DRDO engineers build strategic tunnel
The construction of one of the world’s most strategic motorways - the Rohtang Pass highway tunnel - in the Himalayas of is likely to be completed by 2020, according to the project engineers. A daunting task ahead is to make the avalanche-prone roads, located at altitudes ranging above 3,000 metres and leading to the tunnel, safe for motorists and accessible round the year. The 8.8-km long horseshoe shaped tunnel the world’s longest motorable tunnel 3,000 metres above sea level, under the 3,978metre Rohtang Pass in the Pir Panjal range has 45 avalanche-prone spots and aims to provide all-season connectivity to the landlocked Lahaul Valley from the picturesque resort town of Manali.
The Chandigarh-based Snow and Avalanche Study Establishment (SASE) has designed mechanical structures to ensure the safety of motorists by countering avalanches on both ends of the tunnel that remain under snow even in peak summer. SASE is a Defence Research and Development Organisation (DRDO) laboratory and this is the first time it has designed snow galleries. SASE Scientist Rajesh Verma said three snow galleries are under construction at the tunnel’s south portal. The length of a gallery varies from 40 metres to 130 metres and would be constructed before completing the tunnel.
He said the other mechanical structures on the 12-km stretch towards the south portal are five deflector steel walls and a bridge to withhold an avalanche. Likewise, a 250-m long catch dam is under construction towards the tunnel’s north portal to check erosion of falling debris along the road. Officials said sensors would be installed along both roads to monitor the behaviour of snow and flash floods round the year. The most ambitious and expensive undertaking of its kind, excavation of the tunnel was completed in October 2017. Now the civil engineering work is on. The tunnel is likely to be made operational by May-June 2020.
The project is being undertaken by the Border Roads Organisation (BRO), a wing of the Defence Ministry, in collaboration with Afcons, a joint venture with Strabag AG.
The INR 1,495-crore tunnel’s foundation stone was laid by United Progressive Alliance (UPA) chairperson Sonia Gandhi on June 28, 2010, in the Solang Valley near Manali, some 300 km from Chandigarh.