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Submarines – The Growing Relevance

At present we have severe constraints both in conventional submarine as well as SSBN deployment capability. The absence of SSN imposes a serious capability deficit in our tactical choices.

Issue: 5-2021 By Vice Admiral K.N. Sushil (Retd)Photo(s): By Indian Navy
Torpedo Firing Trials of INS Kalvari

The Past

In the Battle of Jutland, Admiral John Jellicoe failed to deliver the prescribed Mahanian “coup de grace” on the retreating Imperial German Navy’s High seas fleet under Admiral Reinhard Scheer, because he feared that Scheer may lead him into a torpedo trap. Admiral Scheer on the other hand, despite having inflicted greater causalities on the Royal Navy’s Grand fleet, felt that the High Seas fleet could not challenge the Royal Navy and would recommend the extensive use of submarines. The 1915 Sussex pledge was rescinded and the Zimmerman telegram of January 1917 announced the beginning of unrestricted submarine warfare. In Jutland, though both parties understood the power of the submarine, it was not openly acknowledged. Subsequently, World War II saw some very impressive submarine actions in almost all maritime theaters, their prowess limited by the limitations of technology of those times.

The end of the Second World War saw the emergence of the Aircraft Carrier as the fountainhead of Naval power. Carrier Battle groups were the objects of desire of almost all navies. The post WW II era saw the emergence of the nuclear submarine. That development was the final stage in the metamorphosis of the submersible to a true submarine. The Cold War security paradigm was based on Nuclear Deterrence, and the stability of deterrence depended, paradoxically on MAD (Mutual Assured Destruction). The SSBN, because of its unmatched stealth and endurance, was the most reliable platform on which to base the assured second-strike capability, so vital to deterrence. The SSBN also represented the role metamorphosis of the submarine, from an “illegal” commerce raider to the final arbiter in deterrence. The SSN with unlimited endurance and high speeds gave the submarines the ‘seek and destroy’ capability allowing the submarine to act effectively in both, sea denial and sea control roles.

A close look at historical progress of our security and technology challenges will reveal similarities in the post-World War II saga of submarine development. There were perceptible ongoing efforts in Pakistan in the eighties towards creating a nuclear weapons capability, that became the starting gun for a subdued sub continental nuclear arms race, analogous to the beginnings of the cold war.

Two decades after independence INS Kalvari, ushered in the Indian Navy’s submarine capability. In the 1971 baptism by fire the submarines acquitted themselves well in the tasks assigned to them, but did not sink any ships. This was essentially because strict positive identification was mandated in the Rules of Engagement. Pakistani submarines scored one hit, but lost PNS Ghazi.

As early as 1966 the Indian Navy had embarked on developing indigenous surface ship building capability. The surface ship building programme was indeed a great success story which continues to deliver state of the art ships to the Navy. As far as Submarines were concerned it would be almost two decades after the arrival INS Kalvari, that Mazagoan Docks would undertake the construction of INS Shalki, with design and construction assistance from Germany. Another two decades later, after having constructed two submarines we would once again seek foreign assistance, this time from the French, to design and construct the P75 submarines.

The delays in the delivery of Project 75 submarines, the aging of the Shishumar and Sindhugosh classes of submarines and nonimplementation of P75(I) will have a telling effect on our conventional submarine force level availability and operational viability

It is important to note that in the eighties, using design knowledge gained from the German submarine deal, tentative attempts were made to ‘technology demonstrate’ submarine nuclear propulsion. The ATV programme, started in 1990, would become the vehicle through which our nuclear submarine building was progressed. INS Arihant, the first submarine of this class was launched in 2009 and commissioned in 2016. The puzzling question is Why is it that we, who can build quality warships, have not yet developed indigenous submarine design capability, despite the stipulations in the 30-year submarine construction programme and experience gained from the HDW, P75 and ATV construction programmes?

The Present

The delays in the delivery of Project 75 submarines, the aging of the Shishumar and Sindhugosh classes of submarines and non-implementation of P75(I) will have a telling effect on our conventional submarine force level availability and operational viability. Torpedoes intended for the P75 have not yet been inducted. The inability of the DRDO to deliver the AIP system would mean that no submarine will have that capability in the near future. This will stymie the tactical capabilities of the submarine considerably. Without AIP the submarines will have a higher forced indiscretion rate that would make them vulnerable to modern airborne surveillance. Recently the ISI had posted a video of a snorting submarine (definitely not ours) being tracked by their maritime patrol aircraft. INS Chakra, during the currency of the lease had provided us great tactical advantages in submarine operations in most aspects of the conventional warfare spectrum. The return of the submarine compresses our tactical choices to some extent. For example, it will be difficult for a conventional submarine to shadow an enemy nuclear submarine for considerable durations.

Our SSBN capability is currently based on INS Arihant and INS Arighat (reportedly ready for commissioning). These will be followed by two more submarine that would, reportedly, have greater payload.

The value of deterrence of a SSBN is based on the weapon range and the embarked payload. INS Arihant currently has the capability to launch 12 short range ballistic range missiles. Patrol areas for submarines are so chosen that they can launch simultaneous attacks on their designated targets. If we took two important targets separated by a distance, it is obvious that the submarine must be in the area where the missile range arcs, drawn from these targets, overlap. Therefore, for the enemy it is easy to derive such ‘vulnerable’ areas and focus their ASW surveillance efforts. Therefore, short-range ballistic missile imposes severe limitations that increase the vulnerability of the submarine to sustained and focussed surveillance....a risk they can ill afford to take. The second severe limitation that short range missile imposes is that the submarine will have to transit long distances to their patrol areas, thereby limiting their actual time spent in the patrol area. The second SSBN when commissioned will reportedly have much longer-range missiles however, the payload will only be four missiles. While a missile each can be launched at different targets, the effectiveness of such an attack needs to be analysed. Even with these missiles the submarine will have to transit long distances to their patrol areas. With these limitations our ability to sustain deterrence patrols is severely constrained. This will seriously affect the credibility of deterrence.

Delivery of Fourth Scorpene Submarine ‘Vela’ to Indian Navy

In the present we have severe constraints both in conventional submarine as well as SSBN deployment capability. The absence of SSN imposes a serious capability deficit in our tactical choices, especially if a deterrent riposte mission is required.

It is not as if the submarine force level requirements were not foreseen. The Thirty-Year Submarine construction programme was a clear road map for acquisition of National Competence in Submarine Building. This was a CCS approved directive in which even the first part of the first phase has not been completed thus far. Between 2008–2009 the requirement for more capable SSBNs with long range missiles and SSNs was accepted by the government. Some reports appearing in the media indicate that approvals for constructing SSNs and newer more capable SSBNs have been approved. In this scenario the first submarine under P75(I) would take at least a decade to fruition. The SSN and SSBN programme will take much longer, at least 15 years. After the AUKUS announcement there were reports that France, miffed with the loss of the Australian deal, are willing to offer the Barracuda class submarine to India. If this were to happen, it would not only enable us to deploy a credible SSN in a reasonable time frame but, more importantly allow us to overcome technical and technological infirmities that have thus far prevented us designing and constructing submarines.

The Future

After the second Pokhran testing in 1998 our status changed to a de-facto nuclear weapons state. The Nuclear doctrine announced a Credible Minimum Deterrence capability based on No First Use. The deterrent capability was envisaged to be delivered from a triad of land, sea and air delivery platforms. The ATV programme was initially intended to construct an SSN based on the first Chakra. Realising the importance of a submarine based nuclear weapons capability the design of the SSN was suitably modified to give it the vertical launch capability. The first SSN morphed to an SSBN, much like the USS George Washington launched in 1959. This is a good example of how a tactical program was modified to deliver a strategic platform that would attempt to provide capability dictated by the Nuclear policy.

The thirty-year submarine construction programme is a good road map for building up the conventional submarine capability. The SSN and the new SSBN programmes need to implemented as quickly as possible. Maybe the Barracuda offer may be able to hasten the programmes.

A look at the developments so far indicate that our submarine induction plans were well thought out. What we need is to identify the reasons why we failed to establish an indigenous submarine design and construction thus far. Our brilliant success in the surface warship building programme needs to replicated for submarines. One of the most important steps that the Navy took to establish the design and construction capability was to identify and standardise the shipbuilding steel.

The conventional and nuclear submarine design and build requirement pose immense challenges. There is a crying need to approach the problem holistically and create an integrated submarine design agency that can spell out areas, materials, systems, equipment and processes which are common across platforms, so as to bring in optimum economy of effort and economy of scale. If, for example the torpedo is common then the weapon control system can become common. This could be applied to periscopes, radars and ESM systems. Sonars would have to match the form and other platform specific idiosyncrasies, but the materials and processing technologies would be from the same stable. The success of USHUS and PAYAL validate this. Similarly with many systems and equipment that support the platform functions - HP air, Hydraulics firefighting and DC etc.

In short, the industrial support system and the MSME involvement needs to be modelled in the same lines as it obtains in most submarine manufacturing nations. A comprehensive submarine build ecosystem that would truly ensure Atmanirbharta.


In the late eighties, whilst the induction process of the Shishumar and Sindhugosh class submarines was underway, agreements were signed with the erstwhile USSR for the induction of the Gorshkov and the lease of a Charlie Class SSN. The nineties saw this cooperation extending to many high-tech areas resulting in the induction of missile launch capable submarines and establishing the BrahMos joint venture company. It was also about the same period that the Chinese PLA Navy began induction of the 877EKM Class submarines. The Chinese were also leaning on the Russians for defence cooperation. The Chinese were struggling with the 092 Xia Class SSBN. They were already working on the 094 Jin Class SSBN which looked very similar to the Russian Delta IV. The 094 was first noticed in 2006 or 2007 about two years before the launch of INS Arihant.

In the eighties and nineties, the Chinese technological capabilities were probably same as (if not inferior to) ours. It is pertinent to mention that when the Peace and Tranquillity Treaty was signed in 1993, the technology and capability levels may have figured in our back-ground calculations. In almost three decades after signing of this treaty the technology and capability trajectories show stark differences. The Chinese have six Type 094 SSBNs already commissioned. These submarines carry 12 long range JL2 missiles. They are progressing on the improved Type 096, six of which are planned to be inducted shortly. They appear to have sorted out design deficiencies of the Han class and are reportedly progressing the 093 Shang Class SSNs. After having acquired the 877EKMS in the nineties they now indigenously design and manufacture the Yuan class. The developments on the Indo-Chinese border indicate a slow moulting of the Peace and Tranquillity agreement. The visible disparities in our mutual capabilities appear to erode the prevailing deterrence as Chinese attempt to alter the status quo, slowly and inexorably.

When one party decides to alter the status-quo then deterrence has failed. To be able to sustain deterrence there most be a perceptible power to hurt that is held in reserve. As Thomas Schelling notes ‘Power to hurt is a bargaining power. To exploit it is diplomacy.’ The SSBN represents that power, especially in a NFU scenario, because the weapons carried in board are readily and instantaneously deployable.

We need to bridge the capability gap quickly so that Credible Minimum Deterrence is indeed credible. It is obvious that a stated policy without commensurate capability will lack credibility. We have promises to keep and miles to go before we sleep.

The writer is former Inspector General, Nuclear Safety and FOC-in-C, Southern Naval Command. He was the senior-most submariner of the Indian Navy at the time of retirement.