The Span That Fell at Lunchtime | West Gate Bridge Collapse True Story

Chapter 111:50 am: The Span Falls

On 15 October 1970 in Melbourne, Australia, it was nearly midday, and dozens of workers were busy building the West Gate Bridge. The bridge was meant to link Melbourne's city centre with the western suburbs, and it was not yet finished. At 11:50 am, a 112-metre span, an entire section of the bridge, broke away between piers 10 and 11 and fell. It dropped from a height of about 50 metres onto the ground and water below, and it weighed about 2,000 tonnes.

As it hit the mud of the Yarra River, there was a violent blast of gas, dust and twisted metal. Buildings hundreds of metres away shook. The fire that followed and the roar of the collapse could be clearly heard more than 20 kilometres away. Thirty-five workers died and 18 were injured, making it Australia's deadliest industrial accident. Many workers were on their lunch break in huts built beneath the bridge, and those huts were crushed under the falling span.

How could such a strong steel bridge fall? Was it the result of one mistake, or of many decisions? How was it fixed afterwards? And what changed in workplaces after the disaster? This documentary follows those three questions and looks for answers in the sources.

Chapter 2A River That Needed a Crossing

To understand the story, we have to go back. Connecting Melbourne's western areas with the city was an old problem, and the problem was the Yarra River. According to the sources, in 1888 Victoria's Public Works Department proposed a tunnel under the Yarra. The road routes between the west and the city ran well to the north of the river's lower reaches. In the lower part, people crossed the river in small skiffs until 1912, when ferries began. Among them, the Newport steam ferry, run by the City of Williamstown, was the most prominent from 1931 to 1974.

In August 1957 the Western Industries Association was formed. It claimed to represent the industries of Altona, Footscray, Sunshine, Werribee and Williamstown. In 1958 it asked Premier Henry Bolte to urgently consider a traffic tunnel under the Yarra. Shipping interests had told the Association that a bridge would not be acceptable for the crossing. A tunnel was expected to carry 30,000 cars a day, while the ferry of the time was overloaded and, by various estimates, could handle only between 1,200 and 2,000. Commissioner for Public Works Thomas Maltby gave the government's reply: public funds were insufficient, and such a project needed private investment.

In 1961 Lower Yarra Crossing Limited, a non-profit company, was formed to develop the crossing. Earlier, in the middle of 1960, it had been announced that the Association would raise money and the government would help with low interest rates. Test drilling began in late 1961, and around then the Association appeared open to the idea of a bridge again. Even so, the Danish tunnel engineering firm Christiani and Nielson was appointed as consultants. The biggest objection to the tunnel was the limit on certain cargoes. Flammable material in particular could not easily be carried through a tunnel legally or safely.

According to the state government's analysis, the bridge and the tunnel cost the same. The Harbour Trust strongly supported the tunnel, but opinion among the decision-makers was divided. They thought petrol tankers could pass more easily over a bridge, so the bridge was preferred. The Lower Yarra Crossing Authority then received a franchise through an Act of Parliament, and construction of the West Gate Bridge began in 1968. Newspapers of the time wrote that the Fishermen's Bend airstrip would have to be removed because of the bridge's eastern approaches. So the decision was made: a bridge, not a tunnel. But what kind of bridge? That question leads us to the box girder in the next section.

Chapter 3Why a Box Girder?

What is a box girder bridge? In simple terms, its main beams are shaped like hollow boxes. The box is usually made of prestressed concrete, structural steel, or a composite of steel and reinforced concrete, and its cross-section is usually rectangular or trapezoidal. Such bridges are common in highway flyovers and elevated light rail structures. A box girder bridge is usually a beam bridge, though box girders can also be used in cable-stayed bridges.

The design has an interesting military history. In 1919 Major Gifford Martel was made head of the Experimental Bridging Establishment, and he also built a modular box girder bridge. The British Army adopted it in 1925 as the Large Box Girder Bridge, and a smaller version, the Small Box Girder Bridge, was adopted in 1932. Many countries, including Germany and the United States, made copies, and both designs served extensively in World War II. Martel's modular design later became part of the foundation of the Bailey bridge.

During the great expansion of roads in the 1960s, the non-modular box girder bridge became a popular choice, especially in Western countries. Many new bridge projects were running at the same time in that era, and the design was credited with several advantages, such as being cost effective. Steel box girders are usually made off site, lifted into place by crane, and joined by bolting or welding. The advantages include reduced slab thickness, lower self-weight, greater concrete strength per unit area, and quality assurance for girders precast off site. There are drawbacks too, especially with non-modular designs: structural steel girders are expensive, and logistics and transport costs rise.

Now to the West Gate Bridge. The sources describe it as a steel, box girder, cable-stayed bridge that crosses the Yarra River and Westgate Park. Its design took ships into account. Large cargo ships had to reach the Port of Melbourne, so there is 58 metres of clearance beneath the main span. The bridge's total length is 2,582.6 metres, which makes it the fifth longest bridge in Australia, and twice as long as the Sydney Harbour Bridge. Its road deck is among the highest in Australia, higher even than the Sydney Harbour Bridge's 49 metres.

But between 1969 and 1971 several steel box girder bridges collapsed during construction, and West Gate was among them. So how was work on this bridge proceeding by 1970, and who was building it? We find out in the next section.

Chapter 4Two Years of Building

Construction of the West Gate Bridge began in 1968. A huge steel structure slowly rose above the Yarra River. Steel box girder bridges were part of the rush to build roads in that period, and many new bridges were under construction at the same time in the 1960s. This was no small project. When finished, the bridge was to be 2,582.6 metres long, twice the length of the Sydney Harbour Bridge. Ships needed 58 metres of clearance under the main span so that large cargo ships could reach the Port of Melbourne, so the bridge had to be high. That same height later puts it among Australia's highest road decks. To get a sense of the scale, the span that fell weighed about 2,000 tonnes and stood about 50 metres above the ground and water.

Who designed the bridge? According to the Royal Commission, the design firm was Freeman Fox & Partners. The project's main contractors were World Services and Construction, the company involved in building the steel boxes and joining them. West Gate was a steel box girder bridge, meaning its sections were made as large hollow steel boxes, and World Services and Construction handled the preparation and sub-assembly of these boxes. But there was one important point: the Royal Commission later said that World Services and Construction had used an unusual method of construction.

Two years of construction had passed. On 15 October 1970, work was continuing on the 112-metre span between piers 10 and 11, and dozens of workers were on the job. Some were working on top of and inside the span. Many others were on their lunch break in the workers' huts beneath the bridge, directly under the span. So two kinds of people were in one place: some were joining steel above, while others rested below during their meal break.

That day, two half-girders of the span were to be joined, but there was a difference in their height. The decision made to correct that difference turned out to be the biggest turning point of the whole project. What exactly was done to remove the difference? And how did the result appear within about an hour? We find out in the next section.

Chapter 5The Fix That Failed

Now we come to the moment when everything changed. On 15 October 1970, two half-girders were to be joined at the west end of the span. There was an 11.4-centimetre difference in their camber, meaning the two halves were not at the same height. This was about 4.5 inches. It seems a small difference, but on such a large steel structure it was considered necessary to correct it. Until it was gone, the two halves could not be joined properly.

A solution was proposed: the higher part would be pushed down by placing weight on it. Ten concrete blocks were to be used, each weighing 8 tonnes and already on site. That made 80 tonnes of extra load. Think about it: a span not even fully joined was being loaded with such a heavy weight. According to the Royal Commission, the weight of these blocks caused the span to buckle. Buckling means steel bending or crumpling out of place, and it was a clear sign of structural failure. In other words, a serious problem had appeared in the structure of the span. By this time the longitudinal joining, the work of connecting the half-girders along their length, was partly complete.

Then another order was given to remove the buckle. The order was to undo the bolts of the upper flange at the splice between boxes 4 and 5. The upper flange is the top steel plate of the girder. With the bolts out, the plates of this flange could slide over one another. The idea was that if the plates slid, the buckle would disappear. But removing the bolts had exactly the opposite effect. As soon as the bolts came out, a stress concentration developed, meaning pressure built up enormously at one spot. The bridge could not bear it. The Royal Commission gave the reason: the design's factors of safety were insufficient. Think of factors of safety as making a bridge stronger than it strictly needs to be, to leave room for error. Here that room was not enough.

And then time ticked on. About an hour after the bolts were removed, at 11:50 am, the span fell. Our sources do not contain the full details of what happened in that hour. We only know the order, its result and the final outcome. Remember that the Royal Commission did not call the disaster the result of a single mistake. According to it, there were two causes: the design and the method of construction. On the very day an attempt was made to control the buckle, the weakness of the design and the unusual construction method showed their result. Some people think the story might have been different if the weights had not been placed, but that is only speculation, and the Commission's conclusion was broader.

In the next section we will see the moment the span actually fell toward the river, and learn about the people who were there.

Chapter 6Chaos at the River

It was 11:50 am, near lunch break. On 15 October 1970, the 112-metre span between piers 10 and 11 suddenly fell from its place. It dropped about 50 metres toward the ground and water below. The whole span weighed 2,000 tonnes and landed in the mud of the Yarra River. As it fell there was a blast of gas, dust and twisted steel. The noise shook buildings hundreds of metres away, and splashes of mud flew onto nearby houses. Then a fire broke out. The sound of the impact, the blast and the fire afterwards were clearly heard more than 20 kilometres away. Imagine how far that sound travelled.

Now to the people who were there. Many workers were on their lunch break in the workers' huts under the bridge. The falling span crushed those huts. Other workers were working on and inside the span, and they came down with it. In this disaster 35 construction workers died and 18 were injured. It was the deadliest industrial accident in Australia. Behind those 35 were families, friends and colleagues. According to our source, the lives of many more workers and their families were also changed suddenly. These are not just figures. Each number stands for a person who came to work that day.

The next morning, 16 October, Victoria's Premier Sir Henry Bolte announced that a Royal Commission would be set up immediately to find the cause of the disaster. A Royal Commission is an official investigative body that examines the causes of a major event. The question was what went wrong and who was responsible. Prime Minister John Gorton also responded. The gist of his words in English is this: he was sure all of Australia was shocked and grieved by the serious West Gate Bridge disaster, and he sent his deep sympathy to all the families for whom the tragic event had caused so much sorrow. So the very next morning the Royal Commission was announced, and the Prime Minister said that all of Australia was shocked and grieved.

The question now was whether a single decision was responsible, or whether deep flaws in design and construction lay behind it. The answer was in the Royal Commission's report. In the next section we see what it finally concluded.

Chapter 7The Royal Commission's Verdict

The Royal Commission completed its investigation on 14 July 1971, about nine months after the disaster. Its conclusion was straightforward: the failure of the bridge had two causes, structural design and an unusual method of construction. Responsibility for the design fell on Freeman Fox & Partners, the firm that prepared the bridge's structural design. Responsibility for the construction method was placed on World Services and Construction, the project's original contractor.

What was wrong with the design? According to the Commission, the bridge's design had insufficient factors of safety. So when unbolting created a stress concentration, the bridge could not bear it, and that was the result of a design weakness. Then there was the construction method, which the Commission called unusual. It involved joining two half-girders whose camber differed by 11.4 centimetres. It was proposed that 10 concrete blocks be placed on the higher half-girder, each weighing 8 tonnes. The weight of these blocks caused the span to buckle, which according to the sources was a sign of structural failure. But the work went on. The joining was partly complete when the order came to remove the buckle: the upper flange bolts between boxes 4 and 5 were to be undone. With the bolts out, the plates of the upper flange could slide over one another. About an hour later the bridge fell.

One point is important here. The Commission tied the failure to two causes, both design and construction. It was not one decision alone but flaws at two levels. The report was published in August 1971. After that, the Lower Yarra Crossing Authority had to decide its next step.

Now let us look at Europe. West Gate was not alone. Between 1969 and 1971, three other steel box girder bridges collapsed during construction. The first was the Fourth Danube Bridge in Vienna, which fell on 6 November 1969. The second was the Cleddau Bridge at Milford Haven in Wales, on 2 June 1970. The third was the South Bridge over the Rhine River in Koblenz, which fell on 10 November 1971. This series was a heavy blow for box girder bridges. There is a difference between the sources: the article on West Gate counts the 1969 Vienna accident as well, while the box girder article counts three disasters in 1970 and 1971. According to the box girder source, 51 people died in those three disasters together, West Gate, Cleddau and Koblenz.

The UK government set up the Merrison Committee of Inquiry, headed by Sir Alec Merrison. It produced new rules for the design and workmanship of steel box girder bridges. The committee gave an interim report in May 1971, and its final report came in February 1973, so the work took about two years. So the real question remained. If both design and construction were flawed, what would happen to the bridge? Would it be abandoned, or rebuilt?

Chapter 8Rebuilding the Bridge

The Lower Yarra Crossing Authority answered in practical terms. After the report was published, it set up its own Directorate of Engineering. The Authority was a non-profit company. In September 1971, Hans G. Wolfram, a Director of Gutteridge, Haskins & Davey, was appointed Director of Engineering, responsible for the bridge's re-design and supervision. The Authority's Chairman was Oscar G. Meyer, and its Deputy Chairman was Bernard J. Callinan, who also chaired the Technical Committee. In 1971 the name was changed to the West Gate Bridge Authority.

Engineers then examined the bridge closely. They focused on the deck's insufficient strength. The original deck had a 100-millimetre reinforced concrete slab, working together with a steel deck plate stiffened by bulb flats. Reviews found it inadequate. Several proposals were considered, and in the end Wolfram recommended a lighter and stronger orthotropic steel deck, which was the best solution technically and economically. An orthotropic deck is a steel plate stiffened lengthwise with cellular troughs and across its width with cross beams, so the deck stays light and strong.

How could the new design be trusted? For this, Professor Karlheinz Roik, who held the steel construction chair at TU Berlin, was made proof engineer. Roik independently checked the re-design in line with the Royal Commission's recommendations. It was tested against the code DIN 4114 and the Merrison Committee's Appraisal Rules. Four more professors endorsed the re-design: F. B. Bull, N. W. Murray, J. W. Roderick and L. K. Stevens, from Adelaide, Monash, Sydney and Melbourne.

Construction restarted in 1972. World Services and Construction continued to make the boxes and do the sub-assembly, but the steel work was completed by a joint venture of Redpath Dorman Long and John Holland (Constructions). So the responsibilities for the work had changed. There was another problem: during erection, stresses could be higher than in the in-service condition, so additional strengthening had to be designed. The joint venture gave this work to Flint & Neill of London, and the Directorate of Engineering proof-checked their design. So there was a double check.

In October 1974, Charles, Prince of Wales visited the West Gate Bridge project, where he met members of the West Gate Bridge Authority and workers. Finally, after ten years of construction, the bridge was completed in 1978, at a total cost of $202 million. It opened to traffic that same year. Think about it: a project part of which fell in 1970 was completed after a new design and several levels of checking. But did the story end there? No. The disaster was to change not only the bridge but the way work was done across Australia.

Chapter 9What Changed: Lessons and Legacy

The disaster changed the balance of industrial relations in Australia. Unions pushed for a strong role in safety negotiations. As a result, statutory occupational health and safety committees were created, and site inspections that included workers' representatives became mandatory. Safety training, incident reporting and grief counselling also became part of workplace management. According to the source, these reforms have saved countless lives in the decades since.

There is a reminder for engineers as well. In the West Gate garden of the engineering faculty at Monash University's Clayton campus, six twisted pieces of the bridge are displayed. It is said that these pieces remind engineers of the consequences of their mistakes. On 15 October 2004 the West Gate Bridge Memorial Park was opened. Memorial events are held every year on 15 October. The park has a memorial and a sculpture, and it also remembers the six victims of the 1895 Spotswood sewer tunnel collapse.

What about research on box girders? In Britain the Merrison Committee was formed, and a good deal of money was invested in new research on steel box girder behaviour. The bridge is still in use today. It was built for 40,000 vehicles a day, and in November 2023 it was carrying 203,000 vehicles per day. A $347 million strengthening project ran from 2009 to 2011, and on 22 June 2011 five lanes opened in each direction. Then in December 2025 the West Gate Tunnel opened, but according to the source there has still been no notable drop in the bridge's traffic.

So have the lessons been fully learned? That question remains open. Friends, if you liked the video, please like and subscribe, and tell us your opinion in the comments.