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

Report of Investigation

Surface Metal Mine
(Copper)
Fatal Powered Haulage Accident

October 3, 2001

Phelps Dodge Bagdad, Inc.
Phelps Dodge Bagdad, Inc.
Bagdad, Yavapai County, Arizona
ID No. 02-00137

Accident Investigators

Thomas E. Barrington
Mine Safety and Health Inspector

Pete O. Gutierrez
Mine Safety and Health Inspector

Robert S. Setren
Supervisory Engineer

George H. Gardner Jr.
Civil Engineer

Hilario Palacios
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


Vernon I. Allen, senior equipment operator, age 53, was fatally injured on October 3, 2001. Allen was operating a Mack semi-tractor and lowboy trailer moving an excavator when he lost control of the truck while descending a grade and collided with the pit highwall.

The accident occurred because of maintenance problems with the braking systems and the use of an undersized tractor.

Allen had a total of 31 years mining experience, 27 years at this mine. He had received training in accordance with 30 CFR, Part 48.

GENERAL INFORMATION


Phelps Dodge Bagdad, Inc., a surface open pit copper mine, owned and operated by Phelps Dodge Bagdad, Inc., was located in Bagdad, Yavapai County, Arizona. The principal operating official was A. John Broderick, president.

Copper ore was drilled, blasted, loaded on trucks and transported to a primary crushing circuit. Crushed ore was milled, concentrated, and smelted into copper plates. The mining operation worked a four crew rotation, two twelve-hour shifts a day, seven days a week. Total employment at the mine and milling operations was 550 persons.

The last regular inspection of this operation was completed on February 14, 2001. Another regular inspection was conducted at the conclusion of this investigation.

DESCRIPTION OF ACCIDENT


On the day of the accident, Vernon I. Allen (victim) reported for work at 6:00 p.m., his normal starting time. As a senior equipment operator, his assigned duties varied each shift. One of his assignments this shift was to load an excavator onto a lowboy trailer and move it to the primary crusher.

At approximately midnight, Allen arrived at the truck shop. He and Jeffery Ely, a mine operations supervisor, worked for 90 minutes loading the excavator onto the lowboy. The excavator was not secured to the lowboy trailer in any manner. At approximately 1:30 a.m., Allen drove the tractor-trailer from the shop area and was descending the haul road when he was unable to slow the unit. He then radioed a warning to the other miners using the haul road. The tractor and trailer continued down the haul road before it veered onto the north pit haul road, eventually striking the highwall.

Ely heard Allen's call on the radio and drove to the north ramp as he attempted to contact Allen by radio. Ely found Allen pinned in the cab of the tractor, restrained by the seatbelt, and unconscious. The mine dispatcher had already placed a call for the emergency response team who arrived a few minutes later. The jaws of life were used to extract the victim, who was then transported by ambulance to the local medical clinic where he was pronounced dead from blunt force trauma.

INVESTIGATION OF ACCIDENT


On the day of the accident, MSHA was notified at 2:00 a.m., by a telephone call from Bobby Powell, health and safety manager, to Jake H. DeHerrera, assistant district manager. An investigation was started the same day. MSHA's investigation team traveled to the mine and conducted a physical inspection of the accident site, interviewed a number of persons and reviewed documents relating to the job being performed by the victim and the equipment he was operating at the time of the accident. An order was issued pursuant to Section 103(k) of the Mine Act to ensure the safety of the miners. The investigation was conducted with the assistance of mine management, mine employees and the State of Arizona mine inspectors. The miners did not request, nor have, representation during the investigation.

DISCUSSION


  • The accident occurred at the bench highwall about 600 feet from the intersection of the upper pit access haul road (10 percent ramp) and the north pit haul road.


  • The north pit haul road had an elevated grade of 10 percent and a width of 65 to 75 feet and was provided with substantial earthen berms. The construction of the road did not contribute to the accident.


  • The tractor-trailer rig traveled about 3,700 feet when the unsecured excavator fell from the trailer.


  • The tractor was a 1970, Mack Truck, Model DM-800, Serial No. DM863SX1303. It was powered by a Cummins, 335 horsepower, diesel engine with an eight speed Eaton-Fuller Road Ranger transmission. The tractor was provided with two drive axles, service brakes, emergency/park brakes and a Jacob engine brake. The maximum rated gross vehicle weight (GVW) as specified by the manufacturer was 75,000 pounds. The hitch capacity was approximately 60,000 pounds.


  • The tractor's service brake system consisted of an air-operated, two-shoe, internal expanding drum S-cam type arrangement at each wheel of the drive axles. Air rotochambers near each rear brake drum applied force to the slack adjusters when the service brakes were applied. The steering axle was manufactured with service brakes which had been removed prior to the accident.


  • The emergency/park brakes utilized the same brake shoes as the service brakes. Separate spring-loaded air chambers mounted on the tractor's frame were connected to the slack adjusters of each wheel. Upon complete loss of air pressure, these air chambers would apply the brakes.


  • The tractor brake drums were visually examined and no ridges were found. The thickness of all pads were measured and found to the have adequate thickness. The strokes of the tractor's service brake air chambers were measured; 3 of 4 were within manufacturer's specifications.


  • The lowboy trailer involved in the accident was manufactured in 1988 by Load King Trailer, Model 1004DFP, Serial No. 15321. This trailer included four axles, all located at the rear of the trailer, with brakes on each wheel. The trailer's capacity was 100 tons and the empty trailer weighed 44,220 pounds.


  • The trailer's service brake system consisted of an air-operated, two-shoe, internal expanding drum S-cam type arrangement at each wheel of the drive axles. Air rotochambers near each brake drum applied force to the slack adjusters when the service brakes were applied.


  • The trailer included emergency/park brakes which utilized the same brake shoes as the service brakes. Spring-loaded air chambers were connected to the slack adjusters of the wheels on the front two axles.


  • The trailer included an emergency brake system. Activating a control button in the operator's cab would apply all trailer brakes. In addition, if supply air pressure to the trailer fell below a certain level, all trailer brakes would apply.


  • All of the trailer brake drums were visually inspected and no ridges were found. The thickness of all pads were measured and found to have adequate thickness.


  • The strokes of the trailer service brake air chambers were measured; five of the eight were within the manufacturer's specifications.


  • The air system piping for the trailer braking system was examined. The system did not conform to the manufacturer's design. The piping was such that it rendered the emergency brake system inoperable.


  • The excavator weighed approximately 168,230 pounds. The empty trailer weighed 44,200 pounds. The rated design capacity of the trailer unit with its load was 244,200 pounds with 100,000 pounds to be carried equally by the four trailer axles which were rated for 25,000 pounds each. The remaining 144,200 pounds was to be carried by the tractor through the hitch connection. At the time of the accident, the trailer was loaded with 168,230 pounds which required the tractor to accommodate approximately 112,000 pounds hitch load. The Mack, DM800 tractor, attached to the trailer was used beyond its manufacturer's design capacity of 60,000 pounds.


  • CONCLUSION


    The root cause of the accident was the failure to establish procedures that required the proper capacity tractor to transport the excavator. Maintenance problems with the braking systems and the use of an undersized tractor contributed to the cause of the accident.

    ENFORCEMENT ACTIONS


    Order No. 7948828 was issued on October 3, 2001, under the provisions of Section 103(k) of the Mine Act:
    A fatal accident occurred at this operation on October 3, 2001, when a truck driver lost control of his truck while traveling down an elevated haul road. This order is issued to ensure the safety of the persons at this operation and prohibits any 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 mine operator shall obtain approval from an authorized representative for all actions to recover and/or restore normal operations in the affected area.
    This order was terminated on October 6, 2001. The procedures for moving equipment has been revised and miners have been retrained in these procedures.

    Citation No. 6272422 was issued on October 29, 2001, under the provisions of Section 104(a) of the Mine Act for violation of 30 CFR 56.14101(a)(1):
    A fatal accident occurred at this operation on October 3, 2001, when a truck driver lost control of his truck while traveling down an elevated haul road. The service brakes on the 1970 Mack semi-tractor with a Load King lowboy trailer were not adequate. The front brake drum system was altered on the Mack tractor. Slack adjusters were not properly set according to the recommended specifications on the Mack tractor and Load King trailer. The air system to the trailer brakes was not plumbed as required by the manufacturer.
    This citation was terminated on December 18, 2001, when the operator removed from the mine site the Load King lowboy trailer and provided transport equipment with adequate braking systems to protect miners engaged in hauling large pieces of equipment.

    Citation No. 6272424 was issued on October 29, 2001, under the provisions of Section 104(a) of the Mine Act for violation of 30 CFR 56.14205:
    A fatal accident occurred at this mine on October 3, 2001, when the semi-tractor pulling a lowboy trailer was used beyond the design capacity intended by the manufacturers. The loaded Caterpillar 245B excavator exceeded the weight carrying capacity of the tractor.
    This citation was terminated on December 18, 2001, when the operator removed from the mine site the Load King lowboy trailer and provided transport equipment with adequate braking systems to protect miners engaged in hauling large pieces of equipment.

    . Related Fatal Alert Bulletin:
    Fatal Alert Bulletin Icon FAB00M22


    APPENDIX A


    Persons Participating in the Investigation

    Phelps Dodge Bagdad, Inc.
    A. John Broderick ......... president
    Thomas A. Hethmon ......... occupational health and safety director
    Bobby R. Powell ......... health and safety manager
    Charles M. Johnson ......... health and safety representative
    Daniel Cummings ......... health and safety representative
    Kent Cramer ......... mine operations superintendent
    Steve W. Nelson ......... mine maintenance superintendent
    Edward L. Fidler ......... operations manager
    Roy L. Arrington ......... maintenance planner
    Christopher M. Schmitz ......... engineering
    Jackson & Kelly PLLC
    Joseph Ferrara ......... attorney at law
    Jacobson Forensic Engineering
    Olaf Jacobson ......... mechanical engineer
    State of Arizona
    Timothy Evans ......... deputy mine inspector
    Patrick Finch ......... deputy mine inspector
    Philip Howard ......... assistant state mine inspector
    Mine Safety and Health Administration
    Thomas E. Barrington ......... mine safety and health inspector
    Pete O. Gutierrez ......... mine safety and health inspector
    Robert S. Setren ......... supervisory engineer
    George H. Gardner, Jr. ......... civil engineer
    Hilario Palacios ......... mine safety and health specialist
    James Eubanks ......... mine safety and health inspector
    APPENDIX B


    Persons Interviewed

    Phelps Dodge Bagdad, Inc.
    Steve W. Nelson ......... mine maintenance superintendent
    Roy L. Arrington ......... maintenance planner
    Jeffery Ely ......... mine operations
    Kent Cramer ......... mine operations superintendent
    Randy Morgan ......... lead tech
    Jose Vargas ......... lead tech/mechanical
    Garnet Snipes ......... mine operations supervisor
    Jerry Low ......... senior equipment operator
    Christopher Tilton ......... training coordinator