INDIAN INNOVATION IN B'DESH RAILWAY

Afcons-KPTL JV relocated four minor bridges under live railway tracks, busiest in Bangladesh, by cut and cover method in eight hours. Such an activity was undertaken for the first time in the country's history. An engineering record was made in Bangladesh when four minor bridges were relocated under live railway tracks on the super busy Dhaka-Tongi railway route between April-May 2021.

The feat was achieved by Afcons-KPTL JV along the Banani-Tongi (Section II) stretch, oneof Bangladesh's busiest railway routes. The activities were undertaken at locations of bridges BR-35, BR-36, BR-36A and BR-40 adopting a methodology never attempted in the country before. The innovations were aimed at overhauling the Dhaka-Tongi and Tongi-Joydebpur sections.

The Dhaka-Tongi section is one of Bangladesh's busiest railway routes. As many as 146 passenger trains, along with intercity, mail and goods trains, ply along the route daily. Moreover, work on all four tracks was possible only from one end because of an Army boundary wall on the other side.

The team used cut and cover methodology to execute the activity on time. So far, Bangladesh Railway have used the temporary relieving span method for such type of rebuilding works which took around six to eight months. The cut and cover methodology reduced the timecycle to just two days with speed restrictions on running railway traffic.

The Afcons-KPTL team took the challenge head on at BR-35 site. They had to factor in movement of eight to 14 trains on the adjacent track at a distance of 3m from the vertical cutto centre line of the running track. Critical activities such as lifting and placing precast box segments weighing 35MT in one go were executed within tight timelines and ensuring extreme safety measures.

“We were allowed eight hours of traffic block for each line at a time. While we took a huge risk by introducing a new concept, execution proved way more challenging especially due to fast-moving trains on adjacent lines. The biggest challenge was to prevent earth collapse due to the railway traffic. So, cutting and placement of segments were done simultaneously,” says Vinay Shrivastava, Project Manager.

Following the success at BR-35, the methodology was replicated at other bridge locations. Bangladesh Railway appreciated the achievement. Describing the critical nature of the job, Md Afzal Hossain, Project Director, Bangladesh Railway, said, “The Afcons team put in enormous efforts and their contribution led to this outstanding achievement of launching four relocated bridge segments under running railway tracks by cut and cover method. This activity has been executed for the first time in the history of Bangladesh Railway.”

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Project Details:

Name: Construction of 3rd and 4th Dual Gauge tracks in Dhaka-Tongi section, and Doubling of Dual gauge track in Tongi-Joydebpur section in Bangladesh.

Length: 33km.

Work Location: Starts from Kamalapur Railway Station, Dhaka, and ends at Joydebpur Station.

Client: Bangladesh Railway, Ministry of Railways Bangladesh.

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