The pace of tunnel construction in the country has accelerated in recent years, going by the growth in the number of tunnel construction projects involving greater tunnel lengths, especially in the most challenging topographical conditions. A continuous pipeline of infrastructure projects mainly focusing on the development of hydropower projects, creation of mass rapid transit systems, enhancement of road and rail connectivity, and modernisation of water supply and waste management systems has fuelled the growth of tunnel construction in the country. The scope of tunnel construction projects is expanding mainly due to rapid urbanisation and the rising demand for better infrastructure across the country. At present, a total of 1,641 tunnels spanning 3,445 km are at different stages of completion, including announcement, approval, bids, award, under construction and conclusion. Approximately 280 tunnels with a total length of 890 km are estimated to be completed by 2021-22, and another 137 tunnels consisting of a total length of more than 630 km are scheduled to be completed by 2026.
So far, the hydroelectric sector has witnessed the maximum tunnel construction. One of the notable hydroelectric tunnel projects is the Subansiri Lower Hydroelectric Project (SLHEP), which involves the excavation of eight tunnels with a length of 7.09 km and is being implemented by NHPC Limited. The Siang upper hydropower project in Arunachal Pradesh, which includes the development of 30 tunnels in a horseshoe shape as well as the Teesta VI and the Dibang hydroelectric projects are all significant tunnel projects in the field. Tunnels specifically dedicated to water supply have gained impetus owing to the implementation of schemes such as the Indian river interlinking project, the Jawaharlal Nehru National Urban Renewal Mission (JNNURM) and the Pradhan Mantri Krishi Sinchayee Yojana (PMKSY). One of the vital tunnel projects of the water supply sector is the Sleemanabad Carrier Canal Tunnel project, which involves the construction of a 12-km tunnel to irrigate parts of Katni, Satna, Panna and Jabalpur districts of Madhya Pradesh. Tunnel development in the road and highways industry has been minimal, with an exception of a few tunnels being built in the mountainous area. Metro rail tunnelling is a recent phenomenon and has been spurred by the decision of dense cities to develop efficient public mass transport systems. Around 10 per cent of the upcoming length of metro rail projects is planned as underground.
Indian Infrastructure provides an update of the key ongoing and upcoming tunnel projects.
The Rishikesh-Karanprayag rail project, which connects the plains and hills of the Garhwal area, involves the development of 12 railway stations and 17 long tunnels spanning 105.47 km, as well as 98.54 km of long escape tunnels, for a total of 218 km of tunnel construction. A total of 16 significant bridges with a total length of 2,835 metres will also be constructed. In January 2021, L&T Construction emerged as the lowest bidder for Package 4 of the Rishikesh-Karnaprayag rail project in Uttarakhand. Rail Vikas Nigam Limited will award the contract to the company. The project’s scope includes shaft construction, finishing of tunnels, and other essential tasks. Currently, L&T Construction is working on the Rishikesh-Karnaprayag Tunnel 2 package, which is also being implemented by Rail Vikas Nigam Limited. The New Rishikesh-Devprayag railway line will be operational by 2023-24 and the Devprayag-Karanprayag railway line will be operational by 2024-25. With the union budget’s allocation of Rs 42 billion for the Rishikesh-Karnaprayag rail line, the possibility of timely completion of the project has increased.
The Jammu-Udhampur-Katra-Quazigund-Baramulla railway line is the largest endeavour in the development of a mountain railway since India’s independence, according to the Northern Railway Construction Organisation. The 25 km Udhampur-Katra segment, the 18 km Banihal-Qazigund segment and the 118 km Qazigund-Baramulla segment have already been completed. The last segment, which is the 111 km Katra-Banihal stretch, is under construction. Further, 126 km of the 174 km of tunnels on this route have been finished. Reportedly, the tunnels under construction have no leakage issues because they are developed in a horseshoe shape to allow water to drain out. However, seepage issues were discovered in certain older tunnels and necessary steps have already been taken to fix the issue. The project contains numerous firsts, including the longest railway tunnel spanning 12.75 km, the world’s highest railway bridge, and the first cable-stayed bridge, all of which will be engineering paragons of the 21st century. The project is critical for providing an alternative and efficient transportation system to Jammu and Kashmir as well as for connecting Kashmir to the Indian Railways network. It is scheduled to be completed in December 2022.
Other key tunnel projects
Apart from these under-construction tunnel projects, many other key tunnel projects have been launched. The National Capital Region Transport Corporation (NCRTC), which is executing the Delhi-Ghaziabad-Meerut RRTS project, had invited bids for the construction of a 5.6-km underground tunnel connecting New Ashok Nagar to Sahibabad. In January 2021, the NCRTC awarded the contract to Shanghai Tunnel Engineering Company Limited for the development of the underground tunnel. The Mumbai Coastal Road Project, which spans 29.2 km and connects South Mumbai to the Bandra-Worli Sea Link (BWSL) Worli end, includes a tunnel, road and interchange. The first undersea tunnel in India is a pair of twin tunnels, one northbound and one southbound, each measuring 2.07 km in length. As of March 2021, the first 100 metres of the coastal road tunnel have been dug by the Brihanmumbai Municipal Corporation (BMC). The tunnelling construction is projected to be finished by the end of 2022, according to BMC. The Bhenda Hera-Moondiya Eight Lane Tunnel Project is a 59.6 km long greenfield highway that is being developed in Rajasthan as part of the Bharatmala Pariyojana project to improve traffic flow between Delhi and Mumbai. The highway will be built as a tunnel passing through the Mukundra Hill Tiger Reserve.
India has emerged as one of the fastest-growing tunnel construction markets in the world, with a robust tunnelling industry having 876 tunnel projects with a total length of 2666.60 km in its pipeline. In the next five years, Rs 1 trillion will be invested to develop tunnels in strategic regions to facilitate all-weather connectivity. The volume of tunnel projects has risen exponentially during the past few years. The majority of upcoming tunnel projects are of longer length, wider diameter and have a greater contract value. The large pipeline of tunnel projects is expected to create a huge demand for the equipment involved in the drill and blast method (DBM), tunnel boring machines (TBMs), drillers, excavators, loaders, cranes, etc. Generally, 20-25 per cent of the tunnel construction cost is spent on procuring construction materials. The DBM requires more construction material as compared to TBMs and the New Austrian Tunnelling Method. Hence, tunnels being excavated through DBMs are expected to incur higher construction costs. The upcoming projects would require consultancy services for the preparation of various reports such as detailed project reports, feasibility reports, and for securing a number of approvals including environmental clearance, forest and wildlife clearance, coastal regulation zone clearance, etc. The tunnelling industry holds immense opportunities for contractors, consultants, equipment suppliers and raw material providers in the coming years.
Also, with multinational firms actively participating in the construction and consultancy tasks in government-sponsored and private-sector projects, it is evident that tunnelling is no longer a government sector activity.
Impact of Covid-19
The Covid-19 pandemic has negatively impacted the tunnelling industry as a result of the reduced construction activity across most of the regions. The supply chain faced severe blockages during the initial phase of the nationwide lockdown as the supply of critical inputs and raw material was halted. Several key players in the segment witnessed a sharp decline in revenue from operations in the first quarter of FY 2020-21 due to the suspension of construction activities. With several key players facing a cash crunch, the implementing agencies have been unable to find sufficient bids for upcoming projects.
The road ahead
There is a need to ease technical and financial parameters for infrastructure projects, so that small players can be given an opportunity to at least bid for the projects, as it has been noticed that big players, after receiving the contract, assign it to small players, who were unable to bid for the project in the first place. The Ministry of Road Transport and Highways is planning to bring changes in bidding documents regarding the technical and financial capacity for the Hybrid Annuity Model (HAM) and build, operate, transfer (BOT) projects. Apart from this, the central government has been discussing providing general relaxation for tunnel and bridge projects. Given the large pipeline of tunnel projects and the increasing focus of the government on infrastructure development, the tunnelling industry will offer enormous prospects in the upcoming future. Meanwhile, implementing agencies must rely on advanced technology and digital solutions to expedite the completion of tunnel projects in view of the challenges posed by the Covid-19 pandemic.