T.S. Subramanian

The K-15 missiles can carry conventional and nuclear warheads

A nuclear-powered submarine can remain under water for a long duration

Diesel-fired submarine has to rise to the surface every day to eject carbon-dioxide

CHENNAI: A nuclear-powered submarine is a much more complex platform than any other vessel and India building one on its own is a great achievement. This is the unanimous assessment of officials, be they from the Defence Research and Development Organisation (DRDO), the Department of Atomic Energy or the Indian Navy.

What enhances the scale of the achievement is that INS Arihant, India’s nuclear-powered submarine, will be fitted with India’s own K-15 ballistic missiles that can be launched from under water. The K-15 missiles, which are already under production, can carry both conventional and nuclear warheads. They have a range of 700 km. They are 10.4 metres tall and weigh 6.3 tonnes each.

“This is a very big capability,” a DRDO official said. “It means we can launch missiles with nuclear warheads from ground, drop nuclear bombs from air and also fire them now from under water.”

A nuclear-powered submarine bestowed on India the status of a nation possessing a blue-water navy because the boat can travel far and wide.

While the Navy designed INS Arihant, the Bhabha Atomic Research Centre (BARC) built the mini-nuclear reactor that powers the submarine, the DRDO developed the K-15 missiles. The K-15 missiles have been test-fired several times from submerged pontoons off the coast of Visakhapatnam. A missile emerging from the water without losing its fire was a technology in itself.

A distinct advantage of a nuclear-powered submarine is that while it can remain under water for a long duration, a diesel-fired submarine has to rise to the surface every day for ejecting the carbon-dioxide produced by the diesel-generator. Otherwise, the boat’s crew will face problem.

“In a nuclear-energy system used in a submarine, there is no emission of carbon-dioxide. It is a clean form of energy,” a DRDO official explained. “The turbine operating on enriched uranium in INS Arihant is a clean system. But a diesel-generator emits carbon-dioxide. You cannot discharge it into the water. So the submarine has to be brought up to the surface every day to eject the carbon-dioxide into the atmosphere.”

Trials to follow

DRDO officials cautioned that while INS Arihant entering water from the dry-dock in the Ship-Building Centre of the Visakhatpatnam harbour on Sunday was an important step forward, making the boat operational would take time. “The submarine will now go for harbour acceptance trials (HATs). Then it will go for sea acceptance trials (SATs). Later it will go down to a certain depth and come up,” they said.

A nuclear-powered submarine was a highly complex platform and safety regulations had to be adhered to. “There are hundreds of systems on the boat. They have to work one after another. This is called setting-to-work. The HATs and SATs will last about a year-and-a-half. This is the most difficult period of activity and you have to do it perfectly. Then the K-15 missiles will be fitted into the boat.”

M. Natarajan, Scientific Advisor to the Defence Minister, was present when the INS Arihant was launched on Sunday.

The project has been named the “Advanced Technology Vessel” (ATV) programme. Vice-Admiral (retired) D.S.P. Varma is the Director-General of the ATV programme.

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