Westgate Bridge Collapse: A Detailed Analysis of Causes and Solutions

The report analyzes the Westgate Bridge collapse, a significant industrial disaster in Melbourne. The collapse, which occurred on October 15, 1970, resulted in 35 fatalities. The primary causes identified include the 'ripple effect' from design flaws and unapproved construction, specifically the use of concrete cubes for alignment, leading to excessive weight and subsequent buckling. Poor execution in addressing the buckling, including the removal of bolts and the attempt to retighten them, further exacerbated the problem, culminating in the bridge's failure. Preventative measures, such as using kentledge instead of concrete cubes to manage weight and prioritizing worker safety, are discussed. The report highlights the importance of sound engineering practices and safety protocols in preventing such disasters.

West gate bridge
collapse in Melbourne,
Australia
• Major causes of the disaster
• How the disaster could have been avoided

Introduction
 On 15th October 1970, the worst industrial disaster occurred claiming 35
lives at 11.50 am. This was the collapse of the Westgate Bride in
Melbourne. A 120 meter span of the bridge half-way through the
construction collapsed into the Yara.

Major causes
 These include:
1. The ripple effect: this entails unthought design and unapproved construction.
The girders for two spans were 10 cm apart hence got realigned. Concrete cubes were
deployed at the north half span so as to align it to the same level as the south span.
This meant additional weight on the span than the design weight. The excess weight
hence by ripple effect caused buckling of the bridge section. An attempt to straighten
the buckle further escalated the problem(Friedman & Friedman, 2013)
2. Poor execution in correcting the buckle. In attempt to correct the buckle, large
amounts of bolts were being removed and as a result significant degree of slippage
occurred. Later, there was a proposal to retighten the bolts with an air gun. This
resulting pressure caused breakage of the bolts and this sudden reaction tensional
failure of the bolts generated stress. As a result, more slippage occurred such that the
bolt-holes disappeared such that re-bolting was not possible. Several other panels of the
bridge subsequently buckled and the two spans buckled further. The spans eventually
gave in hence the collapse of the Westgate Bridge(Friedman & Friedman, 2013).

How this disaster could have been
avoided
 Use of kentledge to correct the alignment rather than concrete
ballast cubes. Kentledge is lighter hence the weight could have been
within the design specifications hence preventing buckling of the
spans("Westgate Bridge Collapse", 2014).
 Emphasis and priority on workers safety. The site should have been
evacuated immediately as safe remediation techniques and methods
are sought. Instead, workers were kept on site with complete disregard
to the impending and possible collapse of the bridge.

References
 Friedman, L. and Friedman, R., 2013. Australian disasters: four stories
about great disasters in Australia: Cyclone Tracy, bushfires, Westgate
Bridge collapse, Granville train crash. Greythorn, Vic.: Friedman Pub.
 Westgate Bridge Collapse [online], 2014. [online]. Sayfa. Available from:
https://sayfa.com.au/westgate-bridge-collapse/ [Accessed 14 May
2019].