The West Gate Bridge Disaster
On the 15th of October 1970 at 11.50 a.m. a 367-ft. span of the West Gate Bridge collapsed without warning killing 35 men. The particular action that led to the collapse was the removal of a number of bolts from a splice in the upper flange of the span. The bolts were removed in an attempt to straighten out a buckle which had occurred in one of the eight panels making up the upper flange.
The Report of the Royal Commission openly stated that “to attribute the failure of the bridge to this single action of removing bolts would be entirely misleading. In our opinion the sources of the failure lie much further back; they arise from two main causes.”
The Royal Commission also cited the failure of the bridge designers to give proper and careful regard to the process of structural design in addition to giving a proper check to the safety of the erection process proposals put forward by the original contractors. Consequently, the margins for safety for the bridge were inadequate during erection.
A secondary cause cited was the unusual method proposed by the original contractor for the erection of the span(s) in question. The method of erection (if it was to be successful) required more than usual care on the part of the contractor and a consequential responsibility on the consultants to ensure that such care was exercised. The Royal Commission concluded that there was no appreciation of the need for great care on the part of the consultants and the designers to prevent the contractor from using procedures liable to be dangerous.
It is important to understand that for the greater majority of workplace incidents and injuries the causative factors that led to the event were multi-factorial. It is also important to resist jumping to conclusions and looking for the easy answer; such as “human error” or “inappropriate action.” We need to investigate workplace incidents from the perspective of the 5 Why’s to determine root cause.
Put simply; always remember:
- Assess processes, not people
- Human error should not be an acceptable root cause
Keep on asking the question “Why” until the root cause has been determined or you have identified the root cause (or causes) that once eliminated will foreseeably prevent a re-occurrence of the event.
Workplace Partners can assist you in incident investigation and provide training to help you better understand incident investigation and causation methodologies.
Reference: Report of Royal Commission into the Failure of West Gate Bridge
Article by: Dean Taylor