On December 17, 2012, a worker at the Oshawa plant was showing a co-worker how to perform a task on the automatic guided vehicle (AGV) repair crib. The worker provided the co-worker with the preliminary steps to be taken for the task, which involved removing screws from a ball screw assembly, then was called away. The co-worker removed all the screws except one.
Upon returning, the worker began to show how to retract the ball screw and did so while sitting on top of the frame of the AGV with the lift table raised above. There was no blocking material in place between the lift table and the AGV to prevent the lift table from accidentally falling. The lift table and a pallet that is used to hold the car frame fell on top of the worker. Other workers rushed to assist and raised the lift table with pry bars. The worker was taken to Sunnybrook Health Sciences Centre and underwent surgery for injuries that included a number of broken bones.
The Ministry of Labour investigated and its engineer determined that the cause of the lift table collapse was the failure of the assembly’s remaining screw. Although the workers had used a safety bar mechanism which was designed to hold the weight of the lift table, it had accidentally come out of place while the lift table was being raised. The remaining screw could not bear the weight of the lift table and it failed. As a result, the ball screw assembly separated from the lift table, allowing it to fall on the worker.
General Motors of Canada pleaded guilty to failing as an employer to ensure that the measures and procedures prescribed in Section 74 of Ontario Regulation 851/90 were carried out in the workplace. The regulation under the Occupational Health and Safety Act states that “machinery, equipment or material that is temporarily elevated and under which a worker may pass or work shall be securely and solidly blocked to prevent the machinery, equipment or material from falling or moving.”
The company was fined $160,000 by Justice of the Peace Mathilda Lewis in Whitby court.
Source: Ministry of Labour