Dr Jose Paul, former chairman of Mormugao Port Trust and the original conceptualiser of the Fort Kochi-Vypeen underwater tunnel back in 2015, sheds light on the project after the Kerala Rail Development Corporation invited an expression of interest for the project recently. Excerpts
Is the proposed underwater tunnel the first such infrastructure in India?
The tunnel connecting Fort Kochi with Vypeen island will be the first undersea tunnel under a deep shipping channel in the country. It will be around 2.5 to 3 kilometres long, passing 35 metres below the seabed. While it’s a first for a deep shipping channel, India already has two other underwater tunnels: 1) Kolkata’s underwater metro rail, which is part of the East-West corridor, crosses under the Hooghly river.
Inaugurated in March 2024, the 520-metre tunnel passes 13 metres below the riverbed, linking Howrah and Kolkata; 2) Mumbai’s twin undersea tunnel, which passes under the Arabian Sea and Malabar Hill, connects Marine Drive to Worli, greatly cutting travel time. The one-km stretch passes 17-20 metres under the Arabian Sea, making them India’s first undersea tunnels.
Why is the underwater tunnel crucial for the state’s development?
The tunnel is vital to complete the state government’s planned Coastal Highway, a 656-km road from Thiruvananthapuram to Kasaragod. When this highway reaches Fort Kochi, it cannot cross over to Vypeen due to the deep shipping channel. With a bridge already under construction at the northern end (Munambam to Azhikode) of the stretch, the shipping channel remains the only unbridged area.
A permanent, fixed undersea link will ensure seamless transportation along the coastal highway, providing a crucial alternative to the under-construction NH 66. Additionally, it will give a significant boost to tourism across the entire 25-km Vypeen island, enhancing the local population’s prosperity. This new link is also expected to substantially reduce severe traffic bottlenecks in Kochi city.
What is the main engineering challenge, and how will construction affect marine traffic?
The main engineering challenge is constructing the tunnel 35 metres below the seabed, beneath a shipping channel. While the current channel allows ships with a 14.5-metre draught (with proposals to deepen it to 16 metres), the tunnel will run safely at a much deeper level of 35 metres from the seabed. It will not affect marine traffic or normal shipping activity.
How long will it take to build such a tunnel?
Experts estimate the tunnel work to take around 2.5 to 3 years. Advanced boring techniques available in India, as a similar tunnel was recently constructed in Mumbai, will be used. Tunnel boring will start on land from either side of the road, gradually going below the seabed. The process will ensure there is no disruption to ship movement, fishing, or other maritime activities.
Is there any rise in the project cost since it was first mooted a decade ago?
Yes. The initial estimated cost was Rs 1,500 crore. The feasibility report prepared by K-Rail now puts the project cost at Rs 2,672 crore. Given its financial constraints, the Kerala government has decided to execute the project under the design-build-finance-operate-transfer (DBFOT) model, ensuring that the investment will be borne by the contracting agency.
