Rising investment in tunnel construction has resulted in high growth in the tunnel equipment market. The entry of new manufacturers has widened the choice for project developers. Foreign players have now started setting up manufacturing or assembly units in the country, and this has led to lower procurement costs. Despite the expansion in the domestic equipment market, demand far outstrips local capacity and imports thus continue to play a major role. In addition to outright purchase of equipment (common for tunnel boring machines [TBMs]), the rental market for equipment such as excavators and jumbo boomers is also sizeable.
The drill and blast method (DBM) is the most prevalent in the hydropower sector. Other sectors such as railways and water supply also account for significant tunnel length being constructed using this technique. The method is more suitable in tough terrains (Himalayas and Western Ghats) with difficult geological conditions where it is difficult to use TBMs. Some of the major projects that have used the DBM technology are the Teesta V hydro project, the Mumbai-Pune Expressway project and the Gundavali-Bhandup water supply tunnel in Maharashtra.
Equipment used in DBM includes single and double boom jumbos, drilling rigs and roadheaders. Contractors usually purchase or procure these machines. Some of the key suppliers in the segment are Atlas Copco, Terratec, Robbins and Alstom India. Besides supply of equipment, the scope of work also includes inspection of equipment on demand, providing skilled manpower for installation, and maintaining inventory of spare parts. An annual maintenance contract is also offered under which the payment is made on a per metre basis and the entire risk is borne by the equipment provider.
The TBM method is also prominently used in the construction of tunnels, especially in congested urban areas. TBMs dominate tunnel construction in the metro rail sector with about 90 per cent of the completed and under construction tunnels using this technique in combination with other techniques. They are also increasingly being used in the water supply and sewerage sectors. The main types of TBMs used for development of tunnels include open hard rock TBMs suitable for solid rock and shielded TBMs. Shielded TBMs are of various kinds such as slurry shield, mixed shield or earth pressure balance TBMs that are used depending upon ground conditions.
The TBM market in the country is dominated by foreign players. China has the biggest share in the tunnelling equipment market followed by countries such as Singapore, Germany and Japan. Imported equipment is preferred by developers as imported TBMs are duty-free while taxes are applicable on domestically produced equipment.
The TBMs are usually purchased by the contractors. However, in recent years, manufacturers have also started offering buy-back options as the type of TBM used for a particular project depends on the geological conditions. Key suppliers of TBMs in the country include Herrenknecht, Hitach Zosen, Teratec and Robbins. Another upcoming trend is renting of TBM equipment as many projects involve the use of different machines for a short period of time. Many manufacturers have also started offering their services along with the machinery on a contractual basis. Herrenknecht, for example, provides services for the installment of TBMs and rents out equipment as well.
Some notable projects where TBMs were deployed are the Delhi metro, Phase III (Janakpuri West-Botanical Garden) and Phase II (Central Secretariat-HUDA City Centre) projects, the Kishanganga hydropower project and the Mumbai water supply project.
Other tunnelling methods that have gained traction in the past few years are the New Austrian Tunnelling Method (NATM) and the microtunnelling method. The NATM is being progressively deployed in the railway, metro and hydropower sectors. Some of the projects where NATM has been deployed are the Teesta III hydropower project, the Delhi Metro, Phase III, Corridor II and Corridor III projects and the Udhampur-Katra railway tunnel project. Microtunnelling, also known as trenchless or pipe jacking technology, is being used to lay water supply pipelines and sewers in urban areas where open-cut installation is difficult. The Interceptor sewerage project in Delhi that involved the construction of sewerage networks along the Najafgarh, Supplementary and Shahadra drains has used the microtunelling method.
The way forward
The introduction of new high-end technology in the tunnelling sector has resulted in a higher- value equipment market than had been the case earlier. The market size for tunnelling
equipment is expected to expand significantly in the next five-six years. Currently though, the market is experiencing a glut. There is, however, room for expansion given that the lead times for tunnelling equipment delivery are still a matter of concern for developers and contractors.