2008 fatality report: welder electrocuted in boom ... · 17/10/2008 · 3.4 national oilwell varco...

WELDER ELECTROCUTED IN BOOM-SUPPORTED AERIAL WORK PLATFORM Type of Incident: Fatal Incident Date of Incident: October 17, 2008

File: F-254972

2 June 15, 2009 Alberta Employment and Immigration, Workplace Standards

TABLE OF CONTENTS

SECTION TITLE PAGE NUMBER

1.0 DATE AND TIME OF INCIDENT 3 2.0 NAME& ADDRESS OF PRINCIPAL PARTIES 3 2.1 Owner 3 2.2 Employer(s) 3 2.3 Worker 4 3.0 DESCRIPTION OF PRINCIPAL PARTIES 4 3.1 Employers 4 3.2 Worker 5 4.0 LOCATION OF INCIDENT 6 5.0 EQUIPMENT, MATERIAL AND OBSERVATIONS 6 5.1 Equipment and Material 6 5.2 Observations 8 6.0 NARRATIVE DESCRIPTION OF INCIDENT 9 7.0 ANALYSIS 10 7.1 Direct Cause 10 7.2 Contributing Factors 10 8.0 FOLLOW-UP/ ACTION TAKEN 14 8.1 Occupational Health and Safety 14 8.2 Industry 17 8.3 Additional Measures 18 9.0 SIGNATURES 18 10.0 ATTACHMENTS 18

File: F-254972


SECTION 1.0 DATE AND TIME OF INCIDENT 1.1 The incident occurred on October 17, 2008 at approximately 11:00 p.m. SECTION 2.0 NAME AND ADDRESS OF PRINCIPAL PARTIES 2.1 Owner 2.1.1 National Oilwell Varco (Owner of Dreco Energy Services Ltd.)

1 – 506 – 24 Avenue Nisku, Alberta T9E 8G3 2.2 Prime Contractor 2.2.1 Dreco Energy Services Ltd. (Legal name of the company at the site of the incident) 6415 – 75 Street NW

Edmonton, Alberta T6E 0T3 2.3 Employer 2.3.1 National Oilwell Dreco (the entity having the Workers Compensation Account) 506 – 17 Avenue Nisku, Alberta T9E 7T1 2.4 Contractor 2.4.1 National Oilwell Varco (contracted construction at the site of the incident) 1 – 506 – 24 Avenue Nisku, Alberta T9E 8G3 2.5 Contractor 2.5.1 Corporate Projects Inc. 14603 – 118 Avenue Edmonton, Alberta T5L 2M7 2.6 Supplier 2.6.1 Leavitt Machinery and Lift Rentals Inc. 11015 – 186 Street

Edmonton, Alberta T5S 2V5 2.7 Manufacturer 2.7.1 JLG Industries, Inc. 1 JLG Drive McConnellsburg, Pennsylvania, USA 17233-9533

File: F-254972


2.8 Worker

2.8.1 Welder Edmonton, Alberta SECTION 3.0 DESCRIPTION OF PRINCIPAL PARTIES

3.1 National Oilwell Varco designs, manufactures and sells the major mechanical components for both land and offshore drilling rigs and well servicing rigs. National Oilwell Varco has strategically purchased many companies with brand name products and services. In 1997 National Oilwell Varco acquired Dreco Energy Services Ltd.

3.2.1 Dreco Energy Services Ltd. is a subsidiary of National Oilwell Varco. Dreco Energy

Services Ltd. provides for design, construction, modernization, and repair of land and offshore drilling rigs. The fabrication plant where the fatal incident occurred is the facility where Dreco Energy Services Ltd. manufactures and assembles drilling rigs.

3.3 National Oilwell Dreco is the business entity that is listed as the employer at the site

of the incident, as determined through documentation supplied from the Alberta Workers Compensation Board.

3.4 National Oilwell Varco is the contractor with whom Corporate Projects Inc. entered

into an agreement to rebuild a structure that had burned the previous year on the Dreco Energy Services Ltd. property where the fatal incident occurred.

3.5 Corporate Projects Inc. is a small construction company that was contracted by

National Oilwell Varco to demolish a burned structure on the plant property near the site of the fatal incident and rebuild a new structure. Corporate Projects Inc. mainly manages the project and hires sub-contractors for each phase of the project. During the time of the incident Corporate Projects Inc. had a superintendent and a labourer on the site. These two workers were not at the site at the time of the incident as they were only working during the daytime. The reconstruction project was in the groundwork stages.

3.6 Leavitt Machinery and Lift Rentals Inc. is a large construction machinery, rental,

sales and servicing business based in the Pacific Northwest, with a depot in Edmonton, Alberta. Leavitt Machinery and Lift Rentals Inc. rented the Boom-Supported Aerial Work Platform machine (JLG model) to National Oilwell Varco.

File: F-254972


3.7 JLG Industries, Inc. was the manufacturer of the JLG model Boom-Supported Aerial Work Platform that was being used by the Welder at National Oilwell Dreco. JLG Industries, Inc. is a leading designer, manufacturer and marketer of access equipment. JLG Industries, Inc. is owned by Oshkosh Corporation.

3.8 The Welder was a second year apprentice that had been rehired by

National Oilwell Dreco in December 18, 2007. The Welder had worked with National Oilwell Dreco in previous years, but had left for another employer, and then returned. The crew had been working night shifts of 12 hours for 5 nights a week and every second Saturday for an eight hour shift. (night shift starts at 6:00 p.m.) The Welder had worked a 9 hour night shift the previous Monday, then two 12 hour night shifts and then a 12.5 hour night shift the day prior to the incident.

3.9 The Safety Co-ordinator has approximately 10 years experience with

National Oilwell Dreco with six of those years as a safety co-ordinator. The Safety Co-ordinator trained the Welder on the use of the Boom-Supported Aerial Work Platform at the beginning of the shift on the day of the incident. The Safety Co-ordinator did not have Train the Trainer status for operation of Boom-Supported Aerial Work Platforms, but he had experience operating the machine. The Welder had been using the Boom-Supported Aerial Work Platform for parts of the week prior to the incident.

3.10 Steel Fitter 1 was inside the shop having a lunch break at the time

of the incident. Steel Fitter 1 was the person that first found the fatally injured Worker unresponsive, up in the air, and lowered the Boom-Supported Work Platform to ground level. Steel Fitter 1 had current Standard First Aid Certification with Level A Cardio Pulmonary Resuscitation (CPR) that was obtained in April 20, 2007.

3.11 Steel Fitter 2 was the co-worker assistant to the Welder

while the outside Travelling Overhead Crane Runway was being upgraded. During October 17, 2008 he had been preparing steel parts at ground level for installation on the Travelling Overhead Crane Runway. He had been working approximately 33 m away from the Welder and also had been cutting steel parts in the adjacent shop. At the time the incident occurred, the Steel Fitter 2

was in the shop having a lunch break. Steel Fitter 2 did not have Standard First Aid certification.

3.12 The Night Shift Supervisor had worked for National Oilwell Dreco

for approximately 30 years. He had been Night Shift Supervisor for approximately 12 years. The Night Shift Supervisor was on duty the night of the incident and was the second person at the scene of the incident and called 911 Emergency Services. The Night Shift Supervisor had previously received Standard First

File: F-254972


Aid Level A CPR training, but it had expired in May 18, 2008. 3.13 The Night Shift Safety Co-ordinator was the manager of the

National Oilwell Dreco’s Tool Crib. The Night Shift Safety Co-ordinator had accepted the added duty of Night Shift Safety Coordinator.

This duty entailed making tours of the plant site work areas and ensuring all workers were following the National Oilwell Dreco’s policies for personal protective equipment. The Night Shift Safety Co-ordinator had previously been certified in Standard First Aid and Level A CPR, but it had expired in May of 2008.

SECTION 4.0 LOCATION OF INCIDENT

4.1 National Oilwell Dreco is located at 506 – 17th Avenue in Nisku, Alberta. The incident occurred outdoors in the northwest section of the property at the north overhead travelling crane runway. (Attachment A, Map and Attachment B, Photographs 1-4).

SECTION 5.0 EQUIPMENT, MATERIAL AND OBSERVATIONS

5.1 Equipment and Material 5.1.1 Boom-Supported Aerial Work Platform 5.1.2 JLG Industries, Inc.

Model 660SJ Serial No. 0300124479 Year 2008 (Attachment B, Photograph 5).

5.2 Welding Machine 5.2.1 Manufacturer – Lincoln Electric Model – RA – 2501903

Type – D300K 3X3 Serial No. - 105020616 Code – 11214 (Attachment B, Photograph 6)

File: F-254972


5.3 Welding Electrode Holder Assembly 5.3.1 Bernard - Short Stub electrode holder

- model no. not legible (measurements indicate SKU-360-40B) - type – closed end twist-clamp electrode holder - size – 22 cm - thermoplastic elastomeric cover - amperage capacity – 400 amp at 60% duty cycle

5.3.2 Tweco – Twist-type welding cable connector - model not legible (measurements indicate 2-MPC-1) - single ball point brass male end connection (diameter 1.5 cm) - amperage capacity 450 amps at 80 volts AC/DC 5.3.3 Welding current conductor cable - model not legible (measurements indicate #2 size cable rated for 375 amp) - rubber protective cover over interior copper conductor cable for electrical

current - outer diameter size 1.5 cm 5.3.4 Total length of assembly is 4.65 m. Assembly has Bernard Short Stub electrode

holder on one end of the copper conductor cable and the Tweco welding cable connector on the opposite end. (Attachment B, Photograph 7)

*The distance from the Bernard Short Stub electrode holder to the cut found in the outer rubber protective cover of the copper conductor cable was 1.93 m.

5.4 Observations

5.4.1 Description of the Traveling Overhead Crane Runway 5.4.1.1 The Traveling Overhead Crane Runway is one of two above-ground rail systems that

run parallel to each other (running east and west) and support three Bridge Cranes (each with one end of the bridge on a runway). Each Bridge Crane has two hoists that travel back and forth (running north and south) on the bridge, for lifting heavy equipment. The Welder was welding additional bracing onto the north Traveling Overhead Crane Runway’s upper steel beam structure. This steel beam structure was 6.48 m above ground level and was held up by steel pillars located every 12.2 m. Each complete Traveling Overhead Crane Runway is supported by 20 steel pillars. The upper steel beam running the full length of the Traveling Overhead Crane Runway was a 60.9 cm I-Beam. The Welder was performing the final welding on steel 15.2 cm by 15.2 cm angle irons that had been previously tack welded onto the top of the upper steel I-Beam. There had previously been a 38 cm

File: F-254972


channel iron with 8.9 cm lips welded flat side up (lip pointed down) onto the Crane Runway I-Beam bottom edge. (Attachment B, Photographs 3, 8)

5.4.2 Weather Report 5.4.2.1 The temperature at the time of the incident was 10.6 degrees C with a 7 km/h breeze

from the north. Weather conditions were not a factor in the incident. 5.4.3 Lighting at the Incident Site 5.4.3.1 The site of the incident was lit by a large halogen light powered by the welding

machine used by the Welder . This large halogen lamp was mounted on a steel pipe approximately 4 m above ground level and pointed at the Welder’s

work area. (Attachment B, Photograph 5) There was also a smaller portable halogen lamp inside the elevated Work Platform that the Welder was stationed in. The Occupational Health and Safety (OHS) Investigator returned and viewed the lighting at night from the vantage point in the location where the Welder

was found at the time of the incident. The lighting was deemed adequate to operate the controls of the JLG Boom-Supported Aerial Work Platform and to see the ground level path of the machine.

5.4.4 Boom-Supported Aerial Work Platform, Upper Drive Control 5.4.4.1 The upper control in the Work Platform of the Boom-Supported Aerial Work

Platform machine was found by the OHS Investigators to be jammed in the reverse drive position. To operate this control the foot pedal needs to be depressed and the control lever lifted and pushed forward. This control normally retracts to neutral by spring action. It was determined that the control lever had not been lifted high enough above the shoulder to allow for pushing it forward and therefore the lever had jammed through the shoulder of the housing causing it to crack and hold the lever in position. It is not known if this housing rupture was caused on the day of the incident or through prior use. (Attachment B, Photograph 9)

SECTION 6.0 NARRATIVE DESCRIPTION OF THE INCIDENT

6.1 On October 17, 2008 at 6:00 p.m. the Welder began his night shift at National Oilwell Dreco. Early in the shift the Safety Co-ordinator gave the Welder a brief session of training for operation of the JLG Industries, Inc. Boom-Supported Aerial Work Platform. The Welder then proceeded to use this equipment to reach the upper north side section of the Travelling Overhead Crane Runway to finish welding the 15.2 cm by 15.2 cm steel angle irons that were

File: F-254972


previously tacked in place. He had been using the Boom Supported Aerial Work Platform equipment for approximately 5 days previous.

6.2 The Night Shift Safety Co-ordinator had made a tour of the work area where the

Welder was working on the outdoor Travelling Overhead Crane Runway. He had spoken with the Welder at approximately 10:30 p.m. on the night of the incident. Steel Fitter 1 was working in the shop cutting parts.

6.3 Sometime between 10:30 p.m. and 11:15 p.m. the Welder had attempted

to move the Boom-Supported Aerial Platform in reverse while he was up in the air inside the Work Platform. Due to the rear steering wheels being turned in a direction away from the Travelling Overhead Crane Runway, the raised Work Platform hit the Runway steel framework hard enough to sever the rubber insulating coating of the Welding Current Conductor Cable. This allowed the Work Platform to be energized at the same time as the Welder’s elbow hit the frame of the Travelling Overhead Crane Runway, passing electrical current through his body to ground. The Welder became electrocuted.

6.4 On October 17, 2008 towards the end of a crew lunch break (at approximately 11:15

p.m.) the workers in the lunch area noticed that the Welder had not come for his break. Steel Fitter 1 went out to check on the Welder

and found him inside the raised Boom-Supported Aerial Work Platform, slumped over the controls. The machine was not running. The Welder did not respond to calls from Steel Fitter 1 .

6.5 Steel Fitter 1 started the Boom-Supported Aerial Work Platform

machine from the controls on the machine at ground level. He lowered the Work Platform to the ground, approached the Welder and determined he was unconscious and did not have a pulse. Steel Fitter 1 then ran for help and had someone call 911 Emergency Services.

6.6 The Nightshift Supervisor immediately went to the Welder

and called 911 Emergency Services from his cell phone. A number of other workers gathered at the site of the incident including Steel Fitter 1

and the Night Shift Safety Co-ordinator . The Night Shift Supervisor instructed the others to leave the Welder

in his position, slumped over the controls of the Work Platform. After the Night Shift Supervisor had given the 911 Emergency Services Dispatcher instructions as to the location of the incident, he began receiving instructions from the 911 Emergency Services Dispatcher. The Night Shift Supervisor was instructed how to assess the Welder’s condition and that the Welder should be taken out of the Work Platform, laid on his back on the ground and an attempt made to perform Cardio Pulmonary

File: F-254972


Resuscitation. The ambulance arrived at this time. 6.7 The Parkland Ambulance Emergency Service attendants tried, but were unable to

revive the Welder at the scene of the incident. He was pronounced dead at the scene of the incident by the Emergency Service attendants.

SECTION 7.0 ANALYSIS

7.1 Direct Cause

7.1.1 On October 17, 2008 at approximately 11:00 p.m. the Welder became electrocuted while operating the Boom-Supported Aerial Work Platform when it contacted the Travelling Overhead Crane Runway and severed a Welding Conductor Cable which energized the Work Platform.

7.1.2 During operation of the machine from the Work Platform’s controls, the Welder

hit the Work Platform’s edge on the frame of the Travelling Overhead Crane Runway and damaged the protective coating of the Welding Cable Assembly that was hanging over the outer edge of the Work Platform. (Attachment B, Photographs 7, 8 10-12) This energized the Work Platform from the Welding Machine at the same time as the Welder’s elbow hit the frame of the Travelling Overhead Crane Runway, passing electrical current through his body to ground. (Attachment B, Photograph 13)

7.2 Contributing Factors

7.2.1 The Boom-Supported Aerial Work Platform machine had been positioned by the Welder , nearly parallel to the Travelling Overhead Crane Runway. The steering wheels of the Boom-Supported Aerial Work Platform were turned sharply in a direction away from the Travelling Overhead Crane Runway. When the Welder

attempted to drive the machine in reverse this caused the Work Platform to hit and rub on the steel frame of the Crane Runway. (Attachment B, Photographs 5, 14) The Boom-Supported Aerial Work Platform machine was found stalled with the drive control lever stuck in the reverse position. This indicated that the Welder

had been attempting to move the machine at the time of his electrocution. 7.2.2 The Welder had not been wearing his gloves while attempting to move

the Boom-Supported Aerial Work Platform machine. Therefore, his right hand was not insulated from conducting an electrical current through the control of the machine to ground, when his elbow contacted the Travelling Overhead Crane Runway.

File: F-254972


7.2.3 The Welder had not received the training and evaluation outlined in the manufacturer’s instruction for operation of the Boom-Supported Aerial Work Platform machine, to be proficient at its operation. The Welder had received approximately two hours of training at the beginning of the night shift on the day of the incident. The training consisted of watching a 24 minute video, examining some pictures of unsafe manoeuvres with the machine and writing a short true/false examination. (Attachment B, Photograph 15) There was no hands-on instruction or evaluation. According to co-workers the Welder had been using the Boom-Supported Aerial Work Platform prior to the incident for part of 5 nights. The manufacturer required the user of the machine to follow the standards identified below.

• The Manufacturer of the Boom-Supported Aerial Work Platform, JLG Industries,

Inc. supplied a ‘Manual of Responsibilities’ that was placed in the Work Platform’s sealed container for operation manuals. This ‘Manual of Responsibilities’ is published jointly by the American National Standards Institute (ANSI) and the Scaffold Industry Association Inc. (SIA) as A92.5-2006 and was adopted by the manufacturer.

• The ‘Manual of Responsibilities’ states in section 6.11.1 under the heading

Operator Training, “Whenever an owner directs or authorizes an employee to operate an aerial platform, (loading, unloading, inspecting or any form of use) the owner shall assume the responsibilities of the user as specified in Section 7 of this standard and shall ensure the person has been: - (1) Trained, - (2) Familiarized with the aerial platform to be operated, - (3) Made aware of the responsibilities of operators as outlined in Section 8 of this standard.”

• Section 7.6 of the ‘Manual of Responsibilities’ restates the three items mentioned

in Section 6.11.1 and adds a forth item, “the user shall ensure that the person has been: - (4) Retrained, if necessary, based on the user’s observation and evaluation of the operator.”

• Section 8.5.1 of the ‘Manual of Responsibilities’ under the heading General

Training states: “Only personnel who have received general instructions regarding the inspection, application and operation of aerial platforms, including recognition and avoidance of hazards associated with their operation, shall operate an aerial platform. Such items covered shall include, but not necessarily be limited to, the following issues and requirements:

File: F-254972


- (1) The purpose and use of manuals - (2) That operating manuals are an integral part of the aerial platform and must be stored properly in the weather-resistant compartment when not in use - (3) The pre-start inspection - (4) Responsibilities associated - (5) Factors affecting stability - (6) The purpose of placards and decals - (7) Workplace inspection - (8) Safety rules and regulations - (9) Authorization to operate - (10) Operator warnings - (11) Actual operation of the aerial platform. Under the direction of a qualified person, the trainee shall operate the aerial platform for a sufficient period of time to demonstrate proficiency in the actual operation of the aerial platform.” (Attachment B, Photograph 16)

• A representative of the manufacturer of the Boom-Supported Aerial Work

Platform involved in the incident, JLG Industries Inc. , District Manager, Services), stated that the manufacturer supplies training for operation of the Boom-Supported Aerial Work Platforms. This training involves:

- For Train the Trainer – takes one full week, complete with all the training

materials to offer in-house training to the workers of the business

- For In-House Training – should be a minimum of one full day including ½ day of theory, with examination, and ½ day of hands-on with a qualified instructor. During the hands-on training the trainee must be able to demonstrate a certain amount of competency and pass a practical exam before being allowed to use the machine. It is not uncommon for trainees to fail the practical exam because not all people have the acumen to operate the machine.

7.2.4 National Oilwell Dreco chose a Boom-Supported Aerial Work Platform machine that did not have any optional equipment for performing welding duties from the Aerial Work Platform. National Oilwell Dreco used a welding machine on the ground, an electrical power supply from ground level, and had the Welding Conductor Cables and electrical cords and air hose tied to the guardrailing of the Aerial Work Platform. In this location the Welding Conductor Cables were prone to damage from the Aerial Work Platform hitting stationary objects that the Welder would be working near. (Attachment B, Photograph 7) The manufacturer of the Boom-Supported Aerial Work Platform had optional equipment that could be mounted in the aerial work platform called the “Skywelder”. One of the reasons for manufacturing and offering this “Skywelder” equipment was listed in the manufacturer’s literature

File: F-254972


stating, “The Skywelder eliminates potentially dangerous leads hanging over the rails, and eliminates the unnecessary cost of having a stand-alone welder and power supply.” The Welding Conductor Cable hanging over the side of the Aerial Work Platform was found damaged, causing the Aerial Work Platform to become energized with electricity when it was squeezed between the Travelling Overhead Crane Runway’s top I-Beam and the Work Platform of the Boom-Supported Aerial Work Platform. (Attachment B, Photographs 10, 11, 12)

7.2.5 The Welding Machine at the site of the incident had the voltage setting as high as it could be (at over 100 volts). (Attachment B, Photograph 6) The output voltage was measured, with metering equipment, at the end of the Welding Electrode Holder Assembly by striking an arc near the ground clamp from the Welding Machine. This voltage was measured at 107.5 volts. The actual voltage at the site of the Welder

location at the time of the incident would even have been higher, since there would have been more resistance due to the considerable distance from the ground clamp. This voltage was deemed to be sufficient to cause electrocution. There are devices available as an addition to a welding machine to limit the open circuit voltages to a lower voltage where electrocution would be minimized. (One such item is identified as a SafeTac VRD (Voltage Reduction Device))

7.2.6 The control for operating the Boom-Supported Aerial Work Platform machine in reverse was found by the OHS Investigators to be stuck in the position of moving the machine in reverse. This indicated to the OHS Investigators that the Welder

was attempting to move the machine at the time of being electrocuted. This control is designed to retract to a neutral position when it is let go by the operator. This control was constructed of metal and would conduct electricity. The upper control panel was disassembled and examined by the investigators. There were no electrical deficiencies found with the controls. (Attachment B, Photograph 9)

7.2.7 All electrical cables, welding supply cables, power tool electrical connections and the portable plug-in power panel components were examined for deficiencies. Many deficiencies were found and determinations were made by the OHS Investigators as to whether any of these deficiencies could be related to energizing the Work Platform of the Boom-Supported Aerial Work Platform machine. The majority of deficiencies were discounted as not having any connection to the fatal incident. (Attachment B, Photographs 17, 18)

7.2.8 The OHS Investigators requested experts from the supplier of the Boom-Supported Aerial Work Platform machine to examine the electrical and computer systems of the machine for any record that would be associated with the fatal electrocution of the

File: F-254972


Welder . This examination did show an operator error (type of error action not recorded) registered and the foot switch had tripped indicating that the operator had held down the foot switch for more than 7 seconds with no other action with the controls. The examination determined that there were no machine errors that would have caused an electrocution.

7.2.9 National Oilwell Dreco had on file a hazard analysis and safe work practice documentation for above ground work in the vicinity of the Travelling Overhead Crane Runways, but there is no record of this assessment or safe work practice having been discussed with the Welder . The Welder was not involved in a specific hazard assessment for his task of welding on the Crane’s Runway. Some of the procedures in the initial safe work practice were not followed. The electrical power to operate the Travelling Overhead Cranes had not been shut off and locked out.

7.2.10 The co-workers of the Welder , who had current Standard First Aid and Level A CPR certification, did not immediately remove the Welder from the Aerial Work Platform as soon as it was lowered, and try to revive him. When they called 911, the dispatcher instructed them to remove the Welder and start Cardio Pulmonary Resuscitation.

SECTION 8.0 FOLLOW-UP/ ACTION TAKEN

8.1 Employment and Immigration; Occupational Health and Safety

8.1.2 Occupational Health and Safety (OHS) Investigators attended to the site of the incident shortly after the incident and investigated the incident.

8.1.3 OHS Investigators ensured there was third party security (Nisku Security Patrol Inc.)

at the site of the incident through the night to protect the evidence and keep interested parties from entering a potentially dangerous area.

8.1.4 OHS Investigators contacted the Province of Alberta Medical Examiner and alerted

him to the OHS Investigator’s preliminary suspicion that the fatally injured Welder may have been electrocuted, and to examine the body for this possibility.

File: F-254972


8.1.5 OHS Investigators retained the services of Cranemasters Overhead Crane Consulting Inc. to provide an overhead crane specialist and electrical specialists for assessing the electrical hazards at the site, examining the electrical equipment, and disassembling some components of the Boom-Supported Aerial Work Platform’s upper controls.

8.1.6 OHS Investigators contacted the manufacturer of the Boom-Supported Aerial Work

Platform (JLG Industries Inc.) and the Supplier (Leavitt Machinery and Lift Rentals Inc.) of the machine. Arrangements were made for a technician and a specialist to assist with the examination of the machine. The Alberta Chief Electrical Inspector’s Office sent an observer (Technical Advisor, Electrical Safety Services, ) to be involved in the examination of the machine and assist where possible.

8.1.7 OHS Investigators contacted the Province of Alberta Chief Electrical Inspector

and involved him and the local County of Leduc Electrical Inspector in inspection of the electrical system, for the complete north-side Travelling Overhead Crane Runway system.

8.1.8 National Oilwell Varco retained the services of an Electrical Engineer

. With permission of OHS Investigators the Electrical Engineer performed analysis of the functionality of some critical components

that were removed from a portable plug-in power supply panel at the site of the incident and components removed from the operational controls of the Aerial Work Platform. The Electrical Engineer performed an examination of each Bridge Crane and the two Traveling Hoists on each Bridge Crane to determine if there was any stray electrical current coming from these components into the Traveling Overhead Crane Runway system. No deficiencies were found.

8.1.9 The OHS Investigators ensured that three electrical supply cables running along the

bottom of the Traveling Overhead Crane Runway’s I-Beam (one to supply power to a bank of welding machines, one to a portable plug-in power panel and one from the portable plug-in power panel to the Corporate Projects Inc. job trailer) were not a potential source for causing an electrocution due to being damaged or burned by welding or cutting. Along with the OHS Investigators, the Electrical Engineer

and the National Oilwell Varco’s Safety Co-ordinator examined all the electrical equipment, cables, electrical power cords and portable power panel components associated with the incident. Through a process of elimination, the conclusion was reached as to the most likely source of electrical current to cause an electrocution of the Welder .

8.1.10 OHS Investigators contacted the first aid training agency (St. John Ambulance) to

determine how people that have English as a second language are trained and evaluated for competency.

File: F-254972


8.1.11 The OHS Investigators wrote the following orders to National Oilwell Dreco:

• To undertake an internal investigation of the incident and prepare a report of findings for application of corrective measures to prevent a similar incident.

• To supply documentation and information related to the OHS investigation.

• To stop use of all the electrical systems associated with the north Travelling

Overhead Crane Runway system until electrical upgrades could be completed to the satisfaction of the County of Leduc Electrical Inspector . A Stop Use Tag #5175 was affixed and the power shut off at the main power supply panel for the electrical systems associated with the north section of the Travelling Overhead Crane Runway electrical systems.

• To inspect, repair or discard all damaged/faulty electrical power supply cords,

electrical power tools and welding supply cables used by workers. Many deficiencies were found with some of the equipment evaluated during the investigation. (Attachment B, Photographs 17, 18)

• To evaluate the company’s first aid services, supply and equipment.

• To repair any electrical deficiencies associated with all the electrical systems on

the north-side Travelling Overhead Crane Runway system.

• Bring the three Bridge Cranes up to Original Equipment Manufacturer standard. Deficiencies (including electrical deficiencies) were found with these cranes during the investigation.

• Provide additional training to the plant staff that operated Boom-Supported Aerial

Work Platforms. The plant staff operating the machines had only received in-house training or only had work experience operating the equipment. The manufacturer of the equipment required a higher standard of training.

8.1.12 The OHS Investigators communicated the following to Corporate Projects Inc.:

• Receipt of documentation relating to the investigation. 8.1.13 The OHS Investigators wrote the following orders to St. John Ambulance:

• For supply of the examination details for 3 workers that attended to the fatally injured worker and had at some time previously received training in Standard First Aid with Level A CPR.

File: F-254972


• For an explanation of how training people that have English as a second language is handled, so that the trainees clearly understand how to administer first aid.

8.1.14 The Parkland County Emergency Services department was required to supply to the

OHS Investigators, the details of the 911 recorded conversations between the 911 Emergency Services Dispatcher and the caller from National Oilwell Dreco.

8.1.15 Leavitt Machinery and Lift Rentals Inc. were requested to provide technical

assistance for dismantling and assessing the electronic and electrical components of the Boom-Supported Aerial Work Platform machine involved in the fatal incident. Leavitt Machinery and Lift Rentals Inc. were required to examine and repair to original manufacturer standards, where necessary, the machine involved in the incident. OHS Investigators had removed for evidence some of the control components of the machine.

8.2 Industry 8.2.1 National Oilwell Varco retained the services of an Electrical Engineer

to assist with the examination of electrical equipment and the investigation of the incident.

8.2.2 National Oilwell Varco personnel cooperated fully with the OHS Investigators and

complied with all the orders that were written. 8.2.3 Corporate Projects Inc. provided the documentation and information required by the

OHS Investigators and co-operated with the Investigators. 8.2.4 St. John Ambulance provided documentation and gave information on the training

protocol for workers having English as a second language. 8.2.5 Parkland County Emergency Services provided the OHS Investigators with the 911

Emergency Services Dispatch recorded conversations from the time of the incident. 8.2.6 Leavitt Machinery and Lift Rentals Inc. provided a technician and co-operated with

all the OHS Investigators requests during the investigation. 8.2.7 JLG Industries Inc. sent a representative of the manufacturer with specialized skills in

understanding the operating and control systems involved with the Boom-Supported Aerial Work Platform machine.

File: F-254972


8.3 Additional Measures

8.3.1 No additional measures are required at this time. SECTION 9.0 SIGNATURES ____________________________ _____________________ Lead Investigator Date ____________________________ _____________________ Investigator Date ____________________________ _____________________ Manager Date ____________________________ _____________________ North Region Senior Manager Date SECTION 10.0 ATTACHMENTS: Attachment A Map Attachment B Photographs

zoriya.martiuk

Typewritten Text

ORIGINAL REPORT SIGNED

zoriya.martiuk

Typewritten Text


zoriya.martiuk

Typewritten Text


zoriya.martiuk

Typewritten Text


zoriya.martiuk

Typewritten Text

File: F-254972 Attachment “B”

Page 1 of 18

Alberta Employment and Immigration, Workplace Standards

Photograph #1 Shows signage at one of the entries on the south side of the National Oilwell Dreco property. This sign also identified the address of the property where the incident occurred.


Page 2 of 18


Photograph #2 Shows another sign on the south side of the National Oilwell Dreco property indicating that ownership has changed in recent history.


Page 3 of 18


Photograph #3 Shows the north Travelling Overhead Crane Runway looking west at the north side of the National Oilwell Dreco property. The site was left this way with the Boom-Supported Aerial Work Platform on the ground after being brought down to evacuate the fatally injured Welder . The yellow arrow identifies the location on the Crane Runway where the Welder was working at the time of the incident.

The Welder was working in this location at the time of the incident, welding on the Traveling Overhead Crane Runway’s I-Beam top

The Boom-Supported Aerial Work Platform is on the ground behind the Portable Power Panel and the Steel Pillar. See photograph 7


Page 4 of 18


Photograph #4 Shows the north-side Traveling Overhead Crane Runway looking east. Three Bridge Cranes with their hoists can be seen from this perspective. The parallel south side Travelling Overhead Crane Runway can also be seen in this view.

Bridge Cranes that travel on the Overhead Crane Runway


Page 5 of 18


Photograph #5 Shows approximately how the Boom-Supported Aerial Work Platform

was positioned when found by the worker who lowered it at the time he noted the Welder was unresponsive. This picture was taken looking east.

This is the light that was mounted on the Welding Machine the Welder was using

Portable Power Panel identified in photograph 3

Steel Pillar identified in photograph 3

Steering Wheels are turned sharply This would cause the Work Platform to hit the Crane Runway when in reverse. See photograph 13


Page 6 of 18


Photograph #6 Shows a close-up of the Welding Machine that the Welder was using prior to his fatal injury. The right-side control dial shows the voltage to be set at maximum. See the positioning of the machine in proximity to the Boom-Supported Aerial Work Platform ( photograph 13).

The Voltage Control Dial on the face of the Welding Machine


Page 7 of 18


Photograph # 7 Shows how the scene of the incident appeared on the night that the incident occurred and the investigation began. The power tools, small portable light, and the welding cable assembly were removed from the Work Platform by the Emergency Responders so as not to impede the rescuers in attending to the fatally injured Welder .

Welding Electrode Holder that is the front part of the Welding Electrode Holder Assembly

Twist Type Welding Cable Connector. The tail part of the Welding Electrode Holder Assembly

These two Work Platform guardrail posts made rub marks on the Travelling Overhead Crane Runway’s top I-Beam. See photograph 8


Page 8 of 18


Photograph #8 Shows the rub marks left on the side of the Traveling Overhead Crane Runway steel surface. The orange paint left on the lower edge indicates the Boom-Supported Aerial Work Platform rubbed in this location. This was the location of the last weld on the Crane Runway that the Welder

was working on. See photograph 10 for a closer view of what appears to be rubber, and photograph 11 to see what made the rub marks.

Two parallel rub marks on the Crane Runway’s upside-down channel iron that is welded onto the I-Beam base section. The rub marks measured the same distance apart as the Work Platform guardrail posts.

Orange paint from the Boom-Supported Aerial Work Platform rubbed off onto the lower side of the channel iron that was welded to the underside of the Crane Runway’s I-Beam frame.

Rubber that had been left on the metal from the Welding Electrode Holder Assembly See photograph 9

This is the downward pointing lip of the channel irons long flat side that was welded to the base of the Crane Runway’s I-Beam frame work above.


Page 9 of 18


Photograph #9 Shows a close-up view of the Work Platform’s directional control that was found stuck in the reverse position just after the incident occurred. Notice how the shoulder of the knob (that pulls up and retracts down) had not been raised enough, thus jamming the control lever in the machine’s reverse mode. The housing had been cracked from this pressure. The control lever assembly is all metal. The action of having to raise the shoulder is a protection against inadvertent operation of the machine.

The operator’s fingers would wrap around this spring-loaded disk and raise the shoulder above the lever opening. It is shown as being jammed in this picture.

This shoulder (attached to the disk above) is jammed in the control base structure.


Page 10 of 18


Photograph #10 Shows a closer view of where the Work Platform rubbed against the Crane Runway’s steel.

Evidence of orange paint rubbed off the Work Platform onto the Crane Runway steel frame.

Electrical burn mark. See photograph 12

Evidence of black rubber left on the steel


Page 11 of 18


Photograph #11 Shows a closer view of one of the Boom-Supported Aerial Work Platform’s guardrail posts that left rub marks on the Crane Runway framework base. See photograph 7.

These weld edges protrude and left a steel-to-steel rub mark as seen in photographs 8 and 10

A fresh rub mark that had not rusted, indicating a recent removal of the paint


Page 12 of 18


Photograph #12 Shows a close-up view of a break in the rubber protector on the Welding Cable that is part of the Welding Electrode Holder Assembly. This was hanging on the Work Platform at the time of the incident. (This was not a clean cut as would be caused by a knife or a sharp edge.) This indicates that it was forced open as with pressure between two solid objects. There is also evidence that the inside copper wire had arced and melted, and some copper strands have become separated.


Page 13 of 18


Photograph #13 Shows how the Welder who suffered the electrocution would have been operating the controls for the Work Platform. The basket was narrow enough that his left elbow could contact the Crane Runway steel structure at the same time as the Work Platform was rubbing up against it with the Welding Electrode Holder Assembly hanging over the top railing.


Page 14 of 18


Photograph #14 Shows from above how turning the steering wheels of the Boom-Supported Aerial Work Platform machine to the right would have pressed the Work Platform against the Crane Runway as the Welder was attempting to reverse the machine. This picture was taken from the Work Platform that was raised in the air similar to the time of the incident. See photograph 5 for a view from the ground.

The Welding Machine

The steering wheels of the Boom-Supported Aerial Work Platform


Page 15 of 18


Photograph #15 Shows clear instructions posted on the Boom-Supported Aerial Work Platform machine as to the expectations of the manufacturer for the training requirements of the personnel operating the machine.


Page 16 of 18


Photograph #16 Shows writing below the DANGER sign posted on the Boom-Supported Aerial Work platform machine, indicating that the machine is not insulated and electrical current could pass through it with serious results to the operator.


Page 17 of 18


Photograph #17 Shows how a plug-in receptacle inside the portable electrical power panel had sustained a fire. This portable electrical power panel was being used by the Welder who became fatally injured, as a power source for his electrical tools and a small portable light. See photographs 3, 5.


Page 18 of 18


Photograph #18 Shows how a welding current conductor cable in use (at the site of the incident) had been damaged by being run over by the Boom-Supported Aerial Work Platform machine. The copper conductor was exposed to the elements and the electrical current could be dangerous to anyone coming in contact with it.

2008 fatality report: welder electrocuted in boom ... · 17/10/2008 · 3.4 national oilwell varco...

Documents