The project, earlier known as ATV (Advanced Technology Vessel), began way back in 1998 but picked up pace only in mid-2000. In 2009, it was launched by Prime Minister Manmohan Singh's wife, Gursharan Kaur, at a ceremony in Vizag, headquarter of India's Eastern Naval Command.
Those associated with the project from its inception will be satisfied professionals today. Indian Navy designers, engineers, scientists of the Department of Atomic Energy, Defence Research and Development Organisation (DRDO) and most importantly private sector companies led by the redoubtable Larsen & Toubro (L&T) deserve heartfelt thanks from the nation from having achieved the milestone.
In a rare public comment, Prime Minister Manmohan Singh has congratulated those associated with the project. He said: "I am delighted to learn that the nuclear propulsion reactor on board INS Arihant, India's first indigenous nuclear powered submarine, has now achieved criticality. I extend my congratulations to all those associated with this important milestone, particularly the Department of Atomic Energy, the Indian Navy and the Defence Research and Development Organization."
Today's development represents a giant stride in the progress of our indigenous technological capabilities. It is testimony to the ability of our scientists, technologists and defence personnel to work together for mastering complex technologies in the service of our nation's security.
"I look forward to the early commissioning of the INS Arihant," Dr Singh said.
That's the next important step. Now that the reactor is a "go" the submarine will make shallow dives, complete the deep diving trials and prepare for the weapon trials of the torpedoes and missiles with dummy warheads to be ready for commissioning. Once at sea, the vessel will be gradually loaded with weapons and missiles. Each test will be conducted underwater for two months or more. This will include the Submarine Launched Ballistic Missile (SLBM). In the past the Navy has carried out 10 underwater launches of SLBMs code named 'B05' using a submerged pontoon to mimic a submarine. So far the range has been 700 km, while the bigger variant, known as the 'K-4', is designed to hit targets 3,500 km away.
The boat will then be commissioned in to the Indian Navy.
Top government sources indicate it is likely to happen over the next few months.
Like all professionals, the team that brought Arihant to this stage is now focused on the next two submarines in the series being built in the same shipyard. Their aim is to take the indigenous content of the next two nuclear submarines from the 40 to 60 and then to 70 per cent by the time the third submarine is ready for commissioning possibly by 2017. The combined team that has built Arihant is however proud of the fact that its digital control systems are designed completely locally which means no dependence on foreign vendors in this critical aspect.
According to Commodore Ranjit Rai, a former Director, Naval Operations and Naval Intelligence, this project has seen a huge collaborative effort.
Writing in a defence magazine some years ago, he had observed: "A large planning and design office called Akanksha (Hope) in New Delhi, has directed the ATV programme under the current Director General, retired Vice Admiral D S P Verma. Facilities at Vishakapatnam have been built by the DRDO, industry and the Indian Navy with BARC's collaboration with funds and monitoring from the PMO.
"Two Admirals with technical expertise have headed the two large supporting complexes. One is the sprawling Defence Material Department (DMD) at Hyderabad, which collaborates with DRDO labs and BHEL for the heat exchanger turbine propulsion system, and MIDHANI for special steel requirements and other contractors. The large Submarine Building Centre (SBC), tucked behind high walls and barbed wires in the heart of Vishakapatnam, is where the hull was put together in sections provided from engineering and refinery reactor maker L&T. This company is investing heavily in ship building, and already has facilities at Hazira in Gujarat and Mazagon Docks in Mumbai (Bombay).
"Walchandnagar Industries provided the gear box and shafting as it does to Indian Navy's Leanders. Bharat Electronics Ltd (BEL), another state-run company, is fitting out the USHUS sonar, radars and the Combat Management System along with Tata Power Ltd which has a tieup with BAE Systems for the control pedestal. KSB pumps and Jindal pipes have also played a significant role. The submarine is coated with rubber anechoic tiles supplied by a rubber vulcanising firm in Mysore to provide stealth qualities."
BARC, which steered the critical nuclear reactor installation programme in 1975, also manufactures and stores India's fission and fusion atomic bombs. It has provided training to Navy's technical officers in submarine nuclear technology.
"The ATV project has also set up a small submarine reactor training complex at Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam, near Chennai with facilities to test the 80 MW-plus pressure water reactors before insertion into submarine hulls. The reactor is normally sealed into a 600-ton titanium shell of about 10 metres in diameter.
According to a former Indian Navy nuclear boat Captain with command of INS Chakra, "the nuclear submarine operates like any other under water boat, except that it can stay under water for months and it is imperative that the key members learn to operate the computer controlled nuclear power plant... Each crew member has to be aware of all the possible emergencies including emergency shut down that can take place in the ensconced nuclear reactor."
With two more nuclear-powered, nuclear-armed submarines on their way, this public-private partnership can only get stronger. For the moment though, it's time to savour a major milestone in Indian Navy's journey to becoming a powerful force in India's immediate and extended neighbourhood.