Submarines are sea-denial platforms

by Vice Admiral Biswajit Dasgupta (Retd)

The armed forces of the country are equipped and maintained at a great cost. Military hardware is exorbitantly expensive because of several factors, three important ones being the use of leading-edge technology, hardening to withstand shock and vibration caused by battle action and small production quantities that do not allow economies of scale. Technology denial and proprietary nature of several military goods further escalate costs of imported equipment or components.

Submarines are sea-denial platforms, which means that they deny freedom of operation to the adversary’s forces by virtue of their stealth.

The Army is human-intensive, while the Navy and the Air Force are equipment-intensive. The substantial budget allocation of the Navy is maintained at a capital to revenue ratio of 60:40. This means that 60 per cent of the Navy’s budget is spent on modernisation, new platforms and equipment, while 40 per cent is expended for fuel, repairs, pay and allowances and other running costs.

Of the platforms operated by the three services, naval ships and submarines are, by far, the most expensive. A major warship or a conventional submarine would cost approximately Rs8,000 crore at today’s prices. A nuclear-powered submarine would cost much more. This cost is spread over the contract period and build-time of the platform, which could range from five to ten years. So, apart from costing a fortune in public money, accretion of naval assets is time-consuming. The platform would also have to serve the Navy effectively for 30 years or more after its induction. This underscores the critical importance of decision-making about force levels and platform mix.

The Navy comprises ships, submarines and aircraft of several types. Budget limitations result in competing demands and, therefore, debates arise about what platforms and how many of each the Navy must have. Sometimes, ridiculous suggestions are made, like “Choose what you want, aircraft carriers or submarines?” A high school student would be able to understand that one cannot do the work of the other. Coming to a slightly more nuanced discussion, some people suggest, “Choose between conventional and nuclear-powered submarines.” Again, if one could substitute for the other, logic defies building separate categories in the first place.

Submarines are sea-denial platforms, which means that they deny freedom of operation to the adversary’s forces by virtue of their stealth. To appreciate the capability of submarines, an understanding of the broad categorisation of submarines would be in order:

Other factors that determine optimal submarine deployment are dived speed and dived endurance (speed and endurance of the submarine when traversing under the surface), requirement to recharge batteries (for conventional submarines) and underwater noise radiated by the submarine. The dived endurance of nuclear-powered submarines is limited only by human fatigue and resupply of provisions. Conventional submarines have less endurance and their stealth is compromised by the need to surface for recharging batteries that run electric propulsion motors when submerged.

Nuclear-powered submarines are larger and heavier than conventional submarines. They are also noisier, making them more susceptible to detection by anti-submarine forces. On the other hand, they have much higher dived speeds that permit unrestricted options for attack and speedy withdrawal. All modern submarines have long-range guided weapons for carrying out stand-off attacks.

The type of submarines to be acquired by the Navy and their deployment are, therefore, functions of capability creation for foreseen conflict scenarios. Just as a surface ship cannot do the work of a submarine, a conventional submarine cannot do the work of an SSN. If future scenarios envisage ingress of enemy carrier task forces or large numbers of warships into the Indian Ocean, only SSNs can provide effective sea denial. The type and number of submarines we make or acquire should depend on affordability and threat perception. Any comparison akin to that between apples and oranges will be futile.