Half a century on from one of the country’s worst industrial disasters, the collapse of Melbourne’s West Gate Bridge still haunts members of Australia’s engineering community.
At 11:50 am on 15 October, 1970 a 112-metre span of the West Gate Bridge collapsed during construction, killing 35 people as 2,000 tonnes of concrete and steel fell from the structure. Some of those who died were on their lunch break beneath the bridge, while others were working on top and inside the girder when it collapsed.
The bridge, which is the second-longest in the country, was two years into its construction.
A Royal Commission began two weeks later. Its final report, delivered in August the following year, explained that there were many contributing factors.
“Error begat error” leading up to the collapse, the commission found, and “the events which led to the disaster moved with the inevitability of a Greek tragedy”.
According to the report, the principal factor in the collapse was the steel span design, followed by an “unusual” erection method by contractors for span 10-11 on the western side and 14-15 on the eastern side.
Retired civil engineer and past chair of Engineering Heritage Australia Ken McInnes told create that instead of fabricating transverse box sections, raising them onto a temporary support beam and bolting them together, the contractors assembled two half-girders, jacked them to the top of the columns, and then joined the thin top and bottom flanges to form a completed box section
“When the two halves of the spans were raised and placed together, the longitudinal flanges were unable to be joined and were buckled,” he said.
There was a 110 mm difference in camber where the halves met, which was addressed by 10 eight-tonne blocks of kentledge to try and weigh down the north side. This led to the buckling, with a series of bolts then removed in an unsuccessful attempt to ease this.
McInnes, who had toured the site as a young engineer a couple of months earlier, found out about the disaster on a doctor’s waiting room TV.
“On returning back to the office at Scott and Furphy consulting engineers, we were able to see the site from the roof of our building, and see the missing column and the missing span, and realise the horror of what had happened,” he recalled.
In the shadow
AECOM Australia consultant John Connal MIEAust, who finished a civil engineering degree at University of Melbourne in the year after the collapse and has been a bridge designer since, said the sadness for the lives lost, and even apprehension about the bridge’s safety, still persists among some in the city.
Connal joined Maunsell and Partners — who were joint consulting engineers with the firm responsible for the design of the bridge — in 1981.
“For much of my career at Maunsell, the shadow of the West Gate Bridge failure lingered in the background,” he told create.
“It is said that the collapse led to the early death of Miles Birkett, who was the leader of the firm and who had a direct leadership role in the project.
“Many of the more senior people in Maunsell during my early years at the firm had direct experience on the West Gate Bridge site, and one of the bridge inspectors rode the bridge down and survived.”
There were 18 men who reportedly survived the fall.
“The collapse and the resulting Royal Commission has had a profound effect on the engineering community in Australia, but particularly Victoria and Melbourne,” Connal added.
“I think the bridge design community became very wary of pushing the engineering boundaries and perhaps lost some confidence for a period. The focus on design expertise and competence became sharper.”
University of Sydney Professor of Practice (Bridge Engineering) Professor Wije Ariyaratne FIEAust said there is a universe of difference between a half-century ago and now in terms of bridge building safety.
Design codes, such as AS 5100, are much more comprehensive, Ariyaratne said.
He added that there have been important advancements in construction specifications, technology, onsite construction practices and stringent work health and safety regulations. And there is much more accountability for everybody from the site worker all the way up to the owner, he said.
“As a result of this evolution or development, one of the most important things is the safety in design, which was not there at that time [in 1970],” explained Ariyaratne.
“Any project, it doesn’t matter how small or how big, how simple, how complex: you have to go through this process. There are workshops after workshops after workshops to evaluate the risk. What are the issues that you have incurred in constructing this design? What is the safety? What are the drawbacks?… We have moved a long way in the right direction.”
I well remember viewing the bridge that fateful day from the Ormond college tower in my final year of civil engineering. I had completed a construction work study of pier slip forming 2 years earlier as a vacation student and had submitted a report to one of the engineers who was killed. It was a very sad day and had a huge impact on engineers at that time. As noted in the article, safety in design procedures address such construction, operations and maintenance risks these days. A plaque at the base of the bridge pier is a reminder of the lives that were lost
AS 5100 as quoted above is not applicable to any bridge the size of West Gate Bridge
I worked as a structural engineer at Maunsell in the late 70’s well after the collapse. I had the opportunity to do some site visits with the inspector that rode the bridge section down. His description of the failure was chilling.
At the time of the collapse I was attending an in house conference at James Hardie Pty Ltd near the Westgate Bridge. During our lunch break on 14th October several of us drove over to view progress on the bridge standing where the bridge subsequently collapsed.
My boss who was a wise old civil engineer stood and surveyed the bridge and his words to me were, “I hope the designers know what they are doing because it does not look right to me”.
His words of experience can be still relevant today, “If it does not look right it probably is not right”
I was a Civil Engineering student then. A group of us drove to the site that day. What we saw had a profound effect on me. Doing things safely became even more important and, I’m pleased to say, that no major injuries occurred on any of the projects I was responsible for.
1.The illustrated cable stayed main spans of the Westgate Bridge have nothing to do with steel box girder approach spans on the western side of them one of which failed under construction .
2. The article does not mention that four professional engineers were among the men who died when the approach span collapsed. Two were from Freeman Fox and Parners, the British firm who were designers of the bridge, Both were members of the Institution of Civil Engineers, London. Two were from John Holland, the Australian firm who had sucessfully completed the prestressed concrete approach spans on the eastern side of the main spans and had taken over the erection on the western side from the Dutch firm, Werkspoor. when their erection method ran into problems. One was a member of the Institution of Engineers Australia and a one had a BCE degree.
3. Institution members also should be told that following the failure the redesign of the successful bridge which now stands was undertaken in Melbourne by Australian engineers.
I was working as a young engineer in the Bridge Design Section of the NSW Department of Main Roads at the morning of the collapse so it became the major concern for steel box girder design at the time. There is no mention that the analysis by Sydney University Civil Engineering School found inadequate safety factor in the construction design. The stricter Merrison Design Rules followed – which I later used to design the Leura Railway underbridge. Interestingly I subsequently met an elderly steel inspector who had resigned from the Westgate Bridge job three weeks before the collapse because he was most concerned about the construction procedures.
At the time I was the SECV project engineer for the 500kV transmission lines from the Latrobe Valley to Melbourne. I was driving from Gippsland and approaching central Melbourne when (as duty transmission engineer for the week) received a call on my 2-way radio from System Control advising that “we had lost the 220kV circuits” in the Fishermans Bend area. I called on two line crews to start moving to the area as I similarly did. It was about midday and shortly after received advice of an issue with the West Gate Bridge construction.
We went to the site as the lines paralleled the bridge across the Yarra River. The collapsed bridge section had thrown up mud which covered the insulators causing the outage. The circuits were able to be left out of service temporarily, so I offered our services to the emergency teams arriving on site. Still remains in my mind.
At the time I was working for SAA in the then Clunies Ross building in Parkville, giving a good view of the construction in progress. I recall checking progress first thing, then seeing later that something was missing. Being involved in Standards for safe design and operation of engineering installations that often posed a potential risk of major disasters, studies of of causes of historical calamities were required reading, so the final report into the collapse of the West Gate Bridge was very informative.
Technically the report was very good, insofar as it went to explain what happened.
I have always had a reservation, to the effect that it did not nail down the real root cause
In any such case there is always a technical something that went wrong, but there is almost always an organisational failing that allowed it to happen. or ensured that it would happen.
The Authority was exonerated from blame, as being non-technical, and the designer was pilloried. To me the Authority made a grave error in splitting the contract, one firm to design, another to erect, and they were not speaking. I have ever since felt that a “design and erect” contract would have been much safer. A matter of the old “one backside to kick” rule