Conventional submarines, while possessing advantages of stealthy movement under water and reasonable endurance, are not without limitations. Depending on their technology, they will need to take in air to recharge their batteries every day either by coming to the surface or close to it so that the relevant air intakes are exposed. This makes them vulnerable to detection.
At such times, propelled by their diesel engines, they are also more 'noisy' and can be located by sensors quite far away. The frequency of such exposure, as also the duration needed for recharging, have been brought down in the more modern vessels but cannot be done away with altogether.
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Additionally, while on the surface they can proceed at reasonably high speed - though for short periods as fuel consumption is an issue - submerged, the rate of movement is far slower, determined by limitations of the electric motors which provide propulsion. Their endurance depends on fuel availability which also has limits. Nuclear-powered submarines, on the other hand, have no need to move up from their depths and are, therefore, relatively invulnerable to detection from the air. The speeds at which they can move are also high and a function of reactor power.
Their vulnerabilities lie in the noise that they generate while moving. Not depending on replenishment of fuel, their endurance is much greater, limited only by that of their crew. They can also be larger and thereby carry greater weapon loads including missiles which could be fitted with nuclear warheads. While the 'on patrol' period for a conventional submarine, considering all these factors, might range around two weeks, that for the nuclear powered vessel could be as much as a few months. In short, these ships are in a class of their own.
It is not as if Arihant does not have limitations. For one, the reactor power of just under 90 Mw is much less capable than the 250 Mw-plus generated in contemporary submarines of its type. To produce that kind of power in a reactor of this size much more advanced technology is needed and that will be a bridge that will have to be crossed - with assistance if necessary, as has been the case in this instance. When operational in about two years, the Arihant will have nuclear weapon capability, though of limited range, with a longer-distance capability to follow.
Yet, the achievements are considerable. The entire hull, all of special steels and metallurgy, has been fabricated indigenously in a private sector shipyard; this will be repeated in follow-on vessels. Engineering giants and smaller firms in the private sector have contributed with major machinery and auxiliary systems and several public sector units have also played meaningful parts. To bring all of these together and finally create the 'baby' that is Arihant is a formidable achievement by any standard.
The much maligned Defence Research and Development Organisation (DRDO) has steered the so called Advanced Technology Vehicle (ATV) project from inception and should be justifiably proud. And so should the Navy which 'fathered' this dream through several years starting 1984, when a pioneer - the late Vice Admiral MK Roy, our own Admiral Rickover - successfully persuaded then Defence Minister Venkataraman that a nuclear-powered submarine was an idea whose time had come.
This brings us to the substance of this discussion - the role of a platform like the Arihant and its successors. Ordinary submarines they are surely not, and to even think in those terms would be self-defeating. They have endurance and staying power and, therefore, range but to think of them as ships which are there to fight and sink other ships is facile. With their nuclear warheads and invulnerability, they give to the country a strategic capability which no other platform can. Land silos and sites can be detected from space and their activities monitored, and aircraft can be intercepted and destroyed even after they are airborne with their weapon loads, but this underwater vehicle is out of sight and out of reach, literally.
It is the only mechanism in which the warhead and its delivery system, the missile, are mated before being embarked; in all others the two are kept separated till the very end. It does not need to fire any of its weaponry; the fact that it can do so is its power. It is a deterrent against nuclear blackmail by those with sinister intentions and larger capabilities.
One can easily imagine the awesome responsibilities that this unique configuration places on those assigned to command ships like Arihant and the safeguards that need to be inbuilt in the command and control mechanisms for nuclear submarines. Here, we have lessons to learn from the experience of those countries which have managed these platforms for long. India has operated such vessels leased from Russia twice, once in the 1980s and again since 2012, both being named Chakra though the present one is a very much larger and more versatile submarine compared to the former; both nuclear powered but without nuclear weapons. This exposure should facilitate the induction of Arihant.
Dedicated infrastructure ashore to ensure the required degree of safety was set up when the first Chakra came in and must certainly have been updated and augmented by the Navy as found necessary. These facilities are essential wherever such vessels are based and observance of safety procedures has to be strictly enforced. Crew training has to be rigorous and exacting; psychological orientation to cope with prolonged periods spent on deployment underwater is especially important.
The strategic security environment has now shifted to the Asia-Pacific with the seas beginning to play increasingly important roles. Given the focus on energy dependence of most major nations and on overseas trade and the water space through which both move, it is not surprising that this region is beginning to be referred to as the Indo-Pacific.
India is the largest and most capable Indian Ocean littoral - and must continue to retain that profile and discharge the responsibilities that go with that status - but it also has serious interests in the western Pacific through which half of its overseas trade moves. Peace and tranquility in this vast oceanic space linked through several narrow channels of south-east Asia is an essential prerequisite to its own growth.
All of this necessitates having capabilities at sea that will cope with concerns both proximate and strategic. While a mix of conventional forces is needed to meet the first, it will be submarines like the Arihant which will be our shield for the latter. With more than one nuclear weapons power deploying in the Indo-Pacific, it is a capability which we badly needed and will soon have. May fair winds and following seas attend Arihant.