INS Arihant

INS Arihant (अरिहंत, meaning "Slayer of Enemies" (S-73)) is the lead ship of India's Arihant-class of nuclear-powered ballistic missile submarines. The 6,000 tonne vessel was built under the Advanced Technology Vessel (ATV) project at the Ship Building Centre in Visakhapatnam.

The symbolic launch ceremony for the Arihant was held on 26 July 2009, the anniversary of Vijay Diwas (Kargil War Victory Day). The name of the vessel, Arihant, is in Sanskrit and literally translates into destroyer of enemies. The completion of the INS Arihant will make India one of six countries in the world with the ability to design, build, and operate its own nuclear submarines.

Design
The INS Arihant is to be the first of the expected five in the class of submarines designed and constructed as a part of the Indian Navy's secretive Advanced Technology Vessel (ATV) project. The Arihant-class submarines are reported to be comparable to the Akula I-class submarines. Their crew will have the opportunity to train on INS Chakra, an Akula-class submarine, which the Indian Navy leased from Russia. Arihant will be more of "a technology demonstrator", rather than a fully operational SSBN according to Admiral Nirmal Verma.

The vessel will be powered by an 83 MW pressurised light-water reactor with enriched uranium fuel. A land-based prototype of the reactor was first built at Kalpakkam and made operational in September 2006. Successful operation over a period of three years yielded the data that enabled the production version for Arihant. It was reported that an 80 MW nuclear reactor was integrated into the hull of the ATV in January 2008.

The hull for the vessel was built by L&T's Hazira shipbuilding facility. Tata Power built the control systems for the submarine. The systems for the steam turbine integrated with the reactor are supplied by Walchandnagar Industries.

Armament
Arihant has four vertical launch tubes, which can carry twelve (three per launch tube) smaller K-15 missiles or four larger K-4 missiles. The K-4 has a longer range of 3,500 kilometres and is still in development.

Launch
INS Arihant was introduced to the public on 26 July 2009 at a symbolic launch ceremony by Prime Minister Manmohan Singh's wife Gursharan Kaur. The launch coincided with the tenth anniversary of the conclusion of the Kargil War. and consisted of floating the vessel by flooding the dry dock. Defense Professionals Daily claimed Arihant was launched without key systems including its nuclear reactor, surveillance equipment, and ordnance. Per naval tradition, Gursharan Kaur cracked a coconut on the hull to mark the launch of the submarine at the secret naval base 'Matsya' in Visakhapatnam. Photography was prohibited and photos showing the complete vessel are not available. In his address to the crowd, Prime Minister Manmohan Singh billed the submarine as an outcome of a public-private partnership. He also thanked Russia in his address stating "I would also like to express our appreciation to our Russian friends for their consistent and invaluable cooperation, which symbolizes the close strategic partnership that we enjoy with Russia". The launch of Arihant strengthens India's endeavour to build a credible nuclear triad – the capability to fire nuclear weapons from air, land and sea.

Current status
On the condition of anonymity, a nuclear scientist familiar with the project echoed this report in response to the media coverage that India had successfully launched a completed nuclear submarine. It was also expected that the duplication of India's land based reactor, integration of systems, and sea trials are expected to take three to five years.

In 2010, the submarine was claimed to have begun its sea trials with the submarine to be formally inducted into the Indian Navy by 2011. Full integration of key systems and sea trials are expected to be extensive. Admiral Verma told reporters on 7 August 2012 that sea trials of Arihant are commencing in coming months and she is steadily progressing towards operationalisation. On 27 January 2013, Sagarika, the primary armament of Arihant, completed its final developmental test and will now be integrated with the submarine. On 10 August 2013 the nuclear reactor of the submarine went critical, this was done after several months of system checks using shore based high pressure steam.