The Atal (Rohtang) Tunnel: Learning from the Unique Challenge

Abstract

The Atal Tunnel under the Rohtang Pass was completed against great odds and is on record as the longest tunnel above 10,000 ft (3,000 m). The challenges included: working under extreme conditions of weather and altitude with limited access to the North Portal across the Rohtang Pass; working under an extreme over-burden of 1.9 km; and overcoming the geological surprises that the Young Fold mountains of the Himalayan ranges had to offer, becoming even more challenging due to limited initial information, the geological surprises on the Pirpanjal range where it merged into the Himalayan ranges are astride of three faults in this region. The Seri Nala fault along the tunnel alignment was anticipated but appeared early, with huge ingress of water and Riverbed Material, turning into a unique challenge that could have led to aborting the alignment, but for the grit and determination of the team. Though delayed, the tunnel was completed with zero casualties and leaves a legacy of many important lessons in extreme engineering and management in such situations.

Keywords:

• Atal tunnel
• Rohtang
• Seri Nala NATM
• BRO

Disclosure Statement

No potential conflict of interest was reported by the author.