The move comes after a report by the Commissioner of Railway Safety (CRS) highlighted concerns about the structural integrity and safety standards of the bridge, which connects the southern tip of India to the rest of the country.
The CRS in its report mentioned several shortcomings in the planning of the bridge. He pointed out that the lift span girder was non-RDSO standard and was designed using foreign codes, which required RDSO’s involvement in the project. However, a perusal of the records reveals that, with the help of the Railway Board, the RDSO was negligent in its responsibility to design the girder.
The CRS report also notes that for such major bridge projects, a Technical Advisory Group (TAG) is usually formed. However, this step was not followed in the case of the Pamban bridge, due to the decision to exclude RDSO from the project.
The CRS report said that RDSO’s exit from the project resulted in serious consequences, including deviation from standard guidelines.
In response, the Ministry of Railways clarified that Pamban Bridge is a 2.05 km long structure with a vertical lift span of 72 meters, which is one of its kind in the country. The bridge was designed by TYPSA, an international consultant, using European and Indian codes. The design was proof checked by IIT, Chennai.
Given that the bridge was designed by a foreign consultant, the Railway Board recognized technical limitations in the design examination by the Railways and the RDSO. As a result, the Railway Board decided to get the design proof checked from IIT, Mumbai. After a double proof check, the design was approved by Southern Railway.
The bridge has been constructed based on the design of a renowned international consultant and has been rigorously proof-checked by two leading institutions of the country. RDSO’s design modification for approach girders to accommodate local constraints has also been tested by IIT Madras and IIT Bombay, and approved by Southern Railway.
Additionally, welding of structural members, critical to the bridge’s utility, has been 100 percent inspected using state-of-the-art phased array ultrasonic testing and checked by the Welding Research Institute, Trichy, which Final check has been done by Southern Railway.
For corrosion protection, the bridge uses a special painting scheme used in highly corrosive areas around the world, using polysiloxane paint with a design life of 35 years. Reinforced concrete construction incorporates stainless steel reinforcement, fully welded box sections in lift spans, elimination of splice joints in approach span girders, FRP pathways, and improved inspection arrangements and handrails to prevent corrosion. Gone are some advanced features.
The ministry confirmed that the bridge has been constructed using the latest design and best construction practices. It has been cleared for operation by the Commissioner of Railway Safety. However, the ministry said it would fully comply with further concerns raised by the CRS. A five-member committee has been tasked to look into these concerns in detail and recommend necessary measures to further enhance the safety of the bridge.