DEPARTMENT OF LABOR
MINE SAFETY AND HEALTH ADMINISTRATION
Rocky Mountain District
Metal & Nonmetal Mine Safety and Health
ACCIDENT INVESTIGATION REPORT
OPEN PIT METAL MINE
FATAL SLIP/FALL OF PERSON ACCIDENT
Continental Mine [I.D. No. 24-00338]
Butte, Silver Bow, Montana
Date of Injury: June 9, 1995
Date of Death: June 13, 1995
William Tanner, Jr.
Supervisory Mine Safety and Health Inspector
Ronald D. Pennington
Mine Safety and Health Inspector
Rocky Mountain District
Mine Safety and Health Administration
P.O. Box 25367 DFC
Denver, CO 80225-0367
Robert M. Friend, District Manager
Carl Calcaterra, mechanic, age 46, sustained a head injury on June 9, 1995, when he fell approximately 10-ft while trying to reposition himself from an unsecured ladder to the top of the rear tires on a Wabco 170-D haul truck. He died on June 13, 1995, at 4:59 a.m., due to his injury. Calcaterra had a total of 23 years mining experience which included 14 years as a shift foreman/mechanic for a previous company and 9 years as a mechanic for Montana Resources.
Edward J. McGowan, director of safety, notified Darrel Woodbeck, mine safety and health inspector, Helena, Montana Field Office of the accident at 11:55 a.m., on June 9, 1995. On June 13, 1995, an investigation was started after MSHA was notified that the victim was being taken off a life support system.
The Continental mine, an open pit copper mine, had been operating since June 1986, employing 324 permanent, full-time employees. Mine employees worked two, 12-hour shifts per day, 4 days a week.
Shop personnel worked one, 8-hour shift, 5 days a week.
Mining and milling operations were located at the 5800-ft level, adjacent to the City of Butte, Montana.
The ore primarily contained porphyry copper with a molybdenum by-product. The operation processed approximately 17.5 million tons of material per year. The stripping ratio of this mine, (overburden removed compared to raw ore mined) was .9 to 1.
After the raw material was drilled and blasted, it was hauled to plant facilities where it was crushed, milled, and prepared for shipment. Final products were copper and molybdenum concentrates.
Operating officials were:
J. Frank Gardner, President
Raymond V. Tilman, Vice President, Human Resources
Edward J. McGowan, Director of Safety
Robert Solari, Vice President, Maintenance
The Continental mine had an MSHA-approved training plan and training records reviewed indicated that the employees had received the required training under Part 48 and the training was kept current.
The last regular inspection at this operation was conducted
February 17, 1995.
PHYSICAL FACTORS INVOLVED
The victim was installing a new hinge pin and keeper on the bed of the Wabco 170-D haul truck, Serial No. CF31011AFE37-D, Company Unit No. 431. The hinge pin keeper was welded to the truck bed to prevent the pin from working loose. The keeper was located 12-inches above the top of the rear tires.
The air-inflated tires on the Wabco truck were Goodyear RL-4H, Unisteel size 3600 R51, and measured 10-ft in diameter.
The truck was brought into the shop from the crusher apron without being washed. Road conditions in the pit and the shop area were very wet and muddy. The truck's undercarriage was covered with mud and the tires were muddy and slippery. An estimated 12-inches of mud had accumulated on the road and outside the shop area on the day of the accident because of recent rainfall.
The victim was standing on a 10-ft ladder manufactured by Louisville Ladder Corporation; Model FH1010, and met the requirements of ANSI Standard A14-5.
The outside ladder rails were 13-inches apart and constructed of fiberglass. The ladder rungs were constructed of aluminum and had a 12-inch step between the rungs.
The ladder was wobbly because it was leaned at an angle against
the right suspension cylinder of the truck and was not secured.
A similar unsecured, 8-ft ladder was positioned to the left of
the 10-ft ladder for use by another mechanic.
DESCRIPTION OF ACCIDENT
Carl Calcaterra (victim), mechanic, age 46, reported for work at 7:00 a.m., June 9, 1995. Don Gates, foreman, instructed Calcaterra and Wayne Wenger, coworker, to proceed to the crusher apron where Truck Unit 431 was located with a hinge pin problem.
Calcaterra and Wenger proceeded to the crusher apron where they were able to temporarily install a smaller hinge pin on the truck and dump the remainder of the load. The truck was driven to the shop and parked in stall E3 for permanent hinge repairs.
Calcaterra and Wenger positioned a 10-ft and 8-ft ladder at the rear of the truck to provide access to the work area. Calcaterra cut away the hinge pin keeper and ground off the surface in preparation for installation of the new pin. Wenger used a forklift to lift the truck box so the new hinge pin could be installed. Calcaterra, with help from Lonnie Hoppe, mechanic, who was on the 8-ft ladder, installed the hinge pin. After the pin was installed, Hoppe returned to another job. The hinge pin keeper did not fit properly so Calcaterra communicated with Gates for advice. Gates went up the 10-ft ladder (the one the victim fell off) to assess the problem and told the men to use an air arc to dress up the area so the keeper would fit properly.
Calcaterra, still working off the 10-ft ladder, proceeded to weld the keeper into position. Wenger, while on the shop floor and around the side of the truck, heard the ladder rattle followed by a "thump". Wenger went to the back of the truck and found Calcaterra lying on his back on the concrete floor.
Wenger immediately informed other employees in the area of the accident. Hoppe, who was also an EMT, began first aid on Calcaterra. Calcaterra remained unconscious and was transported by ambulance to the St. James Community Hospital in Butte, Montana. His injuries consisted of a severe brain contusion.
Calcaterra never regained consciousness and died in the hospital
at 4:59 a.m., on June 13, 1995.
The accident was directly caused by working from the top of an unsecured 10-ft ladder. A contributing factor was the failure to use a lanyard and safety belt while working in an unsafe elevated position where there was a danger of falling.
The following citation was issued during the investigation:
Citation No. 3908336, 104 (d) (1)
Issued 6/13/95, at 1600 hours for a violation of 56.11004. An accident occurred on 6/9/95, which resulted in a fatality on 6/13/95, when the victim fell approximately 10-ft. The victim was standing on a 10-ft ladder attempting to cross over onto the tires of a Wabco 170-D haul truck. The ladder was not placed securely, in that, the top rung rested on the truck's suspension cylinder, which made the ladder wobbly when used. A foreman had examined this work area and climbed the unsecured ladder prior to the accident. This is an unwarrantable failure.
Terminated 6/15/95, at 0800 hours.
A policy is in place to ensure that the proper scaffold is used when working on the Wabco trucks.
The following order was issued during the investigation:
Order No. 3908337, 104 (d) (1)
Issued 6/13/95, at 1700 hours for a violation of 56.15005.
An accident occurred on 6/9/95, which resulted in a fatality on 6/13/95, when the victim fell approximately 10-ft, striking his head on the concrete floor. The victim was attempting to gain access to the top of the tires of a Wabco 170-D haul truck using a 10-ft ladder. A safety belt and line was not worn and used and there was an obvious danger of falling. This is an unwarrantable failure in that the foreman had received serious injuries when he fell while performing a similar task in 1991.
Terminated 6/15/95, at 0700 hours.
A policy is now in place where the work platform that was designed for working on the Wabco trucks will always be used.
Respectively submitted by:
/s/ William Tanner, Jr.
Supv. Mine Safety and Health Inspector
/s/ Ronald D. Pennington
Mine Safety and Health Inspector
Robert M. Friend
Related Fatal Alert Bulletin: