Kerala: First Underwater Tunnel to link Vypin and Fort Kochi

Kerala is set to construct its first underwater tunnel connecting Vypin and Fort Kochi, a major milestone in the state’s coastal highway development. The project, expected to revolutionise travel across Kochi’s busy shipping channel, will reduce the existing 16 km road journey to just 3 km beneath the Arabian Sea.

Project Overview and Key Specifications

Estimated to cost ₹2,672 crore, the twin-tube tunnel will feature a 2.75 km stretch — including 1.75 km of bored tunnels and 1 km of cut-and-cover sections. Each tube will measure 12.5 metres in outer diameter and 11.25 metres in inner width, running 35 metres below sea level. Designed to meet international safety norms, the structure will include emergency stops every 250 metres, escape routes every 500 metres, and a high-capacity ventilation system.

Travel and Economic Benefits

The underwater corridor will drastically cut travel time by up to two hours and reduce monthly commuting costs for passengers by nearly ₹1,500. Currently, commuters between Fort Kochi and Ernakulam rely on congested ferry routes or long detours via the Goshree Bridge. With the new tunnel, passengers are expected to complete the trip in just 30 minutes at an estimated cost of ₹50–₹100, compared to the current ₹300 average.

Decision to Opt for Tunnel over Bridge

An earlier proposal to build an overbridge across the Cochin Port shipping channel was abandoned after experts deemed it technically impractical and financially unviable. KRDCL Managing Director V. Ajith Kumar explained that a bridge would need extreme height to accommodate ship movement and involve extensive land acquisition. In contrast, the tunnel requires only 100 metres of land on each side, offering a cost-efficient and feasible solution.

Related GK Facts

• India’s first underwater metro tunnel was constructed under the Hooghly River for Kolkata Metro in 2017.
• Tunnel Boring Machines (TBMs) are used worldwide for constructing sub-sea and underground tunnels safely and efficiently.
• The Vypin–Fort Kochi route forms a critical part of Kerala’s coastal highway project connecting Thiruvananthapuram to Kasaragod.
• Underwater tunnels typically use reinforced concrete segments to withstand high hydrostatic pressure and seismic activity.

Timeline and Implementation

The Kerala Rail Development Corporation Limited (KRDCL) has been directed to invite Expressions of Interest (EOI) from firms to implement the project. Construction is expected to take about 30 months, with an additional 18 months earmarked for land acquisition. If initiated by April 2025, officials anticipate project completion by September 2027, marking a transformative step in Kerala’s transport infrastructure and coastal connectivity.