DEPARTMENT OF LABOR
MINE SAFETY AND HEALTH ADMINISTRATION
Accident Investigation Report
(Surface of Underground Coal Mine)
Fatal Machinery Accident
Windsor Mine (I.D. No. 46-01286)
Windsor Coal Company
West Liberty, Brooke County, West Virginia
Savage Construction Company
Contractor I.D. No. E05
Elm Grove, Ohio County, West Virginia
December 9, 1999
Chris A. Weaver
Mining Engineer (Ventilation)
Richard J. Dunst
William L. Sperry
Coal Mine Safety and Health Inspector (Electrical)
Originating Office-Mine Safety and Health Administration
5012 Mountaineer Mall, Morgantown, West Virginia 26501
Timothy J. Thompson, District Manager
A work crew, consisting of three contractor employees, was preparing a P&H Mobile Crane Model T-750 for transport. This included the removal of the outrigger assemblies and a 6-ton counterweight to reduce the gross vehicle weight. To remove the counterweight, a 3/4 inch wire rope assembly was connected to the boom section and the counterweight. Before the crane operator extended the boom a sufficient distance to secure the counterweight with the rope, the two top pins of the counterweight attachment hardware were removed. This prematurely released the counterweight, resulting in failure of the 3/4-inch wire rope assembly and the remaining attachment hardware securing the counterweight to the crane. William Scott Hunter, who was positioned between the counterweight and the crane, was fatally injured. This accident occurred on the surface of an underground coal mine.
The accident occurred because the 6-ton counterweight was not secured with the removal rope prior to the attachment hardware being removed.
The Windsor Mine, an underground coal mine, is operated by Windsor Coal Company. The mine is located on Locust Grove Road, off State Route 88, approximately one mile north of West Liberty, Brooke County, West Virginia. The mine is accessed by 2 shafts and 19 drift openings into the Pittsburgh No. 8 coal seam, which averages 60 inches in thickness.
The mine employs 259 persons, of which 199 work underground. Coal is produced 3 shifts per day, 5 to 6 days per week. An average of 9,060 tons of clean coal is produced daily from 2 continuous-miner sections and 1 longwall section. Coal is transported from the sections to the surface by a belt conveyor system. A track-trolley haulage system is used to transport supplies, materials, equipment and employees into and out of the mine.
The mine is ventilated by two exhausting main fans and one blowing fan located on the surface. The mine liberates approximately 798,224 cubic feet of methane every 24 hours.
Windsor Coal Company contracted Murphy Construction & Equipment Rental Co., Contractor I.D. No. LD4, of Follansbee, West Virginia, to provide crane service to lift various types of mining machinery (such as longwall equipment, shuttle cars, continuous miners, locomotives, power centers, electric motors, etc.) for the Windsor Mine on an as needed basis. Savage Construction Company, Contractor I.D., No. E05, of Elm Grove, West Virginia, was sub-contracted by Murphy Construction to provide crane services at the surface area of the Hoglan Run drift openings. Prior to the accident, Savage Construction Company had provided crane service to support a longwall move in progress at the mine. The principal officials for the Windsor Mine at the time of the accident were:
D.G. Zatezalo General ManagerThe principal officers for the Savage Construction Company at the time of the accident were:
J.B. Matkovich Mine Superintendent
Michael L. Roxby Manager Safety and Health
Charles J. Savage President David Petrini SecretaryThe last MSHA regular Health and Safety Inspection (AAA) was completed on September 30, 1999, and another was ongoing at the time of the accident. The Non-Fatal Days Lost (NFDL) incident rate during the previous quarter was 6.70 for underground mines nationwide and 8.24 for this mine.
DESCRIPTION OF THE ACCIDENT
On December 9, 1999, at approximately 9:00, a.m., Jay A. Powell, crane operator, and William Scott Hunter, truck driver/oiler, arrived at the Hoglan Run drift openings to prepare the P&H Model T-750 truck mounted crane, serial number 38811, for travel. This work included the removal of the outrigger assemblies and a 6-ton counterweight to reduce the gross vehicle weight (refer to Appendix B, Crane Detail). Powell and Hunter had worked together on numerous similar jobs during the past 15 years. They had moved this particular crane approximately 78 times over the past 2 years.
Powell and Hunter first removed the two outrigger assemblies from the crane. Powell utilized the crane to load the outrigger assemblies onto a nearby flat bed trailer. Powell then retracted the boom and lowered it to the horizontal position.
Daniel DiGiovanni arrived at the site at approximately 9:25 a.m. DiGiovanni was to provide pilot vehicle service during transport of the crane to the next work site. Upon arrival, he proceeded to assist in the preparation of the crane for travel.
The three men next prepared to remove the counterweight which was pinned to the back of the crane by four clevis-type attachment points. The method of attaching the counterweight to the crane had been modified by a previous owner to facilitate frequent removal of the counterweight for transportation (refer to Appendix C, Counterweight Attachment Detail). The contractor's normal procedure for removing the counterweight is as follows: (1) attach one end of a 3/4-inch wire rope assembly to the counterweight and the other end to the back of the first boom section; (2) thread the wire rope over a 10-inch diameter sheave located directly above the counterweight; (3) extend the boom approximately nine feet until all slack is removed from the wire rope and the counterweight is lifted slightly; (4) remove the pins from the clevises; and (5) lower the counterweight to the ground by retracting the boom. Powell stated that the pins would normally be removed by standing on a plastic milk crate, placed to either side of the counterweight, and removing both pins from each respective side. A one-foot space between the counterweight and the crane permitted hitting the back side of the pins with a hammer, if necessary.
By approximately 9:45 a.m., the counterweight removal rope had been attached and Powell was extending the boom to remove slack. Looking over his left shoulder, Powell could see DiGiovanni, who was located on top of the crane. DiGiovanni was kneeling, facing toward the front of the crane, while observing the travel of the counterweight removal rope to assure that the rope did not damage hydraulic hoses located in the boom of the crane. Powell stated that, during this phase of the operation, Hunter would normally be securing the outriggers to the flat bed trailer. However, the outriggers were never secured to the truck bed. Instead, Hunter was located under the center of the counterweight and was not visible to either of his co-workers. From this position, Hunter could reach up between the counterweight and the crane to knock out either of the pins from the upper clevises. Removal of both upper attachment pins prior to securing the counterweight with the removal rope would permit the counterweight to rotate downward, around the lower clevises, placing Hunter in a pinch point between the bottom of the counterweight and the crane. Therefore, Powell was not anticipating such action from Hunter at this point in the procedure.
As the boom reached five feet of extension, Powell heard the distinct sound of something striking a metallic object. Powell immediately recognized the sound as that of the counterweight attachment pins being removed with a hammer. Powell realized that the boom was not sufficiently extended to secure the counterweight and attempted to warn Hunter. However, as Powell turned to yell "NOT YET!" he heard a loud snap and then felt the crane shake. DiGiovanni was in the process of standing up when the accident occurred. DiGiovanni turned in time to see Hunter falling backward onto the counterweight which was already laying on the ground. Both top counterweight attachment pins had been removed and were found seven to ten feet to either side of the crane. Hunter's hammer had fallen to the ground just beyond his left hand. The counterweight removal rope had broken and both lower clevis attachments had torn away from the crane, allowing the counterweight to fall to the ground (refer to Appendix D, Motion of Counterweight). The rotation of the counterweight pinned Hunter against the crane, causing fatal injuries.
DiGiovanni went to his truck to call for help as Powell attended to Hunter. Hunter's injuries included severe trauma to the neck and spine. Powell immediately checked Hunter for vital signs, but Hunter was unresponsive and none were detected. The remote location of the accident site made it difficult for DiGiovanni to establish communication using the cell phone or the company radio in his truck. Therefore, he drove toward the main highway searching for emergency telephone availability. Powell also attempted to call for assistance on the mine pager phone, located on the surface near the drift openings. However, Powell was not familiar with the use of the mine phone system and failed to establish communication.
While en route, DiGiovanni established radio communication with the office facility of Savage Construction Company. He informed the office of the accident and requested medical assistance. The Brooke County Sheriff's Department Dispatch Center received a call from Savage Construction Company at 10:04 a.m. and immediately called for Emergency Medical Services (EMS). DiGiovanni waited near the main highway to meet the ambulance and guide them to the accident site. The Bethany Fire Department was the first EMS to arrive at the scene of the accident at 10:17 a.m. and the Brooke County Ambulance Service arrived a few minutes later. The Brooke County Sheriff's Department arrived at the scene of the accident at 11:05 a.m., followed by the Brooke County Medical Examiner at 12:05 p.m. The victim was transported directly to the Chambers Funeral Home in Wellsburg, West Virginia, by the Brooke County Ambulance Service at 12:55 p.m.
INVESTIGATION OF THE ACCIDENT
This investigation was conducted in cooperation with the West Virginia Office of Miner's Health, Safety and Training and the Brooke County Sheriff Department. Other participants included management personnel from Savage Construction Company and Windsor Mine. The UMWA provided representatives of the miners during the investigation. Chris A. Weaver was appointed as lead investigator for MSHA. A list of those persons who participated in the investigation can be found in Appendix A of this report.
A pre-investigation conference was conducted by MSHA upon arrival at the Windsor Mine at 1:30 p.m. on December 9, 1999. The on-site investigation was also initiated on the same day, including preliminary interviews with the witnesses. An MSHA coal mine inspector, Joseph Yudaz, was underground at the Windsor Mine at the time of the accident and he secured the site until the investigation team arrived. All existing conditions were evaluated and recorded in notebooks by investigation team members. Photographs, electronic images, and video recordings were made of the accident site. MSHA received custody of the broken counterweight removal rope during the investigation. An evaluation of static and dynamic forces relating to the failure of components involved in the accident was conducted by MSHA Technical Support. The investigation also included a review of training records.
On December 13, 1999, MSHA and the West Virginia Office of Miner's Health, Safety and Training conducted follow-up interviews of persons with knowledge of the facts surrounding the accident. Additional information was obtained by MSHA and the West Virginia Office of Miner's Health, Safety and Training from the Brooke County Sheriff Department on December 15, 1999.
Local authorities provided significant contributions to the investigation. The Bethany Fire Department was the first response service to arrive at the scene of the accident and secured the site with ribbon. The Brooke County Sheriff Department was the first enforcement agency to respond to the accident site. In addition to photographing and video taping the accident site, the Brooke County Sheriff Department made key observations of the victim's footprints which were destroyed during removal of the victim.
The chain of communication which led to MSHA notification of the accident was also initiated by local authorities. Upon determining that an occupational fatal accident had occurred, the Brooke County Dispatch Center reported the accident to OSHA at 10:31 a.m. By 10:50 a.m., Jerry Good, OSHA, had determined that the accident would likely be under MSHA jurisdiction and contacted District 3. By this time, the contractor had not reported the accident to MSHA or to Windsor Mine officials. District 3 personnel immediately informed the mine of the reported accident which was confirmed by the Brooke County Dispatch Center at 10:59 a.m. There were no mine employees present at the Hoglan Run drift openings at the time of the accident.
Statements made by DiGiovanni and Powell were consistent with physical evidence and provided early explanations as to when and where the accident occurred, as well as who was involved. However, since there were no direct eye witnesses to the event, determining how and why the accident occurred primarily relied on analysis of physical evidence.
Dynamic Analysis - A primary focus of the investigation was to determine the motion of the counterweight and the cause for failure of its support system. Measurements indicated that, prior to removing the top pins, the distance between the counterweight and the back of the crane was approximately twelve inches, with the crane properly level and plumb. During the investigation, the upper pins were located on the ground in line with the pin holes (7.2 feet to the right and 10.2 feet to the left of the crane). These locations indicated that both pins were knocked out using a hammer. After the second pin was removed, the counterweight would have rotated away from the crane around the lower pins. This motion continued to accelerate until the wire rope became taut.
Measurements of the wire rope and attachment points, relative to the sheave, indicated that approximately 30 inches of slack was present in the wire rope when the second pin was removed. This amount of slack allowed the counterweight to rotate approximately 58o from vertical. At this point, the falling counterweight exerted a shock load on the wire rope that was in excess of its breaking strength. Calculations indicated that the rope would have needed a breaking strength in excess of 200,000 pounds to stop rotation of the counterweight prior to failure. However, the manufacturer of the rope (Wire Rope Corporation of America, WRCA), reported an actual breaking strength of 64,800 pounds for a rope sample from the same lot as that used for the counterweight removal rope. Examination of the wire rope confirmed that the cause for failure was most likely a single-event on-axis overload (there was no indication of kinking, corrosion, bending or fatigue failure). Measurements indicated that the location of failure was at the point where the rope passed over the sheave. Since the rope strength was not sufficient to stop the counterweight rotation, it continued to rotate away from the crane as the rope broke.
Examination of the lower clevis attachments indicated that their range of motion ended as the counterweight rotation reached approximately 135o from vertical. At this point, the bottom two clevis attachments were torn loose from the crane body by the rotational momentum of the counterweight. The clevis attachment welds failed by being pulled directly away from the crane body (90o to the crane body) or away from the crane body and downward (>90o). This was evidenced by a �-inch deflection of the steel plating on the crane body at the failed welds and by the condition of the clevis attachment bolts after the accident. The lower left bolt broke under tensile failure, while the lower right bolt pulled through the clevis attachment plate. After the clevis attachments failed, the counterweight continued to rotate as it fell to the ground. A deep impact depression, located just behind the rear wheels, indicated that the counterweight had rotated a total of approximately 225o before hitting the ground. The final position of the wire rope, clevises, and counterweight were all consistent with this motion.
Human Factors - The investigation revealed several factors relevant to the actions and the location of the victim prior to and during the accident.
The Brooke County Sheriff Department found a single set of foot prints which identified the victim's location at the time of the accident. He was standing between the crane and the counterweight, near the center of the back side of the crane. His toes were pointing toward the front of the crane. The victim stood approximately 72 inches tall, while the distance from the bottom of the upper portion of the crane to the ground was 61-� inches. The bottom of the counterweight was even with the bottom of the upper portion of the crane prior to the accident. This placed the victim's head and neck between the counterweight and the upper portion of the crane. As the counterweight rotated, a pinch point was created at the bottom edge of the upper portion of the crane, resulting in severe injuries to the victim's head and neck. The location of the injuries indicated that the victim was looking toward the top right pin at the time of the accident. Injuries to the victim's lower extremities were incurred when the counterweight rotated past 180o, forcing his legs against the undercarriage. This was evidenced by marks left on the victim's clothing corresponding to the undercarriage. The victim came to rest on top of the counterweight, in a position consistent with the footprint evidence. A hammer was found on the ground just beyond the victim's left hand, consistent with the hand most likely to be used to hit the top right pin. The victim was also left-handed. The distance from the ground to the top pins was 94 inches, within reach of the victim when using a hammer from this location. The distance between the top pins was 45 inches, requiring little repositioning from the victim's location in order to strike both upper pins. Powell reported hearing only one hammer strike, perceived as originating from the back right side of the crane, immediately before the accident.
The keepers to all four counterweight attachment pins were removed prior to the accident, reportedly by the victim, and placed on the flat bed trailer. This indicated that the pin removal process was initiated well in advance of securing the counterweight with the removal rope. It is possible that the first pin was also removed at this time, although no evidence was found to confirm this possibility. The investigation, therefore, theorized two possible reasons for the victim's final actions: either the victim misjudged the amount of remaining rope slack and removed both pins immediately before the accident; or the victim was unaware or forgot that the first pin had already been removed. In either case, the first pin may have been easier to remove if knocked out before the removal rope placed an upward force on the top pins.
Crane Specifications - The crane involved in this accident was a P&H Mobile Crane, Model T750, 75-ton capacity crane. A certification plate attached to the crane contained the following information:
Serial # 138811 (The manufacturer's serial number is 38811)The investigation revealed that the crane was certified when purchased by the Savage Construction Company in October 1997. Savage Construction Company had the crane certified as indicated by the above record of certification observed on the crane. Such certification inspections are required by OSHA pursuant to Title 29 of the Code of Federal Regulations. However, such certification is not a requirement of Title 30. The contractor routinely performs work in both jurisdictions.
P&H 150,000 lb. max. crane
Owner ID #GRF515 (#19)
According to the manufacturer (Terex, which now owns P&H), the crane was originally supplied with the counterweight bolted directly to the upper portion of the crane. Nine-inch long, 1� -inch diameter, A325 bolts were specified for this application. The shop manual for the T750 crane includes instructions on how to properly remove the counterweight. However, since the attachment design had been altered, these instructions were not directly applicable. Although, portions of the recommended procedures could be applied to both attachment methods. The manufacturer's recommended procedure requires the outriggers to be extended and set during the entire procedure. At the time of the accident, the rear outriggers were removed and the front outriggers were retracted. The manufacturer's recommended procedures ensure that the slack is removed from the counterweight rope before removing "the hardware which secures the counterweight to the upper frame." Although the existing attachment hardware is different, this procedure is clearly applicable to the modified design and was not followed in two ways: when all four of the pin keepers were removed and when the top pins were removed. The contractor stated that they did not have a written procedure for removing the counterweight with the modified attachment design.
The upper portion of the crane from which the boom extends is capable of a full 360o rotation. At the time of the accident, the three-section boom was facing the front of the crane and the No. 1 section was extended approximately 5 feet. The counterweight weighed approximately 12,100 pounds, measured 45 inches high and 118 inches wide. Its thickness ranged from 8 inches at the right and left sides to 16 inches at the middle.
Wire Rope Specifications - The wire rope used to hoist the counterweight was a �-inch 6x25 filler wire, right, regular lay rope with an independent wire rope core (IWRC). The core was a 7x7 rope. According to the manufacturer of the rope, WRCA, the rope was fabricated from Extra Improved Plow Steel. Although the actual breaking strength of this rope may have been higher, the catalog breaking strength was listed as approximately 29.4 tons (58,800 pounds). Using the catalog breaking strength, the "design factor" (breaking strength of the rope divided by the total rope stress) of the wire rope calculates to approximately 4.9. According to the ASME standard for this application (ASME B30.5d-1999, Section 5-1.7.1(a)(1)), the design factor should not be less than 3.5.
The rope was fabricated into a sling with one end terminating in a zinc socket and the other end terminating in a mechanical splice and thimble. The zinc socket and the thimble were both the proper size for the rope, i.e., �-inch. The rope was attached to the counterweight with the zinc socket. The zinc socket appeared to be undamaged. The thimble end of the rope was attached to the boom with a shackle. The thimble and mechanical splice remained intact; however, a slight elongation of the thimble was visible.
Additional Contractor Information - Typically, Teamster members (such as Hunter) working jobs associated with Savage Construction Company are employed through Dump Truck, Inc., an independent company with the same principal officers as Savage Construction Company. However, according to Savage Construction Company, Teamster members working on State or Federally funded jobs are employed directly by Savage Construction Company. On the day of the accident, the victim was assigned to transport the crane counterweight and outriggers from mine property to a State road construction site. Pay records presented to the investigation team showed that the victim was paid by Dump Truck, Inc., for work performed on the day of the accident. However, representatives of Savage Construction Company stated that the victim should have been paid by Savage Construction Company for that day. Salary personnel utilized by Savage Construction Company, including DiGiovanni, are employed through Executive Supervisors, also an independent company with the same principal officers as Savage Construction Company. Powell was employed by Savage Construction Company.
Murphy Construction & Equipment Rental Co. was contracted by Windsor Coal Company to load and haul equipment from mine property. Savage Construction Company was subcontracted by Murphy Construction & Equipment Rental Co. for this particular job. The Independent Contractor Register, maintained at the Windsor Mine pursuant to 30 CFR 45.4, contained the required information for Murphy Construction & Equipment Rental Co. However, no independent contractor information was listed for Savage Construction Company, Dump Truck, Inc., or Executive Supervisors in this register. Also, no records of hazard training were available for Savage Construction Company employees. Appropriate citations were issued for these violations during the concurrent Safety and Health Inspection.
The accident occurred because the 6-ton counterweight was not secured with the removal rope prior to the attachment hardware being removed. Removal of both top pins, with 30 inches of slack remaining in the wire rope, allowed the counterweight to rotate around the bottom pins. This motion subjected the rope to a shock load in excess of its breaking strength, resulting in the continued rotation of the counterweight. As the counterweight rotated, a pinch point was created between the bottom of the counterweight and the crane, resulting in fatal injuries to the victim.
1. A 103(k) Order (No. 7142395) was issued to Windsor Coal Company to ensure the safety of all persons until an investigation was completed and the area and equipment were deemed safe.
2. A 103(k) Order (No. 7142396) was issued to Savage Construction Company to ensure the safety of all persons until an investigation was completed and the area and equipment were deemed safe.
3. A 104 (a) Citation (No. 7142397) was issued to Savage Construction Company for violation of 30 CFR 77.210 (b) for failure of persons to stay clear of hoisted loads.
Related Fatal Alert Bulletin:
Listed below are the persons furnishing information and/or present during the investigation:
WINDSOR COAL COMPANY
Michael L. Roxby ..................... Manager Safety and HealthSAVAGE CONSTRUCTION COMPANY
Jack Savage ..................... OwnerEXECUTIVE SUPERVISORS
Charles J. Savage ..................... President
David Petrini ..................... Secretary
John E. Gompers ..................... Attorney
James T. McClure ..................... Attorney
Daniel DiGiovanni ..................... Salary EmployeeSAVAGE CONSTRUCTION COMPANY EMPLOYEES
Jay A. Powell ..................... Crane OperatorUNITED MINE WORKERS of AMERICA
Dennis O'Dell ..................... UMWA International Safety RepresentativeBROOKE COUNTY SHERIFF DEPARTMENT
Roger Sparks ..................... UMWA Local 6362
Peter A. Girdano ..................... Deputy SheriffWEST VIRGINIA OFFICE of MINER'S HEALTH, SAFETY and TRAINING
Matt Rogerson ..................... Deputy Sheriff
Roger Powell ..................... Inspector-At-LargeHAZARD RESEARCH SERVICES, COAL, INC.
John Larry ..................... Assistant Inspector-At-Large
Terry Farley ..................... Administrator
Colin D. Simmons ..................... District Inspector
Brian Mills ..................... District Inspector
Robert Beisel ..................... Safety ConsultantMINE SAFETY and HEALTH ADMINISTRATION
Chris A. Weaver ..................... Mining Engineer (Ventilation)Headquarters Office
Richard J. Dunst ..................... Chemical Engineer
Robert L. Phillips ..................... Coal Mine Safety and Health Specialist (Electrical)---Arlington
William L. Sperry ..................... Coal Mine Safety and Health Inspector (Electrical)