India’s tunnelling sector has been the backbone of many hydropower, metro, irrigation, wastewater, road and railway projects. The rapid growth of infrastructure in India has created a high demand for tunnelling. Tunnelling techniques are gradually maturing with greater technology adoption in tunnelling projects for faster execution and cost optimisation. At present, there is a growing need to indigenise tunnelling equipment to reduce overall costs.
Need for tunnels
Tunnelling began primarily to cater to the power generation segment, wherein hydropower was paid the maximum attention. With the emerging requirement for logistics infrastructure, metro and railway tunnel construction has gained traction. This has led to reduced travel time, resulting in less fuel consumption and cost optimisation, especially in Tier 1 and Tier 2 cities. Water irrigation in agriculture, which supports the livelihood of over 70 per cent of India’s population, is also facilitated by the tunnelling infrastructure. Furthermore, the need to safeguard India’s geographical borders such as the Himalayan region and the north-eastern territory call for robust tunneling infrastructure.
Most of the tunelling projects have achieved world-class quality in the last 60 years. Dependence on foreign support has been reduc-ed with the widespread implementation of the Make in India initiative. Many of the tunnel projects at the higher altitudes of north India under the National Highways Authority of India have seen a successful conversion. Improving the water supply network through tunnels connecting rivers to different locations suffering from water shortage is also a promising area for India.
The industry has warmed up to technologies. While the tunnel boring machine (TBM) technique was previously considered complex and difficult, many projects have now been implemented using the TBM technique. With respect to the safety of these projects, specifications by contractors include most of the necessary measures. TBM, the New Austrian Tunnelling Method, automated tunnel monitoring system, and drill-and-blast tunnelling systems are the prevalent methods being used.
Key challenges
Financing of tunnelling projects is a common issue faced by contractors. For the bidding of projects, contractors need a thorough site and design investigation, which would define the specifications of the contract. The limited time for bidding and assessment of the contract before tendering, as against the extensive requirement of a detailed project report, creates unreasonable expectations for contractors. Any changes in the location of the site, its layout or geographical uncertainties further lead to a huge cost implication for contractors.
Projects funded by international agencies, such as the Japan International Cooperation Agency and the Asian Development Bank, are monitored well for their financial allocations, whereas the state governments pass on the responsibilities to the contractors in case of lack of funds. In certain cases, low bidding on a project also reduces the accountability of contractors regarding the project outcome.
The encouragement of foreign companies for these projects also has drawbacks. They usually do not comply with the Make in India policy as part of their contract in order to augment their own revenues. This leads to a skewed bidding structure. Many Indian companies still import equipment, admixtures and chemical products for tunnel projects, raising the concerns of added container and freight costs. There is a long way to go before the requisite manufacturing support could be generated within India itself.
The risks involved in tunnelling projects are mostly borne by contractors. Despite their role of a service provider, they are subject to arbitrations due to changes in specifications that arise from the change in other aspects of projects. This leads to further delays in project completion, thereby making risk sharing between the clients and the contractors even more important. Meanwhile, the liability of huge bank guarantees, long contract and maintenance periods and huge penalties associated with large-scale and cost-intensive projects make contractors wary of bidding for such projects.
Another challenge is the mismanagement of contracts by the client. The lack of clarity in clauses has led to many contractors suffering throughout the course of the projects. The interpretation of the clauses is open-ended, and little transparency is provided by the client on many aspects of the projects. The cost of equipment, manpower and other financials that are borne by contractors following a delay in project implementation are neither compensated by the client nor made part of the contract. The willingness of the client to complete the projects on time drives their speed and outcome. Contractors have to face the consequences of the low motivation of clients. Delay in payments is another discouraging factor for them. With a marginal share of profit from the whole budget of a massive project, the contractor has to additionally bear the running costs due to these delays.
The lack of coordination among government departments also impacts the progress of projects. Issues related to approvals and clearances lead to time and cost overruns.
The way forward
The timely mobilisation of resources and manpower through proper access to capital is one of the critical requirements for the successful implementation of tunnel projects. Support from the government or project owners to contractors will decide the fate of projects. Automation is also becoming the new way of sustainable and faster tunnelling with the introduction of computerised controls for two- and three-boom rigs for excavations. Technological advancements will help in the achievement of safe and quality products in a short time that would lead to profitable returns on these projects.
Ventilation is a critical aspect of tunnelling projects with a minimum oxygen requirement laid down by the client to
provide a safe work environment for labourers and operators. Apart from adopting energy saving methods for these ventilation systems, it is important to maintain the safety and quality of the fans required for ventilation. Electrically powered equipment, noise control mechanisms, robotic excavators (used in the Mumbai metro), electric drum cutters are other sustainable measures that have the potential to be scaled up. With the lowest bidding mechanism in place, the narrowed approach of bringing forward optimum solutions by suppliers and vendors make the sector leave a negative footprint. There is a need to reinnovate the project awarding systems for better quality control and creation of a low-risk environment for contractors to effectively deliver projects in time, for the benefit of all stakeholders and the overall development of the sector.
Based on a panel discussion among Sanjay Dave, Vice-President and Sector Head, Engineering, HCC; Sadashiv N. Nayak, Senior Vice-President, Patel Engineering; Mallikarjun Rao, Executive Vice-President and Head, Business Unit, Hydro & Underground, Afcons Infrastructure; and Sunil Vishwakarma, Head Planning, Tata Projects, at a recent India Infrastructure conference