India's first nuclear submarine remains shrouded in secrecy - despite its public launch.
The cloak of secrecy over the project, the existence of which has been denied by successive governmentscloak since its inception in 1984, was lifted on Sunday when the defence ministry took journalists for the launch ceremony at this port city. However, no photography or filming of the submarine was allowed.
The official photographs of the event did not show a clear image of the submarine either.
The only glimpse of the vessel - that has made India the only nation in the Indian Ocean region to have a nuclear submarine and the sixth in the world to have the capability to design and construct a nuclear submarine - was in the photograph of Prime Minister Manmohan Singh at the ceremony.But the journalists, naval officers, 143 Russian technicians and diplomats could see the 110-metre-long and 11-metre-broad sea leviathan from the closest possible distance.
The design of the submarine that has a surface displacement of 6,000 tonnes clearly resembles the Russian Borei class nuclear-submarine. Its surface is uneven and its hull sits on a mat rolled with black square tiles, which are capable of absorbing sound waves and help it in maintaining stealth.
The white snub nose of the gleaming black submarine is the sonar (sound navigation and ranging) sheet of the vessel. It helps in recognising a vessel in the vicinity by receiving the reflected sound waves from its surface.
The conning tower is closer to the bow rather than the centre as in conventional submarines.
The orange beacon atop the conning tower came to life Sunday as the prime minister's wife Gursharan Kaur pressed the button to symbolise the launching of the vessel into water. On the conning tower stood the commander of INS Arihant Captain Anshuman Dutt.
In the middle of the body - comprising an outer hull through which the water goes in and and an inner pressurised hull - on the starboard side are two rectangular vents, meant to take in water when the vessel dives into the sea. It is like a "cocoon within a cocoon", explained an official.
INS Arihant is longer than any of the submarine in the Indian Navy's fleet so far. A nuclear submarine is powered by a nuclear reactor, which generates tremendous heat driving a steam turbine. It has unlimited underwater endurance and speed twice that of its conventional counterparts.
"Miniaturising the nuclear reactor was a big task and if you want people inside the vessel, it has to be self sufficient in terms of energy and power," VK Mehra, director, Reactor Project Group, Bhaba Atomic Research Centre, told IANS.
The submarine can carry 12 nuclear missiles K-15 and is the sea-leg of the nuclear troika of India - capability to launch nuclear weapons from land, air and sea. Keeping in line with its "no first use policy", the submarine will help India in developing a "credible second strike capability" in case of nuclear attack, said officials.
Indian Navy has been operating conventional diesel-electric submarines, which have to surface to charge their batteries.