Rishikesh-Karanprayag Rail Link: L&T sets world record in constructing tunnel using boring machine

The construction firm Larsen and Toubro achieved a remarkable feat on the Rishikesh-Karnaprayag Rail Link project on June 29, a day ahead of the baseline schedule, setting a new world record in tunnel construction using a single-shield hard rock tunnel boring machine.

"The TBM Team has broken the world record by achieving a maximum progress of 790 metres in a month (31 days) using Single Scheid Hard Rock TBM named Shiv," S V Desai, the Whole Time Director, L&T Limited, told PTI on Tuesday.

The company officials stated that this was the first time that anywhere in the world a single-shield hard rock tunnel boring machine (TBM) was used in such an efficient manner.

"In the last leg of the boring work in the month of May-June for the longest rail tunnel of the country, the TBM, named Shiv, excavated 790 meters in 31 days and achieved a breakthrough," Rakesh Arora, Project Director, added.

This 13.09-km-long tunnel is the downline one, running parallel at a 25-metre distance from the first one, a 14.57 km long upline tunnel, which achieved breakthrough earlier on April 16, 2025.

Completed by L&T, these twin tunnels between Devprayag and Janasu make the country's longest transportation tunnels, and they are part of the ambitious 125-km Rishikesh-Karnaprayag Broad Gauge Rail Link Project in Uttarakhand, scheduled to be operationalised in December 2026.

L&T officials said that the total length of both tunnels is 30 km, which includes, besides the main tunnels, escape tunnels, cross-passages and niches.

While 70 per cent work (21 km) was done through TBMs, the remaining 30 percent (9 km) was completed using drill and blast (also known as New Australian Tunnelling Method).

"While the first TBM, named Shakti, completed 10.47 km of the upline tunnel on April 16, 2025, 12 days ahead of schedule, the second TBM, Shiv, finished 10.29 km of the downline Tunnel on June 29, 2025, a day ahead of schedule," Arora said.

He added, "On an average, we did over 400 metres of tunnelling per month by TBMs and over 70 metres by NATM." K Bhavani, Heavy Civil Infrastructure IC, congratulated the whole team.

"The progress at both TBM as well as at NATM fronts was fantastic, enabling completion of excavation work ahead of the baseline schedule for the longest transportation tunnel in India." Suresh Kumar, Head, Hydel and Tunnels Business, appreciated efforts made by Rakesh Arora, Project Director; Chris Cooper, team leader (Expat); Sunil Dutt Vats, project manager of NATM in overcoming several difficulties during the work such as geological challenges (loose rock/ shear zones and high ingress of water) and adverse working conditions like high temperature and humidity in long tunnels On the day of successful completion, Arora remembered the day he landed at the project with other officials in February 2021 and started from the scratch right from mobilising the resources (Manpower, Machinery, Material, etc.), establishment of Infrastructure facilities, starting of tunnelling works and progressing to receive and launch two big Tunnel Boring Machines.

Senior officials from the construction sites narrated unprecedented logistics management in TBM transportation from port to project site, as well as assembling and shifting to launching position; segment and muck handling, and their transportation, besides multiple tunnel logistics along with several other activities.

"Besides geographical and logistical challenges, issues such as skilled staff and workmen mobilisation and retention, quarry approval and operations while managing other stakeholders such as customers, local people and local authorities were equally cumbersome," Sureshkumar from Hydel. & Tunnels Business said.

Both Desai and Arora appreciated the great vision and very good support from Rail Vikas Nigam Limited (RVNL) for making this happen in such a fantastic manner.