DEPARTMENT OF LABOR
MINE SAFETY AND HEALTH ADMINISTRATION
Metal and Nonmetal Mine Safety and Health
Report of Investigation
Surface Nonmetal Mine
(Cement Plant)
Fatal Fall of Person Accident
April 4, 2000
Royal Cement Company (mine)
Royal Cement Company, Incorporated
Logandale, Clark County, Nevada
ID No. 26-01977
Accident Investigators
Danny A. Frey
Supervisory Mine Safety and Health Inspector
Steve I. Pilling
Mine Safety and Health Inspector
Terence M. Taylor
Civil Engineer
Originating Office
Mine Safety and Health Administration
Rocky Mountain District
P.O. Box 25367 DFC
Denver, CO 80225-0367
Claude N. Narramore, District Manager
OVERVIEW
Charles D. Stone, laboratory technician, age 58, was fatally injured on April 4, 2000, when he fell into a pit of hot precipitator dust. Stone was attempting to obtain a sample for quality control analysis.
The accident occurred because a safe means of access had not been provided for collecting samples. Railings, barriers or covers were not provided at the pit opening.
Stone had a total of 1-1/2 years mining experience, all as a lab technician at this mine. He had received training in accordance with 30 CFR Part 48.
GENERAL INFORMATION
The Royal Cement Company mine, a quarry and cement plant, owned and operated by Royal Cement Company, Incorporated, was located just east of Logandale, Clark County, Nevada. The principle operating officials were Aldo R. DiNardo, president; Thomas Hamp, vice president of production and safety officer; and Abie John Patrick, Jr., general manager. The mine was normally operated three, 8-hour shifts a day, seven days a week. Total employment was 48 persons.
Limestone was drilled and blasted from a single bench in the quarry and transported to a crusher by front-end loaders. Crushed material was transported by a conveyor belt to the mill for processing into Portland cement. The finished product was stored in silos for bulk shipment to customers.
The last regular inspection at this operation was completed on September 2, 1999. Another inspection was conducted in conjunction with this investigation.
DESCRIPTION OF ACCIDENT
On the day of the accident, Charles Stone (victim) reported for work shortly before midnight, his regular scheduled shift. Stone went to the laboratory where he worked most of the time. His duties included obtaining dust samples for analysis from various locations at the plant to check for consistency of the product.
At about 1:45 a.m., Robert Thurman, front-end loader operator, found Stone lying on his side in the pit of hot precipitator dust. Thurman attempted to pull him out but was unable to move him, so he called on the radio for help. Brian Johnston, supervisor, Glen Lais, kiln operator/relief supervisor, and Cody Barnes, shift laborer, all heard the call and responded. Barnes called the local 911 emergency assistance number while Johnston, Lais and Thurman got Stone out of the pit. Stone could not talk and lost consciousness a few minutes later. Stone was transported by ambulance to the local airport, then flown by helicopter to a hospital where he died later that day. Death was attributed to cardiac arrhythmia and shock, due to 30 to 35 percent surface burns.
INVESTIGATION OF THE ACCIDENT
MSHA was notified at 2:38 a.m., on the day of the accident by a telephone call from Abie John Patrick, Jr., general manager for the mining company, to William Wilson, Western District, assistant district manager. An investigation was started the same day. MSHA's investigation team traveled to the mine and made a physical inspection of the accident site, interviewed a number of persons, reviewed documents relative to the job being performed by the victim, and reviewed the victim's training records. An order was issued pursuant to section 103(k) of the Mine Act to ensure the safety of miners. The miners did not request, nor have, representation during the investigation.
DISCUSSION
Dust was removed from the hot gases leaving the kiln by the precipitators, using an electrostatic process. The clean gases were discharged to the air out through a stack. The collected dust was carried by the No. 1 and 2 (east-west) screw conveyors to transfer points into the No. 3 (north-south) screw conveyor. The dust in the No. 3 screw conveyor was then either transferred to the No. 4 (east-west) screw conveyor to recycle it back toward the kilns, or it was discharged onto the ground through an opening at the end of the No. 3 screw conveyor. The hot dust would flow into a pit located adjacent to the opening. The temperature of the precipitator dust was reportedly between 190 and 200 degrees Fahrenheit, and it contained caustic material. To discharge the dust onto the ground, the No. 4 screw conveyor would have to be turned off.
The pit into which the dust was discharged was approximately 25 feet long in the north-south direction and 29 feet long in the east-west direction. The pit tapered from ground level at its northern edge to approximately four to five feet deep at the southern edge, which was parallel to the No. 4 screw conveyor. Every 30 minutes, a front-end loader would be used to clean out the precipitator dust in the pit and transport it to a storage area.
Dust samples were taken once every eight-hour shift to determine the composition of the dust, including the alkaline content. If the alkalinity was low enough, it could be reused in the kiln. However, if the alkalinity was too high, the dust would be stockpiled for possible reuse in a masonry grade cement.
When the No. 4 screw conveyor was not operating, the dust would be sampled at the discharge hole on the No. 3 screw conveyor. To access this location, a laboratory technician would walk along a hard packed path parallel to the north side of the No. 4 screw conveyor. The path was between the conveyor and the south edge of the pit.
The travelway was approximately 40-inches wide and consisted of natural ground, as well as some hard packed dust. When the dust was discharged to the pit, it would flow over the travelway into the pit. On the night of the accident, the dust had accumulated on the path and a pile had formed under the discharge point. With dust on the travelway, and the pit full of material, it was reportedly difficult to distinguish where the edge of the pit was located.
Two PVC pipes (2-inch diameter water lines) were buried in the vicinity of the No. 4 screw conveyor, and one hose was laying on the surface. All three were oriented parallel to the direction of the No. 4 screw conveyor.
On the morning of the accident, water leakage was evident on the path leading to the dust discharge location. The wet travelway was very slippery, and the hose was a tripping hazard. At a location on the travelway near where the victim may have fallen, there appeared to be a slip mark on the wet surface along the edge of the pit. The slip mark was beneath the exposed water hose.
To access the discharge sampling point, a laboratory technician would reportedly need to wade approximately waist deep into the dust pile at the end of the travelway on the western end of the No. 4 screw conveyor or they would have to stand at the edge of this discharge pile, hold the conveyor with one hand, and lean toward the discharge point to take the sample. An alternative means of reaching this location would be to walk on top of the flat cover for the No. 4 screw conveyor. The screw was 14 inches in diameter and the cover was measured to be 18-1/2 inches wide. The cover of the screw conveyor was four feet above the original ground surface. Two sets of footprints were found on top of the No. 4 screw conveyor the morning following the accident. According to plant personnel, none of them had walked on top of the screw conveyor.
Prior to the accident, there were no signs indicating hot material, nor was there a handrail or barrier at the edge of the travelway to prevent falling into the pit.
The pit area appeared to be well illuminated.
CONCLUSION
The accident was caused by failure to provide a safe means of access to the location where sampling was done and failure to provide railings or a barrier at the edge of the travelway to prevent a person from falling into the pit.
ENFORCEMENT ACTIONS
Order No. 7971972 was issued on April 4, 2000, under the provisions of Section 103(k) of the Mine Act:
A serious accident occurred at this operation on April 4, 2000, when a lab technician was found lying in a hot dust pile beside the precipitator. 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 for all actions to recover persons, equipment, and/or return affected areas of the mine to normal.This order was terminated on April 8, 2000. Conditions that contributed to the accident have been corrected and normal mining operations can resume.
Citation No. 7912433 was issued on May 2, 2000, under the provisions of Section 104(d)(1) of the Mine Act for violation of 30 CFR 56.11012:
A fatal accident occurred at this operation on April 4, 2000, when a lab technician fell into a pit filled with hot precipitator dust. The open pit was adjacent to a travelway and was not protected by railings, barriers or covers. Failure to protect the pit opening is a serious lack of reasonable care constituting more than ordinary negligence and is an unwarrantable failure to comply with a mandatory safety standard.This citation was terminated on May 2, 2000. The pit was filled with limestone and is no longer in use.
Order No. 7912434 was issued on May 2, 2000, under the provisions of Section 104(d)(1) of the Mine Act for violation of 30 CFR 56.11001:
A fatal accident occurred at this operation on April 4, 2000, when a lab technician fell into a pit filled with hot precipitator dust. The victim was attempting to obtain a sample of the dust for quality control analysis, a task he performed regularly. A safe means of access was not provided for obtaining these samples in that the travelway was narrow and the ground was slick from moisture and precipitator dust. Further, when the pit was full, it was difficult to ascertain the exact location of the edge of the pit. Failure to provide a safe means of access for collecting samples is a serious lack of reasonable care constituting more than ordinary negligence and is an unwarrantable failure to comply with a mandatory safety standard.This order was terminated on May 2, 2000. The pit was filled with limestone and is no longer in use.
Citation No. 7912435 was issued on May 2, 2000, under the provisions of Section 104(a) of the Mine Act for violation of 30 CFR 56.18002(a):
A fatal accident occurred at this operation on April 4, 2000, when a lab technician fell into a pit filled with hot precipitator dust. Work place examinations had not been conducted for conditions which may adversely affect safety or health.This citation was terminated on May 2, 2000. Examinations of work places are being conducted at least once each shift.
Related Fatal Alert Bulletin:
FAB2000M10
APPENDIX A
Persons
participating in the investigation
Royal Cement Company Incorporated
Abie John Patrick, Jr., general managerMine Safety and Health Administration
State of Nevada, Department of Business & Industry
William Collins, mine inspector
Danny A. Frey, supervisory mine safety and health inspectorAPPENDIX B
Steve I. Pilling, mine safety and health inspector
Robert D. Flowers, mine safety and health inspector
Terence M. Taylor, P.E., civil engineer
Persons Interviewed
Royal Cement Company
Abie John Patrick, Jr., general manager
Kelly Soltis, laboratory technician
Gilbert Sosa, mechanic and repairman
Robert Thurman, front-end loader operator
Glen Lais, kiln operator and relief supervisor
Brian Johnston, shift supervisor
Corey McCafferty, front-end loader operator
Michael W. Burns, chief chemist and victim's supervisor
William R. Howard, laboratory technician