UNITED STATES

DEPARTMENT OF LABOR

MINE SAFETY AND HEALTH ADMINISTRATION

COAL MINE SAFETY AND HEALTH

 

REPORT OF INVESTIGATION

Shaft Construction for Underground Mine

Fatal Fall of Persons

August 10, 2007

 

Frontier-Kemper Constructors Inc. (A01)

Evansville, Indiana

 

at

 

Gibson Mine

Gibson County Coal, LLC

Princeton, Gibson County, Indiana

ID No. 12-02215

 

Accident Investigators

 

Charles H. Grace, P.E.

Assistant District Manager, Technical Programs, District 7, Barbourville, KY

 

Michael G. Kalich, CMSP

Senior Mining Engineer, Headquarters Safety Division

 

J. Jarrod Durig, P.E.

Civil Engineer, Technical Support, Pittsburgh, PA

 

Michael P. Snyder, P.E.

Mining Engineer, Technical Support, Triadelphia, WV

 

Kevin L. Doan

Roof Control and Ventilation Specialist, District 7

 

Originating Office

Mine Safety and Health Administration

Office of the Administrator

Coal Mine Safety and Health

1100 Wilson Boulevard

Arlington, VA 22209

Kevin G. Stricklin, Administrator

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 100^th 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.

 

 

 

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.