Skip to content
UNITED STATES
DEPARTMENT OF LABOR
MINE SAFETY AND HEALTH ADMINISTRATION
Metal and Nonmetal Mine Safety and Health

REPORT OF INVESTIGATION

Surface Nonmetal Mine
(Sand and Gravel)

Fatal Electrical Accident
August 30, 2000


Crusher No. 520
Mark Sand and Gravel Acquisition Company
Fergus Falls, Otter Tail County, Minnesota
I.D. 21-00645


Accident Investigators

Gary L. Cook
Supervisory Mine Safety and Health Specialist

Alan J. Brandt
Mine Safety and Health Inspector (Electrical)

Arlie B. Massey
Supervisory Electrical Engineer

John Kathmann
Mine Safety and Health Specialist


Originating Office
Mine Safety and Health Administration
North Central District
515 West First Street, Room 333
Duluth, MN 55802-1302
Felix A. Quintana, District Manager




OVERVIEW

On August 30, 2000, Thomas A. Haus, crusher operator, age 36, was electrocuted when he contacted the tip of a welding rod (electrode) with his bare hand. Haus was in the process of using the rod to gouge off a section of the outer tooth on each side of the jaw crusher. Haus had used three rods and was inserting the fourth rod into the electrode holder when contact was made.

The accident occurred because management failed to ensure that gloves and other personal protective clothing were worn while welding. Working in a confined space was a contributing factor.

Haus had a total of five years mining experience, four years as a crusher operator, three years at this mine. He had received annual refresher training in accordance with 30 CFR Part 48 and was task trained in the operation of the crusher unit. Haus had previous experience welding.

GENERAL INFORMATION

Mark Sand and Gravel Acquisition Company, a portable surface sand and gravel operation, owned and operated by Mark Sand and Gravel Acquisition Company, was located near Pelican Rapids, Otter Tail County, Minnesota. The principal operating official was Mark Thorson, president. The mine normally operated one, 13-hour shift, five days a week. Total employment was two persons.

Sand and gravel was extracted from the Okke Pit by stripping the material with a dozer. The raw material was pushed by the dozer to a surge pile, screened, crushed, and stockpiled. The finished product was sold for use as road construction material.

The last regular inspection of this operation was completed on June 13, 2000. Another regular inspection was conducted following this investigation.

DESCRIPTION OF THE ACCIDENT

On the day of the accident, Thomas Andrew Haus (victim) arrived at the mine site at 6:00 a.m., his normal starting time. Haus and one other employee, Mark Foss, dozer operator, were assigned to set up the portable plant and begin the crushing operations. They finished the set-up procedures and began crushing at approximately 1:00 p.m.

At approximately 4:00 p.m., Haus called Mark Pederson, aggregate supervisor, and discussed the need to shut down the crusher and cut off the surface of two of the teeth on the wear plate. About 6:00 p.m., Haus notified Foss that he was going to shut down the plant and Foss was to keep stripping material in the adjacent corn field until quitting time. At 7:00 p.m., Foss went to the plant to tell Haus it was quitting time and saw that the rock kicker and generator were still running.

Foss climbed up to the work platform, looked down into the jaw crusher, and saw Haus laying on the conveyor belt under the crusher. Foss yelled to get Haus' attention. There was no response. Because of the background noise of the generator, Foss climbed down off the platform and went to where Haus was working and yelled to Haus. Again there was no response. Foss shut down the generator and called Paul A. Nelson, foreman trainee, on the radio.

Craig Kaehler, truck driver for Krause Brothers Trucking, who had First Responder training, and Nelson arrived a few minutes later. Nelson called 911, then all three extricated Haus. Kaehler began CPR while Nelson went out to direct emergency crews to the site.

Emergency personnel arrived and attempted to revive Haus. He was pronounced dead at the scene. Death was attributed to electrocution.

INVESTIGATION OF THE ACCIDENT

MSHA was notified at 9:15 a.m. on August 31, 2000 by a telephone call from Gregory Marcus, administrator for Mark Sand and Gravel Acquisition Company, to Steve Richetta, assistant district manager. An investigation began the same day and an order was issued pursuant to Section 103(k) of the Mine Act to ensure the safety of the miners.

MSHA's accident investigation team conducted a physical inspection of the accident site, interviewed employees, and reviewed training records and work procedures performed at the time of the accident. The miners did not request, nor have, representation during the investigation.

DISCUSSION

� The accident occurred at the electrically powered jaw crusher. The crusher was powered by a trailer mounted, diesel rotated Kamag generator that supplied 480 volts, wye-connected electrical power. The open circuit phase-to-phase voltage measured 480 volts alternating current (VAC). The open circuit phase-to-ground voltage measured 277 VAC. The main breaker was a 225 ampere (amp), variable magnetic-trip breaker. It was supplied power through three 250 MCM conductors.
� The welder was manufactured by Miller Electric Manufacturing Company and was an SRH-444 model. The primary side of the welder was listed as 230/460 VAC, 80/40 amps, three phase, 60 hertz (Hz) unit. The secondary side was rated at 36 volts direct current (VDC), 400 amps. The circuit to the welder was found in the "on" position.
� The ground lead of the welder was set on the "Low A" setting and the amperage was set at approximately 295 amps. The measured open circuit voltage of the welder was 83.3 VDC.
� The welder had no abnormalities or defects. The welder cables, PrestoFlex #2GA 600 volt, were in good condition.
� The victim was laying on his right side on top of the crusher discharge conveyor in a confined space measuring 80 inches long, 38 inches wide, and 12 inches high.
� Statements gathered during interviews indicate the normal procedure to perform this task was to enter the work area of the jaw crusher through the top opening.
� Welding gloves and protective clothing were not being worn at the time of the accident. During the investigation no gloves were found at the mine site but, reportably, there had been gloves on the site approximately three weeks prior to the accident.
� The victim received a small burn on his second finger, left hand, that would have been consistent with contact with the tip of a welding rod.
� The weather at the time of the accident was approximately 72 degrees Fahrenheit, a slight wind out of the southeast, with a storm front coming through from the west.

CONCLUSION

The primary cause of the accident was management's failure to ensure that protective clothing was worn while welding, cutting, or working with molten metal. A contributing factor was failure to plan the task safely to eliminate the need to enter an extremely confined space where there was minimal room to work.

ENFORCEMENT ACTIONS

Order No. 7839216 was issued on September 1, 2000, under the provisions of Section 103(k) of the Mine Act:
On August 30, 2000 (as modified), a fatal accident occurred at this operation while the crusher operator was performing maintenance on the crusher. This order is issued to assure the safety of all persons at this operation until the area affected can be returned to normal operations as determined by MSHA. The mine operator shall obtain prior approval from an authorized representative for all actions to recover and/or restore operations to the affected area.
This order was terminated on September 2, 2000, after it was determined by MSHA that the affected area of the mine could resume normal operations.

Citation No. 7827618 was issued on September 14, 2000, under the provisions of Section 104(a) of the Mine Act for violation of 30 CFR Part 56.15007:
A crusher operator was electrocuted on August 30, 2000, while he was attempting to gouge a section of the jaw crusher wear plate using an arc welder. The victim came in contact with the energized tip of the welding rod with his bare hand. He was not wearing welding gloves and the proper protective clothing.
This citation was terminated on September 14, 2000. The company's existing personal protective clothing policy was reemphasized in training classes conducted at all mine sites. The company resupplied welding gloves to all mine sites and purchased an Arcair-Slice cutting system to provide the employees a better way to perform the task.

Related Fatal Alert Bulletin:
Fatal Alert Bulletin Icon FAB2000M37

APPENDICES

A. Persons Participating in the Investigation
B. List of Persons Interviewed During the Investigation

APPENDIX A

Persons Participating in the Investigation:

Mark Sand and Gravel Acquisition Company
Mark Thorson. . . . . . . . . . . . . . . . . . . . . . . . . president
Mark Pederson. . . . . . . . . . . . . . . . . . . . . . . . aggregate supervisor
Gregory E. Marcus. . . . . . . . . . . . . . . . . . . . . .administrator
Mark A. Foss. . . . . . . . . . . . . . . . . . . . . . . . . dozer operator
Paul A. Nelson. . . . . . . . . . . . . . . . . . . . . . . . .supervisor (trainee)
Crane Engineering and Forensic Services
John E. Brynildson. . . . . . . . . . . . . . . . . . . . . . metallurgical engineer
Mine Safety and Health Administration
Gary L. Cook. . . . . . . . . . . . . . . . . . . . . . . . . supervisory mine safety and health specialist
Alan J. Brandt. . . . . . . . . . . . . . . . . . . . . . . . . mine safety and health inspector (electrical)
Arlie B. Massey. . . . . . . . . . . . . . . . . . . . . . . .supervisory electrical engineer
John Kathmann. . . . . . . . . . . . . . . . . . . . . . . . mine safety and health specialist
APPENDIX B

Mark Sand and Gravel Acquisition Company
Mark Pederson. . . . . . . . . . . . . . . . . . . . . . . aggregate supervisor
Mark A. Foss. . . . . . . . . . . . . . . . . . . . . . . . dozer operator
Paul A. Nelson. . . . . . . . . . . . . . . . . . . . . . . supervisor (trainee)
Craig Kaehler . . . . . . . . . . . . . . . . . . . . . . .  truck driver
Lake Region Hospital
Dr. Gregory M. Smith, M.D.