DEPARTMENT OF LABOR
MINE SAFETY AND HEALTH ADMINISTRATION
District 5
ACCIDENT INVESTIGATION REPORT
(UNDERGROUND COAL MINE)
FATAL ROOF FALL ACCIDENT
Mine #5 (I. D. No. 44-06551)
Minutemen Coal Company, Inc.
Wise, Wise County, Virginia
July 15, 1997
By
Benjamin S. Harding
Mining Engineer
Charles E. Upchurch
Coal Mine Safety and Health Inspector
Originating Office - Mine Safety and Health Administration
P. O. Box 560, Wise County Plaza, Norton, Virginia 24273
Ray McKinney, District Manager
GENERAL INFORMATION
Mine #5 of Minutemen Coal Company, Inc. is located one-tenth mile east of Route 823, on Indian Creek. The mine was opened by six drifts into the Dorchester coal seam. The coal seam averages 42 inches in height.
Coal is mined from the active faces with a continuous mining machine and transported to the belt feeder in shuttle cars. The coal is then transported to the surface via belt conveyors. The mine operates two shifts per day, producing coal on the day shift and performing maintenance on the owl shift. The mine has eight underground and two surface employees. There is no production history as the accident occurred during the first production shift after the mine was reactivated on July 14, 1997.
The main mine roof strata consists of 30 feet, or more, of sandstone. The immediate roof consists of six inches, or more, of shale. The mine floor consists of six inches, or more, of shale. The Approved Roof Control Plan, dated July 11, 1997, provides for full roof support in all entries, crosscuts, and rooms. The plan stipulates, as a minimum, the use of 36 inch mechanically anchored roof bolts, 48 inch fully grouted resin rods, or 60 inch point anchor/combination anchor bolts. The maximum entry and crosscut widths are 20 feet, except for the belt entry, which is allowed a width of 22 feet. Entries and crosscuts can be developed on 50, 55, 60, and 70 feet centers. When adverse conditions are encountered, entry centers can be developed from 80 to 200 feet. The plan contains provisions for extending cut depths to 30 feet during development and for partial pillar extraction during second mining utilizing a three-cut system.
Principal officers of Minutemen Coal Company, Inc. are:
Stephen Halsey................................President
Carl A. Hamilton..............................Secretary/Treasurer
A Mine Safety and Health Administration safety and health inspection had not as yet been conducted because the mine was reactivated on July 11, 1997.
DESCRIPTION OF ACCIDENT
On Tuesday, July 15, 1997, the day shift crew, under the supervision of David Francis, Section Foreman, entered the mine at 7:05 a.m., and arrived on the 001-0 Section at approximately 7:30 a.m. The section had been developed with seven headings by a previous operator. There were four rooms driven off the No. 7 entry.
Mining began in the No. 3 room off the No. 7 entry. Darrell Sanders, Continuous Mining Machine Operator, started the cut, and was later relieved for lunch by Sheldon Gray, Shuttle Car Operator, who operated the continuous mining machine during completion of the cut. Gray then trammed the continuous mining machine to the No. 1 room and Robert Smith, Roof Bolting Machine Operator, began the roof bolting cycle in the No. 3 room.
Gray began cutting coal in the No. 1 room and loaded two shuttle cars. Sanders returned from lunch and began operating the continuous mining machine while Gray returned to operating a shuttle car. After loading one more shuttle car, Sanders was directed by Carl Hamilton, Secretary/Treasurer, and Clayton Linkous, Mine Foreman, to cease mining in the No. 1 room due to sandstone in the mine floor.
Sanders trammed the continuous mining machine to the face of the No. 7 entry and began to cut and load coal. The shuttle car operators floated each other out for lunch during the cut. Sanders attempted to keep the continuous mining machine from cutting the soft shale mine floor. He backed out numerous times to grade the bottom, thereby extending the time needed for a complete cut of coal.
After completing a 20 foot cut, Sanders backed the continuous mining machine out and cleaned up the mine floor. The continuous mining machine and Gray's shuttle car were moved outby approximately 25 feet. Sanders stopped the continuous mining machine to move the machine power cable and waterline. Linkous, Hamilton, and James Steele, Repairman, walked up the right side of the machine to a position near the loading pan to look at the metal sideboards. At approximately 1:10 p.m., Gray was looking back over his shoulder when he observed a large section of mine roof fall, striking Sanders, Steele, Hamilton and Linkous. The fallen roof measured approximately 50 feet long by 1 to 17 feet wide and ranged from 3 inches to 4 1/2 feet thick. Gray ran to the accident scene and observed Hamilton (Injured) crawling from the edge of the fall. Hamilton and Sanders (Injured) retreated to safety, while Steele (Injured) and Linkous (Victim) were trapped.
Gray, on instructions from Hamilton, went to gather other crew members. He notified the roof bolting machine crew and then took the battery-powered scoop tractor, used on the section, to the loading point for timbers and cribbing material. He called outside, reported the accident, asked for more cribbing material and then trammed the scoop tractor to the accident scene. Rick Fletcher, Weekly Examiner, took the call and immediately contacted the Wise Rescue Squad, the Mine Safety and Health Administration (MSHA), and the Virginia Department of Mines, Minerals, and Energy (DMME) and then traveled to the section on a track-mounted personnel carrier. Hamilton, Sanders, Smith, Francis, Ronnie Hileman, Shuttle Car Operator, and Jimmy Haywood, Roof Bolting Machine Operator, removed enough of the fallen roof material to free Steele, and beg an searching for Linkous. Gray then attempted to raise the cutter-head of the continuous mining machine, with remote and manual controls, with no success. Hamilton located Linkous' cap light by looking up the right side of the continuous mining machine. The crew began to install supplemental roof supports (cribs and timbers) for additional protection.
At approximately 3:40 p.m., Fletcher transported Steele and Sanders to the surface where they were transported by Wise Rescue Squad to St. Mary's Hospital. Sanders was treated and released and Steele was hospitalized. Hamilton was brought to the surface at 6:20 p.m. and was later treated and released at Johnston Memorial Hospital in Abingdon, Virginia.
Recovery efforts continued with the assistance of MSHA and DMME personnel. Linkous was recovered from the fall at 7:15 p.m. and transported to the surface, arriving there at 8:10 p.m. He was transported by the Wise Rescue Squad to Norton Community Hospital, arriving at 8:35 p.m. He was pronounced dead by Dr. Linwood Briggs as a result of injuries which had occurred at 1:14 p.m.
PHYSICAL FACTORS INVOLVED
The investigation revealed the following factors relevant to the investigation.
- Tuesday, July 15, 1997 was the first production shift by
Minutemen Coal Company, Inc. employees at Mine #5. The mine
was reactivated on Monday, July 14 after being idle for
approximately four months.
- The Approved Roof Control Plan allowed for cut depths of 30
feet. However, the cut taken in the No. 7 entry prior to
the accident was only 20 feet deep and 20 feet wide.
- This mine had experienced one roof fall in an outby area
during the past 12 months.
- The 001-0 Section was bolted to standard utilizing 36 inch
conventional roof bolts.
- The section of mine roof that fell was a large slip
measuring approximately 50 feet long, 1 to 17 feet wide, and
from 3 inches to 4 1/2 feet thick. The slip broke at full
thickness at the face of the No. 7 entry and continued to
the outby intersection. Roof bolts were broken at the edges
of the fall and the caved area was above the anchorage
horizon at the apex of the slip.
- The slip was nearly parallel to the direction of the No. 7
entry.
- The Joy 14CM10 Continuous Mining Machine was not equipped
with an operator's deck and was operated by remote control.
- There was no unusual roof activity during the mining of the
cut in the No. 7 entry. All crew members stated that the
roof appeared in good condition. A shuttle car operator
small crack in the mine roof over his shuttle car. The
crack had not been there, he thought, before his lunch
break. He stated that there were no audible or visible
signs of roof movement and that he felt the mine roof was in
a safe condition.
- The Dorchester Coal Seam averages 42 inches in thickness at
this mine. The mining height at the scene of the accident
was 68 to 70 inches.
- Examination of a test hole located in the intersection of
the last open crosscut and the No. 7 entry approximately 45
feet outby the face, revealed a horizontal crack in the mine
roof at 39 inches.
- All face areas were supported in accordance with the
Approved Roof Control Plan.
- There were no training deficiencies relevant to the accident.
CONCLUSION
The accident occurred when mining was conducted beneath an area of roof that contained a large, undetected roof slip. The roof, weakened by the slip, fell without warning, starting in the freshly mined and unsupported face area. The fall continued outby, where the momentum of the falling roof overcame the permanent roof support installed in the intersection.
ENFORCEMENT ACTIONS
There were no violations of 30 CFR which contributed to the occurrence of the accident observed during the accident investigation.
The following order was issued:
A 103-K Order No. 4377129 was issued to ensure the safety of all persons in the mine until an investigation was completed and the area deemed safe to work.
Respectfully submitted :
Benjamin S. Harding
Mining Engineer
Charles E. Upchurch
CMS&H Inspector
Approved:
Ray McKinney
District Manager
Related Fatal Alert Bulletin:
FAB97C18