Why INS Kalvari is Very Important for Indian Navy

INS KALVERI during sea trials, Wikimedia Commons

Just a week to the moment we have been waiting for. The Indian Navy can breathe a sigh of relief as it waits to induct the first of Kalvari class attack submarine, INS Kalvari.

Ins Kalvari, would be Indian Navy’s newest sub induction in 17 years, the last being INS Sindhurashtra in 2000. Designed by the French giant DCNS, it is the first of the Kalvari class (Indian version of Scorpene class) being built in India.  The subs are built under the modernisation drive christened ‘Project 75’ to acquire state-of-the-art attack submarines to aid the ailing submarine fleet of the IN.

The project was awarded to French firm DCNS for their Scorpene class submarines. The work started on April 1, 2009 and was commissioned for trials by then Defence Minister Manohar Parrikar on April 6, 2015. The delivery was expected in 2016 but got delayed due to ‘extensive’ trials.

INS Kalvari during sea trials

Project 75 was a life saver for Indian Navy, who faced massive criticisms for its obsolete Soviet subs. Another important aspect of P75 is that, all subs would be fabricated in India and about 30% of the equipments are sourced locally. Advanced electronics and additional systems are R&Ded in Indian labs to be integrated into coming subs.



An infographic on Scorpene class subs, Credits:NST Graphics
  • Designer: DCNS (France)
  • Manufacturer: Mazagon Docks Ltd, Mumbai
  • Class: Scorpene/Kalvari class
  • Subtype: CM-2000
  • Displacement: 1590 tonnes (submerged), 1450 tonnes (surfaced)
  • Length: 63.5 m (202 ft)
  • Beam: 2 m (20 ft)
  • Draught: 4 m (18 ft)
  • Draft: 8 m (19 ft)
  • Propulsion: Diesel-electric, batteries (AIP in future)
  • Speed: >20 knots (37 km/h) (submerged), >12 kn (22 km/h) (surfaced)
  • Range: 6,500 nmi (12,000 km) at 8 knots (15 km/h; 9.2 mph) (submerged) ,  550 nmi (1,020 km) at 5 knots (9.3 km/h; 5.8 mph) (surfaced)
  • Endurance: 40 days (compact) , 50 days (normal)
  • Test depth: >350 metres (1,150 ft)
  • Crew: 32

Since submarine technology is heavily guarded by countries, the above information is bound for change. Insider input suggests some key changes can be expected in the Kalvari class subs.

  • Superior stealth capability: Kalvari class boasts of superior stealth than previous diesel-electric submarines. This gives thin deep strike capability giving an upper hand in specialised operations like mine laying, area surveillance, Anti-Submarine warfare, intelligence gathering.
  • High level of system redundancy: DCNS promises a massive sea-time of 240 days per year due to its high system redundancy.
  • Strengthened Hull: Incorporation of high tensile steel (80HLES) in hull fabrication enables the sub to operate under a max. Pressure of 700MPa.
  • Advanced Indigenous systems: DRDO is working on health monitoring for both P75 and P75i subs.
  • Air Independent Propulsion (AIP): DRDO subsidiary Naval Material Research Labortaries (NMRL) is developing air independent propulsion. It would enable the submarine to remain submerged longer and gives a much less noisy audio profile.
  • SUBTICS combat management system and advanced Sonar suite for enhanced enemy detection.


  • 6x 533mm (21 in) Torpedo tubes: Purchase of 98 torpedoes from WASS (a Finmeccanica/Leonardo company) remains suspended, due to Augusta Wetland case.

As a worthy alternative Indian made Varunasthra heavyweight torpedoes are considered.

Indigenous heavy weight torpedo Varunasthra test fired from an IN ship. credits:IndianNavy
  • Anti ship missiles: MBDA’s tube-launched Exocet SM-39 anti-ship missiles.
  • Mines: Mines only configuration capable of deploying 30 mines.
Then Def Min Manohar Parrikar after commissioning INS Kalveri

The Kalvari class is definitely a mighty boost for the Indian Navy’s flotilla. The recent reports of increased Chinese presence in Indian Ocean region could be effectively tackled with this modernization drive. Even though concerns regarding Pakistan navy are minimal, their extreme closeness to Beijing could prove fatal. If reports are to be believed Pakistan navy has already begun construction of 8 Chinese Type 039B, an export variant of Type 039A subs. These subs are near comparable but still are far away from integrating advanced mission control systems that Kalvari class is to possess.

INS Kalvari was the name of the first Indian submarine (S23), a Soviet Foxtrot class submarine. It served the Indian navy from 1967 to 1996.

The IN will get their hands on state-of-the-art sonar suite includes a long-range passive cylindrical array, an intercept sonar, active sonar, distributed array, flank array, a high-resolution sonar for mine and obstacle avoidance and a towed array. This gives her the ability to detect enemy presence quicker and act swiftly.

With the P75i project on its development stages, Indian Navy is about to take a massive arsenal upgrade to counter enemy activities in her waters and re-kindle her dreams of becoming a ‘Blue Water Navy’.