L&T Achieves World Record in Tunnel Boring for Rishikesh-Karnaprayag Rail Project.

Larsen & Toubro (L&T) has achieved a new world record in tunnel construction on the challenging Rishikesh-Karnaprayag Rail Link project. The company accomplished an unprecedented 790-meter monthly excavation using a single-shield hard rock Tunnel Boring Machine (TBM).

S.V. Desai, Whole-Time Director at L&T, proudly announced, "The TBM team has broken the world record by achieving a maximum progress of 790 meters in a month (31 days) using single-shield hard rock TBM named Shiv." This remarkable feat was completed on June 29, a day ahead of schedule.

Twin Tunnels Nearing Completion

The record-breaking performance took place on the 13.09-km-long downline tunnel, excavated by TBM 'Shiv'. This tunnel runs parallel to a 14.57-km-long upline tunnel, which saw its breakthrough earlier on April 16. Both tunnels are situated between Devprayag and Janasu, forming a critical part of the 125-km Rishikesh-Karnaprayag Broad Gauge Rail Link project, slated for completion in December 2026.

According to L&T, this marks the first time a single-shield hard rock TBM has been utilized in this manner globally, highlighting the innovative engineering involved. TBM 'Shakti' completed 10.47 km of the upline tunnel on April 16, 12 days ahead of schedule, while TBM 'Shiv' finished 10.29 km of the downline tunnel on June 29.

Rakesh Arora, Project Director, stated, "In the last leg of the boring work in the month of May-June for the longest rail tunnel of the country." He added, "On average, we did over 400 meters of tunneling per month by TBMs and over 70 meters by NATM."

Overcoming Significant Challenges

The twin tunnels, including escape tunnels, cross-passages, and niches, span a combined 30 km. L&T officials noted that 70 percent of the work was executed using TBMs, while the remaining 30 percent was completed with the drill and blast method, also known as the New Austrian Tunnelling Method (NATM).

Recounting the project's inception, Arora said, "I remember the day we landed at the project in February 2021 and started from scratch — mobilizing manpower, machinery, and materials; establishing infrastructure; and preparing for tunneling."

Senior project officials highlighted numerous logistical hurdles, including the complex transportation of massive TBMs from port to site, their assembly, shifting them to launch positions, and the intricate process of segment and muck handling. Challenges such as skilled labor mobilization, quarry operations, and effective stakeholder management also required meticulous coordination and problem-solving throughout the project.