New Delhi: Amid reports raising questions on why under-construction Silkyara tunnel in Uttarkashi did not have a separate escape tunnel, the government on Wednesday said a separation wall was provided in the tunnel with egress openings at regular intervals that could be used as an escape route during an emergency.
The 41 workers, who were trapped in the tunnel from November 12, were rescued on November 28. In a written reply to a question in the Rajya Sabha, Union Road Transport and Highways minister Nitin Gadkari said, "In the Silkyara bi-directional tunnel on Dharasu-Yumunotri highway (NH-134), a provision of separation wall has been provided at the centre of the carriageway along with egress openings at an average interval of 565 metres for vehicular crossover and at an average interval of 300 metres for pedestrian cross passage for escape purposes during the emergencies."
Gadkari was asked whether the government has conducted a probe as to why Navayuga Engineering Company Ltd (NECL) did not build a rescue route, as is the norm in tunnel construction. The National Highways and Infrastructure Development Corporation Ltd (NHIDCL) is constructing the tunnel through Hyderabad-based Navayuga Engineering Company Ltd.
Silkyara tunnel is a single-tube tunnel divided into two inter-connected corridors by a partition wall. Each inter-connector corridor can work as an escape passage for the other. Whether the government had reviewed safety norms after the collapse of the tunnel in 2019, the minister said the Silkyara tunnel on the Dharasu-Yumunotri highway (NH-134) is being built under the Engineering, Procurement and Construction (EPC) mode, wherein the design responsibility lies with the EPC contractor.
"After encountering minor spalls/falling of debris-forming cavities during construction in 2019, the construction sequences and primary support system are reviewed from time to time on the basis of actual ground behaviour observed and are approved by authority's engineer engaged for the project, which are executed under the supervision of officials of NHIDCL," he added.
The minister said on the intervention application filed by the Ministry of Defence, the Supreme Court in 2021 permitted widening of the three strategically important National Highways -- Rishikesh-Mana (NH-7), Rishikesh-Gangotri (NH-34) and Tanakpur-Pithoragarh (NH-9) -- to two-lane with paved shoulder (10-metre wide pavement) under Char Dham Pariyojana.
Asked whether the Char Dham Maha Marg Vikas Pariyojana of 900 km was approved without any environmental impact assessment by dividing the project into smaller projects, Gadkari said as per the Ministry of Environment, Forest and Climate Change (MoEFCC) notification, expansion of National Highways greater than 100 km involving additional right of way or land acquisition greater than 40 metre on existing alignments and 60 metre on re-alignments or bypasses requires prior environment clearances.
Chardham Mahamarg Vikas Pariyojana comprises improvement of five existing National Highways connecting the Chardham -- Yamunotri, Gangotri, Kedarnath, and Badrinath -- including Tanakpur to Pithoragarh section of Kailas-Mansarovar yatra, having a total length of about 825 km under 53 projects, each with a length of less than 100 km.
"Each project is independent, having a distinct start and end points that are important places on these highways. There was no requirement for Environment Impact Assessment for these projects," Gadkari said. The 4.5-kilometre Silkyara tunnel project in Uttarakhand, which is part of the Centre's strategic 900-km 'Char Dham Yatra All Weather Road', aims to improve connectivity to the four holy towns.
