Building Infrastructure: Focus on construction, maintenance and expansion of railways

Focus on construction, maintenance and expansion of railways

The railway sector has been growing steadily for the past few years, in terms of both infrastructure and investment. In addition to this, new and innovative methods to improve operational efficiency and passenger experience are being explored. The sector has played a critical role in addressing the supply chain challenges faced during the lockdown, imposed in the wake of the Covid-19 crisis, as other modes of transport came to a halt. While construction activities were severely impacted by the pandemic in the first quarter of 2020-21, they have almost returned to pre-Covid levels from the third quarter onwards. Indian Railways (IR) also utilised the lockdown period and the resultant suspension of passenger services to address the long-pending maintenance work on the rail network.

Indian Infrastructure takes a look at the construction activities being undertaken by IR and the issues and challenges associated with it…


Tunnelling activities in India have gained momentum in the past few years owing to a plethora of growth drivers. These include increased government support, adoption of the latest technologies and techniques, accelerated investments and the need to provide connectivity in remote areas. The construction of tunnels is being carried out through the latest tunnelling techniques and equipment such as tunnel boring machines, the New Austrian Tunnelling Method (NATM), and cut and cover. As of December 2020, IR has undertaken approximately 863 tunnel projects spanning a length of about 658 km. These tunnels entail an investment of over Rs 155 trillion. Of these, 668 projects stand completed, 173 are ongoing and contracts for 22 projects have recently been awarded. Himachal Pradesh accounts for the maximum share of 16 per cent in the total number of tunnels in the pipeline. In terms of tunnel length, Jammu & Kashmir has the maximum share of 22 per cent.

The construction of tunnels is restrained by geological conditions. It is therefore crucial to choose appropriate construction methods, materials, tunnel layout and excavation methods, which suit the local conditions. The ingress of water pockets and weak geology further creates barriers in tunnelling work. Further, tunnelling through the NATM has led to problems as controlled blasting was required in hard rock conditions, besides the extensive use of lattice girder and rock bolt. Another factor that requires attention is the cost of tunnelling. There is a need to ensure that the most efficient mix of tunnelling technologies is deployed to reduce the cost of tunnel construction.


India has the fourth largest railway network in the world after the US, China and Russia. The railway network during 2019-20 stood at 68,155 route km (rkm.) From 2015-16 to 2019-20, the track network has grown at a compound annual growth rate of 0.54 per cent. The length of railway tracks commissioned from 2014-15 to 2019-20 stood at 12,666 km. Of this, 2,933 km were new lines, 3,358 km was gauge conversion and 6,315 km was doubling. As of December 2020, the total number of ongoing projects (new line, gauge conversion, doubling and electrification) stood at 875 (100,174 km) entailing an estimated investment of Rs 1,065.5 billion. Under the Union Budget 2021-22, the central government has allocated Rs 162.46 billion for the construction of news lines, Rs 18.03 billion for gauge conversion, Rs 30 billion for doubling and Rs 106.95 for track renewals.

IR had suffered huge losses in terms of revenues and infrastructure development during the Covid-induced lockdown period. However, making full use of the opportunity, the national transporter addressed the issue of long-pending maintenance work on its network. Nearly 500 modern heavy-duty track maintenance machines along with track, signal and overhead equipment maintainers worked regularly for 10,749 machine days and completed overdue track maintenance of 12,270 km of tracks and 5,263 turnouts. Besides, ultrasonic flaw detection of 30,182 km of track and 134,443 rail welds was carried out. The idea was to wipe out the maintenance arrears and take up the execution of work without affecting the train service.

IR has decided to invest in the highly utilised Golden Quadrilateral-Golden Diagonal route between the four metropolises of Delhi, Kolkata, Mumbai and Chennai, and 11 other routes that enable last-mile connectivity for much of the traffic. Three new dedicated freight corridors – the East Coast Corridor, the East-West Corridor and the North-South Sub-Corridor – have been planned, and seven new high speed rail corridors have been identified. Further, it aims to achieve multi-tracking (doubling, tripling and quadrupling) of nearly 12,000 rkm of track length by 2024. Besides, the upcoming Delhi-Panipat-Karnal, Delhi-Gurugram-SNB and Delhi-Ghaziabad-Meerut Rapid Regional Transit System corridors will offer major construction opportunities. IR has also drawn up an ambitious plan for station redevelopment, which aims to open up about 20 million square feet of real estate, attracting Rs 500 billion in investment.

New construction techniques are being deployed by IR for track construction. The Khurja-Dadri section of the eastern dedicated freight corridor (DFC) is among the first tracks in the country where the new track construction (NTC) machine is being used. Currently, there are seven NTC machines that have been deployed along the DFC. While four machines have been deployed in eastern DFC, three have been deployed in the western DFC. The NTC machine has the capability to lay 1.5 km of track per day.


As of April 1, 2020, IR had 150,390 bridges. Of these, 702 are important, 12,256 are major and 137,432 are minor bridges. During 2019-20, 1,367 bridges were strengthened/rehabilitated/rebuilt to enhance the safety of train operations. Around 11,500 road over bridges (RoBs)/road under bridges (RuBs) have been sanctioned for repair works in the past five years. Of these, 4,168 bridges were sanctioned for repairing and rehabilitation during 2019-20. During 2019-20, the number of bridges rehabilitated increased by 35 per cent, from 1,013 in 2018-19, to stand at 1,367. The budget allocation for bridge works, including RoBs/ RuBs, increased from Rs 4.51 billion in 2017-18 to Rs 9 billion in 2021-22.

The construction of bridges is expected to create huge opportunities in the railway sector. The Ministry of Road Transport and Highways has launched a major scheme for the construction of RoBs/RuBs, Setu Bharatam, which includes 208 stand-alone RoB/RuBs. In addition, 1,500 bridges will be widened, rehabilitated or replaced. The scheme is expected to entail an investment of Rs 500 billion. More than 55 per cent of the RoBs/RuBs identified under Setu Bharatam are situated in six states. These are Andhra Pradesh, West Bengal, Bihar, Karnataka, Maharashtra and Assam.

The rail bridge over the Chenab river in Jammu and Kashmir is in the last stages of construction. The bridge has been constructed in hostile terrain and the massive arch-shaped structure needed over 5,462 tonnes of steel for construction. It has a height of 359 metres above the riverbed. The Chenab bridge is expected to form an important link in the 111 km long stretch between Katra and Banihal. It is part of IR’s Udhampur-Srinagar-Baramulla rail link project. Another engineering marvel under construction is the Anji bridge, which will be the first cable-stayed bridge of IR. The bridge is being constructed over Anjikhad, a tributary of the Chenab river.

The construction of bridges in India faces logistical issues as supplying construction material to remote project sites is a challenge. Heavy construction material takes weeks and months to reach the project site due to which work is delayed. In addition to this, detailed studies have to be conducted before work can commence. Such studies take a lot of time and add to the project cost. It is also difficult to monitor the progress of construction activity.

Future outlook

Railway infrastructure is witnessing rapid development with various upcoming and ongoing mega projects in the pipeline. Construction work on these projects has been progressing in full swing, with the challenges posed by the Covid-19 pandemic having been addressed. The projects have also opened up several avenues of investment for the various stakeholders involved. Going forward, tunnelling, bridges, track renewals and new line construction are some of the segments that offer maximum opportunities in the construction sector. With the uptake of new techniques and technologies, the national transporter is expected to further improve safety and operational efficiencies.