Collapse of West Gate Bridge in 1970
About the collapse of the West Gate Bridge in Melbourne Australia in 1970, history of the disaster.
THE COLLAPSE OF WEST GATE BRIDGE
It was to be a masterpiece among bridges, and by far the largest in Australia. But from the beginning the 8-lane 8,500' West Gate Bridge, across the Yarra River in Melbourne, Australia, had more than its share of bad luck. First there was dissension among the workers that led to strikes. Then there were errors of judgment that compounded themselves until, by sheer weight of accumulation, they caused the collapse of a 393 3/4' span. It was one of the worst disasters in bridge-building history.
When: At 11:50 A.M. ON October 15, 1970.
Where: Melbourne, Australia.
The Loss: 35 out of 68 workers were killed. The damage was estimated at $10 million.
The Cause: From designers, prime contractors, suppliers, and engineers, West Gate's roster included the "Who's Who" of bridge building. Construction that began in 1968 like a well-oiled machine soon began to deteriorate. The big, happy, bridge-building family of more than 1,000 people broke up into small bickering groups. A workman would send out for a ham on rye without mustard. If it came back with mustard, a whole crew would stop work until the mistake was rectified. Such incidents developed into work-delaying labor strikes. In the 1st 1 1/2 years of construction, because of poor on-site supervision, the building schedule fell 7 months behind.
Then a counterpart of the West Gate "box-girder" bridge--one under construction in Milford Haven, Wales--collapsed on June 2, 1970, killing several workmen. This news spearheaded more problems for West Gate. Unions demanded greater safety measures for workers. Contractors argued among themselves. Engineers had to recheck their mathematical equations. Workmen by the score insisted on taking unscheduled days off.
The Disaster: Construction problems, too, were pyramiding. One big headache was the almost 400'-long span between piers 10 and 11. It was decided to assemble 2 sections of the span on the ground, then hoist them into place and bolt them together. A not uncommon method of assembly, and usually successful when done with utmost care. But when the 2 sections of this particular span were brought together in August of 1970, the north half section was 4 1/2" above the south half section.
Rather than take the sections down for correction, engineers decided to put an 8-ton weight on the high section to bring it level with the lower. On September 6 there was a major buckle. Work came to a halt, followed by a month of deliberation. Then engineers decided to unbolt the 2 sections on each side of the buckle. They theorized that the weight of the high section would cause it to lower and match the level of the lower section. Then it could be rebolted. Operation "unbolt" began at 8:30 A.M. on October 15. At 1st it appeared successful. The high section sank to within 1 1/8" of the lower, but before the sections could be rebolted, the buckle became greater.
At 11:50 A.M. the huge 2-section span could tolerate no more tampering--the stresses were too great. With a terrible grinding roar, bridge, men, and equipment tumbled 160' into the river. More than half the workmen on and under the 2-section span lost their lives.
Aftermath: In the investigation that followed, only the suppliers were deemed to be blameless. Designers, contractors, and engineers were dismissed, to be replaced by counterparts who, hopefully, would complete West Gate Bridge without further mishap.
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