UNITED STATES
DEPARTMENT OF LABOR
MINE SAFETY AND HEALTH ADMINISTRATION

District 7

ACCIDENT INVESTIGATION REPORT
Underground Coal Mine

Fatal Electrical Accident

No. 4 Mine, I. D. No. 01-01247
Jim Walter Resources, Incorporated
Brookwood, Tuscaloosa County, Alabama

August 6, 1995

by

Walter W. Deason
Federal Coal Mine Inspector

and

Dean F. Skorski
Electrical Engineer


Originating Office - Mine Safety and Health Administration
H.C. 66 Box 1762; Barbourville, Kentucky 40906-9206
Joseph W. Pavlovich, District Manager

OVERVIEW

At approximately 9:50 a.m., on Sunday, August 6, 1995, a fatal electrical accident occurred at the No. 1 Longwall Section in the No. 4 Mine of Jim Walter Resources, Incorporated.

Hilburn Hulsey, Maintenance Foreman, was electrocuted when he was attempting repairs and came in contact with energized parts inside a Miller Dialarc welding machine. The accident and subsequent fatality occurred as a direct result of the failure to deenergize the power circuit and lock out and tag disconnecting device(s) when performing electrical work on the equipment.

GENERAL INFORMATION

The No. 4 Mine, Jim Walter Resources, Incorporated, is located in Brookwood, Tuscaloosa County, Alabama. This is a shaft mine approximately 2,000 feet in depth which liberates an average of approximately 20,000,000 cubic feet of methane gas in a 24-hour period. This mine employs 554 miners and has an average daily production of 9,307 clean tons of coal. The mine operates three shifts per day, five to six days per week. The continuous mining machine sections are used for development of main air courses and longwall gate entries. The continuous miner sections develop a maximum of six entries and use various size pillars to control strata subsidence and floor heave. The last MSHA regular health and safety inspection was completed on June 29, 1995 and an MSHA health and safety inspection which began on July 5, 1995 was in progress at the time of the accident. Company officials are listed below.

William Carr................................President
K. J. Matlock..............................Vice President
James M. Sims............................Vice President
W. H. Weldon.............................Treasurer
John F. Turbiville..........................Secretary

DESCRIPTION OF THE ACCIDENT

On Sunday, August 6, 1995 at 7:00 a.m., Hilburn Hulsey (victim), Maintenance Foreman; Jens Lange, Longwall Foreman; Rayford Naramore, Welder; Don Nolan Sloan, Longwall Helper; David Edward Douglas, Electrician and James A. Blankenship, Inside Laborer, entered the mine to perform maintenance work in the No. 1 Longwall Section.

The crew arrived on the section at approximately 7:40 a.m. Hulsey and Lange divided the work crews into pairs. Lange accompanied Sloan and Douglas down the longwall face to repair hydraulic return valves on shield No. 53.

Hulsey accompanied Naramore and Blankenship to weld metal straps across the return idler sprocket at the headgate on the longwall face. The owl shift crew had informed Hulsey that the welding leads had been pulled apart while transporting them to the headgate.

The welding machine was located 317 feet outby the face line of the longwall in the No. 3 intake entry in the crosscut to the right of survey spad No. 13337. The No. 2 cable welding leads were 457 feet each in length.

Hulsey instructed Naramore to examine the welding leads and to make the necessary repairs. Naramore found two locations where the leads were separated. He then twisted the leads together and taped them. Blankenship was sent to find metal straps to weld across the return idler sprocket at the headgate. Naramore and Blankenship met back at the headgate to begin the welding operation.

When Naramore began welding, he only got a "cold arc." A "cold arc" is one in which the power provided was insufficient to create enough heat with which to weld with the rod being used. Naramore informed Blankenship who then informed Hulsey, who was located outby at the welding machine to turn the machine up. Naramore attempted to weld again and got a "cold arc" the second time.

Blankenship, classified as an inside laborer, also retains an electrical qualification. According to statements obtained during interviews, Blankenship asked Hulsey to insure that the welder control was set on the high or maximum amperage setting. Hulsey informed him that it was. Naramore went to the welding machine to examine the reset button. However, this particular welding machine was not equipped with one. Naramore also found that the amperage control indicator knob was missing and a loose lug nut had been previously installed on the adjustment shaft of the rheostat control.

Naramore removed the lug nut and turned it twice with his pliers to make sure it was on the maximum amperage setting. When Naramore returned to the headgate, he was still getting a "cold arc." Naramore suggested to Hulsey that the rheostat was inoperative. Blankenship and Hulsey went to the welding machine while Naramore re-examined the welding leads for damage.

Hulsey instructed Blankenship to remove the top cover of the welding machine to permit access to the rheostat. Blankenship switched the welding machine off and, with the unit still energized by the power source, removed the bolts from the top cover and slid it back. Naramore alternately turned the rheostat selector shaft up and down still checking it's operation. Hulsey was on his knees on the damp mine floor with his left hand on the metal post of the welding sled, observing the rheostat. Hulsey then stated that he thought the rheostat was working and asked for a can of lubricant. According to his statement, Blankenship pointed at the welding machine and informed Hulsey that the unit was still energized.

Blankenship then observed Hulsey spray lubricant inside the energized welding machine. Eight to ten seconds later, at approximately 9:50 a.m., Hulsey stuck his bare hand inside the welding machine, coming in contact with energized parts.

Naramore, an eyewitness to the accident, stated that he immediately came to the victim's aid and separated Hulsey from the electrical current using his foot.

Naramore remained with Hulsey and began CPR while Blankenship called to the surface dispatcher for an ambulance and for Lange's crew from the longwall face to assist them. Hulsey was placed onto a stretcher and CPR continued as they transported him to the surface where Lifesaver Helicopter awaited his arrival. The mine notified Ron Vass, Federal Coal Mine Inspector, via telephone at approximately 10:20 a.m. Vass notified Ken Ely, Acting Subdistrict Manager of the accident at approximately 10:30 a.m. and the investigation was begun at 12:30 p.m.

PHYSICAL FACTORS INVOLVED IN THE ACCIDENT

1. At the time of the investigation, the established lock-out system for the disconnecting devices at the No. 1 Longwall Section power center was not being maintained in working order. The metal lock box was damaged and could not be locked as originally designed. There were holes drilled in the cable plugsū fork-keyed cock, but the shaft on the locks provided, were larger than the holes in the plugs.
   
   
2. Statements obtained during interviews indicated that the welder was energized and not locked out and tagged while work was being performed. Further statements revealed that other work had been performed previously on energized equipment without the equipment being locked-out and tagged, indicating an unsafe work practice.
   
   
3. Both Hulsey and Blankenship were qualified electricians.
   
   
4. The welding leads on the welding machine, S/N HK317619, did not meet the manufacturer's recommendations in relation to length and size. The manufacturer recommends that when a No. 2 cable is used, the length should not exceed 50 feet each for a total of 100 feet of cable. The welding machine being used was supplied with 457 feet of cable for each lead for a total length of 914 feet. This is a recommendation made by the manufacturer and is not a violation of the Federal Regulations.
   
   
5. Overcurrent protection was not provided for the 575 Volt AC Miller Dialarc welding machine, S/N HK317619. A violation was issued during a separate inspection for this condition as non- contributory to the accident.
   
   
6. The amperage adjustment dial indicator was missing on the 575 Volt AC Miller Dialarc Welding Machine, S/N HK317619. A violation was issued during a separate inspection for this condition as non-contributory to the accident.
   
   
7. Investigators observed improper connectors being used to splice the welding leads in two locations. A violation was issued during a separate inspection for this condition as non- contributory to the accident.
   
   
8. Testing conducted at the mine by MSHA's Technical Support on August 8, 1995, found the maximum current the welding machine could produce was 110 amperes when the ends of the welding leads were connected together to create a bolted fault. This relatively low value of current supports the statement that only a "cold arc" was possible. The welding leads were shortened from 457 feet to the manufacturer's recommendations of 50 feet each for No. 2 welding cable. The fault test was repeated and a current of 220 amperes was found to be available from the welding machine. This value is 10 percent above the 200 ampere rating for this type of machine. By maintaining the welding lead length at the manufacturer's recommendation, the voltage drop across the leads remains low while the current is maximized. This reduces the possibility of a "cold arc" occurring.
   
   
9. Additional testing conducted on this date found the open circuit voltage at the dc terminals of the welding machine to be 120 volts (RMS). According to information obtained from the manufacturer, the maximum open circuit voltage at the dc terminals should be 76 volts. Discussions were held with representatives from the Miller Electric Manufacturing Company regarding the high open circuit voltage. It was decided to perform additional testing to determine why the high open circuit voltage existed at the dc terminals. On October 23, 1995, MSHA's Technical Support and a representative from the manufacturer were at the mine site to conduct further testing. A resistor utilized as part of a surge suppressor circuit was found to be open. When this resistor was replaced, the open circuit voltage was measured to be 84 volts (RMS). This voltage was higher than the manufacturer's suggested maximum of 76 volts. It is possible that an increase in the supply voltage into the welder caused this higher voltage to appear on the dc output. This condition was non-contributory to the accident and was not a violation of the Code of Federal Regulations.

CONCLUSION

The accident occurred because repair work was performed on the energized welding machine, a piece of electrical equipment. It is the consensus of the investigation team that work being performed on energized electrical equipment without locking and tagging such equipment directly contributed to the fatality. The length of cables used was a contributing factor in that they decreased the power available at the welding site causing doubt as to the output of the welding unit.

ENFORCEMENT ACTIONS

1. A 103-K Order No. 3198332 was issued to insure the safety of all persons in the mine until the investigation was completed.
   
   
2. A 104-D-2 Order No. 3198340, a violation of 30 CFR Section 75.511, was issued as a contributing factor to the fatality. During the investigation, it was observed on that the established lock out system for the disconnect device for the 575 Volt AC Miller Dialarc Welding Machine was not used nor maintained in working order. The metal lock box was damaged and could not be locked as designed. Further statements obtained during interviews revealed that work had previously been performed on energized equipment without locking out and tagging such equipment, indicating an unsafe work practice at this mine.
   
   
3. A 104-D-2 Order No. 3021235, violation of 30 CFR Section 75.509, was issued as a contributing factor to the fatality. Work was being performed on the 575 Volt AC Miller Dialarc Welding Machine while the equipment was energized.

Respectfully submitted by:

Walter Deason
Coal Mine Safety and Health Inspector

Dean F. Skorski
Electrical Engineer

Approved by:

Glenn R. Tinney
Acting Subdistrict Manager

Joseph W. Pavlovich
District Manager

Related Fatal Alert Bulletin:
FAB95C24