A 100 metre (m) long steel bridge has been completed over an underground metro tunnel in Ahmedabad district for the Mumbai–Ahmedabad Bullet Train Project. The structure is the 13th steel bridge to be finished in Gujarat out of 17 planned for the project in the state. The bridge was delivered as part of the corridor works and the completion was presented as a targeted engineering solution to protect existing metro infrastructure.

The Bullet Train viaduct in Ahmedabad is being built using span-by-span structures with spans typically ranging from 30 to 50 m, but the alignment at this location passes over the underground metro tunnel that links Kalupur and Shahpur stations. To ensure that no load from the Bullet Train structure would be transferred to the metro tunnel, foundations were kept well away from the tunnel and the span length was increased to about 100 m. The superstructure was therefore redesigned from a span-by-span viaduct to a Steel Truss Bridge to secure safety for both corridors.

The bridge was assembled at a height of 16.5 m on temporary trestles and, after assembly, temporary supports were dismantled as the structure was lowered and placed on the permanent support system to ensure structural accuracy. Weighing 1098 tonne (t), the steel bridge sits parallel to the Ahmedabad Sabarmati main line of Western Railways and measures 14 m in height and 15.5 m in width. The main elements were fabricated in a workshop in Wardha, Maharashtra and were transported to the site on trailers.

To facilitate assembly a temporary platform measuring 11.5×100 m was constructed and the main structure was connected using approximately 45,186 Tor-Shear Type High Strength bolts with a C5 system protective paint and elastomeric bearings for enhanced durability. The bridge incorporates Make in India fabrication and finishing processes and is expected to contribute to long term operational safety of the corridor. Project teams highlighted that the design and execution approach prioritised both the Bullet Train alignment and the protection of the metro tunnel.