UNITED STATES
DEPARTMENT OF LABOR
MINE SAFETY AND HEALTH ADMINISTRATION
WESTERN DISTRICT
Metal and Nonmetal Mine Safety and Health
Surface Nonmetal Mine
(Cement Plant)
Fatal Fall of Person Accident
October 12, l999
Batterton Waterproofing, Inc. (BIJ)
Durkee Cement Plant
Ash Grove Cement Company
Durkee, Baker County, Oregon
ID No. 35-02970
October 20, 1999
by
Larry Larson
Supervisory Mine Safety and Health Inspector
Ralph Payton
Mine Safety and Health Inspector
Darren Blank
Civil Engineer
Originating Office
Mine Safety and Health Administration
Western District
2060 Peabody Road, Suite 610
Vacaville, CA 95687
James M. Salois, District Manager
OVERVIEW
On October 12, l999, David E. Cleland, contractor laborer, age 26, was fatally injured when he fell off a suspended work scaffolding while cleaning cement from the inside of a silo.
The accident occurred because the load-bearing portion of the scaffolding support frame had become weakened from extensive corrosion, abrasion, and from fractures in the frame near the scaffold support rail. Contributing factors were the failure of the contractor to promptly initiate appropriate actions to correct defective conditions on the scaffolding which adversely affected the safety or health of the miners and the failure of the mine operator and contractor to require the use of fall protection when working on the elevated scaffolding.
Cleland had a total of 5 weeks mining experience; however, he had 6 years experience at this job. He had not received training in accordance with 30 CFR Part 48..
GENERAL INFORMATION
The Durkee Cement Plant, a surface quarry and cement mill, owned and operated by Ash Grove Cement Company, was located near Durkee, Baker County, Oregon. The principal operating official was Michael J. Hrizuk, plant manager. The mine was normally operated three, eight-hour shifts, seven days a week. Total mine employment was 126.
Limestone, shale, and clay were drilled and blasted from multiple benches and transported to a primary crusher by haulage trucks. Crushed material was then transported by conveyor to the mill for further sizing and processing into Portland cement. The finished product was stored in silos or a dome for bulk shipment.
The victim was employed by Batterton Waterproofing, Inc., located at York, Nebraska. The principle operating official was Michael Batterton, president. The contractor normally worked one nine-hour shift a day, five or six days a week. Total employment at the Durkee facility was 14 persons. Batterton Waterproofing Inc., had been hired to refurbish the clinker silos and began work at the mine on September 1, 1999.
The last regular inspection of this operation was completed on April 15, 1999. Another inspection was conducted at the conclusion of this investigation.
DESCRIPTION OF THE ACCIDENT
On the day of the accident, David E. Cleland (victim) reported to work at 7:00 a.m., his regular starting time. He was assigned by Perry Pickens, Superintendent, to help with the cement spraying (gunite) operation inside the No. 2 cement clinker silo in the mill. Cleland proceeded to the assigned area with Christopher Rademacher and Robert Johnson, laborers. They rode a manlift elevator to the top of the No. 2 cement clinker silo, then descended eight feet down a ladder into the silo through an access opening to a suspended work scaffolding. Working from the scaffolding, the three men caulked between the silo wall and the liner then cleaned up the surrounding area in preparation of relocating the scaffolding to another elevation within the silo. Rademacher began blowing gunite onto the inside wall of the silo while Cleland and Johnson were cleaning spilled and hardened cement from the scaffolding deck and frame assembly.
Work continued normally until about 9:40 a.m. As the victim was cleaning cement from the scaffolding frame, a weakened section of the frame broke, throwing the victim off the plank(s) to the silo floor. Cleland was not wearing a safety belt and lanyard and fell approximately 100 feet. Rademacher heard noise behind him, turned and saw Johnson scrambling to a safe area on the scaffolding planks. Realizing that Cleland had fallen, Rademacher immediately radioed to the ground crew to shut down the spraying equipment. He then requested emergency assistance for Cleland. Workers in the area responded immediately and attempted to revive Cleland without success. Local authorities and emergency medical personnel arrived shortly. Cleland was pronounced dead at the scene by a local coroner. Death was attributed to massive trauma to the chest and head.
INVESTIGATION OF THE ACCIDENT
Larry Stevenson, mine safety and health inspector in the Boise, Idaho, field office was notified of the accident at 10:l5 a.m., on the same day by a telephone call from Michael Henigan, maintenance planner, Ash Grove Cement Company. MSHA's investigation was started the same day and an order was issued under the provisions of Section 103(k) of the Act to ensure the safety of the miners. MSHA conducted the investigation with the assistance of mine management, the contractor, and the miners. The miners did not request nor have representation during the investigation.
DISCUSSION
Clinker discharged from the cooler was conveyed through a drag conveyor and deep bucket elevator and stored in six, 7000-ton clinker storage silos. The accident occurred at the No. 2 silo which measured 145 feet high by 40 feet in diameter. The inside height of the silo was approximately 122 feet. The bottom of the silo contained two 14-foot diameter hoppers. The southern hopper had been abandoned and was not being used. The northern hopper discharged material onto a belt which conveyed clinker to the finish mill. An access opening, measuring 44 inches square, was located on the side of the silo. The opening was approximately 23 feet above the bottom of the silo, and was accessible from an elevated platform. A 30-inch diameter access opening was located on the roof of the silo.
The heating and cooling cycles and abrasion from the hot clinker material had caused the concrete walls on the inside of the silo to spall. The walls were constructed of reinforced concrete, strengthened with spliced sections of rebar. Eventually, the rebar splices became exposed and had separated. As a result of this damage, the company decided the silos inside walls should be relined with new rebar and gunite to prevent further damage.
Sixteen foot long by twelve-inch wide by two thick planks of southern white pine and 4-foot by 8-foot by ½-inch sheets of plywood were laid on thirteen Hi-Lo climbers, model D-800, to construct a moveable work platform inside of the silo. Each climbers consisted of an "A" frame measuring 32-inches wide and 54-inches high. They were constructed of 1-inch-outside-diameter 14-gauge steel tubing. The climbers were designed to support staging and scaffolding. The climbers being used were said to be approximately 25 years old. At the time of the accident, nine of the climbers were installed evenly spaced radially and about 1½ feet from the inside wall of the silo. The remaining four climbers were placed inside the center portion of the silo in a square pattern. Two planks were placed between each of the outside climbers forming a ring. Eight planks were placed between the four interior climbers. A total of 27 planks spanned the outer ring and the interior climbers. To complete the working surface, 30 to 40 sheets of plywood were laid on the planks. Spans between the climbers ranged from nine feet to thirteen feet. The climbers had a rated load capacity of 1000 pounds per unit. The cables supporting the climbers and platform were anchored to various structural and non-structural members on the roof of the silo. Each cable was secured using three "U" type clamps. (See Appendix D).
Each climber was powered by a single 5/8-inch electric drill. To lower or raise the platform evenly, power to the drills was controlled by a main switch on two circuit breaker boxes. Each box was wired to control one side of the platform. If an individual drill was required to be operated, the circuit breaker to that drill would be closed, the breakers to the other drills opened, and the main switch for the box would be closed. A minimum of two men were required to raise or lower the platform.
Work in the storage silos was accomplished in two phases. The first phase consisted of the placement of steel rebar; the second was application of the gunite coating. Rebar had already been installed in the No. 2 silo and the gunite spraying operation was being completed. The design specifications required that at least four inches of concrete be sprayed onto the wall. To achieve this thickness, the gunite was applied in two steps. First, a 3½ inch thick layer of cement was applied starting at the bottom of the silo and progressing upwards. A two man crew typically performed this spraying activity. To prevent over spray from building up on the elevated platform, the plywood sheets were moved toward the center leaving a gap approximately three feet wide between the platform and the wall of the silo. Once spraying was completed, the sheets would be moved back to their original positions. Then, a finish coating of gunite, approximately one inch thick, would be applied by starting at the top of the silo and progressing toward the bottom. Three workers would normally apply the coating with one miner spraying the gunite while the other two would apply a broom finish to the cement. This finish coating was being applied at the time of the accident.
Based on an examination of the recovered section of the climber frame and subsequent analysis of the loading conditions at the time of the accident, the following factors contributed to the failure of the frame:
1. Where the frame broke, the thickness of the metal tubing measured .028 inch in some areas. This measurement was approximately one half of the wall's original thickness. The reduction was attributed to corrosion and wear as a result of handling and use over an extended period of time. This loss of area reduced the strength capacity of the frame.
2. One end of the framing tube had corrosion on the entire separated surface. No connecting surface could be identified. The other end of the tube had what appeared to be fresh break on approximately one-half of the circumference of the separated surface. The remaining surface was corroded and showed microscopic traces of green, red, and blue paint. Deterioration of a similar nature was found by MSHA investigators after the accident on the other climbers in the silo.
3. An analysis of the climber's structure after the accident indicated that it would have had the capacity to carry the weight of the platform, equipment, and work crew if it had been properly maintained. The estimated total weight of the platform, equipment, and crew at the time of the accident was 6700 pounds. As a result of it's deteriorated condition, the structure did not have the capacity to safely carry this weight because it's strength had been reduced due to surface separation and loss of cross-sectional area from wear and corrosion.
4. Cracks and holes were noted on several other climbers being used in the silo at the time of the accident. Also, many of the other climbers had bends on the scaffold support sections and/or the tubes comprising the lower portions of the "A" frame. These conditions also existed on the climber which was involved in the accident.
5. The contractor's written policy on safety belts and lines was discussed during a safety meeting held on April 20, 1998, and on August 2, 1999.
6. The structural deterioration found on the Hi-Lo climber should have been identified if an examination of its components had been conducted as recommended by the manufacturer. The investigation determined these components were last examined two weeks prior to the accident while the scaffolding assembly was being constructed.
CONCLUSION
The primary cause of the accident was the failure to promptly initiate appropriate actions to correct defective sections of the High-Lo climbers. Failure to require the use of safety belts and lines when working from elevated heights also contributed to the accident.
ENFORCEMENT ACTIONS
Order No. 7977894 was issued on October 12, 1999, under the provisions of Section 103(k) of the Mine Act:
A fatal accident occurred at this operation on October 12, 1999, when an employee of Batterton Waterproofing, Inc., fell to the bottom of clinker silo No. 2 while guniting the silo. This order is issued to assure the safety of persons at this operation until the mine or affected areas can be returned to normal operations as determined by an authorized representative of the Secretary. The mine operator shall obtain approval from an Authorized Representative of the Secretary for all actions to recover persons, equipment, or return the affected area(s) of the mine to normal operations.
The order was terminated on October 29, 1999. Conditions that contributed to the accident have been corrected and normal mining operations can resume.
Batterton Waterproofing, Inc.
Citation No. 7976431 was issued on December 15, 1999, under the provisions of Section 104(d)(1) for violation of 56.15005:
A laborer was fatally injured when he fell about 100 feet from a suspended work scaffold on October 12, 1999. The victim was working to repair the wall inside the No. 2 silo when a section of the scaffolding support frame (Hi-Lo climber) failed, causing him to lose his balance and fall. The victim was not secured by a safety belt and line. Failure to ensure that persons working at elevated locations are secured by safety belts and lines is a serious lack of reasonable care constituting more than ordinary negligence and is an unwarrantable failure to comply with a mandatory safety standard.
The citation was terminated on December 16, 1999. The contractor is no longer on the mine site and the conditions which contributed to the accident have been corrected.
Order No. 7976432 was issued on December 15, 1999, under the provisions of Section 104(d)(1) of the Mine Act for violation of 56.18002(a):
A laborer was fatally injured when he fell about 100 feet from a suspended work scaffold on October 12, 1999. The victim was working to repair the wall inside the No. 2 silo when a section of the scaffolding support frame (Hi-Lo climber) failed, causing him to lose his balance and fall. Several weeks prior to the accident the contractor had examined this scaffolding support frame and failed to promptly initiate appropriate actions to correct conditions that posed hazards to the miners. Failure to promptly correct those hazards is a serious lack of reasonable care constituting more than ordinary negligence and is an unwarrantable failure to comply with a mandatory safety standard.
The order was terminated on December 16, 1999. The contractor is no longer on the mine site and the conditions which contributed to the accident have been corrected.
Order No. 7976433 was issued on December 15, 1999, under the provisions of Section 104(d)(1) of the Mine Act for violation of 56.14100(b):
A laborer was fatally injured when he fell about 100 feet from a suspended work scaffold on October 12, 1999. The victim was working to repair the wall inside the No. 2 silo when a section of the scaffolding support frame (Hi-Lo climber) failed, causing him to lose his balance and fall. Safety defects in the scaffolding device(s) had not been corrected in a timely manner. Failure to correct these safety defects is a serious lack of reasonable care constituting more than ordinary negligence and is an unwarrantable failure to comply with a mandatory safety standard.
The order was terminated on December 16, 1999. The contractor is no longer on the mine site and the conditions which contributed to the accident have been corrected.
Ash Grove Cement Company
Citation No. 7976434 was issued on December 15, 1999, under the provisions of Section 104(d)(1) of the Mine Act for violation of 56.15005:
A laborer was fatally injured when he fell about 100 feet from a suspended work scaffold on October 12, 1999. The victim was working to repair the wall inside the No. 2 silo when a section of the scaffolding support frame (Hi-Lo climber) failed, causing him to lose his balance and fall. The victim was not secured by a safety belt and line. The mine operator knew that the contractor's personnel were not using safety belts and lines when they were working from the suspended scaffold. Failure to ensure that persons working at elevated locations are secured by safety belts and lines is a serious lack of reasonable care constituting more than ordinary negligence and is an unwarrantable failure to comply with a mandatory safety standard.
Related Fatal Alert Bulletin:
 FAB99M37
APPENDIX A
Persons participating in the recovery
Ash Grove Cement Company
Charles Yates, first responder
Eric Bronson, emergency medical technician
Merlin McMullen, shift production supervisor
Leaf Roa, shift supervisor
Batterton Waterproofing, Inc.
Perry Pickens, superintendent
APPENDIX B
Persons involved in the investigation
Ash Grove Cement Company
Donald Guyer, Safety and Environmental Manager
George Minshall, Corporate Safety Manager
Michael Henigan, Maintenance Planner
Batterton Waterproofing, Inc.
Michael Batterton, Co-Owner and President
Perry Pickens, Supervisor
Mine Safety And Health Administration
Larry Larson, Supervisory Mine Safety and Health Inspector
Ralph Payton, Mine Safety and Health Inspector
Darren Blank, Civil Engineer
APPENDIX C
Persons interviewed
Ash Grove Cement Company
Donald Guyer, Safety and Environmental Manager
Merlin McMullen, Production Shift Supervisor
Leaf Roe, Shift Supervisor
George Minshall, Corporate Safety Manager
Matthew Nawahine, Plant Engineer
Batterton Waterproofing, Inc.
Michael Batterton, Co-Owner and President
Perry Pickens, Supervisor
Robert Johnson, Laborer
Christopher Rademacher, Laborer
James Sievers, Laborer
Dolan Winfield, Laborer
Allen Parkerson, Laborer
Jamie Hullinger, Laborer
Appendix D
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