Indian Navy has for many years had an interest in midget submarines

Defence major Larsen & Toubro (L&T) will display it's SOV-400 diesel electric midget sub. Fitted with twin torpedo tubes & with advanced conformal sonar & radio electronic sensors.

Susceptibility to subsurface attacks has led the Indian Navy to regenerate interest in procuring two mini-submarines from private manufacturer Larsen & Toubro (L&T) Defence. This diesel-electric midget submarine designed and developed by L&T Defence is called the SOV400. An IN order could extend to six vessels, Shephard has learned.

Displacing less than 490t, the 44m-long SOV400 is fitted with a conformal-array sonar and radio frequency sensors for detection, surveillance, planting limpet mines, communication and interception.

The SOV400 is primarily meant for deployment and recovery of special forces, and thus it can carry two four-person swimmer delivery vehicles.

The SOV-400 appears optimized for Special Forces missions, carrying 10 SF operators. Two 4-person SDVs (Swimmer Delivery Vehicles) can be hung on the lower hull. This gives the SF combat swimmers a means to conduct longer-endurance missions. So for a cross-beach mission a 4-6 person team could be inserted by the two SDVs, with two remaining as drivers. 2 more SF personnel would remain aboard the SOV-400 to coordinate and support the mission according to a report by defence website Covert Shores.

For self-defence, or targets of opportunity, the SOV-400 is armed with two 533mm (21") heavyweight torpedoes carried externally. There is a modest sonar in the bow, but logically this will primarily be for surface targets. The exact model of torpedo is unspecified and likely to be adaptable to customer needs.

SOV-400 Specifications

Displacement: <490 tons surfaced, <550 tons submerged
Length: 44 m
Beam: 4.3 m
Operating Depth: 100 m
Speed: 10+ kt submerged, 6+ knots surfaced
Operating depth: 1,000m (3,300ft)
Power plant: 2 x 400 kW generators driving 1 x 300 kW electric motor
Crew: 10 + 10 PAX
Endurance: 21 days
Armament: 2 x 533mm (21") heavyweight torpedoes
Payload: 2 x 4 PAX swimmer delivery vehicles (SDVs)