OVERVIEW
At 10:43 a.m.
on Friday, August
10, 2007 an accident involving a fatal fall of persons occurred at the Gibson County Coal, LLC.,
Gibson Mine, North Portal 2 shaft sinking site, resulting in the deaths of two
employees and one retired employee of Frontier-Kemper Constructors, Inc., an
independent contractor. Appendix A lists
the names of the victims fatally injured as a result of the accident.
The accident
occurred when the three men were being lowered inside the sinking bucket into
the shaft to observe the bottom station concrete work. A nylon sling and shackle attached to the
bottom of the sinking bucket lodged into a shaft collar door, thereby tipping
the sinking bucket. This resulted in the
men falling from the bucket to the bottom of the shaft, a distance of
approximately 550 feet. At the time of
the accident, the shaft had not yet been connected to the underground mine
workings.
The accident
occurred as a result of Frontier-Kemper’s failure to ensure the hoist was under the control of the
hoistman at all times when persons were in the shaft. The toplander was not at his station as the
bucket was being lowered through the shaft collar doors and the hoistman had no
visual contact with the bucket at this point.
The hoistman lost control of the bucket when the nylon sling and shackle
entangled with the shaft collar door.
The independent contractor also failed to ensure that adequate fall
protection was utilized while persons were transported in the sinking bucket.
GENERAL INFORMATION
The principal officers for the mine
at the time of the accident were:
Gibson County Coal,
LLC:
Jimmy
Allen Brown........................................... Superintendent
Mark
David Kitchen............................ Director,
Health & Safety
Frontier
Kemper Constructors, Inc.
Galyn
Rippentrop........................................ President
and CEO
Christopher
T. Richardson Mine Development
Division Manager
George Zugel.................................... Corporate
Safety Director
Prior to the
accident, the Mine Safety and Health Administration (MSHA) completed the last
regular safety and health inspection of the Gibson Mine on July 25, 2007. The Non-Fatal Days Lost (NFDL) injury
incidence rate for the Gibson Mine in 2006 was 2.05 compared to a National NFDL
rate of 4.90. For 2006, Frontier-Kemper
Constructors, Inc. had an NFDL rate of 10.90 compared to a National NFDL rate
of 2.43.
The Gibson Mine
Main Portal is located approximately 2 miles north of Princeton, Indiana
and 1 mile west of US Highway 41. The
North Portal 2 site, where the accident occurred, is located approximately 2
miles northwest of the intersection of Indiana State Highways 64 and 65, and the
Gibson Mine and the North Portal 2 site are located in Gibson County, Indiana. The mine is operated by Gibson County Coal,
LLC., a subsidiary of Alliance Coal, LLC.
The mine began production in the Illinois Number 5 seam in December
2001. The average thickness of the seam
is 78 inches. The last recorded total
liberation for the mine indicates 3,472,207 cubic feet of methane liberated
every 24 hours. The principal
operating officer for Gibson County Coal at the time of the accident was Mike
Stanley, General Manager.
The North
Portal 2 Shaft Sinking Project is operated by Frontier-Kemper Constructors,
Inc., a subsidiary of Deilmann-Haniel International Mining and Tunneling GmbH, Dortmund, Germany. The shaft construction began in October 2006,
and the shaft was at the coal level, 570 feet below the surface, at the time of
the accident, but the shaft had not yet been connected to the underground mine
workings. The person in charge of the
operation for Frontier-Kemper was Kyle Wooten, Project Manager. The shaft sinking operation consists of three
8 hour shifts per day, 7 days a week.
DESCRIPTION OF ACCIDENT
Crew A, led
by George Foster, Walker Boss, began work as usual at 8:00 a.m. on the day of
the accident. Foster, Greg Clevidence (Miner/Driller),
Chris Girten (Mucker Operator), Daren Stout (Miner/Driller), Jerry Rhodes, Jr. (Miner/Driller),
and Cody Robinson (Miner/Driller) entered the shaft shortly after starting
time. The scheduled work in the shaft that day was to “spade tights,” which
involved manually removing rock from the shaft wall that protruded excessively
into the concrete pour area and to otherwise prepare for a concrete pour.
Work proceeded normally, with 2 pieces of 6-inch angle iron being called
for and subsequently lowered in a bucket, using a nylon sling and shackle
attached to the bottom of the sinking bucket. (See Exhibit 1) Cody Robinson exited the shaft at
approximately 10:30 a.m. to drop off some parts.
On the
surface, Jarred Ashmore, Project Engineer, was assisting and supervising Frank
Peavler, Parts Runner, and Cliff Schass, Electrician, in building forms for two
work deck hoist platforms. This was
being done in preparation for splitting the work decks to construct the curtain
wall from the shaft bottom to the collar, since the shaft had reached its
approximate designed depth.
On the
day of the accident, Frontier-Kemper was celebrating the 100th Anniversary
of Kemper Construction Company and had several guests from their Evansville, Indiana
headquarters as well as from their parent company, Deilmann-Haniel
International Mining and Tunneling GmbH, on site being trained in preparation
for a tour of the surface facilities.
Christopher (Todd) Richardson, Mine Development Division Manager for
Frontier-Kemper, and Daniel McFadden, Retired Senior Executive Vice President
and Director of Frontier-Kemper, requested to view the operations in the
shaft. Ashmore met with them, and after ensuring
that Peavler and Schass could continue building the concrete forms, Ashmore,
Richardson and McFadden boarded the sinking bucket for a trip to the shaft
bottom. Dennis Splittorff, Toplander, reportedly
rang the appropriate code to have the bucket raised to clear both the bucket
and nylon sling above the collar doors.
Splittorff then opened the collar doors, signaled to have the sinking
bucket lowered and then resumed cleaning bolts in the
top shack.
Charles
(Chuck) Crandell, Hoistman, began lowering the bucket. He stated he saw the hoist rope move in an
unusual manner and stopped the hoist. He
next called Splittorff and asked him to look and see if anything was
wrong. At the same time, John Branson,
Master Mechanic, and Robinson reportedly heard a clang and saw the ropes
slackening or “shaking” and ran to the shaft collar. Branson then went in the freeze cellar to get
a better view of the bucket and saw that the bucket was inverted and empty. On the work deck, approximately 570 feet below
the collar, Foster and Girten reportedly saw objects falling and moved to
protected positions. They next heard an
impact noise on the work deck. They
moved from their separate positions behind the concrete forms and saw that
Ashmore was lying on the work deck. Rhodes stated he saw a second victim (later identified as
McFadden) had fallen through the hoist well in the work deck and onto the shaft
bottom. Branson, who was on the surface, called on the mine phone to the work
deck and asked if everyone was alright.
Foster informed him that all those working at the shaft bottom were uninjured,
but there were two men fatally injured. Branson
called Crandell on the mine phone and had him bring the bucket up slowly. Branson removed the sling and shackle from
the bottom of the bucket. The sinking
bucket was then lowered to bring Crew A from the bottom of the shaft.
Kyle
Wooten, Project Manager, and Rhodes subsequently traveled to the shaft bottom
so Wooten could verify the victims’ conditions.
They located the third victim (Richardson) who was on the shaft bottom
next to the concrete forms and shaft wall.
Richardson
had apparently fallen between the work deck and the forms.
George Zugel,
Corporate Safety Director, notified the MSHA call center of the accident at
10:53 a.m. CDT. Jeff Williams, MSHA Roof
Control Specialist, learned of the possibility of an accident when he returned
to the surface after conducting normal inspection activities at the Gibson
Mine. Williams traveled to the North Portal
2 site and immediately issued a 103(k) Order at 11:25 a.m. Mark Odom, Mike Rennie and Ron Stahlhut, MSHA
Supervisors arrived on the scene a short time later. The Gibson County Coal mine rescue team was also
called to the site and assisted in the recovery of the victims.
Stahlhut
had the hoist rope and attachments thoroughly checked before lowering anyone
into the shaft for recovery work. A team
was assembled to perform the recovery work.
This team consisted of Rennie, Stahlhut, Don “Blink” McCorkle, Deputy Commissioner,
Indiana Bureau of Mines, and
Terry Phegley and Rod Dilbeck from the Gibson County Coal mine rescue
team. This team entered the shaft at 1:25 p.m. and
began recovering the victims. The first
victim arrived on the surface at 1:56 p.m., and the recovery work was completed
with the removal of the third victim at 3:09 p.m.
INVESTIGATION OF THE ACCIDENT
On August 10, 2007
MSHA began an investigation of the accident pursuant to the Mine Safety and
Health Act of 1977. The Administrator
for Coal Mine Safety and Health assigned an investigation team consisting of
personnel from MSHA Coal District 7, Headquarters Safety Division, MSHA
Pittsburgh Safety and Health Technology Center,
MSHA Approval and Certification
Center, MSHA Educational
Field Services and the United States Department of Labor, Office of the
Solicitor. Charles Grace, Acting
District Manager for District 7, was assigned as the accident investigation
team leader.
Preliminary
information was gathered from the MSHA District 8 Office, located in Vincennes, Indiana,
the Indiana Department of Labor, Bureau of Mines, the Gibson County Coal, LLC. Office,
and the Frontier-Kemper Constructors Inc. operations office at the site.
Persons
were identified for the purpose of interviews.
Interviews were conducted with 11 persons thought to have pertinent
information regarding the accident. The
interviews were conducted at the MSHA District 8 Office, at the Evansville
Marriot Hotel, at the Quality Inn Evansville North in Haubstadt, Indiana
and via telephone. Kyle Wooten, Project Manager for Frontier-Kemper
Constructors, Inc., declined to be interviewed.
Appendix B lists the persons interviewed.
The accident
investigation team made site visits on August 11, 12 and 16, 2007. The team took measurements, photographs and made
sketches on the surface and at the shaft bottom. The accident investigation team also
conducted tests of the rope and all hoist safety systems. The uniform mine file, the shaft sinking plan
and all training records were reviewed for compliance with procedures and appropriate
standards.
In order to
determine the actual manner in which the sling/shackle combination could have
lodged in the collar doors, several configurations were tested. The collar doors were moved to the open position,
and the nylon sling and shackle were attached to the sinking bucket, as on the
day of the accident. The arrangement
shown in the drawing labeled Exhibit 2 and the photograph, labeled Exhibit 3,
(with the shackle pin end down at the floor side of the Wide Flange section (I-beam)
and the rounded end atop the lower end of the I-beam, with the sling coming
over the top) would bind tightly with downward pressure and release easily with
upward pressure. This confirmed witness’
statements that the sling/shackle tightly engaged with downward pressure and
released easily when the bucket was raised.
No other tested arrangement produced this result.
DISCUSSION
PHYSICAL
FACTORS:
1) GENERAL: Frontier-Kemper began making preparations for
sinking the shaft in October 2006. The
design indicated the depth of the shaft from the top of the collar to the
bottom of the shaft to be 570 feet. The
shaft log, maintained in the office trailer, indicated that as of January 8, 2007
freezing of the outer strata had been accomplished and excavation had begun. Installation of lagging and I-beams continued
until March 4,
2007. Further excavation continued
until March 16,
2007, and the first concrete was poured on March 19, 2007. The concrete for the hornset was poured on March 28, 2007
and subsequent concrete pours continued toward the collar of the shaft until April 7, 2007. At that point, conventional shaft sinking
procedures (drilling, blasting, and mucking) were implemented. Setting forms and pouring concrete followed the
excavation portion of the shaft development cycle. A water ring was installed between the
hornset and the station of the shaft.
The excavation of the shaft was nearing completion at the time of the
accident.
2) DESCRIPTION OF THE HOISTING
EQUIPMENT/OPERATION: The shaft is
enclosed at the top with a collar deck sub-frame and the deck. The collar deck
consists of one-half inch thick steel plates with a raised pattern on top to
resist slipping. Personnel hoisting and material removal for the shaft sinking
operation is primarily accomplished with the use of a sinking bucket. Typically, the bucket remains idle on the
collar deck when no one is in the shaft.
When personnel, equipment, or supplies are transported into the shaft
with the bucket, the bucket is loaded, raised high enough to clear the two collar
doors, and then lowered into the shaft.
The collar door opening measured 10 feet 9 inches wide (north - south)
and 9 feet 6 inches long (east – west).
Each collar door is 57 inches long (half of the 9’6”), hinged at
opposite sides of the collar deck (east – west) and opens upward. Each door is opened with a pneumatically
driven jack into a vertical position (approximately 90 degrees from the closed
position). Each collar door activates an
electronic limit switch (Rockwell Automation, Allen-Bradley model 802M) mounted
to the head frame. This provides an
indication to the hoist operator that the doors are in the open position. Each door structure consists of a set of
perpendicular W6 x 25 steel beams running north – south and east – west and
welded to the one-half-inch steel plate.
The W6 x 25 section has an inside-flange depth of 5.47 inches. When the doors are in the closed position,
these members are beneath the steel plate of the door and are not visible. When the doors are open, these members are
exposed and face toward the shaft opening.
The bucket had a serial number of “045”
marked along the top outer portion.
Also, the number 6126, representing the listed weight of the bucket, was
marked on the top outer portion of the bucket,.
The inner dimensions of the bucket were measured to be 74 inches in
diameter with a height of 67 inches along the inside wall of the bucket. The bucket was attached to a 25-ton swivel
hook with a master link and four 5-foot-long, ¾-inch link diameter chain
slings. The chain slings were connected
to the bucket in pairs with a 1 ⅛-inch shackle attached to two eyes
welded to the inside of the bucket. The
swivel hook (self closing type) was integrated into the hoisting system with a
1 ¼ - 1 ⅜-inch
resin-poured open-type wire rope socket.
A threaded pin connection and cotter pin secured the swivel hook to the
wire rope attachment. With the bucket on
the collar deck, the hoist rope travels over the main sheave wheel to the hoist
house. Approximately 245 feet of wire
rope is exposed with approximately 15 feet extending from just outside the
hoist house to the top of the hoist drum.
The hoist rope construction was listed as a 1 ⅜-inch diameter, 19 X 7 EEIPS IWRC,
Non-Rotating wire rope. The hoist was a
model 4023 (FKCI No. 02-0021) manufactured by Ottumwa Iron Works, Ottumwa, Iowa,
with the following specifications:
Drum
Diameter 120 Inches
Drum
Width 120 Inches
Flange
Depth 14 Inches
Bull
Gear 351 Teeth
Pinion 21
Teeth
Rope
Size 1.375 Inches
Gear
Ratio 16.71
: 1
Motor 1,200 HP
Motor
Speed 591 RPM
Motor
Torque 127,919 Inch Pounds
Drum
Torque 2,138,071
Inch Pounds
Drum
Speed 35.36
RPM
Wraps/Layer 85
Two additional hoists were used to
support and move the work deck in the shaft.
Both hoists were manufactured in Canada by New Era Tool and Die
Limited. As viewed from the hoist
operator’s position, the hoists were numbered left to right, with the hoist on
the operator’s left being the No. 1 hoist.
The Frontier-Kemper identification number for the Nos. 1 and 2 hoists
were 03-5528 and 03-5527, respectively.
Each hoist was driven by a 30-horsepower electric motor and had a rated
line pull of 45,000 pounds. The maximum
rope speed for each hoist was listed at 22 fpm. The hoist ropes were manufactured by Bridon
American Corporation. The rope construction
was a 1 ⅜-inch
diameter, 18 X 26 DY 18 RREG lay. This
construction has a nominal breaking strength of 212,000 pounds and a nominal
weight of 4.17 pounds/foot. A Bridon
American Corporation test certificate with order No. 44023, and a test date of August 26, 2005,
provided by Frontier-Kemper personnel, indicated an actual breaking strength of
242,000 pounds. Additional break test
information was provided by Hanes Supply Incorporated test certificate dated April 11, 2006,
indicating an actual breaking strength of 217,900 pounds.
3) WIRE ROPE EXAMINATION: A visual examination was conducted on the
hoist rope, crosshead block and end attachment.
The visual examination did not reveal any broken wires or corrosion at
the load end attachment or crosshead block.
At the time of the examination, a field dressing was applied to these
areas of the rope to protect the rope from the environment. Caliper measurements were also taken at
100-foot intervals along the entire working length of the rope, starting with
the bucket located just below the collar doors.
Table 1 shows the measurements along with the averages and a comparable
measurement location documented in the August 6, 2007 daily report of Frontier-Kemper
‘s hoisting equipment book.
Table 1.
Caliper measurements taken at 100-foot intervals with the sinking bucket
starting at the top of the shaft and traveling to the bottom.
|
Distance
(Feet)
|
#1
(Inches)
|
#2
(Inches)
|
#3
(Inches)
|
Average
(Inches)
|
FKCI 8/6/07
(Inches)
|
|
0
|
1.375
|
1.374
|
1.377
|
1.375
|
1.375
|
|
100
|
1.378
|
1.378
|
1.378
|
1.378
|
1.375
|
|
200
|
1.363
|
1.363
|
1.362
|
1.363
|
1.365
|
|
300
|
1.369
|
1.369
|
1.370
|
1.369
|
1.370
|
|
400
|
1.368
|
1.371
|
1.369
|
1.369
|
1.370
|
|
500
|
1.375
|
1.377
|
1.375
|
1.376
|
1.375
|
4) HOIST ROPE SPEED TESTS: Tests were conducted to verify the speed of
the hoist rope under various conditions.
The hoist rope was marked (painted) in three 50-foot increments for a
total of 150 feet. The distance for each
increment and total distance traveled were timed with a stopwatch to the
nearest half second. Three tests were
conducted with the hoist operating at various speeds including the following:
Test 1 – The speed at which
personnel usually travel through the open doors.
Test 2 – The speed at which
personnel travel when they are within 100 feet of any stop.
Test 3 – The maximum speed at
which personnel are lowered.
During each of the tests the speed
indicated at the hoist operator’s station was recorded along with a timed test
of the rope. Each test was conducted
twice and the results are shown in Table 2.
Table 2.
Hoist Rope Speeds for Hoisting Personnel under various conditions.
|
|
0 – 50 feet
|
50 – 100 feet
|
100 – 150 feet
|
0 – 150 feet
|
Hoist
House
Speed
|
|
Test 1
(a)
|
55 FPM
(55 sec)
|
56 FPM
(54 sec)
|
57 FPM
(53 sec)
|
55 FPM
(162
sec)
|
20 FPM
|
|
Test 1
(b)
|
58 FPM
(52 sec)
|
59 FPM
(51 sec)
|
59 FPM
(51 sec)
|
58 FPM
(154
sec)
|
|
|
Test 2
(a)
|
120 FPM
(25 sec)
|
136 FPM
(22 sec)
|
130 FPM
(23 sec)
|
129 FPM
(70 sec)
|
100 FPM
|
|
Test 2
(b)
|
130 FPM
(23 sec)
|
136 FPM
(22 sec)
|
136 FPM
(23 sec)
|
134 FPM
(67 sec)
|
|