India today joined an elite club of nations with the induction of indigenously-built nuclear-powered submarine, reaching a significant milestone in completing its nuclear triad with capacity to launch missiles from land, air and sea.
The 6000-tonne nuclear submarine, known as boomer in popular parlance and named Arihant (destroyer of enemy), will carry 'Sagarika' ballistic missile and will come in handy in for retaliation in case of an enemy nuclear strike. The missile will have a range of 700 km.
With the launching of the sea trials of the Arihant, India's dream of 25 years culminated in the form of a 110 metre-long and 25 metre-wide submarine moving out from its building base 'INS Virbhau' here into the Bay of Bengal.
It is expected to continue its sea and harbour trials for another 12-16 months before it joins the naval fleet with its complement of around 23 officers and 72 men.
With a diving depth of around 500 metres, Arihant will have the capability to keep itself hidden from the enemy's probing eyes for very long periods and can fire the 700 Km range submarine launched ballistic missile (SLBM) K-15, which was tested from pontoon docks by Defence Research and Development Organisation (DRDO) last year.
The submarine can carry a component of 12 SLBMs. The DRDO is working on increasing the range of the missile up to over 3,000 km.This stealth capability of the Arihant gives more strength to India's 'no first nuclear strike' pledge in its nuclear doctrine as it can retaliate strongly, in case of an enemy attack, lying deep in the oceans.
The Indian doctrine calls for a high survivability of its nuclear weapon launch platforms against surprise attacks and for rapid punitive response to the enemy. Nuclear-powered and conventional diesel-electric submarines are differentiated on the basis of their propulsion systems.
The nuclear reactor of the submarine generates heat to turn water into steam in a generator which, in turn, drives the turbine generators which supply the ship with electricity and drive the main propulsion turbines and propeller. It does not need to come to the surface to breathe oxygen, which is a must for a conventional submarine.
Arihant's outer hull, covered by thick rubber tiles studded with conical gaps that trap sound, also keeps the submarine hidden from Sound and Navigation Ranging (SONAR) probes by the enemy warships.
With the induction of Arihant, India would be able to deliver nuclear weapons from under water platforms adding to its capability to deliver nuclear weapons from a range of surface and aerial platforms.
After the first trial of the steam cycle and turbines, Arihant will be hooked up to the nuclear reactor, which was built in Kalpakkam in Tamil Nadu. The reactor's fuel rods are currently locked and sealed. They will be unlocked and neutrons will be introduced to start up the 85 MW pressurised water reactor.
The reactor will work continuously for anything up to 10 years till the fuel runs out. Then it will be brought back to the dock, the reactor compartment will be cut open, new fuel rods inserted and resealed.
Arihant's journey began in late 60s when the Navy and the Bhabha Atomic research Centre (BARC) officials mooted the proposal of nuclear propulsion systems for naval vessels.
In 1970, a year before the war with Pakistan, then prime minister Indira Gandhi directed BARC and DRDO to work on developing a nuclear submarine but the project could take off only in 1984 when the project codenamed 'Advanced technology Vessel' (ATV) was launched here.
Around the same time, India signed an agreement with the erstwhile Soviet Union to lease a nuclear submarine. India's first stint with a nuclear submarine started with the induction of Russian Charlie Class submarine in 1988 for three years which was named INS Chakra in India.
The programme received a major thrust in 1998 with Indian private sector company Larsen and Toubro starting the construction of the submarine at its facility in Hazira. In 2007, the 85 MW nuclear reactor of the submarine was fused into Arihant's hull.
By the time, the Indian nuclear submarine comes out of the sea trials, the Navy would have trained its crew in handling a modern boomer on a leased Russian Akula II Class submarine, which is expected to join the Navy by the year-end and is undergoing trials in Russia.
Delivery of the submarine to India was delayed after a mishap postponed the sea trails of the Nerpa submarine. Another Russian nuclear submarine is expected to join Indian fleet in thw near future.
India plans to have 10 nuclear-powered submarines by 2020 to catch up with the Chinese fleet of 20 nuclear-powered submarines. The United States, Russia, France and United Kingdom are the only other nations who have nuclear submarines in their armada.