A Blueprint For Building Bridges To Last

Analyses of bridge failures are shared across the world. In India, enquiry panels examine mishaps under a cloak of secrecy. As a result, we learn nothing and fail to improve processes

- AMITABHA GHOSHAL

Bridges are the most important element in a surface transport network. Once built, they are extremely difficult to replace and it becomes challenging even to close them for a few days for essential repair work. A sudden failure disturbs normal life, affects development and causes economic losses. So it's important for the public to be aware of the reasons for their failure and raise voices to prevent them.

Bridges have failed across the world for long. In developed countries, such failures are analysed, the studies shared and the lessons recorded to prevent recurrences. In India, the trend has been to form enquiry committees without checking the technical competence of the members and hide the proceedings in confidentiality, keeping the public uninformed. Reports are often allowed to 'disappear' to protect those responsible.

The classical case of the Tacoma Narrows bridge failure in the US in 1940 was instantly shared across the world; the video of the failure became standard teaching material for engineering students across the world. The result: there has been no such failure ever and every engineer knows that a lightweight, long-span bridge needs to be checked for aerodynamic stability and model tests have to be done in a laboratory.

The failure of the West Gate bridge in Australia in 1970 was similarly explored; the enquiry commission came out with a comprehensive analytical report that became a bible for the makers of design codes across the world. People came to know of the problems with thin-walled box girders made with steel plates that had become the favourite of engineers trying to cut steel consumption. Such failures never recurred.