DEPARTMENT OF LABOR
MINE SAFETY AND HEALTH ADMINISTRATION
Metal and Nonmetal Mine Safety and Health
REPORT OF INVESTIGATION
Surface Nonmetal Mine
Fatal Machinery Accident
October 26, 2000
Lebec Cement Plant
National Cement Co. of CA, Inc.
Lebec, Kern County, California
ID No. 04-00213
Supervisory Mine Safety and Health Inspector
Mine Safety and Health Inspector (Electrical)
Mine Safety and Health Specialist
Mine Safety and Health Administration
2060 Peabody Road, Suite 610
Vacaville, CA 95687
Lee D. Ratliff, District Manager
On October 26, 2000, Wayne Hand and Philip Wilson, maintenance mechanics, and Gary Poffenroth, maintenance supervisor, were seriously injured when a cement kiln burner and trolley assembly fell and struck them. The burner was being inserted into the kiln when it fell from the overhead rail support system. Wayne Hand, age 59, died on October 28, 2000, from his injuries.
The accident occurred because the defects in the trolley support system were not corrected once it was recognized that the trolley would not track properly.
Hand had a total of 20 years experience as a mechanic, all at this mine. He had received training in accordance with 30 CFR Part 46.
Lebec Cement Plant, a quarry and cement plant, owned by National Cement Co. of CA, Inc., was located eight miles southeast of Lebec, Kern County, California. Principal operating officials were Bruno Frery, vice president of operations, and Byron McMichael, plant manager. The mine and cement plant operated three 8-hour shifts a day, seven days a week. Total employment was 120 persons. A major modernization project was underway involving numerous subcontractors. Each independent contractor had their own work schedules.
Limestone was drilled and blasted from multiple benches in the quarry. The blasted limestone was loaded into haul trucks with front-end loaders and transported to the nearby cement plant where it was crushed, dried, heated, and processed into cement. The finished product was stored in silos for bulk shipment to customers.
The cement plant was under going a major modernization project. One aspect of this involved the replacement of the kiln burner, trolley, and overhead rail support system. The mine operator had contracted Becon Construction (Becon) to provide the engineering, design, and overall site management for the new system. In turn, Becon subcontracted Morton Engineering and Construction, Inc., (Morton) to manage on-site construction and installation of the new system. Horizon Steel Co., fabricated the components for the rail support system from plans supplied by Becon and shipped them to the site for erection by Morton. The trolley and burner assembly were built and shipped to the plant by the Fuller Company (Fuller).
The last regular inspection of this operation was completed on April 13, 2000. Another inspection was conducted following this investigation.
DESCRIPTION OF ACCIDENT
On the day of the accident, Wayne Hand (victim) reported to work at 3:00 p.m., his normal starting time. He performed his normal job activities until approximately 8:15 p.m., when he was sent to the kiln burner floor to remove steel handrails and toe boards to facilitate insertion of the new burner into the kiln. Hand obtained an oxygen-acetylene cutting torch and proceed to the kiln area where he was met by Gary Poffenroth, maintenance supervisor, and Phillip Wilson and Duane Beck, maintenance mechanics. Poffenroth, Wilson, and Beck had been moving the new burner into the kiln when a fuel supply line caught on the handrail and toe board of an adjacent walkway. Hand cut and removed the handrails and toeboards. Poffenroth, Wilson, and Beck then resumed moving the burner into position while Hand began storing his tools and torch hoses onto a cart mounted on the front of a small fork lift.
The new burner was supported by an overhead trolley support system mounted on two steel rails. Movement of the trolley was with a hand-operated, gear reduction drive unit mounted on the front drive wheels of the trolley. This unit was connected to a pulley and rotated manually using a chain wrapped around the pulley. As the burner was being moved into the kiln, the chain fell off the pulley which stopped forward movement. Beck climbed onto the burner and reinserted the chain. As the crew resumed moving the burner, it suddenly fell from the trolley rails without warning and struck Hand, Poffenroth, and Wilson. Beck, who had remained on top of the burner, was thrown free and was not injured.
Other personnel in the area heard the noise, telephoned for assistance, and administered first aid to the injured miners. Emergency response teams arrived shortly and the injured miners were transported to a local hospital. Poffenroth and Wilson received serious injuries due to the accident. Hand died on October 28 as a result of his injuries. Death was attributed to blunt trauma.
INVESTIGATION OF THE ACCIDENT
MSHA was notified of the accident at 12:15 a.m., on October 27 by a telephone call to assistant district manager Bill Wilson. An investigation was started that same day. An order was issued pursuant to Section 103(k) of the Mine Act to ensure the safety of miners. An MSHA team conducted an inspection of the accident site, examined the equipment involved, interviewed a number of persons, and reviewed documents relative to the jobs being performed by the victims. The team was assisted by mine management, independent contractors, miners, and miner's representatives.
� The accident occurred at the cement kiln area where a new burner was being installed into the kiln for the first time by plant personnel. The old burner, trolley, and supporting components had been dismantled and were being replaced with a completely new unit.
� The burner was supported by an overhead trolley installed on a rail support system. This system allowed the burner to be inserted and withdrawn from the kiln for maintenance or adjustment. The combined weight of the trolley and burner was approximately 16,636 pounds. Fuller provided specifications to Becon regarding the dimensions, weight, and load distribution for the trolley and burner. Becon designed the trolley rail support based on these requirements then provided specification designs to Morton and contracted with them to build the system.
� The trolley was attached to the rear of the burner with the burner anterior freely suspended in front of the trolley. This arrangement placed a cantilever load on the trolley system. The load on each of the two front trolley wheels was specified by Fuller to be 11,465 pounds in the down direction. Fuller also specified that the load on each of the two rear wheels was to be 3,147 pounds in the up direction. The load was specified to be upward because the front-heavy load lifted the rear of the trolley upward. To counteract this unbalanced weight transfer, the trolley was equipped with a double set of rear wheels sandwiching each trolley rail - one wheel on top of the rail and one wheel below.
� The trolley was examined and found to be in accordance with the design specifications. The distance between the outside edges of the trolley wheels was 6 feet, 6 3/4 inches. The distance from the centerline of the trolley front axle to the centerline of the rear axle was 8 feet, 2 7/16 inches. Each trolley wheel had a flange, similar to a railcar wheel. The diameter of each front wheel was 9 inches at the running surface and 10 1/4 inches at the flange. The diameter of each rear wheel was 7 1/16 inches at the running surface and 8 1/4 inches at the flange. Total thickness (width) of each wheel, including the flange, was 3 1/2 inches. The flange was 1 3/16 inches wide. These measurements left a remaining wheel width available to travel over the rail of 2 3/8 inches. The outside edge of each wheel (opposite the flange side) was beveled at a 45-degree angle, 3/16 inches back from the outside edge. The maximum possible wheel to rail contact width was therefore 2 3/16 inches. This contact would occur when the wheel flange was touching the trolley rail.
� The trolley wheels traveled on two rails consisting of two W18 x 50 W Beams (Wide Flange I-Beams) approximately 52 feet long. Structural L angles (angle irons) were welded to the bottom inner flanges and web of the beams forming a rectangular box cross section on each of the bottom inner flanges of the beams. The box structure ran the length of each beam and measured 3 9/16 inches wide and 2 3/4 inches high. MSHA determined that the specifications furnished by Becon to Morton were deficient in that they required the beams to be built one-half inch farther apart than the distance required to meet the Fuller specifications.
� Fuller's burner load drawing (No. 1.595780) specified that a minimum of 1 3/4 inches and a maximum of 2 3/16 inches of contact must be maintained between the trolley wheel and trolley rail. If the trolley was pushed fully to the left or right so that the wheel flanges on one side of the trolley were touching the rail, a minimum wheel contact of 1 3/4 inches would have to be maintained on the opposite side to meet the design specifications.
� The measured distance between the inside edge of the trolley rails, where the trolley fell, was 6 feet, 3 5/8 inches. When the wheel flanges on one side of the trolley were touching the trolley rail, the wheel-to-rail contact would be 2 3/16 inches. Given that measurement, the wheel-to-rail contact on the opposite side would be approximately 9/16 inches, a distance which did not meet the 1 3/4 inch dimension specified by Fuller for the minimum allowable wheel-to-rail contact.
� Measurements showed that the bottom flanges of the I-Beams were farther apart than the top flanges by approximately 1/2 inch where the trolley fell from the rails. At points farther away from that area, the bottom flanges were approximately 1/4 inch farther apart than the top flanges.
� Since the weight of the trolley was carried on the inner flanges of the I-Beams, a torsional component of load was placed on the beams. The torsional load would cause the bottom of the beams to twist outward, increasing the separation between the rails. The combination of minimal wheel-to-rail contact and torsional deflection allowed the trolley to fall from the rails.
� During final construction and testing of the system by Becon and Morton personnel, the trolley drifted to, or favored, one side of the support rail several times. On one occasion, their personnel had to use a come-along on the trolley to realign the wheels parallel with the support rails. The failure of the trolley to properly track was known to management of the two contractors.
The root cause of the accident was the failure to correct the defective trolley support system once it was recognized that it would not track properly. The inadequate design of the trolley support rails was a contributing factor to the accident.
National Cement Co. of CA, Inc.
Order No. 7996012 was issued on October 27, 2000, under the provisions of Section103(k) of the Mine Act:
An accident occurred at this operation on October 27, 2000, during insertion of the burner and trolley assembly into the kiln. Three maintenance workers were injured when the burner assembly fell from the supporting rails. This order is issued to assure the safety of persons at this operation until the mine or affected areas can be returned to normal mining operations as determined by an Authorized Representative of the Secretary. The mine operator shall obtain permission from an authorized representative for all actions to recover persons, equipment and/or restore operations in the affected area.This order was terminated on November 3, 2000, when it was determined by MSHA that the conditions which contributed to the accident no longer existed and normal mining operations could resume.
Citation No. 7994801 was issued on January 2, 2001, under the provisions of Section 104(d)(1) of the Mine Act for violation of 30 CFR 56.14100(b):
A fatal accident occurred on October 27, 2000, when the kiln burner and trolley system fell from the supporting rails at this cement plant. One miner was fatally injured and two others seriously injured when the burner and trolley system fell. It was known to management that the trolley was not properly tracking on the rail system prior to the accident yet adequate steps were not taken in a timely manner to prevent this safety defect from creating a hazard to person in the area. The site manager engaged in aggravated conduct constituting more than ordinary negligence in that he was aware of this defect and did not correct it in a timely manner. This violation is an unwarrantable failure to comply with a mandatory standard.This citation was terminated on January 2, 2001, when the trolley and burner system was modified and rebuilt.
Morton Engineering and Construction Co.
Citation No. 7994802 was issued on January 2, 2001, under the provisions of Section 104(d)(1) of the Mine Act for violation of 30 CFR 56.14100(b):
A fatal accident occurred on October 27, 2000, when the kiln burner and trolley system fell from the supporting rails at this cement plant. One miner was fatally injured and two others seriously injured when the burner and trolley system fell. It was known to management that the trolley was not properly tracking on the rail system prior to the accident yet adequate steps were not taken in a timely manner to prevent this safety defect from creating a hazard to person in the area. The site superintendent engaged in aggravated conduct constituting more than ordinary negligence in that he was aware of this defect and did not correct it in a timely manner. This violation is an unwarrantable failure to comply with a mandatory standard.This citation was terminated on January 2, 2001, when the trolley and burner system was modified and rebuilt.
Related Fatal Alert Bulletin:
A. Persons Participating in the Investigation
B. Persons Interviewed
C. Drawing of front trolley wheels and trolley rails
Persons Participating in the Investigation
National Cement Company of CA, Inc.
Byron McMichael ............... plant managerMine Safety and Health Administration
John Widows ............... supervisory mine safety and health inspectorState of California
John Pereza ............... mine safety and health inspector (electrical)
Ronald Medina ............... mechanical engineer
Dennis Tobin ............... mine safety and health specialist
Department of Industrial Relations
Division of Occupational Safety and Health
Pete Dizon ............... senior engineerPACE International Union
Sylvia Riley ............... associate engineer
Jerel Snapp ............... associate engineer
(Paper, Allied Industrial, Chemical and Energy Workers International, AFL-CIO 80-471)
Jennifer Schultz ............... associate directorAtkinson, Andelson, Loya, Ruud & Romo
Jack Hammond, Jr. ............... International representative
James Taggert ............... president, local 80-471
Christian Hess ............... miners representative
Phillip Toler ............... miners representative
Abby McDevitt ............... safety representative
Eugene McMenamin ............... attorney at lawDoyen and Associates, Inc.
Javi�r Valenzuela ............... business development manager
National Cement Company of CA, Inc.
Duane Beck ............... minerBecon Construction
James Taggert ............... miner
Ronald Harris ............... miner
John Rhoades ............... miner
James Pugh ............... miner
Michael Bryan ............... miner
Sean Burke ............... miner
Christian Hess ............... miner
Daniel Holcomb ............... miner
Joseph Popejoy ............... miner
Rudy Beard ............... miner
Bobby Rodgers ............... miner
Clyde McKinzie ............... miner
Raymond Graham ............... miner
William Mulliniks ............... miner
Jack Rode ............... site managerMorton Engineering and Construction, Inc.
Scott Meter ............... project field engineer
Mark Braccia ............... professional engineer
Alan Miller ............... site superintendentF.L. Smidth-Fuller Engineering Group
Gary Wieand ............... design engineer
Carlos Pintado ............... commissioning engineer-consultant