The work of laying bitumen on the Majerhat bridge will be completed by this week setting the stage for load tests, the final step before it is thrown open, PWD officials have said.

The work of painting the bridge, in blue and white, has already begun and lights have been installed. Once the bituminous coat on the suspended section of the bridge over the rail tracks is given, the approach road on either side will be taken up.

The state government will then request clearance from the railways for a “load test” on the bridge after completing the formalities of checking the cables.

“We will request engineers of the Swiss company that has provided the cables to do the final fine-tuning for stress-modulation immediately after the work of laying bitumen is over. Once that is completed, we will go for the load test,” a PWD official said.

The load test will be a three-day affair. Vehicles will be mounted on the bridge and the performance of the cables will be monitored to understand if they are working according to the provisions laid down in the design or whether there is any deviation, a PWD engineer said.

Eighty-four cables, brought from Switzerland, hold the 260m deck slab of the bridge. The work of installing cables — beneath each cable-sheath is a cluster of 19 to 43 strands — was completed ahead of Durga Puja. Engineers now want to ensure their load-bearing capacity is perfectly tuned.

A portion of the earlier bridge had collapsed on September 4, 2018.

Approach to the bridge. Sanat Kr Sinha

“Only 40 per cent of the total load-bearing capacity of each of the cables will be utilised for the Majerhat bridge,” the PWD official said. “So, there is no threat even if there is a sudden rise in the static load on the bridge because of vehicles.”

A cable-stayed bridge emerged as the best alternative among all designs proposed for the new Majerhat bridge. A portion of the bridge goes over the rail tracks and is adjacent to the ongoing Joka-BBD Bag Metro project.

Once completed, the bridge will be the third cable-stayed bridge after Vidyasagar Setu and Nivedita Setu.

Apart from laying bitumen, work on the four service roads around the new bridge is being carried out at top speed. Once the bridge is thrown open, these roads will see an increase in traffic, police said.

“We have reached almost the end. Some tests and a few finishing touches and the bridge will be ready for inauguration,” the PWD official said. “We have not set any specific deadline. The idea is to ensure that all boxes have been checked before the bridge is thrown open.”