DEPARTMENT OF LABOR
MINE SAFETY AND HEALTH ADMINISTRATION
District 5
(UNDERGROUND COAL MINE)
FATAL MACHINERY ACCIDENT
Mine No. 5 (44-06836)
Capital Coal Corporation
Pilgrims Knob, Buchanan County, Virginia
December 3, 1998
By
Roy D. Davidson
Electrical Engineer
Arnold D. Carico
Mining Engineer
Originating Office - Mine Safety and Health Administration
P.O. Box 560, Wise County Plaza, Norton, Virginia 24273
Ray McKinney, District Manager
GENERAL INFORMATION
Capital Coal Corporation's Mine No. 5 is located .95 miles west of Pilgrims Knob approximately 300 feet south of Route 638 on Dismal Creek in Buchanan County, Virginia. Production began on November 11, 1997, with four drift openings into the Jawbone Coal Seam, which locally averages 3.5 feet in thickness. The immediate mine roof consists of approximately 6 inches of shale which is overlain by a main roof of sandy shale and sandstone. The mine is eight entries wide and 1600 feet deep. Ventilation is provided by a single exhausting fan installed in the No. 4 Drift which produces approximately 83,000 cubic feet per minute of air. The latest laboratory analysis of return air samples at the fan showed a total methane liberation of 79,810 cubic feet per day. The face areas are ventilated using a double split system of ventilation and exhausting line curtains.
Employment is provided for 11 underground and 2 surface personnel. The mine operates one shift per day, five days a week to produce 450 tons of coal per day from a single Mechanized Mining Unit (001-0). A room and pillar system of mining is employed using continuous mining machines, shuttle cars, scoops, and single and dual head roof bolting machines. Coal is transported from the faces by shuttle cars, and out of the mine via belt conveyor. A battery-powered track haulage system is used to transport both personnel and materials.
The Roof Control Plan in effect at the time of the accident was approved by the Mine Safety and Health Administration (MSHA) on October 9, 1997. The Roof Control Plan requires, as a minimum, the installation of four foot resin grouted roof bolts on a four foot by four foot pattern. Maximum entry and crosscut widths are 20 feet in all entries and crosscuts, except the belt and track entry which is limited to 22 feet in width. Entry and crosscut centers from 60 to 100 feet are permitted with extended centers of up to 200 feet permitted in adverse conditions. Roof test holes are required to be drilled at intervals of 20 feet and are to be drilled at least one foot deeper than the length of the bolt being used.
The Training Plan was approved by the MSHA District Manager on September 5, 1997. The Plan includes provisions requiring training on the Roof Control Plan.
The principal officials for Capital Coal Corporation at the time of the accident were:
| President: | Hank K. Matney | |
| Vice President: | Rick A. Matney | |
| Secretary/Treasurer: | Fred Matney | Mine Superintendent: | Ray Kinder |
An MSHA Safety and Health Inspection (AAA) was completed on August 5, 1998 and another was ongoing at the time of the accident.
The third quarter fiscal year 1998 incidence rate for the mining industry was 8.89 as compared to 0.00 for this mine.
DESCRIPTION OF ACCIDENT
On Thursday, December 3, 1998, the coal production crew under the supervision of Eddie Looney, section foreman, entered the mine at 7:05 AM. The crew proceeded with normal production activities which included the operation of two dual head roof bolting machines by a two person crew and a single head machine operated by one person. These activities included cutting and roof bolting approximately eight places, three of which were bolted by Danny Lester (victim) using the single head Model LRB-15A Long Airdox Roof Bolting Machine. Plans for that day included some of the crew staying after the end of the shift to cut a trench with the continuous mining machine along the No. 7 Entry to direct water to a sump between Nos. 7 and 8 Entries.
At approximately 12:00 Noon, Ray Kinder, superintendent, came underground via a battery powered scoop. He delivered supplies to all three roof bolting machines and unloaded the remaining supplies in the supply hole. The last known contact with the victim was by Kinder at approximately 2:00 PM when he supplied Lester's roof bolting machine just before Lester entered the No. 3 Entry to begin roof bolting the place. Kinder then assisted moving the continuous mining machine to the No. 5 Entry. At approximately 2:30 PM, Looney and Kinder began making preparations to cut the trench. Looney began replacing bits on the continuous mining machine while Kinder began hanging line curtain in the No. 7 Entry to ventilate the trenching operation.
At approximately 3:00 PM, as the remainder of the crew was preparing for the end of the shift, Eddie Brown, one of the roof bolting machine operators for the dual head machines, went to the other dual head machine to retrieve his coat. As he passed the opening to the No. 3 Entry, he heard the single head machine still running in the face area of the entry. He signaled with his cap light and called to Lester, the machine operator, but received no response. Brown went to the roof bolting machine where he found Lester at the front of the machine at the drill controls. Lester was in a kneeling position with his head caught between the ATRS and the frame of the machine which protruded forward of the panic bar. Brown saw a cardboard box containing resin grout tubes on top of the ATRS levers. He removed the box and activated the tilt jack lever, resetting the ATRS to an approximately vertical position. Brown raised Lester up and upon seeing the extent of Lester's injuries, he immediately left the place and traveled toward the mantrip yelling for help.
Looney was in the No. 7 Entry setting bits on the continuous mining machine when he heard Brown yelling that Lester was seriously hurt. Looney went to Brown who informed him of Lester's location. Looney, a First Responder, immediately went to the No. 3 Entry Face where he found Lester at the drill controls. He called Lester's name several times and, receiving no response, he checked Lester's neck for a pulse but could detect none. Not knowing that Brown had raised the ATRS, Looney did not know how Lester had been injured. He raised Lester's head and saw that he had severe head injuries. He yelled to Kinder that Lester was injured and for Kinder to come to him.
Kinder had been in the No. 7 Entry when he first overheard Brown saying that someone was injured. As he traveled toward Brown, he heard Looney yell to him and he proceeded directly to the accident scene. Looney directed the crew to have someone outside call for an ambulance and for the crew to bring the first aid box. Kinder asked about Lester's condition and was informed that he was seriously injured. The two men then moved the victim away from the machine and placed him on the mine floor. Looney tilted the victim's head back and examined him for signs of breathing. He again checked the victim for a pulse and found none. Looney stated that a more complete visual examination revealed massive head injuries. The victim was strapped to a backboard and transported by scoop to the end of the track. He was then transferred to a rail vehicle and subsequently transported to the surface of the mine. The Dismal River Rescue Squad transported the victim to Buchanan General Hospital where, at 4:38 PM, he was pronounced dead on arrival by the county medical examiner, Dr. Segen.
PHYSICAL FACTORS INVOLVED
- The mining height at the accident scene was 48 inches.
- The machine involved in the accident was a Long Airdox Single Head Roof Bolting Machine,
Model LRB-15A, Serial Number 62-599.
- The Automated Temporary Roof Support (ATRS) System for the roof bolting machine was
manufactured and retrofitted to the machine by Safe Shield Corporation of Cedar Bluff, Virginia,
which is no longer in business.
- This system uses a hydraulic tilt jack to fold the ATRS onto the machine in a near horizontal position on top of the drill head when the machine is trammed from place to place.
After arriving at a new work place, the tilt jack raises the ATRS to a vertical position. A set of roof support jacks is then activated, setting the ATRS's supporting surface against the mine roof.
- The control lever for the tilt jack is approximately 12 inches long and is located nearest the machine frame. The control lever for the two roof support jacks is approximately 13 inches long and located adjacent to the tilt jack control lever. Both control levers are located on the side of the machine in the tram control deck.
- When downward pressure is applied to the tilt jack control lever, the tilt jack folds the ATRS toward the front of the machine. When downward pressure is applied to the roof support jack control lever, the roof support jacks lower the ATRS. Either of these levers cause activation of their respective jacks with minimal downward pressure. Neither of these levers is protected against unintentional activation from falling objects nor accidental contact.
- Testimony revealed that a cardboard box of resin grout tubes was laying on the ATRS control
lever(s) when the victim was discovered. The box contained two tubes of resin grout. Tests
conducted during the investigation revealed this partial box of resin grout tubes had enough
weight to depress either or both the ATRS control levers and cause activation of the jack(s).
- The investigation revealed that the ATRS would not fold back onto the machine if it was
positioned firmly against the roof as required by the approved Roof Control Plan. The
investigation also revealed that the ATRS would initially set firmly against the mine roof but
would lose pressure against the roof when bolting operations were conducted. This loss of
pressure was caused partially from leakage in the machine's hydraulic system, but most of the
separation from the mine roof was caused by the feet of the ATRS settling in loose coal and soft
bottom.
- The ATRS system is not designed to provide for continuous hydraulic pressure to be applied to
the roof jacks after the jacks have been set; therefore, the ATRS cannot compensate for loss of
pressure against the roof due to hydraulic leaks occurring in the system or movement from
settling of the ATRS's feet in loose coal or soft bottom.
- The tilt jack lever, when actuated, caused the tilt jack to fold the ATRS back onto the
machine at a rapid rate (approximately one second).
- 11. The drill controls are located at the front of the machine. When the operator is installing roof bolts, he is positioned between the ATRS and the front of the machine.
- The ATRS system does not contain a diversion valve or other method to prevent the operation of the tram/ATRS controls while the operator is located at the drill controls.
- When the victim was found, the machine was still running. The panic bar located at the drill
controls would de-energize the machine with little contact pressure.
- At the time of the initial accident site visit, the ATRS was in a near vertical position. Statements made during the investigation revealed the ATRS was raised to recover the victim.
The roof bolting machine had a two section hydraulic pump. The 9 Gallon Per Minute (GPM) section supplied flow for the control valve which controls the ATRS functions and the drill and cable reel control valve which controls the stabilizer, the drill boom lift, and the cable reel. The flow from this pump section went to the ATRS control valve before going to the drill and cable reel control valve located at the drill station. The 28 GPM section supplied hydraulic flow for the tram and drill rotate circuit. The flow from this pump section went to the tram valve before it went to the drill rotate valve located at the drill station
The ATRS lift jacks were held in place against the roof by the load locking valves attached to the bottom of the ATRS lift jacks. Once the control valve, which activated the ATRS lift jacks, was released, there was no further flow to keep the ATRS tight against the roof.
Tests were conducted which determined the ATRS tilt jack could not fold the ATRS back onto the drill boom, if the ATRS was tight between the mine floor and roof. Although the ATRS could not be folded back when it was tight against the roof, the ATRS loosened from the roof and could be folded back when, during bolting operations, a hole was drilled in the roof. One reason this happened was the flow from the 9 GPM pump section went to the ATRS control valve, before going to the drill and cable reel control valve. This caused hydraulic pressure to build inside of the ATRS control valve when the drill boom lift section was activated. When a hole was drilled, the pressure generated inside of the ATRS control valve would cause hydraulic flow to bypass the spool in the lift section of the ATRS control valve. The hydraulic flow that bypassed the spool would enter the lift jack of the ATRS and apply pressure to the pilot operated release mechanism of the load locking valve. This action released the load locking valves, which allowed the ATRS to loosen from the roof. Another reason for the ATRS to loosen from the roof was a leaking load locking valve on the left lift jack. This problem, which would contribute to loosening of the left side of the ATRS, was found during tests of the ATRS lift jacks at a hydraulic machine shop.
CONCLUSION
The accident occurred because the unprotected ATRS tilt jack control lever was unintentionally actuated by a falling box of resin grout tubes. The ATRS support surfaces were not set firmly against the mine roof, allowing the tilt jack to rapidly fold the ATRS inward toward the front of the machine, crushing the victim against the machine.
ENFORCEMENT ACTIVITIES
The following orders/citations were issued due to conditions revealed during the investigation.
A 103-K Order (No. 7299909) was issued to ensure the safety of all persons in the mine until an investigation was completed and all areas and equipment were deemed safe.
2. A 104(a) Citation (No. 7296900) was issued citing 30 CFR 75.220(a)(1), the approved Roof Control Plan, for the ATRS system installed on the subject roof bolting machine not being maintained firmly against the mine roof at the time of the accident.
Respectfully submitted:
Roy D. Davidson
Electrical Engineer
Arnold D. Carico
Mining Engineer
Approved:
Ray McKinney
District Engineer