Kamorta Class : Analysis of India’s Deadly Anti-Submarine Corvette | World Defense

Kamorta Class : Analysis of India’s Deadly Anti-Submarine Corvette


Nov 26, 2017
248 23 0


Anti-Submarine corvettes are a particular class of ships which are the unsung heroes in a Navy. They are overshadowed by frigates, destroyers and aircraft carriers and seldom get the attention they need from the public. Many navies lack this category of ships as they depend on bigger combatants to do the job. But the increasing threat of modern submarines has made Anti-Submarine Warfare (ASW) ships, a basic need for a powerful Navy. Different navies have different designations for their ASW ships. The US Navy has the Littoral Combat Ship, the Royal Navy depends on bigger ASW frigates, the Russian and Indian Navies uses ASW corvettes and so on. Each navy has different tactics and roles for their ASW ships, so here in this article, we will analyse the Kamorta class ASW corvette of the Indian Navy and see what it is capable of.

Since 1968, ASW corvettes have been a part of the Indian Navy’s operational strategy. They procured 11 Petya class frigates from the Soviet Union between 1968-72 and designated them as Arnala class ASW corvettes. These 1150 ton ships were fast and good at ASW, but had the following drawbacks.

  • They lacked the range and endurance for blue water operations
  • Had poor quality hulls which needed major and frequent refits
  • Lacked the ability to carry an ASW helicopter
  • Had almost no self-defense capability
An Arnala Class corvette of the Indian Navy fires its RBU-2500 ASW rockets
These corvettes were restricted to escort role for missile boats which were also short-range vessels. They were also used to a limited degree as ocean-going escorts. The Indian Navy was happy with these ships in the following role until its transition into an aspiring blue water navy. They realized that these ASW corvettes needed to be replaced by a ship which overcame all the drawbacks of the existing class. They also needed a ship which would be equally effective in the littorals as well as in the deep oceans. This resulted in the development of the Kamorta class corvette. The Kamorta would offer the following performance enhancements over the Arnala class.

  • Thrice the displacement, resulting in more space for weapons and sensors
  • Provision of hangar and helipad for an ASW helicopter
  • Advanced radars and sonars
  • Long endurance, enabling it to operate in blue water
  • Ultra quiet propulsion and engines
  • High standard build quality
  • 1519732623604.png
  • The Kamorta class has been designed for the sole purpose of hunting submarines. It has a displacement of 3400 tons, a length of 109 m and a beam of 13 m. These dimensions are comparable to that of a frigate as the Kamorta has been designed for blue water ops as well. The Kamorta is touted by the Indian Navy as having over 90% indigenous content. The steel and composites which have been used in construction are indigenously made along with a majority of the weapons and sensors. It is powered by 4 Pielstick diesel engines generating 3888 kW each, which drive 2 controllable pitch propellers via the gearboxes. Each ship has a crew of 150 sailors and 15 officers and a very ergonomic design which focuses on crew comfort.

    It has the following advanced design features which make it a suitable platform for submarine hunting.
    • X-form hull with sloped superstructure sides which reduce radar cross-section and make it very stealthy.
    • Raft mounted gearbox and engines, which damp the vibrations and reduce the acoustic signature of the ship. This is important to remain undetected from hostile submarines.
    • Range of 6500+ km at 18 kts ( 33km/hr) which allows long deployments
    • Combined Diesel and Diesel (CODAD) propulsion for quiet and efficient running of the ship
  • You can see from this that special emphasis has been laid on reducing the acoustic signature of the ship as much as possible. This is very important while it is searching for hostile submarines. The Kamorta needs to detect the submarines and engage them before it itself is detected and engaged.

    The Kamorta is the first ship of the Indian Navy to be operationally deployed with an indigenously developed primary radar. The Revathi is a 3D radar operating in the S-band. It is a multi-role radar and is used for both surface and air search up to a distance of 200 km. It is designated as the Central Acquisition radar (CAR) as it is used to acquire aerial and surface targets before the fire control radar can direct the gunfire towards them. It will also act as a target acquisition radar for the VL-Mica surface to air missiles which will be fitted in the future. This missile doesn’t need a fire control radar as it has an active radar seeker in its nose which finds and locks onto targets on its own.

    Revathi 3D CAR
    The TMX EO Mk2 is an X-band fire control radar with secondary electro-optical and IR sensors for targeting. 2 such radars are fitted, one at the fore and another at the aft. The one at the fore provides fire control for the 76 mm gun and the one at the aft provides fire control for the Ak-630 guns.

    TMX EO Mk2
    They have an indigenous bow mounted sonar and an Atlas Elektronik towed array sonar. The bow sonar is the primary underwater sensor and the VLF towed array is used to detect submarines hiding under thermoclines in the water. The sonar gives targeting data for the ASW rocket launcher. The embarked helicopter will have its own dunking sonar and drop sonobouys as well.

    The Indian Navy needed a ship which has the armament of a 1200 ton corvette and the endurance of a 3400 ton frigate
    The weapons suite comprises of a collection of systems to attack submarines and defend itself. The following weapons are present on the Kamorta
    • 1 x 76 mm Oto Melara Super Rapid Gun Mount (SRGM) for engaging surface and aerial threats up to 16 km away.
    • 2 x RBU-6000 ASW rocket launchers designated as IRL (Indigenous Rocket Launchers). Each launcher is 12 barreled and has a reload of 96 rockets under the deck. They are retained because of their hardkill ability and immunity against countermeasures. These rockets have a range of 4500 m and a shaped charge warhead which can be set to explode at a particular depth. It can punch a hole in the hull of a submarine or be used to defend against an incoming torpedo. The rocket, after it is fired, reaches the required location and falls in the water where it sinks until it reaches its target. Usually, 24 rockets with various warheads are ripple fired against the incoming target to achieve maximum kill rate.
    • 2 x Ak 630 Gatling guns are placed above the helicopter hangar. They are the Close in Weapons System (CIWS) and are used for last-ditch defense against anti-ship missiles. This 30 mm 6-barreled gun has a rate of fire of 5000 rounds per minute and can be used to engage aerial targets at a range of 3 km and surface targets at 4 km.
    • 533 mm torpedo tubes for launching heavyweight torpedoes. These have a maximum engagement range of around 20 km.
    • Space left for the installation of 16/32 VL-Mica Surface to Air Missiles. They will be procured under the category of SR-SAM and locally named as Maitri.
    • 1 helicopter hangar for housing an ASW helicopter. The S-70B Seahawk will be embarked on it in the future after the Indian Navy receives it. This will be an extremely vital weapon system as the helicopter can engage submarines several hundred kilometers form the ship.
  • ak630.png
    Ak-630 CIWS
    76 mm Oto Melara Super Rapid Gun Mount (SRGM)

    The Kamorta is not under-armed, but over-sized
    There is a widespread misconception that the Kamorta is poorly armed for a 3400 ton ship. But it is very wrong to look at things like that at face value without understanding the logic and naval doctrine for behind them. The Indian Navy needed a ship which has the armament of a 1200 ton corvette and the endurance of a 3400 ton frigate. Basically it is not under-armed, but over-sized. By 2017, it is expected to receive its SAM package consisting of 16-32 VL-Mica missiles which have a range of 15 km and an active seeker. This missile can intercept sea-skimming and supersonic cruise missiles and protect the Kamorta class from submarine launched cruise missiles.

    533 mm torpedo tubes A Kamorta Class Corvette under construction. Note the space where the SR-SAM will be installed in the future.
    However, one question always arises. “Why build an ASW corvette with limited capabilities, when you can build a multi-role frigate which can do much more?”

    The answer to this question can be obtained from observing the latest ships in the Indian Navy. The Shivalik class frigates and Kolkata class destroyers have an ASW specific equipment suite consisting of ASW rocket launchers, torpedo tubes, medium range guns, anti missile guns, sonars and surface to air missiles. What the Kamorta does is it just puts all the ASW and self-defense equipment from these 6400+ ton ships on a 3400 ton ship. This means that you now have a ship with the same ASW capabilities as a larger one and at a fraction of the total cost! So instead of sending a 1 billion $ destroyer for patrolling the oceans to hunt submarines, you can send a 250 million $ corvette to do the same job, just as effectively. This allows the Indian Navy to have 4 such corvettes for the price of 1 destroyer.


    The main role of these ships will be to hunt the quiet submarines of Pakistan’s growing underwater fleet and the Chinese submarines which have been venturing into the Indian Ocean. 4 ships of this class have been ordered under Project 28 and a further 8 may follow on. There is no official information available regarding how the Kamorta class will be used in combat. That’s why i have presented the following ideas about what these ships will do during war and peace.
    • Carrier Escort
  • INS Vikramaditya being escorted by the frigate INS Talwar
    In this role, it will accompany the aircraft carrier and be integrated into the carrier battle group (CBG). It could be used as the initial detection screen where it sails 50 km ahead of the CBG and searches for submarines waiting to ambush the carrier. It can be paired with friendly submarines and ASW aircraft like the P-8I to offer superior protection to the aircraft carrier. It may be integrated into the INS Vikramaditya CBG in the future along with the Talwar class frigates and Kolkata class destroyers.
    • Littoral Warfare
  • inskirch.jpg
    Kora class corvette
    In this role, it will basically accompany the Kora and other classes of missile boats which serve in the Indian Navy during operations in shallow water. These missile boats lack any sort of ASw capability and will be totally dependent on the Kamortas for protection. A similar combination was used successfully by the Indian Navy in the 1971 war.
    • Surface Combatant Escort
  • In this role, they basically accompany a major surface combatant like a frigate or a destroyer. Here, the Kamorta will act as a mini frigate with the same ASW capabilities as the larger ship. Hence larger ships can be saved for more important tasks.

    INS Kamorta with the frigate INS Satpura
    • Submarine Shadowing
  • Instead of sending a 7000 ton destroyer just to shadow an enemy submarine, a Kamorta class corvette does the same job. It will be more economical than sending a larger ship and the destroyers can be used for more important tasks. They will be used in peace and war to trail hostile submarines and destroy them if needed. These ships will be networked with ASW aircraft for more efficient tracking and detection of submarines.

    P-8I ASW aircraft

    INS Kamorta in China during a naval exercise ©Liuwangne

    The Kamorta class are future proof and will remain as front line warships for several decades. The total number of ships in the class may end up being 12 if the Indian Navy goes for a follow on order of 8 more ships. These ships will be vital for patrolling Indian and International waters and keeping shipping lanes free from hostile submarines. Constant upgrades in the future will keep them in top fighting condition and give a headache to hostile submarines.


Nov 26, 2017
248 23 0
I know its an old article but well worth reading .

Joe Shearer

Nov 25, 2017
995 70 0
Have they undergone a recent upgrade. Some looks dusty to me.

Definitely so.

On another note, I've just sent a detailed backgrounder to @jbgt90 for his viewing before submitting it to the forum. To me, knowing what these ship categories are, and what they were in the recent past and the distant past, is an irreducible minimum for thinking about these things.

I also thought it would be useful, a little less than a discussion of ship classes, to remind readers about the underlying ship names derived from the Age of Sail, but perhaps that should come later, and in a foundation thread on naval matters.

Joe Shearer

Nov 25, 2017
995 70 0
As a supplement to the OP, I offer some explanations and elaborations of these ship names, that might help us to understand why some things are considered strange, some others, seemingly strange, are accepted in a matter of fact way.

  1. Going into the Second World War, Britain had Battleships, Heavy Cruisers (8” main guns), Light Cruisers (6” main guns) and Destroyers, besides Aircraft Carriers, in the Fleet. There were smaller boats for in-and-out work, the motor boats, the gun boats, the torpedo boats (recall that the name “Destroyer” was originally Torpedo Boat Destroyer). If any vessel were to go to sea, either in attendance on a fleet or on its own, or along with other boats, it was generally termed a sloop or a cutter.
  2. Corvettes and Frigates were new categories, war-time responses to the unrestricted submarine war launched by the Germans, which nearly foundered Britain before it was collared. Corvettes were coastal escorts (today’s Littoral Combat Ships) diverted to convoy escort duties. As your article points out, they were quick and agile, but in the very rough sea conditions of the North Sea and further, on the Russia convoys, they were miserable vessels for the crews. The larger displacement frigates were built to overcome these difficulties.
  3. This transition to higher tonnages and displacements is precisely what is happening to Indian corvettes. Why we do not rename the ‘corvettes’ as light frigates is not clear.
  4. Before this, during the Age of Sail, the Royal Navy had Ships of the Line – they gave their name, in their shortened form, to the capital ships of pre-carrier maritime hierarchy, from Line of Battle Ships, to Battle Ships. These, and smaller vessels, were rated as
    1. First Rate – formerly known as Royal Ships, then as ‘first rank’, then as this ‘Rate’
    2. Second Rate – formerly Great Ships, then as ‘second rank’, then as this ‘Rate’
    3. Third Rate – formerly Middling Ships, then as ‘third rank’, then as this ‘Rate’
  5. Around the time of the Napoleonic Wars, ‘rank’ was substituted by ‘rate’. Thenceforth, ships were known by their ‘rate’.
  6. The largest, First Rate, Second Rate and Third Rate, were Ships of the Line, or Line of Battle Ships, giving rise to the later name Battleships. There were smaller ships; initially, the levels below the ‘third rank’ were populated by sloops, corvettes and cutters
    1. Fourth Rate – formerly Small Ships
    2. Fifth Rate – new category from the Napoleonic Wars era
    3. Sixth Rate – new category from the Napoleonic Wars era
  7. The names from the WWII categories were variously derived. ‘Cruiser’, ‘frigate’, ‘corvette’, ‘battleship’ (or close to that), ‘sloop’, ‘cutter’, were all earlier names, but then they were used in a hugely different form and for hugely different vessels.
  8. ‘Battleship’ was in the Age of Sail a Line of Battle Ship, or a Ship of the Line. In the naval practice of that period, starting from about a half-century after the encounter between the Spanish Armada and the English Navy, it was customary to assault the rival fleet in line ahead formation, all vessels in the fleet able to fire sufficient weight of cannon balls being in that line; other, smaller, lesser-gunned ships stayed out and skirmished.
  9. There are incidents from the Anglo-Dutch Wars when a deadly sea battle was interrupted by helpless laughter when the English King’s yacht, a tiny little cockleshell next to the mammoths battling it out over its head, got within gunshot of the Dutch flagship and fired off its popgun at the bigger ship. The Dutchmen were laughing too hard to retaliate.
  10. Readers of the Hornblower series will recognise the 74 as a typical Third Rate ship, the smallest of the Ships of the Line. This was a typical gun array on a two-decker ship.
  11. ‘Cruiser’ actually came as a smaller ship than a ‘frigate’, as ‘frigates’ were built heavier, with far greater gun complements. The Royal Navy had this unfortunate habit of building frigates with smaller gun complements – 28 was not uncommon – and in their engagements with the ‘Continental’ Navy of the American insurgents, they were often overwhelmed by the hugely stronger American 44 gun frigates. ‘Cruisers’, on the other hand, were any ships other than a ‘frigate’ that could be assigned detached duties: carrying despatches, patrolling offshore off an enemy shore, escorting a convoy and protecting it against privateers, with no fear of heavier ships such as ‘frigates’ or ‘battleships’ attacking it. A sloop, or a sloop of war (same thing), could be a ‘cruiser’. Current practice of a cruiser being a battleship in miniature is current, and it was not what it was in the Age of Sail.
  12. A ‘frigate’ was typically a Fourth or Fifth Rate ship with a single deck (with very heavy ‘frigates’, sometimes an upper deck) that supported the line of battle, sailing independently, sometimes fighting independently. Some of the greatest battles at sea in the Age of Sail were ‘frigate’ actions. It was carefully defined for speed and firepower and protection all three optimised to make a good fighting vessel. However, while the British Navy looked for liveability at sea, for crew comfort in extended voyages, most continental powers packed in the maximum firepower and were nonchalant about living space or about living comforts.
  13. The name was re-used by the Royal Navy in WWII to a design for convoy escort, with essentially an ASW role, but with considerably enhanced comfort for the crew at sea compared to the temporary stop-gap corvettes, coastal patrol boats diverted to convoy duties. Again, there are differences between British practice and that of either the Americans or the continental powers; in this case, the relevant continental power being Russia.
  14. The Americans started in the 19th century, in their battles against their former brothers in arms, the British, with very heavy frigates that normally carried the day in frigate actions; the term fell into disuse (as in all navies) during the transition to steel and to coal or oil propulsion; it was then revived in a very confusing way as the term the US Navy used for very heavy destroyers, with large, almost light cruiser displacements. This was reversed, and today’s American frigates are far more conventionally slower escort or dedicated AA, ASW or AShW vessels not engined sufficiently to keep up with a battle fleet or with a carrier task force, as that was not their role.
  15. The term was used after the Second World War and until it was withdrawn and re-applied; there were no frigates in any of the epic US Navy engagements with the Imperial Japanese Navy in the Pacific. It may help to consider the American designations of DDL, DD and DDE: Leader, Destroyer and Escort, corresponding to Royal Navy equivalences of a fleet destroyer, a regular workaholic destroyer and a frigate. The Americans called these a frigate, a regular destroyer and an escort ship! It is good that their usage now conforms to the Royal Navy usage.
  16. The Russians, from the outset, packed their vessels with ordnance; a Russian frigate was designed to fight off threats under the sea, on the sea and over the sea, all alike. This has a bearing on the article that we are reading.
  17. A ‘corvette’, in the Age of Sail, was the French name for a boat (ship in that age was a square-rigged vessel; strictly, all else were boats) that was smaller than a ship with a rating; something like a sloop or a cutter, perhaps larger. In WWII, when the Royal Navy pressed its coastal escorts into emergency service, Churchill suggested using the old French term for these ships. The French had no use for the word; their own fleet was awaiting either confiscation by the Germans in Toulon or bombardment and destruction by the British in Algiers.
  18. ‘Sloops’ and ‘cutters’ were very specific hulls and sail rigs in the days of sail, but are used in a generic fashion for smaller boats of 500 MT or less. It is traditional to call Coast Guard ships sloops (larger) or cutters (smaller), as originally His Majesty’s Department of Excise used precisely the sailing equivalent of those to patrol the shores and prevent brandy smuggling from France into the United Kingdom.
  19. In terms of sail plan, both these were very simple: one mast, a headsail and mainsail for sloop, many (more than one) headsails and one mainsail for cutter; if a simple mainsail for sloop, it is a Bermuda-rigged sloop, also known as a Marconi-rigged sloop, and, if gaff-rigged, it is a Jamaica-rigged sloop.
  20. Considering that the original use was so different from today’s uses, it can be a headache keeping track of what is what, and it can be a greater headache trying to figure out why some naval decision seems odd. For instance, why does the Kamorta configuration raise eyebrows in some quarters? There was some method in this madness, but it is helpful to keep in mind the original application of these terms. I will try to attach a table to clarify the whole thing, soon.