Key Highlights
- A 100‑metre steel truss bridge was finished on 29 January 2026 in Ahmedabad under the Make‑in‑India drive.
- The bridge spans an operational metro tunnel without imposing any load on the tunnel structure.
- Design shifted from conventional concrete viaducts to a long‑span steel truss to protect the underground infrastructure.
- Construction employed temporary trestles at 16.5 m height, after which the bridge was lowered onto permanent bearings with zero disruption to existing rail services.
- The achievement underscores India's growing competence in dense‑urban, high‑speed rail projects.
Detailed Insights
The Mumbai‑Ahmedabad bullet‑train corridor traverses the Kalupur‑Shahpur stretch of Ahmedabad where an active metro line already runs beneath the planned viaduct. Traditional concrete spans of 30‑50 m would have required foundations dangerously close to the metro tunnel, risking structural interference. Engineers therefore opted for a single 100‑m steel truss, eliminating the need for intermediate piers and guaranteeing that the dynamic loads of the bullet train are transferred solely to purpose‑built supports, leaving the metro tunnel untouched.
Steel truss bridges excel in long‑span applications because their triangulated members efficiently distribute loads while keeping the overall weight manageable. In this case, the truss not only satisfied the span requirement but also offered the flexibility to be erected using temporary trestles set at 16.5 m above ground. After the truss was fully fabricated on‑site, the temporary supports were dismantled, and the bridge was carefully lowered onto permanent bearings, preserving uninterrupted operation of both the metro and the adjacent railway tracks.
This engineering solution reflects a broader shift in Indian infrastructure policy: projects are increasingly tailored to the complexities of urban environments rather than imposing generic templates. The bridge serves as a vivid illustration of indigenous design, manufacturing, and execution capabilities championed by the Make‑in‑India programme.
Key Concepts
- Steel Truss Bridge: A structure composed of interconnected triangular elements that efficiently carry loads over long distances without intermediate supports.
- Span: The horizontal distance between two consecutive supports; here, a 100‑metre uninterrupted span.
- Make‑in‑India Initiative: A government policy encouraging domestic design, production, and assembly of critical infrastructure components.
- Temporary Trestles: provisional, height‑adjustable supports used during erection of a bridge, removed after the permanent bearing system is in place.
- Bullet Train Corridor: A high‑speed rail line designed for speeds above 250 km/h, requiring specialized track, signaling, and structural standards.