DEPARTMENT OF LABOR
MINE SAFETY AND HEALTH ADMINISTRATION
Metal and Nonmetal Mine Safety and Health
REPORT OF INVESTIGATION
Surface Nonmetal Mine
Fatal Electrical Accident
October 2, 2001
Javens Electric Inc. (KLT)
Mankato, Blue Earth County, Minnesota
Ottawa Pit and Plant
Unimin Minnesota Corporation
Le Sueur, Le Sueur County, Minnesota
I.D. No. 21-00790
Fred H. Tisdale
Mine Safety and Health Inspector (Electrical)
Kevin D. Dolinar
Chad D. Huntley
David T. Couillard
Mine Safety and Health Specialist
Mine Safety and Health Administration
North Central District
515 West First Street, Room 333
Duluth, Minnesota 55802-1302
Felix A. Quintana, District Manager
On October 2, 2001, Larry D. Velzke, contractor electrician, age 44, was fatally injured when he inadvertently contacted an energized high voltage line while moving the elevated basket of the manlift he was working from. The accident occurred because there were no established procedures in place to address/prohibit the use of high profile equipment near overhead power lines.
Velzke had a total of four years experience as an electrician with this contractor. He had received training in accordance with 30 CFR, Part 46.
Ottawa Pit and Plant, a surface silica sand operation, owned and operated by Unimin Minnesota Corporation, was located at 39770 Ottawa Road, Le Sueur, Le Sueur County, Minnesota. The principal operating official was Charles A. Collins, plant manager. The mine operated three, 8-hour shifts, seven days a week. Total employment was 39 persons.
Industrial sand was mined using front-end loaders. The material was fed into a hopper and was conveyed to a wet plant where it was screened and pumped as slurry to the main plant for drying and packaging. The sand was sold to the oil industry, glass manufacturers, and foundry operations.
The victim was employed by Javens Electric Inc., located in Mankato, Blue Earth County, Minnesota. Javens Electric Inc. was contracted to install electrical service to the portable wet plant located in the north quarry at this operation. This construction consisted of the installation of junction boxes, conduit, wiring, primary transformer, motor control center, and control booth. The principal operating official was Kenny Javens, president. Javens Electric Inc. employed 23 persons, two of which were assigned to work at this mine.
The last regular inspection of this operation was conducted on January 25, 2001. Another inspection was conducted following the investigation.
DESCRIPTION OF ACCIDENT
On the day of the accident, Larry D. Velzke (victim), reported for work at the Javens Electric shop at 7:00 a.m., his normal starting time. After collecting his tools, Velzke and Daniel J. Reichel, apprentice electrician, were assigned to Unimin's Ottawa Pit and Plant to continue the electrical construction work in progress at the north quarry wet plant.
Velzke and Reichel arrived at the mine at 7:30 a.m. and briefly discussed the work they would be doing; pulling wire through conduits and terminating them at their respective connection points. Velzke was positioned in a JLG manlift basket at a junction box mounted about 15 feet above ground level on the east side of the wet plant building, pulling wires using a metal fish tape. Reichel was about 40 feet away, around the corner on the north side of the building standing on a conveyor walkway, feeding the wires that Velzke was pulling. The two men were out of sight and hearing from each other. The ambient noise level around this building was 85 dBA.
At about 11:15 a.m., Velzke decided to pull four No. 12 AWG THHN control wires through a 3/4 inch conduit. Two No. 12 wires had been installed in this conduit from a previous pull earlier in the job. This conduit had two, 90 degree bends. As Velzke was pulling the wires, they became jammed about 4 feet away from the end of the conduit. In order to clear the jam, Reichel would have been required to pull the wires back the other way briefly and then retry the pull forward. It is believed Velzke moved his manlift basket to the side in order to make eye contact with Reichel. After making that move, Velzke likely found that his vision was still obscured by an open electrical enclosure door in front of Reichel. He then moved the basket upward to see over the door and he contacted a high voltage power line.
Reichel had been standing in front of the electrical enclosure mounted on the north side of the building. He was holding and feeding the wire that Velzke had been pulling and realized that Velzke had stopped pulling wire. Reichel heard the manlift engine rev up as if the basket had started to move. As he placed the wire spools on the walkway, he saw a flash over the enclosure door and heard a loud buzzing noise. Reichel ran down the conveyor walkway to where he could see, and observed Velzke laying motionless on the floor of the manlift basket.
John Gehrke, plant operator, who had been in the wet screen building, also heard a loud noise, ran outside and met up with Reichel. Gehrke called for assistance on the two-way radio but he was not sure of a response, so he and Reichel got in a pickup truck and drove to the plant and reported the accident.
Charles Collins, plant manager, heard of the call and he and Kathy Wetzel, safety director, drove to the scene. The Le Sueur County Sheriff's deputies arrived and directed Reichel to use hot line gloves to activate the auxiliary controls and lower the manlift to ground level. Rescue workers on the scene could detect no pulse or other vital signs and the Le Sueur County Coroner was summoned. He pronounced Velzke dead at the scene.
Death was attributed to electrocution.
INVESTIGATION OF THE ACCIDENT
MSHA was notified at 12:05 p.m. on October 2, 2001, by a telephone call from Mike Wallenius, regional general manager for Unimin Corporation, to Steven M. Richetta, assistant district manager. An investigation began the same day. An order was issued pursuant to Section 103(k) of the Mine Act to ensure the safety of miners.
MSHA's accident investigation team conducted a physical inspection of the accident site, interviewed employees, and reviewed training records and work procedures at the time of the accident. Management officials, employees of both the mine operator and the contractor, and the miner's representative assisted in the investigation.
� The accident occurred at the wet screen portable plant located in the north quarry of the Ottawa Pit and Plant operation. This was a new electrical construction project started about September 15, 2001. It consisted mainly of a portable skid-mounted platform with a motor control center, transformer bank and plant operating control tower. The surface of the area was damp soft sand.
� At the time of the accident, the wet screen plant was in operation. While operating, the noise level in front of the east side of the building was measured at 85 dBA.
� The victim was operating a 1998 JLG Industries telescoping boom lift, Model 40H, Serial Number 0750710300037454. The lift was owned by Rental Service Corporation and was rented to Javens Electric Inc.
� The Model 40H boom lift had a maximum platform height of 40 feet, a maximum horizontal reach of 33 feet, and the turntable was capable of being rotated 360 degrees. A gasoline engine supplied power to the hydraulic system.
� All functions of the lift could be operated from either the basket or the ground. The control handle for the main lift, drive/steer and swing functions in the work platform contained a locking mechanism to prevent accidental operation of these controls. All the control and safety functions tested after the accident operated normally.
� The work platform measured 36 inches by 96 inches with a guard rail 45 inches high. It consisted of a steel-tubing frame covered with expanded metal on the floor and on the lower half of the sides.
� Evidence of arcing was observed in three locations on the work platform; on the steel tubing to the left of the control panel, on steel tubing to the left of the entrance gate, and on the expanded metal on the side nearest the wet screen building. Burn marks were observed in two locations; on the main lift control handle, and on the steel tubing to the right of the entrance gate.
� The tires of the telescoping boom lift were sunk into the sand to the level of the tire rim. Tire impressions were observed approximately perpendicular to the east side of the wet screen building and leading up to the position of the lift at the time of the accident. Several tire impressions in the sand approximately parallel to the wet screen building were also noted.
� Approximately 8 feet of metal fish tape extended out of one piece of � inch rigid metal conduit at the enclosure on the east wall. This � inch conduit contained two additional No. 12 AWG wires. The fish tape extended into the conduit approximately 40 inches where it was attached to four No. 12 AWG type THHN wires. The fish tape appeared to be jammed at this location. The four wires exited the conduit at the enclosure on the north wall. These wires were coiled on four spools.
� Several pieces of fish tape were lying on the ground near the telescoping boom lift. One of these pieces of fish tape had evidence of arcing. The total length of these pieces of fish tape would reach from the enclosure on the east wall to the work platform. The fish tape was cut during the rescue of the victim.
� Exel Energy supplied power for the mine at 13.8 kV in a grounded wye configuration. A gang operated disconnecting switch, 40 ampere fuses, lightning arresters, and metering were installed at the point of connection to the utility. Three overhead No. 2 ACSR lines carried the 13.8 kV to the south quarry, north quarry, and dewatering pumps.
� Power to the north quarry was tapped from this line approximately 1700 feet from the point of connection to the utility. Power was fed to the north quarry through three single fused disconnecting switches, then through an underground No. 2 XLP aluminum cable for 600 feet. At this point the power was brought up a pole. Power was then distributed through three overhead No. 2 ACSR lines to a second pole in the north quarry approximately 200 feet north of the first pole.
� The north quarry overhead lines ended at the portable plant building approximately 150 feet north of the second pole. The overhead lines ran in a north-south direction approximately parallel to the east side of the wet screen building. The lines were spaced 41 inches apart horizontally and installed 23-� feet above the ground. At the closest point, they were 20 feet from the wet screen building. A burn mark was observed on one of the overhead lines. This burn mark was directly over the center of the work platform. One, 40 ampere fuse at the point of connection to the utility blew during the accident. This fuse protected the phase with the burn mark. Two lightning arresters protecting this phase were also blown.
� At 11:35 AM CDT, anythingweather.com recorded the temperature at nearby Mankato, Minnesota to be 78 degrees Fahrenheit with a south wind at 12 miles per hour.
The root cause of the accident was the failure to establish procedures prohibiting movement of equipment near high voltage lines without taking effective measures to eliminate the hazard of accidental contact. The cause of the accident was the movement of the manlift too close to the energized high voltage power lines. The accident occurred when the victim's body contacted the high voltage line and current was carried to ground through the fish tape and the frame of the manlift. A contributing factor was the lack of communications equipment.
Order No.7849029 was issued on October 3, 2001, under the provisions of Section 103(k) of the Mine Act:
A fatal accident occurred at the north quarry portable plant, at this operation, when a contract electrician in a JLG manlift basket contacted overhead power lines containing high voltage. This order is issued to assure the safety of all persons at this operation. It prohibits all activity at the north quarry portable plant, including the JLG manlift, until MSHA has determined that it is safe to resume normal mining operations at the plant and the JLG manlift is safe to operate. The mine operator and contractor shall obtain prior approval from an authorized representative for all actions to recover and/or restore operations at this plant.This order was terminated on October 3, 2001, after it was determined by MSHA that the conditions which contributed to the accident no longer existed and normal mining operations could resume.
Citation No 7849030 was issued on October 16, 2001, under the provisions of 104(a) of the Mine Act for violation of 56.12071:
A fatal accident occurred at this operation on October 2, 2001, when a contract electrician in a JLG manlift basket, contacted energized overhead high voltage power lines. The manlift being used had the reach capacity to contact overhead power lines yet the lines were not de-energized nor were other precautionary measures taken to protect persons.This citation was terminated on December 3, 2001, after the operator implemented procedures to ensure the safety of workers. All employees were trained in these procedures.
. Related Fatal Alert Bulletin:
Persons Participating in the Investigation
Unimin Minnesota Corporation
Mike Wallenius ......... regional general managerJavens Electric Inc.
Kenny L. Javens ......... presidentLe Sueur County Sheriff's Department
Dave Struckman ......... sergeantRental Service Corporation
Tony S. Anderson ......... store operations managerCrawford Claims Management Services
Robert Lamb ......... adjusterMine Safety and Health Administration
Fred H. Tisdale ......... mine safety and health inspector (electrical)
Unimin Minnesota Corporation
Mike Wallenius ......... regional general managerJavens Electric Inc.
Kenny L. Javens ......... president