DEPARTMENT OF LABOR
MINE SAFETY AND HEALTH ADMINISTRATION
District 5
ACCIDENT INVESTIGATION REPORT
(UNDERGROUND COAL MINE)
FATAL ROOF FALL ACCIDENT
Big Creek Seaboard No. 2 Mine (I. D. No. 44-03479)
Sea "B" Mining Company
Jewell Ridge, Tazewell County, Virginia
October 1, 1997
By
Benjamin S. Harding
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
Sea "B" Mining Company's Big Creek Seaboard No. 2 Mine is located six miles north of Richlands, Virginia on State Route 67 at Jewell Ridge, Tazewell County, Virginia. Sea "B" Mining Company is a subsidiary of Thames Development. The mine was opened in December 1973, with nine drift openings into the Lower Seaboard Coal Seam which ranges in height from four to six feet. The immediate roof typically consists of four to five feet of shale or sandy shale with a main roof of ten or more feet of sandy shale.
Employment is provided for 62 underground and six surface personnel. The mine operates three shifts per day, seven days per week. Coal is produced on one advancing continuous mining section (002-0 Mechanized Mining Unit -MMU) on both the evening and the midnight shifts. The ten-hour production shifts overlap and maintenance work is performed on the eight-hour day shift. The mine produces an average of 980 clean tons of coal daily.
A room-and-pillar system of mining is employed utilizing a Joy 14CM10 remote control continuous mining machine, Joy 21SC shuttle cars, and a Fletcher DDO-15 dual-head roof bolting machine. A trolley-powered track haulage system is used for transportation of personnel and supplies. The advancing 1 Left off 3 Mains (002-0 MMU) Panel has been developed approximately 1100 feet from 3 Mains.
The Roof Control Plan in effect was approved on September 7, 1993 by the Mine Safety and Health Administration (MSHA). The Roof Control Plan requires as a minimum the installation of four-foot resin-grouted roof bolts on a four by four-foot pattern. Maximum entry and crosscut widths are 20 feet except for the combination belt/track entry which is limited to a width of 22 feet. The maximum cut depth was limited to 30 feet on advancing sections. Entry and crosscut centers from 45 to 100 feet are permitted. The plan stipulates that where adverse roof conditions are encountered cut depth shall be limited to 20 feet or less to provide effective roof support. Roof test holes twelve inches longer than the longest roof bolts being installed are required at 20-foot intervals.
A supplement to the plan which permitted mining 35-foot deep cuts during retreat mining of coal pillars developed on 70 by 70-foot centers was approved on June 23, 1997. A second supplement to the plan requiring a crib and four breaker timbers to be installed in crosscuts while retreat mining was approved on July 25, 1997. This supplement also required, in each intersection prior to retreat mining, the installation of nine six-foot resin-grouted roof bolts. As an alternative, nine six-foot resin-grouted roof bolts could be installed in intersections during development mining, in lieu of nine four-foot resin-grouted roof bolts installed in the normal bolting pattern. A third supplement to the plan which, during retreat mining, permitted the option of using cribs set in line with breaker timbers in lieu of three turn timbers and permitting wider turns during pillar lifts (24 feet for four linear feet) to increase maneuverability of the continuous mining machine, was approved on August 25, 1997.
The principal officers of Sea "B" Mining Company are:
Michael D. Wright......................................Superintendent
R. Thomas Asbury.....................................Manager of Safety
Blaine Hileman...........................................General Mine Foreman
An MSHA Safety and Health Inspection (AAA) was completed at this mine on September 5, 1997.
The fourth quarter fiscal year 1997 incident rate for the mining industry averaged 8.33 and was 6.40 for this mine.
DESCRIPTION OF THE ACCIDENT
On Monday, October 1, 1997, the evening shift crew, under the supervision of George McDonald, Section Foreman, entered the mine at 4:00 p.m. and arrived on the 1 Left off 3 Mains (002-0 MMU) at approximately 4:15 p.m. The day shift crew, under the supervision of Steve Morgan, Section Foreman, departed. No unusual conditions were discussed as everything appeared normal across the section. Billy Whited and Chester Yates, Roof Bolting Machine Operators, having started their shift at 2:00 p.m., remained on the section.
The day shift crew had left the continuous mining machine in a partial cut in No. 4 Right Crosscut. McDonald conducted an on-shift examination of the section. Observing no hazardous conditions, he assigned duties to the crew. Mining began in No. 4 Right Crosscut with Danny Joyce, Continuous Mining Machine Operator/Helper, operating the continuous mining machine. McDonald traveled to the No.5 Entry to conduct examinations. After returning to the No. 4 Entry, McDonald advanced the centerline, preparing the entry as the next place to mine. The 23 foot cut in No. 4 Right Crosscut was completed. McDonald examined the No. 4 Entry face area and helped install line curtain as the continuous mining machine was trammed to the No. 4 Entry face by Earl Absher, Continuous Mining Machine Operator.
Production began in the No. 4 Entry face with Earl Absher operating the continuous mining machine and Danny Joyce helping. McDonald observed the loading of two to three shuttle cars and then traveled to the No. 3 Entry and No. 3 Right Crosscut to make examinations and advance center lines.
As the cut in the No. 4 Entry neared completion, Absher and Joyce observed a piece of draw rock (3' x 3' x 4") inby permanent roof supports on the right side. Absher signaled for Ronnie Hess, Shuttle Car Operator, to back up and then backed the continuous mining machine out of the face and toward the left rib to allow the draw rock to fall without hitting the machine. Absher sat down on a plastic bucket and Joyce sat on his hammer near the right outby corner of the mining machine to observe the draw rock, which would have been taken down using the continuous mining machine if it failed to fall on its own.
At approximately 5:05 p.m., Joyce decided to reposition the mining machine's power cable. Just as he was reaching for the cable the draw rock fell and the roof collapsed above the two men. The falling roof knocked Joyce down and into a void beside the boom of the machine. This void was created as the falling roof broke apart after hitting the machine. Absher was crushed by the roof fall.
Hess ran to the inby end of his shuttle car and called out for Joyce and Absher. Joyce responded. McDonald quickly arrived on the scene and instructed Hess to go to the mine phone and notify mine office personnel. Other crew members from the section began to arrive.
During this time Joyce removed his mine belt and turned away from the mining machine to look for Absher. He was able to find and reach Absher's arm, shake it, and check for vital signs. Receiving no response and fearing additional falls, he moved as far as possible toward the boom of the mining machine. McDonald sent Billy Richardson, Scoop Operator, for cribbing material and the crew began moving rock in an attempt to free Joyce.
On the surface, Wayne Yates, Electrician, answered the mine phone page and was notified of the accident by Hess. Yates, Gary Stiltner, Chief Electrician, and Blaine Hileman, General Mine Foreman, immediately started toward the section. Ronnie Stevenson, Safety Inspector, contacted Larry Worrell, MSHA Supervisory Coal Mine Inspector at 5:10 p.m. with available details of the accident.
At the accident scene, crew members continued moving rock and Joyce tried to dig his way out. A small opening was made and at approximately 5:20 p.m., Joyce was assisted out of the fall area. As cribbing and rock removal continued, Joyce walked to the end of the track. Approximately five minutes later, Hileman, Stiltner, and Yates arrived at the end of the track. Hileman, Stiltner, and Hess went to the accident scene and Yates transported Joyce to the surface. Joyce was transported by Richlands Rescue Squad to Clinch Valley Hospital where he was treated and released with minor injuries.
Hileman, Stiltner, and Hess arrived at the accident scene as the last of six cribs were constructed. Hileman immediately called for scoops and hydraulic jacks and recovery efforts continued.
Representatives of the Virginia Department of Mines, Minerals and Energy (DMME) and the Mine Safety and Health Administration (MSHA) arrived at various times and assisted in recovery efforts. Absher was recovered from the fall area at approximately 9:15 p.m. He was transported to the surface by rail and from the mine site by Richlands Rescue Squad to Clinch Valley Hospital where he was pronounced dead by Dr. Mario Stefanini due to multiple internal injuries.
PHYSICAL FACTORS INVOLVED
- Observations by the investigators at the accident site
revealed the section of mine roof that fell in the face of
the No. 4 Entry consisted of a high-angle slickensided slip
measuring approximately 50 feet long, 18 feet wide, and from
4 to 8 feet thick. The outby edge of the fall was located
approximately 30 feet inby Survey Station 4683. The fallen
material was composed of laminated shale. The left side and
outby end of the fall had slickensided features common to
such roof anomalies. The right side of the fall was broken
and jagged indicating that the edge of the slip continued
past the right coal rib and above the coal pillar. Yellow
mud common to mud seams or mountain breaks was observed on
the inby end of the fall.
- The cut of coal removed from the No. 4 Entry prior to the
accident was approximately 19 1/2 feet deep and 18 feet
wide. The mine roof fell from the mud seam in the face,
through the unsupported area and continued outby, falling
above or pulling out all or part of eight rows of permanent
roof supports (approximately 30 feet).
- The 002-0 MMU roof was supported in compliance with the
minimum requirements of the Roof Control Plan using four-foot
resin grouted rods on centers of four feet by four
feet. Intersections contained nine or more six-foot resin
grouted roof bolts.
- The 002-0 MMU was being developed on 70 by 70-foot centers.
- The No. 4 Entry face, prior to the last cut extracted by the
evening shift crew, had been developed to a point
approximately 78 feet inby Survey Station 4683 by the day
shift crew. Larry Whited, Day Shift Roof Bolting Machine
Operator, stated that he paced off this area prior to
bolting the last cut extracted by the day shift crew. He
determined that, since this area would be part of the next
intersection created, he and his partner should install two
rows of four-foot roof bolts and two rows of six-foot roof
bolts. They drilled a 66 to 72-inch test hole in the middle
of the first row of four-foot bolts installed. This test
hole did not reveal any hazardous conditions. It did not
extend completely through the 8-foot thick overlying slip
which later fell nor would it have if it had been 84 inches
as required by the Roof Control Plan. This violation did
not contribute to the occurrence of the accident and was
cited under a separate spot inspection (CAA).
- Roof test holes were located at intervals of 20 feet or less
throughout the section. At least nine six-foot resin-grouted
roof bolts were being installed in each intersection
during advance mining as provided for in the supplement to
the approved Roof Control Plan, dated July 25, 1997. In
some intersections the test holes were not at least twelve
inches deeper than the longest roof bolts being installed.
This condition did not contribute to the occurrence of the
accident and was cited under a separate spot inspection
(CAA) as a part of the citation detailed in Item 5.
- Investigators observed a test hole located in the sloping
outby edge of the roof slip that fell. Larry Whited stated
that, during the drilling of this test hole, no cracks or
other hazardous conditions were observed.
- The left edge of the slip lay parallel to, and was obscured
by, the left ribline of the No. 4 Entry. The slip continued
over the right side coal pillar and broke from its own
weight along the right ribline.
- The Joy 14CM10 continuous mining machine was designed and
manufactured as a radio remote control machine and not
equipped with an operator's deck.
- There were no hazards detected in the No. 4 Face area prior
to the accident during preshift/on-shift examinations or
during mining. Statements of the miners interviewed and
investigator's observations indicated that the roof in all
the face areas had visibly improved during the previous
three shifts.
- Danny Joyce stated that the piece of draw rock observed
before the roof fall was common and not indicative of the
overlying slip. According to Joyce, the draw rock fell
immediately prior to or simultaneously with the roof slip.
- After recovery of the continuous mining machine from the
fall area, MSHA investigators examined the machine's
illumination lights. Those lights not broken by the roof
fall were operable.
- The investigation revealed no training deficiencies.
Continuous mining machine operators and helpers had the same
training and alternated jobs between cuts. Roof bolting
machine operators had received proper training.
- Proper preshift and on-shift examinations had been made in
the No. 4 Face area and recorded in books on the surface.
- From the roof fall location, the horizontal distance to the
seam outcrop was approximately 190 feet and the thickness of
the overburden was approximately 138 feet. The approved
Roof Control Plan contains special provisions when mining
approaches within 150 feet of an outcrop.
- Deep cuts (30 feet) had not been taken on the 002-0 section for several days preceding the accident due to the presence of adverse conditions (draw rock, cracks) located one to two crosscuts outby the face areas.
CONCLUSION
The accident occurred when advance mining in the face of the No. 4 Entry removed the coal under a hidden high-angle slickensided slip to the point where the slip intersected a perpendicular mountain break (mud seam). With the support of the coal removed, the slip broke from its own weight along the right ribline and fell without audible or visual warning. The roof fall began in the unsupported face and continued outby, overcoming or falling above the anchorage horizon of two rows of six-foot and six rows of four-foot roof bolts.
ENFORCEMENT ACTIONS
There were no violations of 30 CFR which contributed to the occurrence of the accident observed or attested to during the investigation.
The following order was issued:
- A 103-K Order (No. 3151729) was issued to ensure the safety of all persons in the mine until the investigation was completed and the area deemed safe to work.
Respectfully submitted:
Benjamin S. Harding
Mining Engineer
Approved:
Ray McKinney
District Manager
Related Fatal Alert Bulletin:
FAB97C25