DEPARTMENT OF LABOR
MINE SAFETY AND HEALTH ADMINISTRATION
Metal and Nonmetal Mine Safety and Health
Accident Investigation Report
Surface Nonmetal Mine
Fatal Machinery Accident
Anchor Rock Products
Anchor Rock Products Company
Pottsville, Maury County, Tennessee
Mine I.D. 40-02921
Date of Injury
April 28, 1998
Date of Death
April 29, 1998
William L. Wilkie
Supervisory Mine Inspector
Terry G. Lingenfelter
Mine Safety and Health Inspector
Mine Safety and Health Administration
135 Gemini Circle, Suite 212
Birmingham, Alabama 35209
Timothy L. Prater, secondary crusher operator, age 36, was seriously injured at about 1:45 p.m. on April 28, 1998, when he contacted a pinch point while attempting to clean a moving conveyor pulley. He died from the injuries the following day. The victim had a total of two years mining experience, all with this company. He had not received training in accordance with 30 CFR, Part 48.
Gary A. Farmer, Sr., president, notified MSHA of the accident at 6:45 a.m. on April 29, 1998. An investigation was started the same day.
Anchor Rock Products, a crushed limestone operation, owned and operated by Anchor Rock Products Company, was located off highway 431 South and Hardison Mill Road, three miles west of Pottsville, Maury County, Tennessee. The principal operating official was Gary A. Farmer, Sr., president. The mine was normally operated one, nine-hour shift a day, five days a week. Total employment was sixteen persons.
Limestone was drilled and blasted in the quarry and the material was hauled by truck from the quarry to the primary crushing plant, where it was crushed and conveyed to a surge pile. Three draw points, located in a tunnel below the pile, pulled the material onto a belt, where it was conveyed to a secondary plant. At the secondary plant, the material was further crushed, screened and stockpiled. The final products were sold for road building and general construction material.
The last regular inspection of this operation was completed on May 22, 1997. Another inspection was conducted at the conclusion of this investigation.
PHYSICAL FACTORS INVOLVEDThe conveyor involved in the accident moved material from the primary plant to the secondary plant and consisted of 316 feet of belt. The belt angled at 16 percent, traveled at 300 feet per minute and was 48-inches wide.
The accident occurred at the surge belt drive pulley area. The drive pulley was located approximately nine feet above ground on a conveyor support structure that also supported a 100-horsepower electric drive motor, a 32-inch diameter take-up pulley and three 24-inch diameter bend pulleys. The structure was constructed of 6-inch H-beams with cross braces made of angle iron to support the conveyor. There was no designated access to any of the conveyor components.
Two of the bend pulleys were above the drive pulley. The belt looped over the first bend pulley, around the drive pulley, and back up over the second bend pulley and then passed over the motor and sloped to the tail pulley.
The distance between the drive motor and the drive pulley was 20 inches. The second bend pulley, closest to the drive motor, was approximately one foot from the motor and approximately one foot above the drive pulley. There were no floors provided on the structure. The framework was open, except for one support beam that centered the H-beams.
The returning conveyor belt was approximately 4-1/2 feet at its highest point which was above the H-beams where the drive motor was mounted. The belt continued to slope down toward the end of the structure, with about 2-1/2 feet between the conveyor and the end I-beam. Controls for starting and stopping the conveyor were in a control house about 50 feet from the conveyor structure.
Normally, the primary crusher belt system fed material to surge piles which provided material for the secondary crushing plant. On the day of the accident, the number 1 draw hole was fed with a front-end loader because the primary crusher unit was down for repairs.
It had rained earlier on the day of the accident and material had built up on the conveyor belt, causing the belt to track to one side.
DESCRIPTION OF ACCIDENT
On the day of the accident, Timothy L. Prater (victim) reported for work at about 6:30 a.m., his regular starting time. Prater went to the control house and started the conveyors for the secondary plant. For about an hour and a half that morning he used the loader to feed the surge pile that provided material to the secondary plant. The rest of the morning he attended the plant.
At 11:30 a.m., it started raining so the crew broke for lunch and left the plant running on its own. When Prater returned to work at around 12:30 p.m., he attended the plant while John Farmer, front-end loader operator, fed the draw hole. Work continued without incident until about 1:45 p.m. when Farmer observed Prater standing on the ground below the conveyor, holding a shovel and looking up toward the pulleys. Because of the rain, material had built up on the bend pulleys and had caused the belt to track to one side. This caused material to fall off the opposite side of the belt instead of feeding the dump point as designed.
Farmer drove the loader to the other side of the surge pile to get another load of material. As he was returning, he saw Prater lying on the ground. Using the radio in his loader, Farmer called the office for help. When Farmer got to Prater he found him lying face down, with his left arm severed. Both the severed arm and the shovel were laying close by Prater. The shovel handle had been cracked in three places.
Gary Farmer, Sr., owner, heard Farmer's call for help and immediately went to the scene. At the same time, the scale house operator heard the call and summoned the local rescue unit. Shane Cothren, a truck driver with EMT training, was returning to the mine when he heard the call on the radio. When he got to the mine he was taken to the accident scene and he assisted in caring for Prater until an ambulance arrived. Prater was in and out of consciousness and the employees packed his arm with ice where it had been severed.
Attendants from the regional ambulance service arrived and stabilized Prater before transporting him to a pick up point for life flight. He was airlifted to a Nashville, Tennessee hospital where he died the next day. Death was attributed to blunt force injuries.
Footprints in the built-up material on the H-beams indicated that Prater climbed the structure and accessed the area between the drive motor and the drive pulley, placing him near pinch points for the drive pulley and the bend pulley. It is believed that he intended to use the shovel to clean the build-up of material from the pulley and when the shovel contacted a pinch point he was pulled into the moving machine parts and then fell 9 feet to the ground. It could not be determined if he contacted a pinch point on the take-up pulley or the bend pulley.
The accident was caused by failure to stop the conveyor before attempting to clean an elevated pulley. Contributing to the severity of the injuries may have been the fall.
Citation No. 7750010 was issued on May 6, 1998, under the provisions of Section 104(a) of the Mine Act for violation of 30 CFR: 56.14202:
A fatal accident occurred at this operation on 4-28-98, when the secondary plant operator became entangled in the take-up pulley for the 48-inch surge conveyor belt. He was using a shovel to clean material from the pulley while the conveyor was in motion.
The citation was terminated on 5/18/98. The mine operator submitted a plan establishing proper procedures for cleaning conveyor pulleys. The plan was approved by MSHA and all employees have been trained in the new procedures.
Citation No. 7750010 was issued on May 6, 1998, under the provisions of Section 104(a) of the Mine Act for violation of 30 CFR: 50.10:
A fatal accident occurred at this operation at 1:45 p.m. on 4-28-98, when the secondary plant operator became entangled in the take-up pulley of a conveyor belt. He died at 6:45 a.m. the following day. MSHA was not notified of the accident until after the time of death.
This citation was terminated on May 6, 1998. The accident was reported at 6:45 a.m. on 4-29-98.
Related Fatal Alert Bulletin: