Central Railway restores Mumbai-Pune railway line

This picture has been used for representational purposes.

The Mumbai-Pune railway line that has been washed away and shut for traffic had been built by Central Railway in 1984, even as the over-150-year-old lines built by the British engineers in 1863 stand tall and continue to be functional with minor damages. It said to complete restoration by January 15, 2020.

Central Railway is now working to find a permanent solution to the regular landslides in the Monkey Hill-Nagnath section of Mumbai-Pune rail line, whose closure has affected rail traffic since October 3 and should be working by January 15, 2020 if all goes well. The line that was washed away in the rains along the Mumbai-Pune Khandala Ghat stretch is the line built in 1984 by Central Railway, even as the British-built Ghat section opened in 1863 which is the down and middle line also suffered damages in monsoon, but has been now restored it with minor works on it.

Works are being carried out at an extreme level at huge scale with the washed away portion between two tunnels and a deep valley with no access to the work site except rails.

"On October 3, we realised that near Nagnath village on Monkey Hill section of the Bor Ghat, the land at the end of the bridge had settled. We tried to fix it and offer a temporary solution, but then thought it would not work fine and hence decided to find a permanent solution to the problem by removing the settled portion and extend the bridge by two spans of 25 and 18 metres each and secure the land by micro piling, which involves stabilising the base by inserting steel rods deep into the rock," Central Railway's chief public relations officer Shivaji Sutar said.

The challenge

The problem then was how to get labour, material, equipment and excavators for at the site as it is approx 10km away from the nearest road, the damage had occurred between two tunnels with a deep valley on one side and huge mountains on the other side. So we have created special material trains that ferry this to the work site. The trains have to be adjusted with the running traffic, he said.

Leaky cable

There are groups of 40 labourers staying there and getting the work complete by 24×7 hours under strict supervision, who work, stay cook there. Communication was a problem in the section with no network there, but Central Railway has now fixed leaky cables in the area for better communication. A leaky cable is a communication system used in underground mining and other tunnel environments. It consists of a cable running along tunnels which emits and receives radio waves, functioning as an extended antenna.

With commissioning of leaky cable, now it's possible for guard-driver of train and other users of a wireless communication system to communicate seamlessly inside the tunnel no. 49 (which is longest tunnel 2.4kms in Bhor ghat ) between Monkey hill-Khandala stations. This has been done for the first time in Central Railway.

Transporting retarded cement

To build two spans of 25 and 18 to extend the bridge it requires huge quantity of material. Of this one pillar is ready and the other pillar is in the works. The peculiar problem faced at the site is how to transport cement as there is no space. "We prepare the ready mix cement at Lonavala plant, load it on a truck, the process of which takes 45 minutes and then transport it to the site. The material train has to wait for the regular trains to pass by and is often detained. In all this process, the cement would usually dry out but to avoid that, we are mixing a retardant chemical into the cement to slow the drying process," said Ashutosh Gupta, additional divisional manager (infrastructure) Ashutosh Gupta senior official said.

Hill Gang

The railways also gave a demonstration of the hill gang that performed mountain rappling to show how they fell loose boulders in addition to drone and hi-tech technology. "We are trained in this and the ultimate challenge is passenger safety. We mark the loose and dangerous boulders by physically checking them. These are later removed during the block period," Nilesh Marodi, who climbed down a steep mountain said.

Restoration status

Bridge

Location:' Mumbai-bound line at km 117 between Monkey Hill and Nagnath

• Due to heavy rain, the 30 meter approach of embankment has gradually settled.

Work details

• Construction of pier, abutments, micropiling, fabrication and launching of girder work

• Approx. 40 workers at any given time 24 x 7 with lighting arrangement

• Concrete mixer, piling equipment, crane, JCB, etc.

• Material carried by rail on material train

• 2 span of (girder) weighing 100 tonne to be brought to site for which pier is being constructed.

• Boulders 1,100 cubic metres equivalent to 350 trucks

• Quarry dust 350 cubic metres equivalent to 100 trucks

• Concrete 400 cubic metres equivalent to 55 RMC trucks

• Steel 80 tonne

• Micropiling 580 numbers

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