Calcutta, July 16: Efforts are on to ensure that the Howrah bridge does not again have to bear the brunt of a vessel going underneath its belly.

“Proposals are being discussed on ways to provide protection to the bridge so that the main structure is not affected if a vessel hits it again,” a senior Calcutta Port Trust official said.

Rites, a port trust consultant since the eighties, has been asked to make a detailed recommendation. A team from the consultant conducted a survey of the bridge along with port trust officials earlier this week.

The official said the port trust was considering whether to set up a height gauge ? a protective layer on the belly covering the main structure ? or a secondary structure. “The secondary structure would be like a cage covering the bridge’s belly.”

“Costs are being worked out. After that we will see what is viable,” he added.

The port trust will also take administrative steps to protect the Howrah bridge. “A guideline for movement of inland vessels will be formulated. There must also be a body to monitor the movement,” he said.

“It is a national waterway and we cannot stop large vessels from passing under the bridge,” the official pointed out. When the Vidyasagar Setu (the second Hooghly bridge) was constructed, it was made sure that the height was enough to provide clearance for passing vessels.

On the afternoon of June 24, MV Moni, an empty barge cruising along a wrong corridor of the Hooghly had rammed into the bridge.

The survey by the three-member expert team from Rites and port trust engineers last Monday and Tuesday revealed that the accident caused extensive damage to two stringers and a cross girder. The new trolley guide was also damaged considerably.

“Rites experts will give us the final survey report in two months,” said port trust chairman A.K. Chanda. “They will also estimate the cost for the total repair.”

An official said two of the six longitudinal girders, running from the Calcutta end of the bridge to Howrah, were also damaged. Initially, the loss was estimated at Rs 1.5 crore. Later, the authorities said it could be more.

“Initial inspections have revealed that at least 700 metres of the (trolley) track have been damaged,” port trust chief engineer A.K. Mehra said. Later this month, Rites experts will return for a more detailed study.

A scaffold under the bridge to repair the trolley has almost been erected.