CONCERNS have been raised regarding the increasing cost and wisdom of constructing new lines in India’s mountainous northeastern states.

Five lines costing Rs 1.37 trillion ($US 15.64bn) are being built in northeastern states bordering China but have been facing massive time and cost overruns.

The 110.6km Jiribam - Imphal line, launched in 2003, is now targeted for completion in 2027, while costs have climbed from Rs 7.3bn to Rs 250bn. The 45km Sivok - Rangpo line, approved in 2008, is expected to be completed in 2028, while project costs have risen from the original estimate of Rs 13.4bn to Rs 150bn. The 88.4km Dhansiri - Zubza line, launched in 2006, is expected to be completed in 2030, while costs have climbed from Rs 8.5bn to Rs 140bn. Construction of the 108.4km Byringat - Shillong line started in 2010, but is unlikely to be completed before 2040 as the project is currently stalled due to local opposition, and project costs are estimated to have risen from Rs 40.8bn to Rs 650bn.

The 51.38km Bairabi - Sairang line, which received its safety clearance from the Commissioner of Rail Safety (CRS) ahead of opening next month, has taken 17 years to build and witnessed a cost increase from Rs 6.2 bn to Rs 192 bn.

“The cost escalation in real terms is much higher, if the year-on-year inflationary costs are computed,” says Alok Kumar Verma, a former Indian Railways chief engineer. Speaking to IRJ, Verma said the CRS approval for the Bairabi - Sairang line had been granted “in a hurry” and that “design flaws” had been overlooked.  

“The Bairabi - Sairang line runs through uninhabited trough basins in low-relief terrain, yet 96% of its 51.4km length is in tunnels, high cuttings, and bridges,” says Verma. It includes six bridges taller than 50m, including a 106m beam-column bridge.

Verma says construction of colossal bridges in the gentle hills was undesirable and would limit train speeds to a crawl of 25-30km/h.

In a post on social media platform X, Verma said: “In order to maintain a flat gradient of 1 in 80, these lines will be forced to hug valley floors, carving through soft colluvium, landslide-prone slopes, and flood-prone basins. The result: endless tunnels, towering viaducts and slow, risky operations.”

Verma’s concerns appear to arise out of the 2016 experience of the premature opening of the Lumding - Silchar line in Assam. Within the first few months of the start of commercial operations, there were two derailments and dozens of landslides, leading to the withdrawal of train services for three months. In 2022, the line was shut for 48 days. This year, the line has been closed on multiple occasions including a seven-day disruption following a major landslide.

Verma states that Indian Railway’s decision to adopt slope stabilisation by undertaking excessive soil cutting in an unstable Northeastern terrain that receives annual rainfall of 2500-4000mm could lead to catastrophic disasters in the future.