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DSRV and naval UUVs

There is a clear distinction between deep submergence rescue vehicles (DSRV) and unmanned underwater vehicles (UUV) or remotely-operated vehicles. The former is deployed for rescue of submarines/submariners in disaster situations and the latter has a wider repertoire of applications in the military marine domain.

Both before and after the disaster on board the Indian Navy submarine Sindhurakshak in Mumbai’s Naval Dockyard in 2013 the absence of such platforms has been felt by India and there is a steady growth of study, research and development of platforms intended to rectify the situation given that most of the submarines in the Indian Navy fleet are aged.

The safety of submarines and crew is a prime requirement for a nation with as small a fleet as India even while it occupies a massive geographical position at the confluence of such large water bodies as the Indian Ocean littoral and the western Pacific rim. Depths within its extended area of operations range from 6000 ft in the Indian Ocean to 11,000 ft in the Pacific Ocean. Any submarine rescue effort at these depths requires very specialized equipment capable of withstanding the immense pressures per square inch that can squeeze a submarine hull like a cardboard box.

Survivability

It is because of this ever-present danger that the first qualitative staff requirement (QSR) for submarine production must be facilities that will prevent a submarine from settling to the bottom at such depths.

A study of submarine disasters indicates that explosions on board can send the vehicle hurtling towards the bottom of the sea. More often than not the stricken submarine lands on its escape hatch trapping the sailors inside. Even turning the stricken submarine on its side so as to be able to open the escape hatch and extract the survivors takes many days and could result in the death of all those who have not had time to find air pockets within the stricken submarine. The case of the Russian submarine Kursk is an example. All on board died, some after days of surviving in air pockets inside the submarine.

While the Kursk sank in relatively shallow waters of 400 ft for safety at greater depths there is a requirement for a failsafe system of triggering automatic floatation devices that will keep the submarines orientation upright and at the same time prevent it from descending into the deep beyond the capacity of the hull. This would ensure to a very large extent the survivability of most of the crew and the possibility that the vessel can be towed to dock and repaired.

The German HDW submarines bought by India in the 1980s has a special capsule within the hull in which the submariners can enter, detach the capsule from the main structure  and rise to the surface without any ill-effect on the crew. That technology was lost to India when it allowed the contract to lapse after allegations of payment of kickbacks  in the deal surfaced. Given that the German firm violated the contract by allowing middlemen to help secure the deal and later selling the same design to the white racist regime that was ruling South Africa at the time; India can, with justification, resort to reverse engineering of the capsule and incorporate the technology in the new generation of submarines that it is constructing including the follow-on versions of the Arihant class of nuclear submarines.

If the Bofors 155mm howitzer designs can be replicated to produce an indigenous weapon system, the same can be done in the case of the German submarines. If “Make in India” is to make sense in the larger context of reducing dependence on imports in the defence sector this would be an eminently suitable way of going about it.

In the context of providing a viable deep submersible rescue vehicle (DSRV) facility to the Indian Navy, India currently has an agreement with the US to fly in its speciality vehicle in the event of a disaster in an Indian submarine.

However, the time-lapse between making the request and the final arrival of the DSRV in Indian waters is estimated to about 70 hours. This is unacceptable. Given that India and the US had declared themselves to be strategic partners it would be appropriate that New Delhi asks Washington to permanently station its Mystic class DSRV at the Diego Garcia naval base situated just 2,500 km from the southern tip of the Indian peninsula and can be deployed at short notice to any point in the Indian Ocean littoral (inclusive of the Arabian Sea and the Bay of Bengal).

The vessel can evacuate 24 submariners from a depth of 6,000 feet. India needs to evolve standard operating procedures to deal with the eventuality of a submarine mishap at sea. This is all the more necessary because many of the submarines with the Indian Navy have crossed their half-life and have undergone extensive upgradation. There have been several instances of explosions on board including surface vessels like the newly-renovated aircraft carrier Vikramaditya.

In the meanwhile the Defence Research and Development Organisation is also looking at a Russian design for a DSRV. Given the unhappy experience of their own submarines in disaster situations the Russians are expected to come up with a vessel that will be compatible with the Kilo class submarines with the Indian Navy.

Underwater vehicles

Apart from deep sea rescue, unmanned underwater vehicles (UUVs) are finding a prominent place in the defence sector for operations where the presence of man could be a hindrance. Sabotage in enemy harbours, mine clearance, Intelligence gathering, reconnaissance and surveillance can be conducted with a greater degree of stealth and efficiency especially in clearing the several different layers of mines ranging from surface floating mines to tethered mines to acoustic mines laid on the seabed UUVs are being acquired for more widespread deployment.

The much-maligned Defence Research and Development Organization has indicated that it has made considerable progress in autonomous underwater vehicles which can be pre-programmed to execute specific tasks. The Indian Navy has shown interest in acquiring  ten of these AUV’s which are 4X‘1.4 meters in dimension and capable of a speed of seven kmph and dive to a depth of 300 meters (480 ft). Its onboard sensors and computers ensure that it operates within the parameters for which it is designed without human interference. The large prototype is being tested by the Indian Navy but there are smaller versions under development in various DRDO laboratories for specific operations were stealth and deniability are paramount.

Simultaneous with this is a parallel project for the resurrection of the Indian Navy’s clandestine operations chariots of the 1970s which could accommodate two commandos for sabotage in enemy harbours. Once their life cycle was complete they were discarded but now with the establishment of a Marine Commando (MARCOS) unit the need for midget submarines for Special Operations is being felt.

To meet this requirement a fleet of five midgets is being raised with the first two being manufactured at the Hindustan Shipyard Ltd at Vizag. On account of its limited range the midget will have to be towed by a mother ship to a point where the MARCOS can place explosives on enemy ships and other harbor facilities and return to watch the timed devices wreak havoc on the enemy. The insertion of MARCOS by helicopters carries the risk of the enemy hearing the approaching helicopters and be alerted.