DEPARTMENT OF LABOR
MINE SAFETY AND HEALTH ADMINISTRATION
Metal and Nonmetal Mine Safety and Health
REPORT OF INVESTIGATION
Surface Metal Mine
Fatal Powered Haulage Accident
February 16, 2001
Newmont Mining Corp.
Carlin, Eureka County, Nevada
I.D. No. 26-00500
Dennis D. Harsh
Supervisory Mine Safety and Health Inspector
Richard M. Wilson
Mine Safety and Health Inspector
Juan L. Wilmoth
Mine Safety Specialist (Training)
Dennis L. Ferlich
Mine Safety and Health Administration
Rocky Mountain District
P.O. Box 25367, DFC
Denver, CO 80225-0367
Irvin T. Hooker, District Manager
On February 16, 2001, Jon R. Skinner, mechanic, age 38, was fatally injured when the truck he was performing maintenance on suddenly lunged forward and crashed through the shop door.
The accident occurred because the park brake had not been set while tests were performed on the unattended truck.
Skinner had a total of 16 years, 4 months mining experience all at this operation. He had 1 year, 4 months as a mechanic 1. He had received training in accordance with 30 CFR, Part 48.
South Area, a multi-level, open pit gold mine, owned and operated by Newmont Mining Corp., was located 6 miles north of Carlin, Eureka County, Nevada. The principal operating officials were Tom Conway, vice president and general manager, and Mark Ward, surface general mine manager. The mine worked on rotating shifts. Production crews worked two, 10-hour shifts a day and the maintenance crews worked two, 12-hour shifts a day, 7 days a week. Total employment was 806 persons.
Gold-bearing ore was mined form multiple benches. Blasted ore was loaded onto haul trucks with front-end loaders and transported to the mill for crushing, grinding and extraction of gold.
The last regular inspection at this operation was completed on September 7, 2000. Another regular inspection was conducted following this investigation.
DESCRIPTION OF THE ACCIDENT
On the day of the accident, Jon Skinner (victim) reported for work at 7:00 a.m., his normal starting time. Skinner attended a meeting until 9:30 a.m., and then completed a variety of small repairs. At 5:30 p.m., the haul truck, Company No. HT085, arrived at the shop and was parked outside the No. 2 bay door of the No. 2 shop.
At approximately 6:00 p.m., Skinner and Michael Robinson (tireman) started the pre-preventative maintenance on the truck. Robinson got into the operator's cab and activated the control to lift the truck bed while Skinner secured the bed in the raised position. Gauges were then attached to the parking brake filter and behind the torque converter. With the engine running, brake pressures and torque converter readings were taken at low and high idle with the transmission in neutral and in low gear. Robinson then placed the transmission in neutral.
Skinner directed him to release the parking brake. Prior to beginning the test, he cautioned Robinson that the truck might move. Skinner then disconnected the electrical harness wires to both the downshift solenoid and the upshift solenoid in preparation to determine if the lock-up clutch seals were leaking. When Skinner inadvertently connected the down- shift harness wire to the upshift solenoid, the transmission shifted into gear and the truck started to move forward. Skinner yelled to Robinson who was standing outside the truck cab, to shut the truck down. Before Robinson could stop the truck, it plowed through the partially closed bay door, causing the panels to fall and strike Skinner. Dennis Zimmerman, mine maintenance foreman, was working in his office when he heard a loud crash. He ran into the bay area and saw the door panels fall. The truck had stopped when its bed hit the top of the door casing and the right wheels struck the concrete door guard located outside the door frame. Zimmerman directed Robinson to shut the truck down and summon some additional help.
Zimmerman attended to Skinner and after determining he was not breathing, he immediately started CPR. The company's ambulance and EMT's arrived and relieved Zimmerman until Skinner was life- flighted to a nearby hospital where he was pronounced dead. Death was attributed to blunt force trauma.
INVESTIGATION OF THE ACCIDENT
MSHA was notified at 7:00 p.m., on February 16, 2001, by a telephone call from Tim Burns, loss control supervisor, for the mining company, to Irvin T. Hooker, district manager, Rocky Mountain District. An investigation began the same day and an order was issued pursuant to Section 103(k) of the Mine Act to ensure the safety of the miners.
MSHA's accident investigation team conducted a physical inspection of the accident site, interviewed a number of persons, and reviewed training records and work procedures being performed at the time of the accident. The investigation was conducted with the assistance of mine management and mine employees. A representative of miners' participated in the investigation.
The truck involved in the accident was a Caterpillar, Model 789, Serial No. 7EK00121, manufactured in 1992. The hour meter read 59,828.6 hours. The empty weight of the truck was 268,837 pounds and the payload capacity was 195 tons. The wheel base was 19 feet; the outside tire track dimension of the rear tires was 22 feet; the truck bed width was 23 feet; and the height at full dump was 37 feet. The engine was a 16- cylinder, Caterpillar, Model 3516 (EUI), diesel, rated at 1,705 horsepower at 1,750 RPM. The steering was hydraulic with two double-acting hydraulic steering cylinders. The transmission was a Caterpillar ICM automatic transmission with six gears forward and one gear reverse. The braking system was an air-over-oil actuated system composed of a hydraulically applied service brake; a spring applied park brake; a secondary (emergency) brake that spring applied the front and rear brakes; and a retarder that hydraulically applied both the front and rear brakes. The front and rear brakes were completely enclosed oil cooled multi-disc brakes. The service brake was actuated by a foot pedal. When actuated, both the front and rear brakes were applied at a rate modulated by the distance the foot pedal was moved. The retarder was actuated by a hand lever on the right side of the steering column. When actuated, both the front and rear brakes were applied at a rate modulated by the distance the lever was moved, but limited to a maximum air supply pressure of 80 psi. The park brake was actuated by a switch on the transmission console, and when actuated, it caused complete spring application of both the front and rear brakes. The secondary (emergency) brake was actuated by a hand lever on the left side of the steering column. When actuated, both the front and rear brakes were spring applied at a rate modulated by the distance the lever was moved.
The garage door was composed of three steel horizontal panels measuring approximately 8 feet high by 26 feet long by 0.5 feet thick. The weight of each door panel was approximately 2,500 pounds. The operation (raising and lowering) of the door was achieved with an electric motor and wire ropes.
The apron leading to Bay 2 of the garage was concrete with steel rails imbedded in the concrete. The apron length was approximately 42 feet long by 25 feet wide. The apron sloped downward away from the garage at a grade of approximately 1%.
The accident occurred at approximately 6:45 p.m.. It was dark outside and the victim was using a penlight flashlight to light the area by the transmission solenoids.
At the time of the accident, the victim was performing a pre-preventative maintenance test procedure called "Park Brake Release With Lockup Engaged (Low Idle)", in accordance with Newmont's PRE-ALPM Inspection, when he inadvertently connected the downshift harness wire to the upshift solenoid. This caused the transmission to move from neutral position to 6th gear forward, resulting in the forward movement of the truck. The park brake was released and the service brakes were not applied when the victim performed the test.
Visual examination of the electrical harness wires and solenoids on the transmission in the area where the victim was working showed that the electrical harness wires to the downshift solenoid and the upshift solenoid were disconnected. The electrical harness wire to the lockup solenoid was connected. This showed that the victim did not disconnect and connect the proper harness wires and solenoids in accordance with Newmont's PRE-ALPM Inspection procedures. In Newmont's procedures, the lockup solenoid and downshift solenoid should have been disconnected versus the upshift solenoid and the downshift solenoid.
The Caterpillar Service Manual, Systems Operation Section for the Model 789 Truck Power Train, Form No. SENR3427, showed that connecting the downshift harness wire to the upshift solenoid when the engine is running and the transmission lever is in neutral will cause the transmission to upshift to 6th gear from neutral. Field tests were conducted and showed that incorrectly connecting the downshift harness to the up shift solenoid does cause the transmission to shift from neutral to 6th gear. During the field testing, the park brake was applied and the rear tire was chocked. Even though the transmission shifted from neutral to 6th gear, the truck remained stationary with no forward movement.
The harness wires leading to the lockup, downshift, and upshift solenoids were found to be color-coded and numbered. The harness wire colors and numbers were compared to the Caterpillar electrical diagram for the Caterpillar, Model 789, haul truck. The harness wire colors and numbers were correct (i.e., matched the electrical diagram).
The Caterpillar, Model 789, utilized the EMS Monitoring System. The stored codes were examined to determine if any fault codes existed related to the accident. Two active fault codes, "Down Solenoid Open Circuit, Code No. 708-05", and Up Solenoid Open Circuit, Code No. 707-05" were found. These codes showed that the only two solenoids disconnected at the time of the accident were the downshift solenoid and the upshift solenoid. The lockup solenoid was not disconnected.
Newmont's test procedure known as "Park Brake Release With Lockup Engaged (Low Idle)" was not a test procedure shown in Caterpillar's Service Manual for the Model 789 haul truck. Caterpillar's Power Train Testing & Adjusting Manual No. SENR6327, specifies a test called "Lockup Clutch Leakage" to determine if there are bad seals in the lockup clutch.
Newmont's PRE-ALPM Inspection narrative procedure on page 2 for "Park Brake Release With Lockup Engaged (Low Idle)" required that the park brake be released, had no caution statements alerting the mechanics of the danger of connecting the downshift harness wire to the upshift solenoid, and did not include instructions defining the locations of the solenoids or the color-coding and numbering of the harness wires.
The engine was running at idle speed, the park brake was released, and front left tire was chocked on both the front and rear of the tire. Reportedly, at the time of the accident, the rear chock was tight against the tire, but the front chock was about 1 foot ahead of the tire. The chocks were made by Checker Industrial Products, Inc.. The chocks used were Model No. MC1812 and they were 22 inches in length, 15 inches in width and 11 inches in height. Each chock weighed 40 pounds.
The cause of the accident was the failure to have the parking brake set during the test procedure.
The following root causes were identified. The failure of the company's written procedure to include caution statements alerting the mechanics that the truck will move forward if the downshift harness wire was connected to the upshift solenoid; there were no instructions defining the locations of the solenoids or the color-coding and numbering of the harness wires; and there were no instructions directing the mechanics to reset the parking brake after performing the previous tests.
Order No. 7944874 was issued on February 16, 2001, under the provisions of Section 103(k) of the Mine Act:
A fatal accident occurred at this operation on February 16, 2001, when a mechanic was servicing a 789 Caterpillar haul truck, Company No. HT-085. The truck moved forward hitting the bay door causing the door panel to drop striking the mechanic. This order is issued to assure the safety of 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 operations in the affected area.This order was terminated on February 19, 2001, after it was determined the mine operator could repair and return this truck to service.
Citation No. 7966600 was issues on February 20, 2001, under the provision of Section 104(a) of the Mine Act for violation of 30 CFR 56.14207:
A fatal accident occurred at this mine on February 16, 2001, when an unattended Caterpillar 789 haulage truck ran through a bay door at the No. 2 shop. A pre-preventative maintenance test was being performed on the truck when the transmission was electronically engaged. The truck's parking brake was not set and, as the truck dislodged sections of the vertical lift bay door, two of the sections fell on the truck striking the mechanic.
Related Fatal Alert Bulletin:
Persons Participating in the Investigation Newmont Mining Corp.
William G. Miles ......... Director of Safety and SecurityNevada State Mine Safety and Training Services
Timothy J. North ......... Area Loss Control Supervisor
Mark Ward ......... Manager of Open Pit Mining
Jared H. Duke ......... Senior Human Resources Representative
John D. Ritter ......... Mine Maintenance Foreman
Jay Bastian ......... Superintendent of Mine Maintenance
Danny Lucero ......... Mechanic III
Dennis Michael Zimmerman, II ......... Mine Maintenance Foreman
Julio P. Garcia ......... Miners' Representative
Joseph N. Rhoades ......... State Mine InspectorMine Safety and Health Administration
Dennis D. Harsh ......... Supervisory Mine Safety and Health Inspector
Richard M. Wilson ......... Mine Safety and Health Inspector
Juan L. Wilmoth ......... Mine Safety Specialist (Training)
Dennis L. Ferlich ......... Mechanical Engineer
Newmont Mining Corp.
Michael Roy Robinson .......... Tire Mechanic Dennis Michael Zimmerman, II .......... Mine Maintenance Foreman Robert Roy Bliss .......... Truck Driver Eldon Richard Gough .......... Welder III Danny Lucero .......... Mechanic III David L. Webber .......... Mechanic III Dennis Stark .......... Mechanic III Bret Lyn Wadford .......... Maintenance Supervisor