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Metal and Nonmetal Mine Safety and Health


Surface Nonmetal Mine
Fatal Powered Haulage Accident
August 7, 2001

Stringtown Materials L. P.
Stringtown Materials L. P.
Stringtown, Atoka County, Oklahoma.
I. D. NO. 34-00056

Accident Investigators

Michael C. Sanders
Mine Safety and Health Inspector

Kendell C. Whitman
Mine Safety and Health Inspector

Michael P. Shaughnessy
Mechanical Engineer

Laman A. Lankford
Mine Safety and Health Specialist

Originating Office
Mine Safety and Health Administration
South Central District
1100 Commerce Street, Room 4-C-50
Dallas, TX 75242-0499

Doyle D. Fink
District Manager


On August 07, 2001 David W. Brown, utility employee, age 63, was fatally injured when he was crushed between the couplings of a railcar and a tractor.

The accident occurred because stop blocks or other devices were not used to prevent the movement of railcars during the coupling and uncoupling process.

Brown had seventeen years mining experience, all at this operation. He had received training in accordance with 30 CFR, Part 46.


Stringtown Materials L. P., a surface crushed stone mine, owned and operated by Stringtown Materials L.P., was located at Stringtown, Atoka County, Oklahoma. The principal operating official was Donnie Estep, plant superintendent. The mine was normally operated two, 12-hour shifts a day, six days a week. Total employment was 46 persons.

Limestone was drilled, blasted and hauled by truck to the plant where it was crushed, screened and stockpiled. The finished product was sold for use in the construction industry.

On the day of the accident, David W. Brown (victim) reported to work at 6:00 a.m., his normal starting time. Brown, Ronnie S. Marley, brakeman, and Kendon R. Cortney, tractor operator, made preparation to move 20 loaded railcars from the load out area to the railcar staging area. Brown and Morley served as brakemen while Cortney operated the tractor.

The three employees started with five railcars that had been parked on the east track. After coupling the railcars to the tractor they pushed them south on the east track just past the west sidetrack switch and parked. The tractor was uncoupled from the north end of the railcars, driven to the south end of the railcars and re-coupled. Morley set the hand brake on the second and third railcars to assist in braking while Brown, acting as the brakeman on the south end of the railcars, coupled the railcars to the tractor. Morley was positioned on the number 5 railcar when they began to push the railcars north on the west sidetrack. After traveling approximately 260 yards to the switch, the wheels of the tractor dipped into a depression in the roadbed causing the railcars to uncouple from the tractor. Brown signaled Cortney to stop and back up. Cortney backed up about three feet from the number 1 railcar. Brown then stepped between the railcars and the tractor to manually release the latching mechanism to open the coupling. The railcars suddenly rolled forward, pinning him between the couplings. Cortney did not see Brown exit from the front of the tractor. He left the operator's seat and from the cab deck he observed Brown caught between the couplings. He returned to the seat and pulled the tractor forward approximately 45 feet. He immediately went to Brown and checked for vital signs. Morley was running towards them when Cortney hollered for him to call 911. Local authorities and emergency medical personnel arrived shortly. Brown was pronounced dead at the scene by a local physician. Death was attributed to crushing injuries.


MSHA was notified at 7:35 a.m., on the day of the accident by a telephone call from Mike Downs, senior safety coordinator, to Dani White, mine safety and health inspector. An investigation was started the same day. An order was issued under the provisions of section 103(k) of the act to ensure the safety of the miners.

MSHA's accident investigation team traveled to the mine, conducted a physical inspection of the accident site, interviewed a number of persons and reviewed information relating to the job being performed by the victim. MSHA conducted the investigation with the assistance of mine management and a number of miners. The miners did not have nor request representation during the investigation.


  • The accident occurred on the west sidetrack approximately 700 feet south of the truck scale. The rail track system consisted of three sidetracks, running north and south and used exclusively by the mine and Union Pacific Railroad for placement of empty and loaded railcars. The track system can accommodated up to 65 open top, bottom dump hopper railcars. The track grade ranges from minus one percent to plus two percent. The tracks, beds and switches, were maintained in good repair with some dip at the track switches.(See appendix C)

  • The railcars, owned and maintained by Union Pacific Railroad, with a gross weight of approximately 133 ton, had a capacity of 100 ton. The railcars were equipped with air actuated friction brakes on the end wheels of each car. These brakes could be manually applied by turning a ratchet wheel on the front of the car when air pressure was depleted.

  • Approximately sixty railcars were delivered to the mine each Monday, Wednesday and Friday. They were parked in the load out area, loaded by a front-end loader and shipped each Tuesday, Thursday and Saturday. During the loading cycle, the tractor moved and parked the loaded railcars until they were picked up by the Union Pacific.

  • The tractor involved in the accident was a 1964 Caterpillar model 660, scraper tractor. The tractor had a total length of 24 feet and weighed 45,700 lbs. After receiving the tractor in 1979, it had been modified by the mine operator to push or pull railcars. An operator's cab with windows and one access door had been fabricated and mounted on the tractor. An 85 CFM, Gardner Denver air compressor had been installed behind the cab for the purpose of charging the railcars brake system.

  • A Janney automatic railcar knuckle coupler was added to the front of the tractor to connect to the railcars. The center of the coupling measured about 38 inches above the track bed. The coupler was not equipped with a safety release bar designed to allow the coupler to be opened from the side of the tractor. Without a safety release bar, the brakeman was required to physically activate the release latch inside the coupler. Due to impaired visibility, caused by the tractor frame and housing, the operator could not see the brakeman when he performed this function.

  • A flat metal plate had been welded approximately 4 inches above the coupler on the tractor to prevent the couplers from disengaging when the tractor ran over uneven ground on the track bed.

  • Statements revealed the air compressor had never been utilized to charge the brake system on railcars. In addition, the metal plate did not prove effective in preventing accidental uncoupling. Employees stated this occurred with some frequency.

  • The car moving crew utilized voice and hand signals during the moving of the cars.


    The root cause of the accident was the failure to establish procedures that required stop blocks or other devices to be used to prevent movement of rail equipment. The accident occurred because the wheels of the railcars were not blocked prior to going between the rail equipment.

    Contributing factors included the failure to install the stand off coupler device to open the tractor coupler from a safe location, and failure to utilize the compressed air for charging the railcars brake system.


    Stringtown Materials L. P.

    Order No. 6210228 was issued on August 7, 2001, under the provisions of section 103(K) of the Mine Act:
    A fatal accident occurred at this operation on August 7,2001, when a miner was crushed between the railcar and the caterpillar tractor. This order is issued to assure the safety of persons at the operation and prohibits work in the affected area until MSHA determines that it is safe to resume normal operations as determined by an authorized representative of the Secretary of Labor.
    The order was terminated on August 7, 2001, when it was determined that the mine could safely resume normal operations.

    Citation No. 6207351 was issued August 7, 2001 under provisions of section 104 (a) of the mine act for violation of CFR 56.9302:
    A fatal accident occurred on August 7, 2001, when an employee was crushed between moving railcars and a rubber tired tractor. The mine operator failed to provide stop blocks or other devices to protect against moving or runaway equipment where necessary to protect persons.
    The order was terminated on October 1, 2001. The operator implemented procedures requiring stopblocks or other devices to be installed to protect persons performing tasks near rail equipment.

    . Related Fatal Alert Bulletin:
    Fatal Alert Bulletin Icon FAB01M20


    Persons Participating in the Investigation

    Stringtown Materials L. P.
    Michael J. Downs ............... senior safety coordinator
    Jimmy D. Muse ............... supervisor
    Donnie L Eastep ............... plant manager
    Mark J. Clark ............... vice president of aggregate operations
    Lee L. White ............... area manager
    Treton S. Horner ............... safety manager
    Sean L. Hammel ............... safety coordinator
    Norman B. Phillips ............... manager railroad operations
    Mine Safety and Health Administration
    Michael C. Sanders ............... mine safety and health inspector
    Kendell C. Whitman ............... mine safety and health inspector
    Michael P. Shaughnessy ............... mechanical engineer
    Laman A. Lankford ............... education field service

    Persons Interviewed

    Stringtown Materials L. P.
    Ronnie S. Marley ............... utility man (train crew)
    Kendon R. Courtney ............... utility man (train crew)
    Donnie L. Eastep ............... plant manager
    John A. McClain Jr. ............... shovel operator
    Donnie L. Boston ............... crusher operator
    Jimmy D. Cole ............... truck driver
    Mark A. Manion ............... loader operator
    Marvin L. Lowe Jr. ............... driller
    Jerry L Maxey ............... truck driver
    Riley L Mayo ............... water truck driver
    Stringtown Police Department
    Jerome C. Reed ............... city police officer
    Union Pacific Railroad
    Ken A. Shires ............... signalman