This second one is the 700-m bridge planned by the Northern Railways in 2005 to replace the British-era iron bridge that connects Shahdara and Old Delhi railway station. Construction on the new bridge began in early 2006 after the railways said the old bridge was endangered. But work was suspended within months. Reason: the Archeological Survey of India (ASI) refused to give permission to scale down a wall of Salimgarh Fort.

The ASI contends that the fort (see box) is a protected monument along with its better known partner — the Red Fort.

A year on, barely 10 per cent of work is complete. The Northern Railways and the ASI are, meanwhile, fighting it out to preserve the 16th century monument and yet find a way to build a new railway bridge to support two tracks across the Yamuna.

“The railways began construction even though we had not given them any permission,” an ASI official said. “The new alignment will damage the fort.” The official said ASI asked railways “to reconsider the gradient” as some 2.5 inches of the wall would have to be pulled down if the current design is implemented.

The bridge was constructed up to the foundation level; work was stopped when it reached the fort walls, for ASI refused to let construction work go further.

A K Lahoti, chief engineer (construction), Northern Railways, said: “We had begun work based on initial meetings with ASI. There is an urgency to replace the old bridge as the pillars are becoming weak in the riverbank's sand. We are now taking up the matter with the Tourism and Cultural ministry to resolve it.”

The Tourism department had taken the matter with ASI in October 2007 but it is far from being resolved. “The fort is a protected monument,” the ASI official reiterated. “How can we give permission to scale down an entire wall?”

But Lahoti said the railways has suggested ASI that they “allow us to bring the new alignment across the fort. We will restore the existing railway crossing on the fort. We have to replace the bridge.”

The British built the existing bridge in the early 1800s by scaling down a bridge built in 1622 by Mughal emperor Jehangir connecting the fort to the city.