Historical rail bridge to be dismantled to pave way for concrete girder

MUMBAI: One of the last iron screw-pile rail bridge on Indian Railways will soon become history. Bridge number 20 over Mithi river in Bandra, which has been holding the rail tracks together since 1888, will be replaced by a cement concrete girder. The bridge came up around the same time that Bandra railway station was taking shape.

There are eight pillars - two on each rail line - underneath the rail tracks on Slow and Fast lines going towards Churchgate and Virar, going east to west. Each pillar is made of cast iron, weighing 8-10 tonne, go down to a depth of 15-20 metres, hitting the bedrock of Mithi River.

The pillars are almost 2 feet or around 600 mm in diametre, with a thickness of 50 mm to ensure that they hold the weight of the steel girders and the rail lines above. The pillars abut the stone wall on the Dadar end, that will also be demolished.

“This is the last remaining screw pile bridge made of cast iron on Indian Railway. We will have to dismantle it as it’s sinking and has become weak. This can prove to be a safety issue for train operations and requires to be replaced. Over the years, we have carried out strengthening works on these piles,” said a Western Railway engineer.

The eight iron piers span 9-10 metres across the four rail lines. The rail bridge on the north-south spans a length of around 50-60 metres and is held by seven cement girders, while the one on the Churchgate end is made of iron piles screwed into the river. The remaining iron piers have been buffed with cement concrete, while only the head of the iron screw is visible at the top. At present, they have placed cofferdams on the east and west side of Mithi River to prevent ingress of water. The water already accumulated there is being flushed out using high power pump, which will enable the railways to dismantle the iron piers.

Night rail blocks

Western Railway authorities will carry out two 9.5 hours block in January. According to WR officials, it will take place on the night of January 24-25 and January 25-26, for 9.5 hours each night.

There is no clarity on the number of train services that will be cancelled and delayed during this block, as the schedules are yet to be chalked out. During the two blocks, the engineers will remove the steel girder on top of the piers and replace it with a 20-metre long concrete girder.

“There will be speed restriction of 15-20 kmph for the first 3-4 days after the blocks. We will inspect the strength of the temporary girder placed below, and after clearance, we will allow trains to run at 40 kmph,” said another WR official.

The speed restriction above Mithi River on the Fast and Slow lines between Churchgate and Virar will continue till May. Between January and May, WR will dismantle the iron piers into pieces. Sources said this will lead to delays in train services. Once the work is complete, WR will carry out another round of blocks for cementing the new pillars with concrete and installing girders above these, after which the rail tracks will be placed.