DEPARTMENT OF LABOR
MINE SAFETY AND HEALTH ADMINISTRATION
Metal and Nonmetal Mine Safety and Health
Accident Investigation Report
Underground Silver Mine
Fatal Fall of Person Accident
Sunshine Precious Metals, Incorporated
Kellogg, Shoshone County, Idaho
ID No. 10-00089
January 27, 1998
William Tanner, Jr.
Supervisory Mine Inspector
David J. Brabank
Mine Safety and Health Specialist
Thomas D. Barkand
Arnold E. Pederson Mine Safety and Health Inspector
Mine Safety and Health Administration
Western District Office
2060 Peabody Road - Suite 610
Vacaville, CA 95687
James M. Salois
Thomas N. Huff, shaft repairman, age 57, was fatally injured at about 5:00 a.m. on January 27, 1998, when he fell down a vertical mine shaft while turning an ore skip preparatory to hoisting waste material. Huff had a total of 32 years mining experience, the past 19 years at this operation. He had worked 11 years five months as a shaft repairman and had received training in accordance with 30 CFR Part 48. Annual refresher training had been conducted on February 27, 1997.
MSHA was notified about 5:15 a.m. on the day of the accident by a telephone call from the safety administrator for the mining company. An investigation was started the same day.
The Sunshine Mine, owned and operated by Sunshine Precious Metals, Incorporated, was located near Kellogg, Shoshone County, Idaho. Principal operating officials were Harry Cougher, vice president and general manager; Michael McLean, mine manager and chief engineer; Gary James, mine superintendent; Terry Jerome, mine foreman; and Noel Robinett, safety administrator. The mine was normally operated two, 8-hour shifts a day, five days a week. Total employment was 274 persons; of this number, 202 worked underground.
The mine was a multiple level underground operation which produced 900 to 1,000 tons of silver, antimony, and copper bearing ore daily. Access to the mine was by vertical shafts and horizontal drifts along the ore veins. The mining method was horizontal cut and fill.
The last regular inspection of this operation was completed on December 5, 1997. Another inspection was conducted in conjunction with this investigation.
PHYSICAL FACTORS INVOLVEDThe accident occurred at the collar of the Jewell Shaft. It was located on a mountain side at an elevation 95 feet above the main hoist access tunnel and could be accessed by road, stairs, north cage, south cage, or personnel cage.
The Jewell Shaft was an intake air ventilation shaft which was divided into four rectangular compartments at the collar level. Each compartment measured 4� feet by 5� feet. The four compartments were designated from north to south in the following order: north main hoisting compartment, south main hoisting compartment, chippy (personnel) hoist compartment, and manway and pipe (service access) compartment.
A Nordberg double-drum production hoist serviced the north and south main hoisting compartments. An ore skip, with an underslung trailer cage for hoisting personnel, was suspended in each of these compartments by a 1 5/32-inch diameter rope. Each skip had a capacity of three tons of waste rock or four tons of ore and each cage could hoist ten persons. The empty conveyance weighed 7,152 pounds and was equipped with safety catches.
A Nordberg unbalanced personnel hoist provided service to the 4000-foot deep chippy compartment. The cage capacity of the personnel hoist was ten persons on each of four decks. The manway and pipe compartment was accessible by ladders.
All four shaft compartments were accessible at the collar level. The service access compartment was guarded with an expanded metal cover provided with a 24-inch by 28-inch access door. The west side of the collar level was guarded by three sets of swinging gates for the north, south and chippy hoisting compartments. The gates were constructed with horizontal rails at 46, 26, and 7 inches above the floor. The west side concrete floor was 5 feet 4 inches wide. A 4�-foot by 21-foot work area on the east side of the hoisting compartments was accessible through a set of gates on the north and south ends of the collar level. Within the east side work area, the chippy hoist compartment was guarded with horizontal rails at 48 and 20 inches above the floor. The north and south compartments were not guarded.
Self-retracting lifelines (Sala blocks) were installed in the east side work area and on the west side of the collar level and were equipped with a speed sensing brake system. On the east side, the self-retracting lifeline was suspended on a 20-foot long, horizontally installed, wire rope secured to the east wall. The west side self-retracting lifeline was hung on an 8-foot long horizontal steel rod secured to the west wall.
Loose material had fallen from the skips and discharge chutes, accumulating on the collar level floor. The headframe structure over the collar level was partially enclosed; however, uncovered openings in the structure and irregularities in the concrete floor permitted precipitation to enter and accumulate around the hoist compartment openings, creating muddy conditions.
The ore storage bin was located on the west side of the collar and the waste storage area was located on the east side. The skips had to be manually rotated 180 degrees to switch between ore and waste hoisting cycles. This task was performed at the collar level by first unlatching and swinging open a 26-foot section of the wood guides in each compartment. The distance between the open guides was 54 inches and the diagonal measurement of the cage was 71 inches. Therefore, the skip and cage had to be forced several feet away from the center line of the shaft so the skip could be rotated.
During the skip rotation procedure at the time of the accident, the skip in the south compartment became jammed between the southwest corner gate post on the west side and the guide support column on the north side. The bottom of the cage was 34 inches above the collar level floor and horizontally displaced from the east side of the shaft wall 21 inches at the southeast corner and 31 inches at the northeast corner. The victim fell down the south compartment from the east side work area through the opening between the shaft compartment and the jammed cage.
DESCRIPTION OF ACCIDENT
On the day of the accident, Thomas Huff (victim) reported for work at 10:00 p.m., his normal starting time. Wendell Ivie, lead shaft repairman, assigned Huff to help hang pipe on the 1700 level.
At about 4:30 a.m., Larry Peterson, cager, went to the 1700 level to get the shaft repairman to help him turn the skips from hoisting ore to hoisting waste. Huff, Ivie, and Peterson rode the chippy cage to the Jewel shaft collar. The three men rotated the north skip/cage combination without problems, then proceeded to turn the south skip/cage. The guides were unlocked and moved out of the way, and the skip hoist was belled above the collar. Ivie, who was standing on the west side of the collar area, pushed on the skip/cage while Huff pulled on it from the east side.
During the swinging process, the suspended skip/cage became lodged, so they decided to use the tugger to pull the skip free. Peterson went to the tugger located at the south end of the station while Ivie hooked up a sheave block on the west side. Huff, who was on the east side, said that he was going to pry the skip free with a bar. Huff threw the bar on the floor of the cage and started to climb into the cage, when he slipped and fell into the open shaft. Both Huff and Peterson were wearing safety belts but were not secured to a lanyard. The shaft compartments were not covered during this activity. Local authorities were notified and efforts were begun to remove Huff's body from the shaft.
The accident was caused by lack of an effective program to ensure the use of personal fall protection when working around the open shaft and to ensure that the open shafts were covered. When questioned, employees indicated that swinging the suspended skips/cages over the open shaft to rotate them, without using personal fall protection or covering the shafts, had been a practice.
Order number 4135582 was issued on January 27, 1998 under the provisions of Section 103(k) of the Mine Act to ensure the safety of persons during recovery operations and until the affected areas of the mine could return to normal.
This order was terminated on January 27, 1998 after it was determined that the mine could resume normal operation.
Due to the presence of additional potential hazards during the accident investigation, a second Section 103(k) order, number 4134807, was issued on January 30, 1998 ensure the safety of miners until all such hazards were eliminated.
This order was terminated on February 6, 1998 after it was determined that the mine could resume normal operation.
Citation number 4662401 was issued on January 29, 1998 under provisions of Section 104(d)(1) of the Act for violation of 30 CFR 57.15005:
A fatal accident occurred at this operation on January 27, 1998 when a shaft repairman fell into the mine shaft. The repairman, lead shaft repairman, and a cager were turning the skip from dumping on the ore side to dumping on the waste side when it became wedged in the headframe above the open vertical shaft. The victim was attempting to climb into the mancage attached below the skip when he fell. The leadman and the victim were not wearing safety belts and lines. This citation was modified on March 3, 1998 to state that the failure to tie off was a violation of the conditions of the Petition for Modification granted May 18, 1984. It was also modified on March 12, 1998 to reflect that the leadman and victim were wearing safety belts; however, they were not attached to lanyards.
This citation was terminated on January 30, 1998 after all employees working around the shaft had been trained in the proper use of personal fall protection and the company had initiated a program to ensure compliance.
Order number 4662402 was issued on February 4, 1998 under provisions of Section 104(d)(1) of the Act for violation of 30 CFR 57.11012:
A shaft repairman was fatally injured on January 27, 1998 when he fell into an open vertical shaft while attempting to climb into a mancage attached below the skip. The opening the victim fell through was not protected by railings, barriers, or covers. These shaft openings are designed to accept covers especially made for work around the shaft.
This order was modified on March 11, 1998 to reflect a violation of 30 CFR 57.11001, in that safe means of access was not provided into the mancage, allowing the victim to fall into the open shaft.
This order was terminated on February 4, 1998 after the mine operator initiated a procedure to ensure that shaft covers were used while rotating the skips.
Order number 4662403 was issued on February 4, 1998 under provisions of Section 104(d)(1) of the Act for violation of 30 CFR 57.18002(a):
Effective working place examinations had not been conducted at the collar area of the Jewel shaft where a fatal accident occurred on January 27, 1998. Conditions which adversely affected safety, one of which contributed to the fatal accident, had not been corrected.
This order was terminated on February 5, 1998 after a meeting was held with mine supervisors. An explanation of work place examinations and safety checks, along with supervisory responsibilities, was conducted. Shift employees were also counseled on the same topic. Workplace examinations are now being conducted.
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