Vadodara:The Vadodara Division of Western Railway has achieved a major engineering milestone by completing the re-girdering of a century-old bridge over the Mahisagar River, replacing eight 320-tonne steel spans on the busy Ahmedabad-Vadodara rail corridor in what is being described as a first for Indian Railways.The ambitious re-girdering of Bridge No. 624 on the Ahmedabad–Vadodara section involved replacing eight steel open-web girders, each measuring 67.5 metres in length and weighing around 320 tonnes. Railway officials said the feat is believed to be the first instance on any railway system where girders of such size have been replaced on a live railway line using 600-tonne and 800-tonne capacity road crawler cranes.Calling it a landmark engineering achievement, Divisional railway manager Raju Bhadke said the project showcased the division’s technical expertise, innovation and coordinated teamwork. He noted that the work was completed within the stipulated timeframe and with minimal disruption to rail traffic despite formidable logistical challenges.Constructed in 1913 during the British era, the bridge is a vital link on the heavily used Ahmedabad–Vadodara route. The presence of perennial water flow in the Mahisagar River added to the complexity of the operation.According to Anubhav Saxena, public relations officer, the project was executed in two phases over a year. Six central spans were replaced in the first phase, while the remaining two end spans were completed in the second. The entire exercise was carried out through eight mega traffic blocks of about five-and-a-half hours each.For the six central spans, engineers deployed two 600-tonne crawler cranes fitted with 200-tonne super-lift arrangements. Since the cranes had to operate within the riverbed, a specially designed 30-metre-wide artificial sand platform was created using a custom-built sand-pumping system mounted on large boats. The cranes were positioned on this temporary foundation to carry out the girder replacement safely.The end spans presented a different challenge due to restricted working space, which ruled out the use of two cranes simultaneously. Engineers overcame the hurdle by deploying a single 800-tonne crawler crane equipped with a 300-tonne super-lift arrangement. Railway officials said the method not only ensured safe execution but also reduced costs and minimised traffic and power block requirements.Officials said available records suggest that re-girdering steel open-web girders of such dimensions using road crawler cranes has never before been attempted on a railway network, making the Mahisagar bridge project a significant milestone in railway engineering.
