DEPARTMENT OF LABOR
MINE SAFETY AND HEALTH ADMINISTRATION
COAL MINE SAFETY AND HEALTH
REPORT OF INVESTIGATION
Surface Coal Mine
Fatal Machinery Accident
February 1, 2008
Thompson Tractor Company, Inc. (DL2)
Birmingham, Jefferson County, Alabama
Reed Minerals, Inc.
Jap Creek Mine
Walker County, Alabama
I.D. No. 01-02996
John M. Church
Mine Safety and Health Specialist (Electrical)
David H. Allen, Jr.
Mine Safety and Health Technical Support
Division of Mechanical and Engineering Safety
Mine Safety and Health Administration
135 Gemini Circle, Suite 213
Birmingham, Alabama 35209
Richard A. Gates, District Manager
On February 1, 2008, a 34-year old field service mechanic for Thompson Tractor Company, Inc., was fatally injured while working on the diesel engine of a Caterpillar D10R bulldozer at the Reed Minerals, Inc., Jap Creek Mine in Walker County, Alabama. To observe movement of a potentially damaged lifter and to place it in a better position for retrieval, the victim requested that a co-worker "bump" the engine. "Bumping" the engine involves supplying power to the engine starter to produce limited movement of internal engine components without starting the engine by turning the ignition key to the start position and quickly releasing it. The victim was struck in the left eye when diesel fuel that had accumulated in the cylinder bore was ejected from the open injector sleeve orifice under pressure at a high velocity when the co-worker "bumped" the engine.
The accident occurred because: (1) the victim had not been provided with hazard training in safe working procedures and the safety hazards related to the failure to remove residual fluid from cylinder bores, (2) power was supplied to the engine starter causing motion of internal engine components while repairs/maintenance was being performed, and (3) the victim was not wearing eye protection.
The Jap Creek Mine, I.D. No. 01-02996, is owned and operated by Reed Minerals, Inc., and is located in Walker County, Alabama. Operations at the Jap Creek Mine began August 1, 1993, and 59 persons are currently employed at the mine. The mine operates 6 days per week with two 10-hour shifts per day. Coal is mined from 5 separate seams ranging from 10 inches to 26 inches in thickness. The mine produced 524,210 tons of coal in 2007.
A safety and health inspection was completed on January 15, 2008, and no inspection was ongoing at the time of the accident. The Non-Fatal Days Lost (NFDL) injury incidence rate for the mine for the previous quarter was 7.09 compared to the national NFDL rate of 1.00 for surface coal mines.
The principal officials of the mine at the time of the accident were:
Robert Reed .......... Owner
Frances Nibler .......... Director of Operations
Allen Scott .......... Safety Manager
Donald Johnson .......... Mine Superintendent
Thompson Tractor Company, Inc. (Thompson), contractor I.D. No. DL2, is headquartered in Birmingham, Alabama, and is the full-line Caterpillar dealer for Alabama, northwest Florida, and most of Georgia. The company specializes in leasing, sales, and service of Caterpillar products, including earthmoving, construction and material handling equipment, and diesel engines used for electric power generation, on-highway and marine propulsion applications. Field mechanics are deployed to sites as needed or as scheduled. There were three field service mechanics working at the mine at the time of the accident.
The Non-Fatal Days Lost (NFDL) injury rate for the contractor for the previous quarter was 0.00 compared to the national NFDL rate of 0.82 for all contractors at surface mines.
The contractor's principal officials at the time of the accident were:
Bob Bacon .......... .Vice President and General Manager Service
Mike Snow .......... Central Region Service Manager
Keith Pardue .......... Birmingham Service Manager Earthmoving
Johnny Wilson .......... Field Service Mining Supervisor
On Friday, February 1, 2008, C. Barret Stratton (victim), a field service mechanic for Thompson, traveled to the Jap Creek Mine to diagnose and, if possible, repair an operational problem with the diesel engine on a Caterpillar D10R bulldozer (dozer). Stratton helped Thomas Frost, a Thompson field service mechanic, work on other equipment at the mine before beginning work on the dozer. Stratton left Frost to begin work on the dozer shortly before 10:00 a.m. Frost joined Stratton at the dozer at approimately 10:00 a.m. Johnny Peterman, a Thompson field service mechanic, worked on a job at a different surface mine before arriving at the dozer at approimately 11:30 a.m.
Stratton, Frost, and Peterman removed guards and shields to epose the diesel engine compartment and work proceeded to diagnose the problem. The number 7 cylinder valve cover, valve rocker arms, and injector were removed. Stratton positioned himself over the number 7 cylinder near the open injector sleeve to observe lifter movement. At approimately 12:30 p.m. Stratton asked Frost to "bump" the engine. Peterman immediately observed what was described as a "mist" of diesel fuel around Stratton's head when Frost "bumped" the engine.
Peterman saw Stratton slump over and called out to him but received no response. Peterman and Frost removed Stratton from his work location on the dozer track and placed him on the ground. Stratton's vital signs were checked and he was not breathing and had either a faint or no pulse. Peterman and Frost began 2-man CPR and Peterman called 911 at 12:34 p.m. CPR resumed for approimately 30 minutes until an ambulance arrived. A medical services helicopter had also been dispatched to the mine but returned to base when notified that their services were not needed. Stratton was pronounced dead at the mine at 1:26 p.m. An autopsy was performed and the cause of death determined to be blunt force trauma.
At approimately 12:45 p.m. on Friday, February 1, 2008, Frances "Buck" Nibler, Director of Operations for Reed Minerals, Inc., notified MSHA Assistant District Manager Gary Wirth that a serious accident possibly resulting in a fatality had occurred at the Jap Creek Mine. MSHA accident investigators were sent to the mine and an order pursuant to ï¿½ 103(k) of the Federal Mine Safety & Health Act of 1977 was issued to ensure the safety of miners until an investigation could be conducted. The accident investigators made an examination of the accident scene, interviewed witnesses, and reviewed work conditions relative to the scene. MSHA conducted the investigation with the assistance of state investigators, Thompson employees, and mine management. Persons participating in the investigation are shown in Appendi A. Eight people were interviewed throughout the investigative process.
The weather was overcast and cool in the morning and sunny in the afternoon. The dozer had been moved to a location away from active mining for repairs. The site was wet and fairly level.
Engine Description and Findings
The engine involved in the accident was a Caterpillar 3412E diesel engine. The Caterpillar 3412E engine is a 12-cylinder, turbo-charged diesel engine with a rating of 661 gross horsepower. This electronically controlled engine is designed with one fuel injector for each cylinder. Fuel is delivered to each injector by a common rail. This engine has a common rail for each bank of 6 cylinders.
Residual fuel from the common rail will drain into the combustion chamber and piston cylinder if the fuel is not drained prior to removing an injector. Representatives of the contractor and manufacturer indicated up to one quart of fuel can potentially drain into the piston cylinder when an injector is removed from this engine model.
On February 6, 2008, investigators and representatives from the mine and Thompson witnessed the removal of the cylinder heads by Frost and Peterman. Residual fluid was observed in the number 7 cylinder (see Appendi B). Nothing internal to the piston cylinder or combustion chamber was observed to be broken. Engine components were eamined for damage. All previously removed hardware was identified and counted and nothing was missing. It was observed, however, that a lifter guide spring was broken, indicating a possible failed lifter or camshaft lobe. The lifter was removed and observed to be damaged (see Appendi B). The lifter and guide spring are eternal to the piston cylinder and any broken pieces would have fallen into the engine oil pan through the oil drains. The engine was subsequently removed from the dozer and taken to the Thompson facility near Birmingham, Alabama, for further inspection.
On February 11, 2008, investigators traveled to the Thompson facility to observe additional dismantlement of the engine. The oil filters contained small metal shavings that, according to shop mechanics, appeared to be lifter fragments. The broken piece of the guide spring was found in the oil pan (see Appendi B) along with additional metal from the damaged lifter.
Recommended Work Procedures
The manufacturer's injector installation manual for this engine emphasizes the evacuation of fluid from the cylinder bore before installing an injector to prevent hydraulic lock of the engine. Installation of the injector creates a closed system. Hydraulic lock occurs in a closed system when a cylinder contains fluid and upward movement of the piston stops short due to the incompressibility of the fluid. This would cause engine damage. The manufacturer's literature does not address the evacuation of fluid from cylinders as a safety precaution to protect persons from injury.
Observations in a Controlled Environment
Rebuilt engines are tested on a dynamometer to ensure compliance with Caterpillar specifications before they are sent to the field. According to a Thompson CRC Engine Supervisor, "about every 6 to 7 months" rebuilt engines contain fluid, which is usually water, in the cylinder bores. If fluid is present in a cylinder bore, it is removed while the engine is on the dynamometer and before the engine is tested. To remove the fluid, the injector is removed, persons are withdrawn to safe locations, and the engine is started remotely. He indicated that the resulting stream of fluid is ejected from the injector sleeve orifice at a high rate of speed and strikes the ceiling, which is approimately 20 feet high, with resounding force.
Hazard Training Program
Thompson developed and submitted a Hazard Training Program that was approved June 24, 2002. The Hazard Training Program requires, in part, that instruction be given in safe working procedures.
Work History and Training
Stratton began his employment with Thompson as a trainee at the shop facility on October 23, 1995. He was promoted to a Class C mechanic on April 21, 1997, to a Class B mechanic on October 19, 1998, and to a Class A mechanic on October 16, 2000. He became a field service mechanic on October 17, 2005. He last completed annual refresher training September 30, 2007.
A mine supervisor had previously observed white smoke from the diesel ehaust system of the company number 5202 Caterpillar D10R bulldozer. The white smoke is often indicative of an injector problem. Stratton, Peterman, and Frost removed guards and shields to open the engine compartment. At the number 11 cylinder, Stratton removed the injector, evacuated fluid from the cylinder bore using a vacuum device, installed a new injector, and completed reassembly. This did not repair the problem.
Net, the valve cover, valve rocker arms, and injector at the number 7 cylinder were removed. With the rocker arms removed from the engine head, all 4 valves (2 intake valves and 2 ehaust valves) of the number 7 cylinder were held in the closed position by the valve springs. Stratton apparently made the determination that there was nothing wrong with the injector and turned his attention to the lifters. According to Thompson officials, the determination that there was a more significant problem with the engine was most likely made after observing a broken lifter guide spring and realizing that the lifter was probably damaged. Stratton tried to retrieve the questionable lifter but was unable to do so. In an attempt to observe movement of the lifter and to place it into a better position for retrieval, he requested that Frost "bump" the engine. Stratton was leaning over the open injector sleeve opening when Frost "bumped" the engine. Stratton had not removed residual fluid from the number 7 cylinder and diesel fuel was ejected from the open 0.33-inch diameter injector sleeve orifice, which was the only opening to the atmosphere, under pressure at a high velocity and struck Stratton in the left eye. Stratton was not wearing eye protection. (See Appendi C for illustrative cylinder sketches.)
According to Frost and Peterman, Stratton normally wore darkly tinted safety glasses and had been wearing them before the accident. Stratton probably removed the darkly tinted safety glasses because he was trying to see lifter movement in the dark recesses of the engine. Thompson provides different styles of safety glasses that range from untinted to moderately tinted to darkly tinted.
Interviews with Stratton's immediate supervisor indicated that Stratton probably did not remove the fuel in the cylinder bore because he was not concerned with hydraulic lock that would occur if the injector was re-installed without evacuating the fluid from the cylinder bore. He further indicated that hydraulic lock would not be a concern because Stratton would have realized that the engine would have to be removed and rebuilt upon seeing the broken lifter guide spring and realizing the lifter was not functioning properly. A Thompson manager indicated that Stratton probably wanted to remove the lifter in the field to show the mine operator proof that the engine had to be rebuilt.
An analysis was conducted to identify the most basic causes of the accident that were correctable through reasonable management controls. During the analysis, three root causes were identified that, if eliminated, would have either prevented the accident or mitigated its consequences.
Root Cause: The victim had not been provided with hazard training in safe working procedures and the safety hazards related to the failure to remove residual fluid from cylinder bores.
Corrective Action: Train all field mechanics in the safety hazards associated with failing to remove residual fluids from cylinder bores.
Root Cause: Power was supplied to the engine starter causing motion of internal engine components while repairs/maintenance was being performed.
Corrective Action: Safe means, such as by manually turning the engine or by using other equally safe and effective alternative means, must be used to cause motion of internal engine components when repairs and/or maintenance are being performed.
Root Cause: The victim was not wearing eye protection.
Corrective Action: Train all field mechanics in the requirements to use appropriate eye protection and require field mechanics to wear clear safety glasses when working in dark areas.
On February 1, 2008, a 34-year old independent contractor employee was fatally injured when he was struck by diesel fuel that was ejected from a cylinder bore through the injector sleeve orifice of the diesel engine of a Caterpillar D10R bulldozer. The diesel fuel was ejected from the orifice under pressure at a high velocity when the engine was "bumped" to place a lifter in a better position for retrieval. The accident occurred because: (1) the victim had not been provided with hazard training in safe working procedures and the safety hazards related to the failure to remove residual fluid from cylinder bores, (2) power was supplied to the engine starter causing motion of internal engine components while repairs/maintenance was being performed, and (3) the victim was not wearing eye protection.
ï¿½ 103(k) Order No. 7691157:
At approimately 12:34 p.m., an employee of Thompson Tractor Company, Inc. (contractor ID DL2) was involved in an accident resulting in fatal injuries on mine property as he was performing maintenance on the company number 5202 Caterpillar D-10R dozer, S/N AKT943. This order is issued to assure the safety of persons until an accident investigation is conducted.
Area or Equipment: The #5202 D-10R Caterpillar dozer (S/N) AKT943), the Thompson Tractor Co., Inc., #134 Ford F-650 service truck, and the access road adjacent to this equipment.
ï¿½ 104(d)(1) Citation Issued to Thompson Tractor Company, Inc., Contractor ID DL2, for Violation of ï¿½ 48.31(a)(3):
On February 1, 2008, an employee of Thompson Tractor Co., Inc. (Thompson), an independent contractor performing services at the Reed Minerals, Inc., Jap Creek Mine, was fatally injured when diesel fuel was ejected from an open 0.33-inch diameter injector sleeve orifice. Thompson has not provided its employees with hazard training in safe working procedures and the safety hazards related to the failure to remove residual fluid from cylinder bores. Thompson management officials had knowledge of the safety hazards caused by failure to remove fluid from a cylinder bore and by starting the engine to remove ecess fluid through an open injector sleeve orifice but did not train field service mechanics in these hazards. This is aggravated conduct constituting more than ordinary negligence and an unwarrantable failure to comply with a mandatory safety standard.
ï¿½ 104(a) Citation Issued to Thompson Tractor Company, Inc., Contractor ID DL2, for Violation of ï¿½ 77.404(c):
On February 1, 2008, an employee of Thompson Tractor, Co., Inc., an independent contractor performing services at the Reed Minerals, Inc., Jap Creek Mine, was fatally injured while performing repairs/maintenance on the diesel engine of the company number 5202 Caterpillar D10R bulldozer. Power was supplied to the starter which caused movement of internal engine components. The movement of the internal engine components caused diesel fuel to be ejected from an open 0.33-inch diameter injector sleeve orifice. The victim received fatal injuries when the diesel fuel struck him in the left eye.
ï¿½ 104(a) Citation Issued to Thompson Tractor Company, Inc., Contractor ID DL2, for Violation of ï¿½ 77.1710(a):
On February 1, 2008, an employee of Thompson Tractor Co., Inc., an independent contractor performing services at the Reed Minerals, Inc., Jap Creek Mine, was fatally injured when diesel fuel was ejected from the open 0.33-inch diameter injector sleeve orifice on the number 7 cylinder of the diesel engine on the company number 5202 Caterpillar D10R bulldozer and struck the victim in the left eye. The victim was not wearing eye protection at the time of the accident.
Persons Participating in the Investigation
THOMPSON TRACTOR COMPANY, INC.
Bob Bacon (Vice President and General Manager Service)
Mark Schropp (Technical Communicator)
Terry Benton (CRC Process & Quality Auditor)
Rick Lansdell (CRC Engine Supervisor)
Johnny Wilson (Field Service Mining Supervisor)
Thomas Frost (Field Service Mechanic)
Johnny Peterman (Field Service Mechanic)
REED MINERALS, INC.
Frances Nibler (Director of Operations)
Allen Scott (Safety Manager)
Donald Johnson (Mine Superintendent)
STATE OF ALABAMA DEPARTMENT OF INDUSTRIAL RELATIONS
MINING AND RECLAMATION DIVISION
Gary Key (Chief, Mine Safety and Inspection)
Ronnie West (Mine Inspector)
David Keeton (Mine Inspector)
Leon Herren (Mine Inspector)
MINE SAFETY AND HEALTH ADMINISTRATION
John Church (District 11 Mine Safety and Health Electrical Specialist, Lead Investigator)
David Allen (District 11 Mining Engineer)
Jarvis Westery (District 11 Surface Coal Mine Inspector)
Phillip McCabe (Mine Safety and Health Technical Support, Division of Mechanical and Engineering Safety Mechanical Engineer)