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MINE SAFETY AND HEALTH ADMINISTRATION
Metal and Nonmetal Mine Safety and Health
Accident Investigation Report
Surface Nonmetal Mine
Fatal Falling Material Accident
Tennessee Diesel Company
I.D. No. 1MZ
Williamson County Highway Department
Franklin, Williamson County, Tennessee
I.D. No. 40-00130
January 20, 1999
Larry R. Nichols
Supervisory Mine Inspector
Clarence F. Holiway
Mine Safety and Health Inspector
Dennis L. Ferlich
Mine Safety and Health Administration
135 Gemini Circle, Suite 212
John R. Green, Sr., contractor welder, age 50, was seriously injured at about 4:45 p.m. on January 20, 1999, when he was crushed between a pan feeder and a control booth while trying to reposition the pan feeder prior to installation. Green had a total of 4 years experience as a welder with the contracting company. He had not received training in accordance with 30 CFR, Part 48.
MSHA was notified of the accident at 7:15 a.m. on January 21, 1999, by a telephone call from the secretary for the mining company. An investigation was started the same day.
The Globe Quarry, a crushed stone operation, owned and operated by Williamson County Highway Department, was located at Franklin, Williamson County, Tennessee. The principal operating official was Charles Meek, highway superintendent. The mine was normally operated one, 8-hour shift a day, five days a week. Total employment was 9 persons.
Stone was quarried by drilling and blasting multiple benches.
Broken material was crushed, sized and stockpiled. The finished product was primarily used by the county for road construction.
The victim was employed by Tennessee Diesel Company, an independent contractor located in Columbia, Maury County, Tennessee. The principal operating official was Jerry Jones, owner. Tennessee Diesel was at the mine site to repair a primary crusher. Repairs were to include replacing a pan feeder and an operator's control booth.
The last regular inspection of this operation was completed on September 14, 1998. Another inspection was conducted at the conclusion of this investigation.
PHYSICAL FACTORS INVOLVED
The accident occurred at the old storage area which contained miscellaneous parked and stored equipment. When the pan feeder and control booth were delivered to the mine site, they were stored in this area until they could be installed. The ground was covered with packed gravel, fairly level and damp. The wind was calm on the day of the accident.
The equipment involved in the accident was a 1983 Ford flatbed boom truck owned by the contractor. The flatbed measured 16-feet long by 8-feet wide and was equipped with 4 outriggers. The gross weight was 27,500 pounds. An Alenco crane, model 8T-2, was mounted between the cab and flatbed portion of the truck. The crane boom was a telescopic three-section type. Mechanically-linked control valves were located on the main structure of the boom to extend, raise and lift the boom. Two sets of control handles provided operation of the crane from either side of the truck. The main boom lift cylinder included a load locking valve to prevent sudden downward movement in case of a catastrophic failure. The lift cable was 1/2-inch diameter and the hook/sheave was a two-part line pull design. A detailed boom angle/load chart was located on the boom to show the reduction in lift capacity. At a horizontal boom angle of 85 degrees (nearly vertical), with the boom fully extended, the crane was rated at 8 tons. At the time of the accident, the boom was fully extended at an angle of about 45 degrees, which produced a maximum lift of 13,500 pounds. The crane was positioned about 15 feet from the control booth.
A Herc-alloy 800, 3/8-inch diameter steel chain 17-feet, 6-inches long was used as a sling to lift the pan feeder. Examination of the links showed no visible nicks or cracks. The hooks and connecting shackles appeared to be in good condition.
The operator control booth was newly fabricated and measured 8-feet long by 6-feet wide. The booth was constructed of 1/8-inch metal and weighed about 4,500 pounds.
The low-head vibratory pan feeder was manufactured by Suedala and had a gross weight of 10,264 pounds. It was delivered to the property on January 7, 1999, unloaded by quarry employees and placed on the ground, face down. The feeder was placed face down because a wooden crate of accessories and the shaker mechanism were attached to the back side. The shaker mechanism and accessories were to be removed and the feeder was to be turned 180 degrees prior to installation.
With the accessories removed the pan feeder weighed about 9,000 pounds and measured 16-feet long, 50-inches wide, and 30-inches deep. Spring support brackets were welded onto both sides at the grizzly end of the feeder. These brackets were made from 1/2-inch steel plate and measured 23-1/2-inches long and 12 inches wide.
Tests were conducted under simulated conditions to determine what caused the feeder pan to tilt unexpectedly. Using the crane and chain sling, the pan feeder was placed on its side, approximating its position and location on the day of the accident. The feeder did not rest flat or solidly on its side because the grizzly end rested on the spring support bracket. With no external forces applied, the feeder remained in position. After about five minutes, the top edge of the pan feeder was lightly pushed by hand in the direction it fell on the day of the accident, causing it to fall in the same manner.
DESCRIPTION OF ACCIDENT
On the day of the accident, John Green, Sr. (victim) reported for work at 6:00 a.m., his normal starting time. He, along with Mark Reese, foreman/laborer, and Kenneth Graham, mechanic/boom truck operator, left the contractor's shop and traveled by service truck to the Globe Quarry. They arrived at about 6:50 a.m. and started removing the sides, floor and support columns of the old feeder bin. Green and Reese used oxygen/acetylene torches while Graham operated the boom truck removing scrap material.
Jerry Jones, owner of Tennessee Diesel Company, arrived at the mine site just past noon. Work continued without incident until about 2:00 p.m., when Reese went with Jones to the pan feeder to decide how to turn it over.
At about 3:15 p.m., Green and Graham joined Reese and Jones to assist in turning the pan feeder over. They removed the crate of accessories and the shaker mechanism from the bottom of the feeder. The pan feeder was then rigged by Jones and Reese to be turned. The feeder was initially turned 90 degrees onto its side with the grizzly end resting on a spring support bracket. The feeder was positioned approximately 22-inches away from the control booth. They were unable to turn the feeder completely due to the uneven weight distribution.
The feeder was lowered to the ground with slack in the hoist cable to see if the feeder would balance. It was determined that another chain and a come-along-type hoist were needed to redistribute the weight. Green was between the booth and pan feeder when it suddenly tipped over, pinning and crushing him.
Jones summoned help by calling the local 911 emergency number on his cell phone. CPR was administered until emergency personnel arrived. Green was transported to the local hospital, where he was pronounced dead at 6:21 p.m., from injuries received in the accident.
The cause of the accident was allowing excessive slack in the lifting cable after the feeder had been lowered to the ground and failure to secure the feeder so it could not fall over.
Tennessee Diesel Company
Citation number 7776426