Investigation Report Worker fatally injured when struck by conveyor equipment November ... ·...

Report No-F-OHS-112266-5CC9F October 2019 of 13

Investigation Report

Worker fatally injured when struck by conveyor equipment

November 1, 2016

F-OHS-112266-5CC9F Alberta

Final Report

Ministry of Labour & Immigration Occupational Health and Safety

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The contents of this report This document reports Occupational Health and Safety’s (OHS) investigation of a fatal incident that occurred in November 2016. It begins with a short summary of what happened. The rest of the report covers this same information in greater detail. Incident summary A tunnel foreman was working underground in a drainage tunnel. Conveyor equipment connected to the tunnel boring machine (TBM) struck the tunnel foreman in the head. The tunnel foreman succumbed to the resulting injuries and was declared deceased at the scene. Background information The City of Edmonton, Integrated Infrastructure Services (the City) obtained approval for the construction of a drainage tunnel. The worksite was at 142 Street & Ellerslie Road, Edmonton, Alberta located in the southwest end of the City (Figure 1).

Figure 1. Illustration of the location where the incident occurred. Map provided by GeoDiscover Alberta.

A. Worksite incident scene

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The City was focused on the development of a construction tunnel drainage system in the southwest part of the City (Figure 2). The City was in the process of constructing a tunnel drainage system near the neighbourhoods in Windermere, Heritage Valley and Riverview (Figure 3).

Figure 2. Photograph of the City sign at the entrance to the worksite.

Figure 3. Photograph of the City worksite involved in the incident.

A. Entrance of the tunnel drainage

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Lovsuns Tunneling Canada Ltd (Lovsuns) manufactured the tunnel boring maching (TBM) involved in the incident. Lovsuns was an owned subsidiary of Liaoning Censcience Industry Co. Ltd based in Toronto, Ontario. Lovsuns had head offices in Etobicoke, Ontario. The company supplied TBM products and services for global customers. The TBMs had been widely used in numerous metro, road, railway, hydro power, cross sea and oil & gas tunnelling projects around the world over the past 40 years (Figure 4).

Figure 4. Photo taken from the web site http://www.railsystem.net/tunnel-boring-machine-tbm/ The tunnel foreman had 15 years of work experience with the City. The tunnel foreman reported to a supervisor. The tunnel foreman worked underground with the tunnel crew during the construction of the tunnel drainage project and was responsible for the process of the daily construction of the tunnel drainage (Figure 5). The tunnel foreman was fatally injured by the conveyor equipment.


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Figure 5. Photograph of the worksite above ground near the tunnel drainage after the incident.

A. Crane B. Entrance of the tunnel drainage C. Ventilation system

The segment erector had 4 years of work experience in the tunnel industry with less than 2 years that were with the City. The segment erector reported to the tunnel foreman. At the time of the incident, the segment erector was working near the segment expander and segment lifting system. Equipment and materials Tunnel Boring Machine (TBM)

The City operated a TMB that was manufactured for the construction of drainage tunnels. The TBM was used to excavate a tunnel for drainage.

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Figure 6. Photograph of the underground drainage tunnel showing the conveyor equipment involved after the incident.

A. The ventilation system B. The conveyor equipment positioned onto the gantry C. The center of the gantry D. The hand operated lever chain hoist E. The tunnel foreman was standing onto the yellow walk-way between the gantry and

tunnel wall Conveyor Equipment The conveyor equipment (Figure 6) was an open belt conveyor system device used for the TBM that provided no pressure-balanced support to the tunnel face. The excavated material (rock, sand, and soil) passed into the cutting head chamber of the TBM and was extracted by the open belt conveyor equipment.

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Figure 7. Photograph of the underground drainage tunnel showing the open belt conveyor equipment on the gantry facing toward the TBM operator after the incident.

A. The center line of the conveyor equipment B. The ventilation system C. The center line of the gantry D. The hand operated lever chain hoist

The open belt conveyor equipment was a mechanical device on the TBM that removed and transported the excavated material that was delivered from the cutting head into the muck cars of the drainage tunnel. The open belt conveyor equipment weighed (without the excavated material) 5662 kilograms (kg). The open belt conveyor equipment operated with variable speed and was reversible; it was mounted from the cutting head through the gantry. The open belt conveyor equipment was manufactured by Lovsuns. It was equipped with belt guide that ran the full length of the conveyor, stainless steel runner, 609 millimetres (mm) lumber roller, 609 mm rigid roller, and 609 mm x 28956 mm long conveyor belt. The gantry was pipe skate mounted and supported the ancillary equipment as part of the TBM. The gantry was manufactured by Lovsuns and weighed approximatively 2104 kg. It was designed to support the open belt conveyor equipment, high voltage cable, electric/hydraulic components, TBM substation and ground conditioning system (GCS) (Figures 7, 8).

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Figure 8. Photograph of the underground drainage tunnel showing the open belt conveyor equipment on the gantry after the incident facing toward the entrance of the drainage tunnel.

A. The ventilation system B. The open belt conveyor equipment C. The high voltage cable D. The hand operated lever chain hoist E. The gantry

Lever Chain Hoist The hand operated lever chain hoist (Figure 9) was manufactured by Columbus McKinnon (CM) and supplied by Gregg Distributors LP. The hand operated lever chain hoists, series 653, were tools that could be used in any position to pull, lift, drag or stretch equipment. The frame, cover and lever were made from steel stampings. The gears were heat treated steel, upper and lower hooks were forged steel and the chains were heat treated, welded link type. The hand operated lever chain hoist had a load rating of 680 kg and 1.5 metre (m) long chains. The hooks with latches were standard, the total net weight of the hand operated lever chain hoist 6.8 kg and lever pull to lift rated load 14.9 kg. The hand operated lever chain hoist had been designed for hand powered operation only. At the time of the incident, they were being used to realign the conveyor system back to the centre line. A worker had secured nylon slings (Figure 10) to the frame of the gantry with the body hook of the hand operated lever chain hoists secured to the

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frame of the conveyor (Figure 9). The chain hoist were functioning properly at the time of the incident.

A. Figure 9. Photograph of the hand operated lever chain hoist that were involved in the incident.

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Figure 10. Photograph of the nylon slings that were involved in the incident.

Sequence of events On November 1, 2016, at approximately 7:00 a.m., a safety meeting was held at the drainage construction worksite trailer with the tunnel foreman and the tunnel workers. Afterwards, the tunnel workers changed clothes at the decontamination shack into their disposable coveralls and protective personal equipment. The tunnel workers walked outside the decontamination shack, proceeded to the man basket at the entrance of the shaft and were lowered down into the shaft of the tunnel.

At approximately 3:00 p.m., the tunnel supervisor went down the shaft into the tunnel, walked northwest a distance of 385 m and observed that something was wrong with the ventilation system and electrical wire above the gantry. The tunnel foreman was directed to resolve this matter by the tunnel supervisor. The tunnel supervisor returned to the surface. The tunnel foreman directed the segment erector to adjust the conveyor with the hand operated lever chain hoist. The tunnel foreman was standing on the gantry walkway between the conveyor system and tunnel wall (Figure 5). When the conveyor system shifted, the tunnel foreman was struck and pinned by the conveyor system and sustained a severe head injury. The tunnel workers immediately assisted the tunnel foreman and initiated the emergency response plan. Emergency medical services (EMS) responded to the incident scene where the worker was pronounced deceased by the EMS.


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Completion A review for enforcement action was held by OHS on January 30, 2018, and it was determined that the file would be referred to Alberta Justice for further review. The entire file was sent to Alberta Justice on June 7, 2018. Alberta Justice conducted a full review and charges were laid on October 26, 2018. On August 9, 2019, the City pled guilty to Section 310(2)(h) of the Occupational Health and Safety (OHS) Code, failure to provide safeguards if a worker could accidentally, or through the work process, come into contact with any hazard of the conveyor system while it was being moved. On August 14, 2019, the City was sentenced to a fine of $85,000 inclusive of the 15% Victim Fine Surcharge. In addition they were ordered, under the OHS Act Section 75, to pay $240,000 in favour of the Alberta Municipal Health & Safety Assn (AMHSA) for the development and augmentation of safety courses in tunneling, boring and trenching operations. This file was closed on October 8, 2019.


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Signatures

ORIGINAL REPORT SIGNED September 30, 2019

Lead Investigator Date

ORIGINAL REPORT SIGNED September 30, 2019

Manager Date

ORIGINAL REPORT SIGNED October 7, 2019

Director Date

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