Scorpene Submarines — An Edge for Indian Navy’s Submarine Fleet Build-up

The Scorpenes are potent underwater platforms which has added much teeth and confidence to submarine fleet and combat Commanders at sea

Issue: 2/2022 By Vice Admiral Shekhar Sinha (Retd)Photo(s): By Indian Navy, Naval Group
First sea sortie of fifth Scorpene Submarine Ins Vagir

The sixth of Project 75 submarines, Vagsheer, was launched on April 20, 2022 from Mazagaon Docks Limited (MDL) shipyard in Mumbai. The culmination of production of six scorpenes for the Indian Navy is significant in many ways.

India’s sub-surface combat potential had been on the decline with only Kilo Class submarines in the armour which are towards the end of their technical life. The Government of the day had approved a 30-year indigenous submarine building plan in two build lines running simultaneously to produce 24 indigenous boats. However, financial constraints resulted in sanctioning only one line of six submarines for which French DCNS (now Naval Group) was selected as the contractor. MDL was chosen as the partner yard under Transfer-of-Technology arrangement. The submarines, S21-S26 were to be delivered between 2012 and 2016. Regrettably, the construction commenced in 2009, six years behind schedule. By then the existing strength of diesel submarines was on further decline whereas our two adversaries, China & Pakistan, kept adding to their existing strength. China is also in the process of supplying eight submarines to Pakistan which will bring the total numbers to 11 submarines with the Pakistan Navy. All these submarines are fitted with Air Independent Propulsion (AIP), which gives it the ability to remain underwater much longer. A submarine without AIP has to come up to snort/surface to breathe air for running its Diesel engines which in turn charges the batteries for underwater propulsion. AIP overcomes the necessity of air breathing since the fuel cells in the AIP are capable of propelling the boat. None of our submarines, including the Scorpene, have AIP which gives it a handicap. Regular surfacing/snorting makes the submarine susceptible to detection by ships, aircraft and helicopters. Having said that, the Scorpenes have added to the availability of submarines manifold.

Launching of INS Vagsheer, the 6th and last of Indian Kalvari class Scorpene Submarine build by MDL

Four submarines have joined the operational formations and the last two are under extensive sea trials. It is expected that by 2023 both the submarines will be in the operational Squadrons. The Scorpenes bring a number of capabilities with them. They perform anti-surface vessel, anti-submarine and ISR/Special Operations roles. She can carry variety and combination of weapon loads which can be discharged from her six torpedo tubes. With total load of 18 Black Shark/SUT torpedoes, Exocet SM39 anti-ship missiles and 30 mines. There is feasibility of carrying A3SM MICA anti-aircraft missiles too. The submarine is fitted with state-of-the-art C303/S antitorpedo countermeasure system which gives it the defensive capability to deflect an incoming torpedo away from line of fire thereby improving its survivability in dense ASW battle space environment.

The sonar systems are highly advanced Thales S-Cube integrated and modular sonar suites which offers safety against wide variety of threats in deep and shallow coastal waters. It comprises sonar arrays, including bow, stern, planar flank, intercept, distributed, towed and active, as well as mine and collision avoidance sonars and self-noise monitoring hydrophones. In addition, the submarine has Sagem surveillance and radar system giving it ability to detect and identify surface targets. Thus, the Scorpenes are potent underwater platforms which has added much teeth and confidence to submarine fleet and combat Commanders at sea.

With the ability to remain underwater for 21 days and attain maximum submerged speeds of 20 Knots it can give run for money to any adversary. It’s ability to dive down to over 350 meters adds to its ability to remain undetected at will when operating in defensive mode.

Platform management system has been fitted for integrated control of propulsion, electrical, auxiliary and safety systems.

Once the DRDO developed AIP is proven on a submerged platform and retrofitted on the Scorpenes, its potency will increase manifold. In the overall analysis the Navy has added to its sub surface offensive combat power, surveillance and special operations capabilities while improving its defensive and survivability aspects.