DEPARTMENT OF LABOR
MINE SAFETY AND HEALTH ADMINISTRATION
Coal Mine Safety and Health
Report of Investigation
Underground Coal Mine
Fatal Fall of Roof
December 22, 1999
DiAnne Mine
Canterbury Coal Company
Maysville, Armstrong County, Pennsylvania
I.D. No. 36-05708
Accident Investigators
Joseph R. O'Donnell Jr.
Coal Mine Safety & Health Inspector
Donald W. Huntley Jr.
Coal Mine Safety & Health Inspector
Dan Baran
Coal Mine Safety & Health Inspector
William J. Gray
Mining Engineer
Originating Office
Mine Safety and Health Administration
District 2
RR 1, Box 736, Hunker, Pennsylvania 15639
Joseph J. Garcia, District Manager
Release Date: February 18, 2000
OVERVIEW
Robert J. Francisco, continuous-mining machine operator, began mining in the M2 Section in No. 23 room with a radio-remote continuous-mining machine. He had completed the extended cut mining on the right side of the room and was in the process of completing the remainder of the mining on the left side of the room. At approximately 5:10 p.m., Marvin Gromley, shuttle-car operator, trammed his shuttle car into the room to be loaded. As he trammed his shuttle car toward the conveyor boom of the continuous-mining machine, Francisco raised the boom when a roof fall occurred. The shuttle-car operator ran toward the continuous-mining machine where he observed the mining-machine operator under the fallen section of mine roof.
The fatality occurred because the victim was exposed to unsupported
roof while operating the continuous-mining machine. Factors contributing to this exposure are discussed in this report.
GENERAL INFORMATION
DiAnne Mine, I.D. 36 05708, operated by the Canterbury Coal Company, is 2 miles off U.S. Route 156 in Maysville, Armstrong County, Pennsylvania. The mine began production on August 1, 1978 and operates in the Lower Kittanning coalbed at a depth of 500 feet with the coal seam ranging in thickness from 48 to 56 inches. The mine produces an average of 6,000 tons of coal daily from two mechanized mining units, operating two production shifts and one maintenance shift. Coal is transported from the working sections to the surface via belt conveyors.
The immediate roof consists of dark shale. Forty-two inch long resin roof bolts provide primary roof support. Supplemental roof supports consisting of posts, cribs and combination roof bolts are also used. Ventilation is induced into the mine utilizing an eight-foot diameter Joy axial vane high capacity exhausting fan, producing approximately 323,019 cubic feet of air per minute. The latest laboratory analysis of samples collected at the fan indicates a total methane liberation of 266,699 cubic feet in twenty-four hours. Two main portals access the mine. Personnel and supplies are transported to the working section by battery powered track mounted and rubber tired vehicles.
The principal officials of the Canterbury Coal Company
President..............................................John GoroncyThe last complete quarterly Mine Safety and Health Administration (MSHA) regular safety and health inspection was completed on September 29, 1999. The first quarterly regular safety and health inspection for FY2000 was ongoing, but had not been completed at the time of the accident.
Superintendent.....................................Dwayne Ross
Safety Director....................................Vernon M. Demich Jr.
DESCRIPTION OF THE ACCIDENT
On December 22, 1999, the afternoon shift crew, consisting of twelve persons and supervised by John J. Zak, section foreman, entered the mine at their regularly scheduled starting time of 3:30 p.m.. The crew traveled from the surface to the M2 working section, mechanized mining unit (MMU) 010-0, via battery powered track mounted and rubber-tired personnel carriers. They arrived on the M2 section at approximately 4:02 p.m.
The M2 section is a multiple continuous-mining machine section, operating with two Joy 14-10 continuous-mining machines, one for pillaring and the other for developing bleeder rooms. Entries, crosscuts and rooms were driven a maximum of 20 feet wide. The section is ventilated with a single split of air; therefore, mining cannot be done simultaneously with both mining machines.
Zak gave out work assignments to the crew. Robert J. Francisco, continuous-mining machine operator, and Mike Hamilton and Dennis Morris, roof-bolting machine operators, were assigned duties on the right rooms side. Calvin John, continuous-mining machine operator, Dallas Buterbaugh and Kevin Crissman, roof-bolting machine operators, were assigned to the pillar line side. Robert Buchinsky, Marvin Gromley, Joseph Zachesky and Gary Gerber, shuttle-car operators, were assigned to haul coal from both the pillar line and rooms. Larry Jones, scoop operator, was assigned to help Francisco with his trailing cable.
Zak examined the faces of the rooms and the pillar line. Mining continued in the No. 9 Block. Zak traveled back to the No. 23 room. He measured the air at the face and traveled up to the No. 9 pillar block. When the push out block was completed, he called Francisco on a hand-held radio to begin mining in the No. 23 room. Zak stayed on the pillaring side to help move the continuous-mining machine across the pillar line.
Francisco began mining in the No. 23 room with a radio-remote, scrubber equipped, continuous- mining machine. Francisco mined the first 20 feet out of the right side of the room. He moved to the left side and mined out 20 feet. Francisco then moved back to the right side and mined an additional 24 feet. He moved to the left side to finish mining the room. At approximately 5:10 p.m., Marvin Gromley, shuttle-car operator, trammed the No. 5 shuttle car into No. 23 room to be loaded. As Gromley trammed his shuttle car toward the conveyor boom of the continuous- mining machine, Francisco raised the boom and a roof fall occurred. Gromley exited the shuttle car and ran toward the continuous-mining machine where he observed Francisco under a section of mine roof. The roof rock, approximately 18 feet wide, 5 feet long on the left side and 15 long on the right side feet and up to 6 inches thick, fell hitting the mining machine on the left and the mine floor on the right, just inby the last row of permanent roof supports.
Larry Jones, scoop operator, was positioned between No. 22 and No. 23 rooms when he heard the roof fall occur. He heard Gromley shout for help and traveled to the area where the fall had occurred. Jones observed Francisco under the roof fall and called Zak by hand-held radio informing him that an accident had occurred in the No.23 room. Zak, an Emergency Medical echnician, went immediately to the accident scene and checked Francisco for vital signs. None were detected. Crew members helped in the recovery. A roof jack was set for support and to prevent the rock from sliding during the recovery. They attempted unsuccessfully to lift the rock off Francisco using posts and a lifting jack. A scoop was used to raise the rock. Francisco was removed and transported to the surface.
Francisco was pronounced dead at the mine site at 6:25 p.m., by Robert Bower, Armstrong County Coroner and was transported to St. Francis Medical Center, Pittsburgh, Pennsylvania, where an autopsy was performed.
INVESTIGATION OF THE ACCIDENT
At approximately 5:45 p.m., on December 22, 1999, Gerald E. Davis, Assistant District Manager--Inspection Programs, was notified by Dwayne Ross, Superintendent, that a serious accident had occurred. An MSHA accident investigation team was assembled. The team consisted of accident investigators, a roof control specialist and a mining engineer (roof control). Upon their arrival at the mine, a 103(k) Order was issued to ensure the safety of the miners until an investigation could be conducted. MSHA and the Pennsylvania Department of Environmental Protection jointly conducted the investigation with the assistance of mine management and miners. Interviews were conducted at the mine site. The on-site investigation was completed on January 6, 2000. The miners elected not to have representation during the investigation.
DISCUSSION OF THE ACCIDENT
The following is a discussion of the relevant factors identified during the accident investigation.
- The M2 section is a multiple continuous-mining machine section,
operating with two Joy 14-10 continuous-mining machines, one for pillaring and the other for developing bleeder rooms. Entries, crosscuts and rooms were driven a maximum of 20 feet wide. Pillar sizes ranged from 30 feet by 70 feet in entries, to 25 feet by 40 feet in the rooms. The section is ventilated with a single split of air; therefore, mining cannot be done simultaneously with both mining machines. Hand held two-way radios are used for communications within the section.
- The immediate roof in the area of the accident consisted of dark gray, thinly laminated shale, and extended to a height of approximately 30 feet above the Lower Kittanning coal seam. The mine roof on the section, including the area just outby the accident scene, was supported with 42-inch long, fully grouted resin roof bolts, installed on a maximum four-foot by four-foot pattern. Typically, two to ten inches of draw rock is cut from the roof during mining. Just outby the accident scene in the No. 23 Room, approximately six inches of draw rock was mined resulting in a 56-inch mining height. The width at the accident scene in the No. 23 Room was approximately 19 feet. No rib sloughage or other signs of significant pillar stresses
were observed anywhere on the section.
- The roof fall material consisted of a large slab of thinly laminated, dark shale, varying in thickness from zero to six inches. The fall was trapezoidal in shape, measuring approximately 18 feet wide across the No. 23 Room, and ranging in length from 5 feet at the left side of the room to 15 feet at the right side of the room.
- The continuous-mining machine had started the final lift on the left side of the No. 23 Room. The left side had been mined approximately 27 feet inby the last permanent row of supports when the fall occurred. The right side of the place had been mined approximately 44 feet deep. The approved roof control plan limits cut depths to a maximum of 37 feet.
- Two Joy 21SC shuttle cars, No. 2 and No. 5, were used to haul coal from the No. 23 Room. The No. 2 shuttle car was used to haul coal only during the removal of the first approximately 20 feet of the cut.
- The approved roof-control plan requires that "the continuous-mining
machine operator (remote-control station) and other persons in the area shall not expose any portion of their body inby the second outby row of permanent supports (next to last row) while the mining machine is in operation." Francisco was recovered on the right side of the No. 23 Room, approximately 27 inches inby permanent supports (roof bolts).
- The approved roof-control plan requires that "for the purpose of identifying the last row of permanent supports for haulage equipment operators on deep cut sections, a re-flectorized streamer shall be placed on the next to last row of permanent supports on or before the cut reaches 20 feet in depth." During the on-site investigation and after interviews with the crew, it was determined that no re-flectorized streamers were hung on the second outby row of roof bolts from the cut. Interviews with the section crew indicated that streamers were used and available on the section.
- The approved roof-control plan requires that "a conspicuous reference mark on the continuous-mining machine or some other visual means shall be provided for the workers to determine when the maximum depth of cut is attained." During the on-site investigation and after interviews with the crew, it was determined that a conspicuous reference mark on the continuous-mining machine was not used. The visual means used was that the mining machine would be advanced until the tail of the machine was at the last row of roof bolts. Mining would continue for one more shuttle car and a clean-up, completing that side of the cut.
- The Joy continuous-mining machine measured 34 feet 3 inches from
the bits to the end of the conveyor boom.
- During the on-site investigation, mining activity prior to the accident was recreated by positioning the No. 5 shuttle car and Joy continuous-mining machine on the right side of the No. 23 room to illustrate the work position of the shuttle-car operator while completing the right side of the cut in No. 23 room. From this equipment location in the measured 44-feet deep cut, the front edge of the canopy over the operator's compartment on the No. 5, Joy 21SC shuttle car was approximately 29 inches inby the last row of permanent
support when the shuttle car was just under the mining-machine boom. When the shuttle car was pulled further under the mining-machine boom to simulate a typical initial loading position, the front edge of the canopy was approximately 79 inches inby.
- The investigation revealed that during the recovery of Francisco, he was found with his body crushed over the remote control unit. The depression in the mine floor from the remote control unit was measured 27 inches inby the last row of roof bolts. The investigation team concluded that Francisco was inby the last row of roof bolts when the roof fall occurred.
CONCLUSION The fatality occurred because the continuous-mining machine operator was inby permanent roof supports when the roof fall occurred. Contributing factors to this fatality were: (1) A re-flectorized streamer was not provided on the next to last row of permanent roof supports on or before the cut reached twenty feet in depth. This streamer provides a reference point as to the mining-machine operator's work position with relation to the second outby row of permanent roof supports. (2) The depth of the extended cut exceeded the approved distance of 37 feet.
ENFORCEMENT ACTIONS
The following citations/orders were issued due to conditions revealed during the investigation.
- A 103(k) Order 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.
- A 104(a) Citation was issued for violation of 30CFR75.202(b). The continuous-mining machine operator while operating the Joy continuous-mining machine remotely, Serial No. JM 4760, in the No. 23 room on the M2 (MMU 010-0) working section traveled inby the last row of permanent roof support. A roof fall occurred and the continuous-mining machine operator was fatally injured.
- A 104(a) Citation was issued for violation of 30CFR75.220(a)(1). The operator's approved roof-control plan was not being complied with on the M2 (MMU 010-0) working section. A reflectorized streamer was not placed on the second outby row of permanent roof supports while mining an extended deep cut in No. 23 room.
- A 104(a) Citation was issued for violation of 30CFR75.220(a)(1). The operator's approved roof-control plan was not being complied with on the M2,(MMU 10-0) working section. A cut was taken in the No. 23 room that exceeded the maximum allowable depth of 37 feet. The cut was measured at 44 feet from the last row of permanent roof supports to the coal face on the
right side of the room.
Submitted by:
Joseph R. O'Donnell, Jr.
Donald W. Huntley, Jr.
Dan Baran
William J. Gray
Approved by:
Joseph J. Garc�a
District Manager-Coal Mine
Safety & Health District 2
Related Fatal Alert Bulletin:
FAB99C33
- A 103(k) Order 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.