DEPARTMENT OF LABOR
MINE SAFETY AND HEALTH ADMINISTRATION
South Central District
ACCIDENT INVESTIGATION REPORT
UNDERGROUND NONMETAL MINE
FATAL ELECTRICAL ACCIDENT
Hobbs Potash Facility, ID No. 29-00170
New Mexico Potash Corporation
Hobbs, Lea County, New Mexico
September 7, 1995
Ronald M. Mesa
Henry J. Mall
Metal and Nonmetal Mine Inspector
South Central District Office
1100 Commerce Street, Room 4C50
Dallas, Texas 75242-0499
Doyle D. Fink
James M. Buffington, underground maintenance mechanic, age 28, was fatally injured about 1:00 p.m. on September 7, 1995, when he contacted the bare conductor of an energized, 480 volt, power cable while removing the cable from an intake face fan. Buffington had two years, ten months total mining experience, all at this mine as an underground maintenance mechanic.
The Hobbs Potash Facility was located approximately 31 miles north east of Carlsbad, New Mexico. The mine began producing potash ore in 1965. Continuous miners cut the ore from the underground room and pillar workings at depths ranging from 800 to 2200 feet within the mine. The mined material was transported to the surface, crushed, leached, crystallized, and sized. The finished product, potassium chloride and muriate of potash, was shipped to agricultural and industrial users all over the world. An average of 11,000 tons of raw ore was produced every day by 140 employees working two 12-hour shifts a day, seven days a week.
Operating officials were:
Melvin Pyeatt..........Vice President of Operations
Curtis Davidson.......Safety Manager
Duane Morris...........Underground Safety Supervisor
Underground Safety Supervisor Duane Morris notified Supervisor Jerry Millard, Carlsbad MSHA field office, of the accident at approximately 2:45 p.m. on September 7, 1995. An investigation was started on the same day.
Mine employees were not represented by a union.
The mine had an approved MSHA 30 CFR Part 48 Training Plan which was last revised in March 1983. Company records indicated that Mr. Buffington had received all the required MSHA training.
Information for this report was obtained by interviewing company
officials and employees during the on-site investigation. The
last regular inspection was conducted on June 6, 1995.
PHYSICAL FACTORS INVOLVED
The accident occurred underground in a face entry of Area 289. This area of the mine was very wet and muddy. The roof was fifty four inches high and 23 feet wide.
Electrical power was supplied to Area 289 by a 4160 volt, 2/0 shielded, power cable which fed into the No. 2, 400 KVA, 4160/480 volt power center. The power center fed the continuous miner, intake and exhaust fans, and the panel conveyor belts. The power center was approximately 75 feet from the intake face fan. The No. 2 power center transformer output was wye-connected and resistance grounded with a 50-ohm resistor. This connection created a 480\277 volt output with fault current, phase-to-ground, limited to 5.5 amperes. The power center was equipped with a Gulton type, Femco GM 1000 ground Sentinel II Monitor which monitors equipment grounding conductors.
The power cable involved in the accident was connected to circuit No. 6 on the No. 2 power center. The cable was a 4 conductor, size 10 AWG, type SOW, 90C rated cable, manufactured by AIW Corporation. It was approximately 175 feet in length and provided the 480 volt three-phase electrical power to the intake face fan. A male Joy flat type nip was spliced on one end of the power cable and connected to circuit No. 6 at the No. 2 power center. A female Joy flat type nip was spliced to the other end of the power cable and plugged into a male connector mounted on the intake face fan. The only splices in the cable were the male and female Joy nips and they were in good condition. The power cable was damaged 2- feet from the female nip exposing bare copper of the white phase conductor through a 1 inch long cut in the cable jacket. The insulation between the white phase conductor and the equipment ground conductor within the cable was intact.
Circuit No. 6 was equipped with a 3-phase, 600-volt rated, circuit breaker. The breaker was a Westinghouse, style #4975 D71G40, 50-ampere rated with shunt trip, which provided for short circuit and ground fault protection.
At the time of the accident, the maintenance crew was preparing
to weld on the Air-Dock haulage system in Area 289. The welding
machine had been moved into the area. Buffington was removing
the 480 volt power cable from the intake face fan so that power
could be supplied to the welding machine.
DESCRIPTION OF THE ACCIDENT
On the day of the accident, James Buffington, maintenance mechanic, was assigned to perform maintenance in Area 289. Buffington reported to work at his normal 7:00 a.m. starting time. Work progressed normally without any problems. At approximately 12:20 p.m. Curtis Pratt, supervisor of the maintenance called Maintenance Mechanic Eugene Galvan, who was working in Area 290, and instructed him to proceed to Area 289 to assist with rewelding a cable tray onto the Air-Dock Haulage system. Galvan and Jerry Cartwright, maintenance mechanic, proceeded to Area 289 arriving at approximately 12:30 p.m. where they found Buffington and the welding machine already set up next to the Air-Dock haulage system. Galvan asked Buffington to retrieve some timbers to hold up the cable tray while it was being welded. Although Buffington was tired, he retrieved the timbers and then took his lunch break.
Buffington sat in his vehicle during lunch as Galvan laid out the welding leads. As Galvan walked passed Buffington with the leads, Buffington asked him if he was going to need power for the welder. Galvan said, "yes". At approximately 12:50 p.m., Buffington left the vehicle and walked over to the intake face fan to disconnect the 480 volt power cable and reconnect it to the welder. At that time, Galvan was proceeding to the welder with his back to the Buffington.
Galvan heard Buffington emit a "yell" and immediately turned and ran to him. He found Buffington standing, holding the power cable with both hands, obviously receiving a severe electrical shock. Galvan ran to the power center to turn off the circuit breaker to the intake face fan. When he arrived at the power center he met Face Boss Lupe Rodriquez. Together they turned off all the breakers and ran back to help Buffington.
When they arrived back at the face fan, they found Buffington
lying on the ground. Rodriquez removed the power cable from
Buffington's hands. Buffington's vital signs were weak to
intermittent so the two men started cardiopulmonary resuscitation
(CPR). Rodriquez called to Julie Nelson in the near by lunch
room and instructed her to call for help. CPR was continued
during Buffington's extraction from the mine. He reached the
surface at 2:12 p.m. and was transported to Guadalupe Medical
Center in Carlsbad, New Mexico, where he was pronounced dead as a
result of electrocution at 3:33 p.m.
The primary cause of the accident was the failure to de-energize
the damaged, 480 volt, power cable before grasping it and
attempting to disconnect it from the intake face fan. A
contributing factor was the failure to use suitable protection
for persons while handling the damaged energized power cable.
Order Number 4447562, 103(k), issued September 7, 1995, 1630 hours:
This order is issued to restrict use of any of the electrical components in Area 289 until MSHA can determine if they are safe to use by other miners.
This order was terminated on September 7, 1995. All the electrical equipment involved in the accident was removed from Area 289.
Citation Number 4447563, was issued under the provision of Section 104(a), for a violation of 30 CFR 57.12014:
A miner was fatally electrocuted when he was attempting to remove an energized 480 volt power cable from the intake face fan. The insulation had a break in it exposing the conductors. The miner made contact with the exposed conductor causing his electrocution. The miner was not using any suitable protective devices when he handled the power cable. The intake face fan was located in Area 289. This citation was terminated on September 14, 1995. The requirements of the standard were discussed with all the employees and company officials. All the employees were instructed in the proper procedures for handling power cables.
Citation Number 4330836, was issued under the provision of Section 104(a)for a violation of 30 CFR 57.12004:
The 4/Conductor type S0W-A-90C 480 volt, 3 phase power cable was damaged exposing a bare copper conductor through the outer rubber covered jacket. A miner was electrocuted when he came in contact with the exposed bare copper conductor. The power cable was energized and was providing power to the intake face fan in Area 289.
This citation was terminated on September 11, 1995. The power cable was removed from Area 289 and taken out of service.
Respectfully submitted by:
/s/ Ronald M. Mesa
/s/ Henry J. Mall
Metal and Nonmetal Mine Inspector
Doyle D. Fink
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