Both types – Kilos and Type 209s – are being modernized with new combat systems. Notably, around half of the Kilos can now fire the Klub-S family of tactical missiles. The Type 209s have received the new Atlas Elektronik ISUS-90 combat management and sonar system. But, actual operational availability of the Indian submarine fleet is, of course, much lower than the 14 boats, as several boats are being upgraded.

Homebuilt nuclear submarine program

Meanwhile, India’s homebuilt nuclear ballistic-missile submarine (SSBN), the Arihant, is reportedly under sea trials or close to starting sea trials. Arihant, built under the secretive Advanced Technology Vessel Project, is said to be around 112 meters long with a surfaced displacement of 6,000 tons.

The Arihant was designed largely by Russian design bureaux like Rubin and Malachite, although the Submarine Design Group of the Indian Navy’s in-house Directorate of Naval Design as well as Larsen and Toubro’s submarine design team played important roles.

The Arihant and other follow-on Indian nuclear submarines have been largely built by Larsen and Toubro as well as other key Indian industrial players – both large and small – such as Bharat Heavy Electricals Ltd. and the small, privately owned Shoft Shipyard. However, final assembly of the submarines – mating of the hull sections – takes place at the Ship Building Centre (SBC) in Visakhapatnam.

The only released photograph shows some similarity to the Russian Yankee (Project 667)-class in its sail and fin arrangement. Arihant carries four missile-launch tubes in a blister aft of its sail. Each missile tube can carry three K-15 Sagarika 750 kilometer short-range ballistic missiles or one of the larger diameter, 3,500 kilometer K-4 ballistic missiles.

Developed by India’s Defence Research and Development Organization (DRDO), the K-15 missile has been developed in both sea- and land-launched version known as the Shaurya. DRDO has also performed several test launches of the 3,500 kilometer K-4 missile from underwater launch pontoons at a depth of around 10 meters to simulate launches from a submarine.

Verma has said that the Arihant is expected to become operational in the latter half of 2012. However, the key to gaining initial operational capability is an operational ballistic-missile system.

Construction of at least two more Arihant-class submarines at the SBC is well advanced. The second, Aridhaman, is slated for launching in late 2012 or early 2013. One more Arihant class may be built before construction shifts to a larger type. Indian Navy plans call for the induction of at least three SSNs and six SSBNs in due course.

30-year submarine building plan

To arrest declining force levels, six Franco-Spanish Scorpene submarines were ordered some years ago. In a bold step, all six boats are being built at MDL under Project 75. But the program has run into serious delays. First delivery is now set for 2015, with all six boats to be delivered by 2019. Notably, the last two boats will be fitted with an air-independent propulsion (AIP) system – most likely a DRDO-developed system. Use of AIP will allow the submarine to operate submerged for around two weeks – thereby lowering its indiscretion rate [the ratio of the time required at periscope depth for battery charging to total operating time]. The Scorpene, according to designer DCNS, leverages technology from French nuclear submarines and has a superior indiscretion rate to comparable German-designed submarines. In other words, it can run faster and quieter.

Besides the Project 75, another six AIP-powered submarines are to be procured under Project-75 India (P-75I). Some $9 billion USD has been budgeted for this program. With a stated aim of fast-tracking induction, two of the boats are to be built at the selected foreign shipyard while the remaining four boats are to be built in Indian yards – possibly at government-owned yards as well as a privately owned yard.

Contenders for the P-75I include:

• Germany’s TKMS, with a variant of the Type 214;
• Spain’s Navantia with the S-80;
• Russia’s Rosoboronexport with the Amur 1650, and;
• France’s DCNS with a modified Scorpene.

While a request of information has been issued, a request for proposal is yet to be issued – a reflection of India’s slow defense procurement decision-making process.

These submarine acquisitions are part of India’s long-held 30-year plan to induct 24 submarines. Initially, half were to be imported, with the balance being built to an Indian design. It is not clear if this number includes the fleet of nuclear submarines.

The 30-year plan, which was initiated about 10 years ago, has been slow to come to fruition. However, Project-75 and Project-75I, when executed, along with the ongoing nuclear submarine programs, would go a long way toward recapitalizing the Indian submarine service.

Not to be left out, India’s neighbor, Pakistan, is also planning to induct at least one Chinese-built nuclear-powered submarine to maintain a degree of parity with the much larger and rapidly expanding Indian Navy. It is also seeking around six or so Chinese-built AIP-powered submarines.