see a kneeling person once the equipment was within 55 feet of the subject. The location of the left front pedestal mounted headlight and the top of the bucket contributed to the size of the blind area associated with forward visibility. The machine traveled backwards until the kneeling subject could not be seen. This distance was measured to be about 183 feet from the front tip of the bucket.


  • Tests were conducted of the equipment's forward illumination. The machine was slowly moved forward while the illumination was videotaped. The headlights were floodlight type sealed beams. The right front headlight was visibly drooping and skewed. The position was measured with a tape with respect to the machine frame and these dimensions were used to calculate the angular position of the headlight. The right front headlight was pointing about 16 degrees to the left of the machine's longitudinal axis when viewed from the operator's seat. The left front headlight was aiming straight out from the machine and parallel to the machine longitudinal axis. The headlights appeared to illuminate the mine roof and the upper portion of the mine ribs. The vertical centerline height of the headlights was about 64 inches from the ground while the top of the bucket was about 63 inches from the ground. This means a large portion of the lower light pattern was blocked by the bucket. The orientation of the front headlights with respect to the bucket resulted in a large shadow being cast in front of the machine.


  • Tests were conducted of the equipment's forward speed. A distance of 100 feet was measured in the entryway and the machine was driven this distance three times at half throttle in second gear forward and the time was clocked with a stopwatch. The average speed was calculated at about 4.4 feet per second or 3.0 miles per hour. The machine was also driven this distance three times at full throttle in second gear and the time was clocked with a stopwatch. This average speed was calculated at about 6.9 feet per second or 4.7 miles per hour.


  • The examination and testing of the equipment involved in the accident revealed no mechanical defects.


  • The visibility tests showed the operator of the LHD was unable to see a kneeling person once the operator's position was within 55 feet of the subject.


  • Testing showed that the kneeling subject could have been seen by the LHD operator within the approaching distances of 183 feet and 55 feet.
    • CONCLUSION The root cause of the accident was the failure of the loader operator to maintain a safe operating speed consistent with conditions of roadway, grade, clearance, visibility and traffic in a congested area.

    ENFORCEMENT ACTIONS

    The following order was issued to Stillwater Mining Company:

    Order No. 6267544 was issued on June 14, 2001, under the provisions of Section 103(k) of the Mine Act:
    A fatal accident occurred at this operation on June 14, 2001, when two miners were setting up to bolt in the 53E footwall lateral heading. This order is issued to ensure the safety of all persons at this operation. It prohibits all activity at the 53E footwall lateral until MSHA has determined that it is safe to resume normal mining operations in the area. The operator shall obtain prior approval from an authorized representative of the Secretary for all actions to recover and/or restore operations to the affected area.
    This order was terminated on June 14, 2001. The conditions that contributed to the accident no longer exist.

    The following citation was issued to Thyssen Mining Construction of Canada Ltd: Citation No. 7935225 was issued on July 11, 2001, under the provisions of Section 104(a) of the Mine Act for violation of 30 CFR 57.9101:
    A fatal accident occurred June 14, 2001, when a miner was struck by the bucket of a loader. The loader operator failed to maintain a safe operating speed consistent with conditions of roadway, grade, clearance, visibility and traffic.
    This citation was terminated on July 26, 2001. The operator conducted safety training that addressed operating speeds and control of mobile equipment. All employees were in attendance.

    Related Fatal Alert Bulletin:
    Fatal Alert Bulletin Icon FAB01M18



    APPENDIX A


    Persons Participating in the Investigation

    Stillwater Mining Company
    Steven D. Wood ............... Corporate Safety Director
    Michael W. Crum ............... Safety and Security Manager
    Thomas K. Fuell ............... Safety Coordinator
    Kenneth G. Lilyblad ............... Mine Trainer
    Thyssen Mining Construction of Canada Ltd.
    Steven B. White, Sr. ............... Mine Superintendent
    Andrew R. Saltis ............... Project Manager
    Ronald T. Hansen ............... Site Safety Coordinator
    William E. Armstrong ............... Master Mechanic
    Mine Safety and Health Administration
    Joseph O. Steichen ............... Mine Safety & Health Inspector
    Rodney Gust ............... Mine Safety & Health Inspector
    Emmett M. Sullivan ............... Mine Safety & Health Specialist
    Phillip L. McCabe ............... Mechanical Engineer
    F. Terry Marshall, Jr. ............... Mechanical Engineer
    APPENDIX B

    Persons Interviewed

    Thyssen Mining Construction of Canada Ltd.
    Steven B. White, Sr. ............... Mine Superintendent
    Ruben F. Gamez, Jr. ............... Shift Supervisor
    Byron Schinmann ............... Miner
    Nathan C. Hill ............... Miner
    Joseph F. Vigil ............... Bullgang
    Adam Zambrano ............... Bullgang
    Justin C. Vogt ............... Equipment Operator
    Randall J. Cloud ............... Miner
    Daniel C. Hundley ............... Electrician
    Katherine M. Hundley ............... Surveyor
    William E. Armstrong ............... Master Mechanic
    Fred C. Cutsinger ............... Miner
    Joseph B. Edwards ............... Miner
    Medcor
    Wayne Armstrong ............... Paramedic