India is seeing a surge in infrastructure development, including tunnel and trench constructions. That said, tunnelling in India is still a relatively new development; hence, the potential for advanced tunnelling equipment is limited, necessitating importing such equipment from various parts of the world, observes Rishabh Gupta, Assistant Manager (Tunnel Planning & Design) at RITES Ltd, Ministry of Railways. Make in India India’s demand for tunnel boring machines (TBMs), trench cutters, automated jumbos and ancillaries like grout plants, rolling stock, segment moulds, etc, is met completely through imports,” agrees Raman Kapil, EVP - Metro, Tunnels & Environment, Tata Projects. While he observes that this import trend has shifted from East Asia towards Europe in recent years, inhouse competency building is yet to see any daylight. Deploying imported equipment brings its own challenges. For starters, the procurement process for imported equipment is more time-consuming and costly as against equipment made locally, points out Gupta. “This financial burden makes it particularly difficult for smaller companies to afford such equipment.” He notes that the Government has thus far shown no interest in providing financial assistance to construction and utility companies utilising such equipment. Second, large machines manufactured abroad must be fragmented into smaller pieces prior to being shipped and then reassembled on site. “Reassembling a machine and deploying it in an urban area or a mountainous region is associated with logistic constraints, such as complex traffic conditions and accessibility in fragile environments,” notes Animesh Sharma, Tunnel and Geotechnical Engineer. Also, continuous tech support for the equipment’s functioning and performance tends to be a greater challenge for imported equipment. Service providers aren’t focusing as intently as needed on the active fleet of equipment at sites, in terms of field services, workshops, maintaining an inventory of critical spares and training schedules for technical and service staff, says Dheeraj Kumar Arora, Managing Director, Saraj Drilling Solutions. “OEMs are also missing asset management agreements. Service must be included in every new equipment deal, whether it is drill and blast rigs or TBMs. Regular audits and preventative maintenance would help to increase the competency of operators and boost machine productivity by up to 10 per cent.” With the Government initiating numerous tunnelling projects in the past five years, Gupta is hopeful that equipment manufacturing companies will start producing specialised equipment within India’s borders. Sharma believes India needs to expand equipment manufacturing capabilities for general as well as specialised tunnelling and trenching machines (such as TBMs and their ancillary or spare parts), and develop and upgrade the technical support rendered during their operations by bringing in industrial and academic research. As long as the sources of supply for new TBMs and ancillaries are limited, Kapil points out that the need gap is being bridged to a large extent by refurbishing or remanufacturing existing equipment. Easing the access to tunnelling and trenching equipment and services is the need of the hour. Tips to optimise the deployment of drilling and trenching equipment Most challenges and even failures that arise while operating drilling and trenching equipment are a direct result of improper drilling practices or incorrect servicing and field strata conditions, observes Dheeraj Kumar Arora, Managing Director, Saraj Drilling Solutions. “Inspecting the drill rig settings (percussion pressure, feed pressure and rotation pressure with optimum speed levels), flushing and lubrication, selecting proper rock drilling tools and, last but not least, focusing on machine/material handling, including proper tools (drill bits) grinding, can help avoid challenges and failures. These concerns should be looked into before considering a product defect.” “Hole misalignment through poorly serviced rigs, bad collaring and wandering holes are the main factors contributing to stress in the drill tools string, which subsequently lead to the breakdown of drill rigs and final production operations,” he adds. “Therefore, as far as possible, reasonable measures should be taken to drill straighter holes.” What would encourage contractors to use modern tunnelling and trenching methods? Better quality of inputs/information: Decisions on the tunnelling method and associated equipment are largely influenced by the quality of inputs on geology, underlying utilities, traffic and urban space constraints and, of course, the cost and time at hand, observes Raman Kapil, EVP - Metro, Tunnels & Environment, Tata Projects. If any of these inputs varies at any stage from conception through delivery, an undesirable outcome may occur, demanding a midway rethink. He points out that the occurrence of such situations pushes “conservative decisions on equipment”. So, he lists thorough due diligence of a project’s ground conditions, central agency for utility mapping and transparency in sharing those inputs during the design stage as imperatives. Geological complexities, especially in the Himalayan terrain, remain the biggest challenge in tunnelling in India and in the Himalayan belt and, sometimes, even in trenching, observes Azhar Jamil, Senior Manager (Geology), Tractebel Engineering. “Identifying existing subsurface utilities (water/sewer pipelines, gas pipelines, electric lines) using GPR or other scanning equipment before trenching in urban areas is essential but is not being given sufficient importance.” Easier approval process: “Obtaining environmental and other approvals from various departments and additional stakeholders can become a challenging and time-consuming process,” says Rishabh Gupta, Assistant Manager (Tunnel Planning & Design) at RITES Ltd, Ministry of Railways. “In some cases, approval issues may even require realigning the tunnel after the project has already been awarded. Failure to comply with regulations can result in fines or other penalties.” “Any time loss in permits, clearances for projects, suboptimal productivity due to varied reasons like shaft size, deferred arrival, challenges in retrieval, etc, impact the RoI severely,” adds Kapil. “Owning the equipment is to date a risky proposition under those circumstances.” Faster delivery: The lead time for the design and fabrication of moving parts (like cutter heads), availability of the OEM’s support team, contract terms and conditions, etc, are also critical determinants of a machine’s availability for a given project, adds Kapil. Lower cost: Some prerequisites for a tunnelling project to deliver a healthy RoI are “careful preparation, extensive planning and sequencing, prior to deployment”, to quote Gupta. “Only then can the project commence on schedule and the machinery be utilised in the proper sequence, ensuring profitability for the contractor. Else, the high expenses associated with the purchase, rental, operation and maintenance of tunnelling and trenching equipment leads to exorbitant cost overruns due to idle machines.” The ecosystem for the operation of modern equipment with new-age technology – trained operators, spare parts, cutting tools, maintenance, assembly, manoeuvrability and logistics, wait time, compatibility with other makes and materials –comes at a premium, making it capital-intensive, adds Kapil. “Developing a coherent self-reliant ecosystem is vital.” More manageable equipment: Contractors may also be put off deploying large tunnelling and trenching equipment that presents manoeuvring challenges within cramped spaces or uneven terrains, points out Gupta. “This aspect often complicates accessing job sites, particularly in urban areas with limited space and in higher elevations.” “Logistics in support of available modern equipment (for instance, battery-operated rolling stock) are constrained by limited surface area size usability,” adds Kapil. Safety guidelines: Worker safety is another issue that contractors must navigate. Improper deployments and other hazards can pose significant safety risks to workers, causing severe injuries or even fatalities. Gupta cites cavity collapses and over-breaking as potential dangers. “What adds to the complexity is the fact that the deployment of such equipment is made more challenging by the absence of a safety handbook for tunnelling in India,” he says. “So, individual companies must adopt international best practices as mentioned in their contract agreement.” Skill development: Less investment in local R&D and a paucity of skills keep contractors from adopting modern tunnelling methods and/or lead them to outsource challenging work to foreign partners. “The lack of competent engineers, design consultancies and construction companies with specialised skills and training hampers the growth of potential customers for vendors, creating a challenging business environment,” opines Gupta. Jamil points out that experienced operators with awareness of equipment safety aspects are in short supply as are experienced mechanics. “Sufficient knowledge of the support systems needed in tunnels after each excavation and providing a supportive trench wall depending on the depth of the excavation is also missing,” he says. “Micro-level planning and engineering are also insufficient.” While gaps exist, Kapil points out that from the last decade, the industry is seeing traction in upskilling manpower and relaxed regulations for OEMs to set up facilities in India, which has improved equipment availability through local support.