UNITED STATES
DEPARTMENT OF LABOR
MINE SAFETY AND HEALTH ADMINISTRATION



Accident Investigation Report
Surface Metal Mine


Fatal Powered Haulage Accident


Mt. Hamilton Mining Company
Mt. Hamilton Mining Company (Mine)
Ely, White Pine County, Nevada
ID No. 26-02254

January 14, 1997


by

Timothy Hannifin III
Mine Safety and Health Inspector

Bobby Caples
Mine Safety and Health Inspector


Mine Safety and Health Administration
Western District Office
3333 Vaca Valley Parkway, Suite 600
Vacaville, California 95688


Fred M. Hansen
District Manager

GENERAL INFORMATION

William E. Black, stacker operator, age 47, was fatally injured at 11:15 p.m. on January 14, 1997 when he attempted to clean a conveyor end-roller and became entangled at the pinch point. Black had two years mining experience, the past 11 weeks at this operation. Black had been trained in accordance with 30 CFR Part 48. He had received Newly Employed Experienced Miner training on October 30, 1996.

Clyde Drake, director of safety and security, notified MSHA of the accident at 11:35 p.m. January 14, 1997. An investigation was started the following day.

The Mt. Hamilton Mining Company mine,located 54 miles west of Ely, White Pine County, Nevada, was a surface open pit, multiple bench gold mine. It was owned and operated by Mt. Hamilton Mining Company, a subsidiary of REA Gold Corp. of Vancouver, B.C. Canada. The principal operating officials were Joe R. Dewey, mine manager, and Clyde Drake, director of safety and security. The mine operated two 12-hour shifts, seven days per week. A total of 143 persons were employed at the mine.

Ore was transported by 40-ton Freightliner over-the-road trucks to the crushing facility where it was crushed, screened to size, and transferred by conveyor to a cyanide leach pad for processing.

The last regular inspection at this operation was completed on September 11, 1996.

PHYSICAL FACTORS INVOLVED

The screen feed conveyor involved in the accident was designated by the company as conveyor Number 2, and was manufactured by U.S. Machinery Company. The conveyor was inclined at 30 degrees and was 115 feet long with a self tracking, 36-inch wide, reinforced nylon, rubberized belt. Raw material from the primary crusher was transferred onto the belt at the tail pulley and conveyed to the head pulley, where it was discharged into the primary screening system. It was powered by a 1750 rpm, three phase, 480 volt AC, 50 horsepower, electric motor with a 15-to-1 gear ratio.

The tail pulley was a self cleaning, 18-inch diameter steel end-roller with slack adjuster bearing saddles affixed to the conveyor framework. The framework was constructed of 3/8-inch thick steel. The underside of the conveyor framework was 18 inches above ground level at the tail pulley. The center of the end roller shaft was 32 inches above ground level. The side opening in the framework was 30 inches long by 11-3/4 inches high. The conveyor belt had tracked to within 1/2 inch of the north (right) side and had a 5-1/2 inch gap on the south side.

The Number 2 screen conveyor was equipped with an emergency stop device which could be activated with a stop cord. The stop cord ran alongside the permanently secured walkway on the conveyor's south side. The stop cord was about one foot from the location where the victim became entangled in the pinch point and could easily be reached. After the accident, the stop cord, as well as the manually activated start-up warning horn, were tested and found to be functioning properly.

The operator's control tower was located about 180 feet from the Number 2 screen feed conveyor tail pulley and 25 feet above the surrounding ground level. From the tower it was not possible to see the area of the tail pulley where the accident occurred.

Conveyor guards were constructed of used screening material. The top guard was 1-inch square mesh and the side and end guards were 3/4-inch square mesh. Guards were secured to the framework with 3/4-inch diameter bolts and nuts. The bolt heads were welded to the frame. The left side guard for the Number 2 screen conveyor tail pulley had been removed and two of the bolt nuts were found in the victim's pocket.

The victim had a company issued, battery powered, CB radio in his possession at the time of the accident.

The heater that the victim had taken to the conveyor to thaw frozen material consisted of a 20-gallon propane tank supplying fuel through a 1/8-inch, 20-foot nylon reinforced, rubberized hose with a weed burner attached. A manual control on the burner allowed the flame to be adjusted up to 18 inches in length. Company policy and past practice, according to mine employees, was to thaw built-up material located at the tail pulley with the guards in place.

Illumination at the time of the accident consisted of four lights mounted on top of the loader used to transport the propane bottle; a pole mounted light about 18 feet northeast of the pulley; and a portable multi-light located about 100 feet southeast of the pulley.

The weather was mostly clear, with a light wind and below freezing temperatures. There were patches of snow in the immediate area; however, the area at the tail pulley had been cleared of ice and snow.

The crusher crew consisted of a crusher operator, loader operator, stacker operator, and crusher helper.

DESCRIPTION OF ACCIDENT

William Black, stacker operator, began work at 6:00 p.m., his regular starting time. Chris Martinez, crusher operator and lead man, assigned Black to clean up around the primary crusher with the loader/backhoe. About 11:00 p.m., Black received a request from Martinez to go to the tail pulley and thaw accumulated material. A propane fired weed burner was maintained on site for this common winter-time occurrence. Normally, thawing of material was undertaken with the guard in place.

Black loaded the propane tank and burner into the loader bucket and transported them to the Number 2 tail pulley. He unloaded the propane tank, removed the guard, and lit the burner. Because it was not the practice to remove guards for thawing, it appears that Black may have set the burner aside and removed the tail pulley guard to dislodge a boulder in the pinch point between the belt and tail pulley. He had two bolt nuts from the guard in his pocket.

Shortly after 11:00 p.m., Tim Helms, crusher operator, attempted to contact Black on the mobile radio but got no reply. He then drove the loader he was operating to the Number 2 screen feed conveyor tail pulley area and found Black, at 11:15 p.m., entangled in the tail pulley pinch point. Helms radioed Martinez and told him to shut down the plant because Black was entangled in the tail pulley. Martinez shut the plant down and called the mine office for assistance. Robert Coca, an EMT, responed to the request and upon traveling to the scene determined that there was nothing that could be done for Black.

Helms used a razor knife to cut the upper section of the conveyor belt to relieve belt tension. The county coroner and deputy sheriff arrived about 1:45 p.m. Black was pronounced dead and later transported to a mortuary in Ely, Nevada. Death was attributed to massive crushing injuries.

CONCLUSION

Failure to deenergize and lockout the conveyor system while performing work around the unguarded conveyor pulley was the primary cause of the accident

CITATIONS/ORDERS

Order No. 7951440

Issued on January 15, 1997 under provisions of Section 103(k) of the Mine Act:

On January 14, 1997, a surface miner was fatally injured when he was drawn into a conveyor tail pulley. This order was issued to insure the safety of persons until the affected areas of the mine could be returned to normal oerations and was terminated on January 16, 1997.

Citation No. 7951441

Issued on January 16, 1997 under the provisions of section 104(a) of the Mine Act for violation of 30 CFR 56.14107(a):

On January 14, a surface miner was fatally injured while melting frozen material when he was drawn into a conveyor tail pulley. He had removed a guard, which allowed exposure to the moving roller and belt pinch points.

This citation was terminated on January 23, 1997. The operator conducted safety meetings on all shifts and posted memoranda informing all employees of proper guarding and lock out procedures.

Citation No. 7951442

Issued on January 16, 1997 under the provisions of Section 104(a) of the Mine Act for violation of 30 CFR 56.12016:

On January 14, a surface miner was fatally injured when he was drawn into a conveyor tail pulley. The electrical power circuits to the Number 2 screen feed conveyor drive motor were not de-energized and locked out. A metal guard was removed for the purpose of cleaning a frozen build-up of mud from the tail pulley end-roller.

This citation was terminated on January 23, 1997. The operator posted a memorandum and conducted safety meetings on all shifts addressing guarding and lockout procedures.

[FAB97M02]