DEPARTMENT OF LABOR
MINE SAFETY AND HEALTH ADMINISTRATION
Metal and Nonmetal Mine Safety and Health
ACCIDENT INVESTIGATION REPORT
SURFACE NONMETAL MINE
FATAL MACHINERY ACCIDENT
Nashville Quarry and Mill
Menefee Crushed Stone Company, Incorporated
Nashville, Davidson County, Tennessee
December 5, 1995
V. R. Denton
Supervisory Mine Inspector
Mine Safety and Health Inspector
Mine Safety and Health Administration
135 Gemini Circle, Suite 212
Birmingham, Alabama 35209
Lamberto Padilla, Jr., loader operator/welder, age 33, was fatallyinjured between 4:40 p.m. and 11:40 p.m. on December 5, 1995. He was welding inside the crusher when a short circuit in the control wiring caused the crusher to start. The victim had a total of 2 years and 6 months mining experience, all at this mine.
The MSHA Southeastern District Office was notified of the accidentat 3:55 a.m. on December 6, 1995, by a telephone call from Albert Menefee, III, owner of Menefee Crushed Stone Company, Incorporated. An investigation was started immediately.
Nashville Quarry and Mill, a crushed limestone operation, owned and operated by Menefee Crushed Stone Company, Incorporated, was located at 2819 Whites Creek Pike, Nashville, Davidson County, Tennessee. The principal operating official was Albert Menefee, III, owner. The plant was operated one, 9-hour shift, 5 days a week. A total of 34 persons was employed.
The limestone was drilled and blasted, then loaded by front-end loader into trucks and hauled to the primary crusher where it was crushed, sized, screened, and stockpiled. The finished product was primarily used in the construction industry.
The last regular inspection of this operation was conducted
June 28, 1995.
PHYSICAL FACTORS INVOLVED
The Missouri Rogers Impactor Crusher, where the accident occurred, was a single rotor crusher powered by two, 480-volt, 200 horsepower motors, which could be operated independently or at the same time, depending on the horsepower needed to crush the rock.
Power was supplied to the crusher from the main switch house. This was approximately 600 feet from the crusher control room, which housed the control switches for the crusher motors, feeder, discharge conveyor and stacker conveyor. The junction box where the short circuit occurred was located outside the control room.
This box contained the control wires where about two months prior to the accident another short circuit, attributed to vibration, occurred. Repairs were made and there had been no additional problems until the time of the accident.
The crusher could have been locked-out at the switch house, however, this was not done prior to work being done inside the crusher.
Madison Security was contracted by Menefee Crushed Stone Company, Incorporated to provide security at the mine after working hours.
Guards were to maintain contact with employees working alone in
the quarry by using two-way radios. These contacts were to be
made every 30 minutes. However, instructions were not clear on
what was to be done if the employee failed to respond.
DESCRIPTION OF THE ACCIDENT
Lamberto Padilla, Jr., victim, normally worked as a front-end loader operator. He worked as a welder, on an intermittent basis, to make necessary repairs on equipment or machinery at the mine site.
On the day of the accident, Padilla reported to work at 6:30 a.m., his regular starting time. He worked as front-end loader operator until the conclusion of the shift at 4:00 p.m. At that time he and his supervisor decided Padilla would stay at the mine to weld on the rotor inside the crusher. Padilla was last seen at 4:25 p.m. on his way to the quarry.
The guard's log book noted that the first attempt to contact Padilla by two-way radio was at 5:15 p.m. All attempts to communicate with him by radio, as recorded in the log book, were unsuccessful.
Visits to the crusher at 11:40 p.m. and 12:15 a.m., established that the crusher and the stacker conveyor were running but there was no sign of Padilla.
Albert Menefee, III, company president was contacted and arrived at the mine at 1:50 a.m. He and the guard went to the crusher.
When they were unable to stop the crusher at the control room panel, they went to the switch house where they noted the branch circuits were energized and not locked out. Menefee turned off the switch for the crusher. They returned to the crusher and after running the discharge conveyor, discovered the victim's remains.
The belt was stopped and they returned to the mine office and called the local police. The police and county medical examiner arrived at the mine and supervised the removal of the victim's remains. The victim was pronounced dead at the scene by the county medical examiner.
Apparently, due to faulty wiring, an electrical short circuit
occurred inside the same junction box where repairs had been made
two months prior to the accident. The short circuit in the
control wiring caused the crusher and the stacker belt to start.
The direct cause of the accident was the failure to de-energize
and lock out the power switch for the crusher.
Citation No. 4554875 was issued on December 7, 1995, under the provisions of Section 104(a) for violation of Standard 56.12016:
The welder was fatally injured while he was welding inside the crusher. The electrical powered equipment was not de-energized nor were the power switches locked out prior to the welding being performed. It was determined during the investigation that the start button conductors had been shorted together causing the crusher to start while the victim was inside.
Citation No. 4554876 was issued on December 7, 1995, under the provisions of Section 104(a) for violation of Standard 56.18020:
A fatal accident occurred to the welder assigned to work alone inside the primary crusher. He was last seen at 4:25 p.m. on December 5, 1995, leaving the shop to go to his assigned work. His remains were discovered at 1:50 a.m., December 6, 1995, below the crusher on the No. 1 belt. There was no positive action taken to prevent the employee from working alone in a hazardous area that could endanger his safety without being communicated with or being seen or heard by others. Security guards tried unsuccessfully to contact the victim by radio reportedly during the first seven hours but did not have a procedure to follow when there was no response from him. The first on-site visit was at 11:40 p.m. and it was also unsuccessful.
Respectfully submitted by:
/s/ V. R. Denton
Supervisory Mine Inspector
/s/ Elton Hobbs
Mine Safety and Health Inspector
Related Fatal Alert Bulletin: