Fatality Assessment and Control Evaluation (FACE) Program |
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Electrician Dies From Being Pinned Between Iron Pipe and Articulated Boom-Supported Aerial Work Platform Control Panel |
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SummaryOn Monday, November 3, 2003, a 55-year-old electrician had been given an assignment to strip out a section of wiring and conduit from an overhead electrical service. He was operating an articulated boom-supported elevated work platform, JLG Model 660SF, (Figure 1) to access an overhead junction box. Another worker had been assigned as a ground person during this construction activity. The ground person indicated he had walked to the front of the unit when he heard a scraping sound. He called out but received no response. As he called out, he and two other employees looked up saw the decedent pinned with his back against a 6-inch diameter iron fire protection water pipe and his chest against the control panel at the front of the work platform basket. The relationship of junction box and water pipe is shown in Figure 2. They tried to override the basket panel controls (Figure 3) the decedent had been using to operate the work platform, but could not do so, because the key that would allow them to access the controls from the ground was missing from the ground control panel switch (Figure 4). They estimated that three to four minutes passed until they could find a key that allowed them to lower the basket. Another employee used a non-JLG key to gain control of the work platform and lower it to the ground. When they did gain control, the basket and the boom fell abruptly to the dirt floor of the plant. The local fire department and its EMS squad responded to the incident. They found the decedent in the basket on the floor of the plant. Emergency treatment was administered at the plant. He was transported to a local hospital where he was pronounced dead approximately one hour after the incident occurred. Recommendations:
IntroductionOn Monday, November 3, 2003, a 55-year-old male electrician died when he was crushed between an iron pipe and the control panel of the articulated boom-supported aerial work platform he was operating. On November 4, 2003, MIFACE investigators were informed by the Michigan Occupational Safety and Health Act (MIOSHA) personnel who had received a report on their 24 hour-a-day hotline that a work-related fatal injury had occurred. On November 10, 2004, the MIFACE researcher interviewed a person in corporate safety at the company’s corporate headquarters who had knowledge of the incident. He described the events on the day of the fatality as they had been told to him. The investigator was shown pictures of the site taken after the incident occurred and obtained several for use in this report. During the writing of the report, the medical examiner's report, the local police department’s incident report, a draft of the company’s internal plant employee fatality report, photographs supplied by the company, and the MIOSHA file and citations were reviewed. The plant in which the decedent worked builds transmissions for automobiles and trucks. It is one plant in a company that employed approximately 75,000 workers. Approximately 2000 employees worked in this plant. The company was 100 years old; the plant was 75 years old. The company had a joint labor/management health and safety committee that met at least monthly. The company had joint labor/management health and safety training programs and specific training in how to operate articulated boom-supported aerial work platforms. The decedent was an electrician. He had been employed by the company and worked in this plant for 32 years. His assignment was to strip out a section of wiring and conduit from an overhead electrical service. He was operating an articulated boom-supported aerial work platform to access an overhead junction box. He was working 8 a.m. to 4 p.m., plus 4 hours overtime. The incident occurred at approximately 4:00 p.m. In accordance with company and plant policy, a ground person was assigned to the area during this construction activity. The ground person had received oral training regarding his duties. The ground person’s duties were to be available on the ground in case the operator encountered an emergency situation, watch from the ground to alert the operator if he was approaching a troublesome situation, and keep the ground area clear of traffic and anything that would obstruct the movement of the aerial lift. Both the ground person and the decedent had received training and were licensed to operate articulated boom-supported aerial work platforms. The training had been given by the plant and by the equipment vendor. The decedent frequently worked with this type of equipment. The MIOSHA investigation resulted in three Serious violations being issued to the company:
Back to TopInvestigationOn Monday, November 3, 2003, construction activity was being conducted at a transmission manufacturing plant. An area of the plant had been cleared and the floor torn out such that the working surface was dirt. The decedent had been given an assignment to strip out a section of wiring and conduit from an overhead electrical service. He was operating an articulated boom-supported elevated work platform, JLG Model 660SF, (Figure 1) to access an overhead junction box. He was using this equipment instead of a scissors-lift because the floor was dirt. Another worker had been assigned as a ground person during this construction activity. The ground person indicated he had walked to the front of the unit when he heard a scraping sound. He called out but received no response. As he called out, he and two other employees looked up and observed the decedent pinned with his back against a 6-inch diameter iron fire protection water pipe and his chest against the control panel at the front of the work platform basket. The relationship of the junction box and the pipe is shown in Figure 2. They tried to override the basket panel controls (Figure 3) the decedent had been using to operate the work platform, but could not do so, because the key that would allow them to access the controls from the ground was missing from the ground control ignition switch (Figure 4). They estimated that three to four minutes passed before they could find a key that allowed them to lower the basket. Another employee used a non-JLG key to gain control of the work platform and lower it to the ground. When they did gain control, the basket fell abruptly to the dirt floor of the plant. The local fire department and its EMS squad responded to the incident. They found the decedent in the basket on the floor of the plant. Emergency treatment was administered at the plant. He was then transported to a local hospital where he was pronounced dead approximately one hour after the incident occurred. The unit had been rented from an equipment rental company. The decedent’s company required a pre-use inspection be conducted and documented on a written form for this type of equipment, but no written inspection form was found for it on this day. Examination of the unit after the incident revealed that the hydraulic basket tilt cylinder located on the boom had failed catastrophically. The hydraulic tilt cylinder was bent into a “C” shape indicating a large amount of pressure had been exerted on the cylinder. The basket controls were found to be in good working order. Although no one observed the events immediately preceding the incident, it appears that the decedent was close to the junction box he was trying to access near the plant ceiling but could not quite reach it. As he attempted to reach it, either the controls momentarily malfunctioned driving the articulated arm against a roof truss, or he inadvertently continued to operate the tilt controls after the arm had become wedged against the lower side of a roof truss. The hydraulic lift cylinder failed presumably because of excess pressure exerted on it. When the hydraulic lift cylinder failed, the basket snapped backwards toward an iron water pipe causing the decedent to be crushed. Paint from the roof truss and a scrape were found on the articulated arm near the basket. Paint from the articulated arm was found on the truss. A simulation of where the articulated arm contacted the truss is shown in Figure 5. According to the manufacturer, the unit was designed such that the key in the ignition switch at the ground controls is held captive when the equipment is engaged in either the platform or ground control mode. No key was found in the switch when the workers tried to operate it from the ground. When the unit involved in the incident was tested with a manufacturer’s key, it was discovered that the key could be removed in either the platform or ground control mode. Control of the unit had been accomplished with a non-manufacturer key at the time of the incident. Interviews with workers familiar with the operation of the articulated boom-supported aerial work platforms indicated that the ground control captive key feature of the equipment could be easily defeated. Also, they indicated that over time the keys became loose, vibrated out of the ignition switch, and were misplaced or lost. The following actions were taken by the company after the incident occurred.
Back to TopCause of DeathThe cause of death as stated on the medical examiner’s report was chest and abdominal injuries. The results of the toxicology tests were negative. Recommendations/DiscussionThe American National Standards Institute (ANSI) should evaluate and consider modifying ANSI A92.S standard titled “The American National Standard for Self Propelled Elevating Work Platforms” and encourage manufacturers and distributors to follow the International Organization for Standardization (ISO) Standard for articulated boom-supported aerial work platforms regarding providing pressure sensor/relief valves on their equipment.It is not possible to purchase or lease an articulated boom-supported aerial work platform in the United States with pressure sensor/relief valves. This safety equipment is required on all such lifts to be sold and used in Europe in accordance with the ISO standard. Efforts are underway to modify A92.5 of the ANSI standard which emphasizes the location, function, and interlocking of the platform controls for all machine functions to incorporate a requirement that pressure sensor/pressure relief valves be required safety equipment on all boom-supported aerial work platforms. This section also addresses the responsibilities of all involved parties including defining rental inspection and operator education and training.
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Figure 5. Simulation of Arm at Truss |
MIFACE (Michigan Fatality Assessment Control Evaluation), Michigan State University (MSU) Occupational & Environmental Medicine, 117 West Fee Hall, East Lansing, Michigan 48824-1315; http://www.oem.msu.edu. This information is for educational purposes only. This MIFACE report becomes public property upon publication and may be printed verbatim with credit to MSU. The author of this report is affiliated with Wayne State University. Reprinting cannot be used to endorse or advertise a commercial product or company. All rights reserved. MSU is an affirmative-action, equal opportunity employer. 6/1/05
MIFACE Investigation Report # 03MI146 Evaluation (see page 10 of report)
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