UNITED STATES
DEPARTMENT OF LABOR
MINE SAFETY AND HEALTH ADMINISTRATION

Northeastern District
Metal and Nonmetal Mine Safety and Health


Accident Investigation Report
Surface Nonmetal Mine
(Crushed Stone)


Fatal Electrical Accident


Overland Services, Inc. (Contractor)
I.D. No. 6VB
at
Stavola Constr. Matl's., Inc.
Stavola Constr. Materials, Inc.
Bound Brook, Somerset County, New Jersey
Mine I.D. No. 28-00015

August 8, 1997


By

Dale R. St. Laurent
Supervisory Mining Engineer

and

Ricky J. Horn
Mine Safety and Health Inspector


Northeastern District Office
230 Executive Drive, Suite 2
Cranberry Township, PA 16066-6415

James R. Petrie
District Manager

GENERAL INFORMATION

Lisa McDowell, age 19, was electrocuted at approximately 7:00 a.m. on August 8, 1997, as she stepped out of the cab of an over-the-road haul truck that had contacted an overhead high voltage power line. She and William Richardson, age 20, were passengers of Michael Austin, age 41, truck driver for Overland Services, Inc., an independent trucking company contracted to haul finished material from the mine. Austin had not received training in accordance with 30 CFR Part 48.

Bruce Todd, purchasing agent, Stavola Constr. Matl's., Inc., notified MSHA at approximately 8:00 a.m., on the day of the accident. An investigation was started the same day.

Stavola Constr. Materials, Inc., was a multiple bench, crushed stone, quarry operation with an associated mill, owned and operated by Stavola Constr. Matl's., Inc., and located in Bound Brook, Somerset County, New Jersey. The principal operating official was Aaron G. Harding, plant superintendent. The mine normally operated one shift, 10 hours a day, 5 to 6 days a week, and employed a total of 46 persons.

Overland Services, Inc. was an independent trucking company contracted by Stavola to haul finished material from this mine to another Stavola operation. Its corporate office was located in Fort Pierce, Florida, and Austin was dispatched out of an area office located in Clarksburg, New Jersey. The principal operating official was Salvatore R. Merola, vice president.

Traprock was drilled, blasted, and then loaded into off-road haul trucks utilizing front-end loaders. The trucks transported the material from the pit to the mill where it was crushed and sized. The finished products were loaded onto railroad cars and over-the-road trucks for transport to customers.

The last regular inspection of the mine was completed on November 21, 1996. Another regular inspection was conducted after the conclusion of this investigation.

Physical Factors Involved

The tractor portion of the tractor-trailer involved in the accident was a 1991 Peterbilt (VIN 1XP-5DB9X-4-NN316483), and the trailer portion was a Ravens 40-foot, aluminum body, rear dump (VIN 1R1D14026NJ923297). The trailer bed was hydraulically-controlled and operated by a control valve located on the left side of the driver's seat. The tractor-trailer was owned and operated by Overland Services, Inc. The truck was perpendicular to the overhead power lines and underneath them at the time of the accident.

According to information provided by Raven Metal Products, Inc., the top forward edge of the trailer measured 37 feet, 2 inches above the ground in its raised position, and the bottom forward edge measured 29 feet, 10 inches. Evidence indicated the power line was initially contacted by the mud flaps hanging down from the front of the raised trailer bed. As Austin pulled away from the stockpile while lowering the trailer bed, the power line slid up the mud flaps and caught on the metal shovel holder bracket located about 1 foot above the trailer floor. This created a path-to-ground through the body of the truck and its tires.

The accident occurred at the 3/8-inch material stockpile. The stockpile was next to a stacker conveyor, which also fed an adjacent bin hopper. Truck drivers routinely filled their own trucks under the 3/8-inch bin using a push button automatic loading system. The power lines running from the primary to the secondary substation passed near the 3/8-inch stockpile. The toe of the stockpile was usually 60 to 70 feet from the power lines, but because several trucks had already dumped product at the pile, the toe distance had been reduced to approximately 50 feet.

Public Services Electric and Gas Company (PSE&G) provided 26,000-volt alternating current to the primary substation which was owned by Stavola and located on the mine property. From the primary substation, the 26,000 volts were carried via overhead lines to a secondary substation located next to the mill, where the voltage was reduced to 480 volts for plant use. The utility's 26,000-volt system was a resistance grounded wye system which utilized a 9 ohm grounding resistor. Utility power was supplied to the mine through a General Electric Oil Blast Circuit Breaker #0139A7613-201 32271319, type Fk 439-69-3500-Y. Three-phase overcurrent and instantaneous protection was provided by three Westinghouse, style #264C901A07, type CO-9 overcurrent relays. Ground fault protection was provided by one Westinghouse, style #1875265A, type CO-8 relay. When working properly, any one of the four relays should trip the oil circuit breaker when an overcurrent or ground fault is detected.

The relays, however, did not automatically trip the circuit breaker during the accident, and a Stavola employee had to trip it manually to cut off the power. PSE&G personnel arrived on-site shortly after the accident occurred and checked the condition of the power lines and the function of the relays at the primary substation. They did not find any damage to the power lines and their tests, reportedly, indicated that the overcurrent relay (CO-9) for Phase 3, and the ground fault relay (CO-8), were out of limits, and the ground fault relay's (CO-8) disk was stuck with dirt particles and would not turn. The pick-up current for the Phase 3 overcurrent relay (CO-9) was 6.0 amperes which equates to a phase current of 480 amperes; the correct value should have been 3.5 amperes or a phase current of 280 amperes. The pick-up current for the ground fault relay (CO-8) was 5.1 amperes or 408 amperes of ground fault current; the correct value should have been 1 ampere or a ground fault current of 80 amperes. PSE&G personnel stated that they then cleaned the relays, possibly readjusted the tension spring of the CO-8 ground fault relay, and retested them. The retest indicated that the relays were within specified limits. Prior tests conducted by PSE&G personnel on November 20, 1996, indicated that the relays were working properly at that time.

On a subsequent visit, MSHA Technical Support personnel, accompanied by PSE&G and company personnel, also examined and tested the relays. The relays operated and tested properly at that time, with the exception that the ground fault relay was observed to have a tendency to occasionally stick in the closed, or tripped position. The utility's digital fault recorder at the Bridgewater switching station indicated the ground fault current started at 175 amperes and gradually increased to 250 amperes on the morning of the accident. If the ground fault relay had been working properly at the time of the accident, the oil circuit breaker should have cleared the fault in less than 3 seconds. No explanation could be found as to why the relays had failed to trip during the accident, other than they may have been dirty.

The 26,000-volt power lines at the accident site were owned and controlled by Stavola. The height of the lowest power line was estimated to be 28 feet at the point of contact with the truck. The distance between the poles supporting the power lines at the accident site was about 173 feet. Each pole was posted with several small signs warning of the hazard of high voltage overhead power lines.

Description of Accident

On the day of the accident, Michael Austin, contractor truck driver and two passengers, Lisa McDowell (victim), and William Richardson, arrived at the mine property at approximately 5:45 a.m. Austin, and several other Overland drivers, loaded their trucks with 3/8-inch material at the self loading material storage bin. At the scales, he was told by William Bird, weighmaster, that he and several other drivers had the wrong material. Bird instructed them to go back to the 3/8-inch material stockpile, dump their loads, and reload with dust material.

At approximately 7:00 a.m., Austin drove back to the plant and backed his truck up to the 3/8-inch stockpile. He stepped out of the cab onto the outside battery box step and watched as he raised the trailer to dump the material. Austin said he did not see any overhead lines or notice any signs warning of a hazard.

After raising the trailer to its maximum dump position, Austin climbed back into the cab and pulled the unit forward several feet to clear the pile. As he lowered the bed, he heard a loud popping noise and saw flames coming from the front of the truck. He immediately stopped lowering the bed and shut off the engine. Austin opened the driver's side door and began to step down from the truck to get away. He grabbed the handrail on the outside of the cab and, as he stepped onto the battery box step, he was knocked off the truck by an electrical shock and fell to the ground stunned. Upon recovering, he shouted to his passengers to get out.

Richardson, who had been in the passenger's seat, had already jumped to the ground without injury. McDowell, who was barefoot, had been in the sleeper compartment behind the front seats. Witnesses stated that she grabbed the outside handrail on the passenger side of the cab and, when she stepped on the fuel tank step, she fell to the ground face down. Austin ran around to the passenger side of the truck and tried to pull her away from the truck but was shocked. Another truck driver, who witnessed the accident and arrived to help, was also shocked when he tried to pull her away. It was at this time that Austin looked up, saw the power lines, and realized what had happened. Austin and the other driver managed to pull McDowell away from the truck by her shirt and started CPR.

Juan Berrios, Jr., plant operator and miners representative, was in the plant control house. He looked out the window and saw the trailer bed up in the air with sparks at the front of the bed where it was in contact with the overhead high-voltage power lines. He called on the radio for George Gilliam, Jr., plant supervisor, to cut the power off. Gilliam received the radio call, drove to the primary substation, and disconnected power to the overhead power lines.

CPR was administered to the victim until the local rescue squad and fire department arrived a short time later. McDowell and Austin were transported to a local hospital where McDowell was pronounced dead and Austin was treated for electrical shock.

Conclusion

The primary cause of the accident was the failure to maintain adequate clearance between the overhead power lines and the mobile equipment that was operating near the stockpile. The height of the truck's trailer bed exceeded the height of the power lines. A contributing factor was the failure of the relays to trip the circuit breaker at the primary substation, shutting off the power.

Violations

Stavola Constr. Matl's. Inc.

Order No. 4434058

Issued on August 8, 1997, under the provisions of Section 103(k) of the Mine Act to protect personnel pending an investigation by MSHA.

This order was terminated on August 12, 1997, after completion of MSHA's onsite investigation and after the area beneath the power lines at the accident site was permanently barricaded with concrete blocks.

Citation No. 7703792

Issued on August 12, 1997, under the provisions of Section 104(a) of the Mine Act for violation of 30 CFR 56.12071:

A fatal accident occurred at approximately 7:00 a.m. on 8/8/97, when a contractor operated tractor-trailer contacted a 26,000 volt overhead electrical transmission line while its bed was raised to dump materials at the 3/8 inch stockpile. The truck caught on fire due to the contact and the driver and two passengers attempted to escape. One of the passengers was electrocuted and the driver received a severe shock. Adequate precautionary measures were not taken to prevent the movement or operations of equipment within 10 feet of the high voltage line. Evidence indicated several trucks had dumped material at the toe of the 3/8 inch stockpile that morning. The height of the lowest power line (the one contacted) was estimated to be approximately 25-28 feet above the ground. Front-end loaders with maximum height of 20 feet or more have loaded trucks and operated in proximity to this power line. Trucks with a dump height exceeding the 10-foot clearance requirement have operated and dumped in proximity to this power line. Agents for the company were aware that the power line presented a hazard, but had not prevented equipment that had clearance less than 10 feet from the power line to move and operate near the energized power line.

This citation was terminated on August 26, 1997. The area around the power lines was blocked off with concrete barriers and new warning signs were posted.

Citation No.7708002

Issued on January 22, 1998, under the provisions of Section 104(a) of the Mine Act for violation of 30 CFR 56.12001:

A fatal accident occurred at 0700 hours on August 8, 1997, when a contractor operated tractor-trailer contacted a 26,000 volt overhead electrical transmission line. The ground fault relay at the mine operator's primary substation failed to trip the circuit breaker, cutting off the power, when the ground fault occurred.

Overland Services Inc.

Citation No. 7703793

Issued on August 12, 1997, under the provisions of Section 104(a) of the Mine Act for violation of 30 CFR 56.12071:

A fatal accident occurred at approximately 0700 hours on August 8, 1997, when a contractor operated tractor-trailer contacted a 26,000 volt overhead electrical transmission line while its bed was raised to dump material at the 3/8 inch stockpile. The truck caught on fire due to the contact and the driver and two passengers attempted to escape. One of the passengers was electrocuted and the driver received a severe shock. Adequate precautionary measures were not taken to prevent the movement or operation of equipment within 10 feet of the high voltage line. Evidence indicated several of the contractor's trucks were dumping material at the toe of the 3/8 inch stockpile that morning. The height of the lowest power line (the one contacted) was estimated to be approximately 25-28 feet above ground. The 40-foot Raven trailer pulled by the Peterbilt tractor involved in the accident exceeded the 10-foot clearance requirement operated and dumped in the proximity of this power line.

This citation was terminated on September 8, 1997. The contractor trained all of their drivers and owner/operators regarding the hazards of overhead power lines on mine sites and to check for overhead wires before dumping.

Public Service Electric and Gas Company

Citation No. 7701172

Issued on March 23, 1998, under the provisions of Section 104(a) of the Mine Act for violation of 30 CFR 56.12001:

An accident occurred on August 8, 1997, at a mine operated by Stavola Constr. Matl's., Inc. in Bound Brook, Somerset County, New Jersey. A tractor trailer contacted an overhead high voltage electrical power line, causing injury to the driver and death to a passenger in the vehicle. The electrical circuit was not adequately protected against excessive overload. Public Service Electric and Gas Comapny was an independent contractor at the mine, responsible for servicing and maintaining the circuit protective equipment.

[FAB97M43]