26 April 2018

Table of Contents for Industry Focus: Tunneling & Trenching

Industry Focus: Tunneling & Trenching

India’s Metro warrens


India’s drive to modernise its cities and the attendant transport infrastructure, especially metro rail, is driving demand for tunneling and trenching equipment majorly. Other demand drivers include pipe laying in water supply and irrigation projects, cables laying in power and T&D, oil & gas, railways, hydropower, etc. And the latest is few more TBMs have arrived for metro rail projects. Satish P Chavan reports.


Two major government initiatives are driving the Indian market for tunneling and trenching equipment, i.e. urban transport infra, which consists mostly of metro rail networks in India’s major metropolises and Tier II and Tier III cities, and the other major initiative is India’s water mission which is generating demand for tunneling, trenching, and pipe laying equipment. In view of India’s rapidly expanding urban footprint urban, building Mass Rapid Transit Systems (MRTS), has assumed a new urgency. High density urban agglomerations demand MRTS, and India has embarked upon a pan India initiative of constructing metro rail systems. In 2006, the National Urban Transport Policy proposed the construction of a metro rail system in every city with a population of 20 lakh (2 million). In 2014, the Union Government announced that it would provide financial assistance, for the implementation of a metro rail system, to all Indian cities having a population of more than 1 million. In May 2015, Union Government approved the Ministry of Urban Development (MoUD), proposal to implement metro rail systems in 50 cities. The majority of the planned projects will be implemented through special purpose vehicles, which will be established as 50:50 joint ventures between the Union and respective State Government. The Union Government will invest an estimated Rs 5 lakh crore ($78 billion). However, in new draft policy unveiled in March 2017, the Central Government stated that it wanted State Governments to consider metro rail as the "last option," and implement it only after considering all other possible MRTS alternatives. The decision was taken due to the high cost of constructing metro rail systems. In August 2017, the Union Government announced that it would not provide financial assistance to new metro rail project, unless some sort of private partnership is involved.

There are currently 10 operational metro rail systems in 8 cities across India, till end 2016 324 km of operational metro lines have been built, and a further 520 km of lines are under construction. The Delhi Metro has the largest network in the entire country.

Considering the ongoing and planned metro rail projects, there is going to be substantial demand for TBMs and trenching equipment.



Apart from metro projects in major cities of Mumbai, Bangalore, Delhi, Kolkata, Chennai, etc, plenty of metro projects in Tier II and Tier III cities are generating demand for TBMs and trenching equipment. The two biggest metro rail mega projects currently going on are in Delhi and Mumbai, respectively. And just these two projects have a substantial requirement for equipment.


“Mumbai Metro is one of the most prestigious metro works in the country, and Robbins’ involvement in providing suitable machines and associated services is an honor,”
Kapil Bhati, MD, Robbins India.





“There are many, actually almost all. As on today in India, none of the major projects are being executed without SCHWING Stetter equipment. SCHWING Stetter India’s presence in all the segments like Road, Railway, HEP, Irrigation are widely noticeable. We have set the world record in 100 MW Sianj Hydroelectric power project and Parbati Hydroelectric power project.”
V.G. Sakthikumar, Managing Director, Schwing Stetter Sales & Services





The Delhi Metro Rail Corporation (DMRC), has a currently deployed a total of 19 Tunnel Boring Machines (TBMs) for their ongoing projects, which are simultaneously engaged in constructing Metro tunnels across the length and breadth of the national capital, Delhi, making it among the largest tunneling projects ever undertaken below any major urban centre globally. As part of its third phase of expansion, Delhi Metro is constructing over 53 km of underground metro lines comprising of 74 different tunneling drives of about 37 km. Approximately, 35 TBMs are to be used for this mammoth assignment during the entire third phase and about 21 km of tunnels (or 41 km of tunnels including up and down tunnels), and 33 tunneling drives have already been completed so far. The entire tunneling work of Phase 3 is expected to be finished by the end of the year. The use of 19 TBMs simultaneously within the confines of one city is probably among the highest used anywhere in the world. In Phase 2, Delhi Metro had used a total of 14 TBMs during the entire span of work. For the current phase, so many TBMs are being used because the quantum of underground construction has increased significantly in comparison to the last two phases. While, Delhi Metro currently has an operational underground section of approximately 47 km, the phase 3 will alone have over 37 km of underground Metro lines.

Delhi Metro is also taking meticulous care to ensure that such massive tunneling activity beneath the surface does not hamper the lives of the people and therefore, before every tunneling drive, detailed soil quality, building condition surveys are done and corrective measures taken if needed. In addition, the progress of the TBMs is very closely monitored and custom made instrumentation is done above the TBM routes to monitor any movement in the earth’s surface or the condition of the structures above.

The tunneling drives of DMRC have so far passed below many important landmarks of the city such as railway tracks, flyovers, existing Metro viaducts, Metro tunnels, etc. The tunnels have passed below railway tracks (at Palam, ITO), flyovers (at Munirka, Hauz Khas, Palam), Metro viaducts (at Kalkaji, Janakpuri West, Lajpat Nagar), Metro tunnels (at IGI Airport) and their construction did not cause any disruption to the flow of traffic on the flyovers or movement of trains on the railway tracks above. The use of so many TBMs has ensured that Delhi Metro has been able to carry out construction work through many congested as well as traffic heavy areas such as Old Delhi, Ring Road, Outer Ring Road etc without any major diversion of the roads or demolition of buildings.



Currently, the Mumbai Metro Rail Corporation (MMRC), is busy overseeing the beginning of execution of its biggest metro rail project, the Colaba-Bandra-SEEPZ Metro-3 project. Recently the MMRC fabricated its first tunnel ring for Metro-3 of the project, which is considered a major step towards implementation of Mumbai’s first underground Metro corridor. Segment rings are essential components as far as tunneling is concerned. It is use as tunnel lining in tunneling operations with Tunnel Boring Machines (TBM). About 40,000 segment rings are required for the entire Metro-3 project which will be casted in 65 moulds imported from France, Korea etc. Some of the moulds are being brought from Delhi Metro project. Each mould consists of a set of six segments. To ensure its quality and strength, the concrete segment rings will be precast and will be manufactured in casting yards. The segments rings required for project will be manufactured in six casting yards of which four have been set up at Wadala, one at Darga and one at Jogeshwari-Vikhroli Link Road (JVLR). MMRC contractors have already placed orders for TBMs with several international suppliers and tunneling activity will take off from October, 2017, onwards for construction of 33.5 km long twin tunnels. Commenting on the progress, Ashwini Bhide, MD, MMRC, said, "Tunneling in Mumbai is full of challenges. However, with the help of advance technology and team of experts we will successfully complete this gigantic task. The MMRC will embark upon huge tunneling activity and we will ensure that there is minimum inconvenience to Mumbaikars during our work.’’

S.K.Gupta, Director (Projects), MMRC, adds, “This is an important milestone for the project and we have been able to fabricate the first segment ring before schedule.” Reviewing progress of the package 2 of Mumbai Metro Line III, Maharashtra Chief Minister Devendra Fadnavis, said, "I appreciate when projects move ahead with required urgency, to achieve desirable results. The 33.5-km Metro-3 corridor (Colaba-Bandra-SEEPZ) is showing promising speed in this direction. Our aim is to complete the project, highly needed to reduce traffic congestion in Mumbai within the schedule time frame. Metros help reduce carbon footprint as well as pollution. It’s the greenest mass rapid transit system.” He was visiting the Azad Maidan, TBM shaft of package 2 and took a stock of the ongoing work. After reviewing the site, he expressed satisfaction on the progress of the project. He went through the civil work being undertaken at Azad Maidan with Bhide, along with senior officials of MMRC and contractors of the package 2. Bhide briefed the Minister on overall progress of the project including the status of the secant piles, arrival of the Tunnel Boring Machines (TBM), manpower working and safety measures adopted on site. Bhide, apprised him about the arrival of second Tunnel Boring Machine, which is expected to reach the Azad Maidan site soon. She also explained him about the Platform Screen Doors technology which is one of the most important safety features of the project.

She informed him about the employment of more than 4,000 manpower, including 800 strong, technical staff and the rest includes skilled and unskilled labors.

She said, “With the arrival of our first TBM we have kicked off our tunnelling activity, which is another most critical part of this project.”

Last month in September, the CM Fadnavis witnessed lowering of the first TBM for the Colaba-Bandra-SEEPZ Metro-3 corridor at the launching shaft in Naya Nagar, Mahim. The highly-mechanised Earth Pressure Balance (EPB) machine procured from German TBM major Herrenknecht AG, manufactured at its facility in Guangzhou, China, will be used to construct twin tunnels with circular cross section. The total depth of this shaft is 25m out of which 16m is in hard rock. The front shield, middle shield, cutter head, erector, screw conveyor and tail-skin shield and other different parts of the machine will be assembled to form a 110m long TBM to construct the 2.5-km long tunnel between Naya Nagar and Dadar stations. “It was very exciting to witness the lowering of the first TBM for Mumbai’s first underground Metro corridor”, said Fadnavis. “This showcases the speed with which the work on this corridor is progressing. This green mass rapid transit system will not only help improve environment but also go a long way in reducing traffic on roads and congestion in suburban

rails.” Ashwini Bhide adds, “Metro corridor