Underwater ejection - Only Indian Navy submarines have integral rescue sphere

(Source - Indian Express)

What would the crew of the Indian Navy's Type 1500 Shishumar class submarines do if they were faced with the disaster that has befallen the Russian Oscar class nuclear submarine The 40-member crew would file into the forward section of the submarine, seal both its hatches and activate an escape lever. A part of the forward section would disengage itself from the stricken submarine and float to the surface. The crew would then be picked up by a ship on the surface. All this in under an hour. A little known fact, but the navy's four Shishumar class submarines are the only ones in world with an integrated escape sphere - the undersea equivalent of the US President's escape capsule on board Air Force One.

The rescue sphere is a tribute to the farsightedness of the Indian Naval brass in the early 1980s who asked the German designers to make it an integral part of the four submarines that were being purchased from HDW in Germany. The reasons lay more in economics. ``It was insisted upon by Naval Headquarters since we had no submarine rescue facility of our own,'' said Commander S Bhatla, a retired naval officer who worked for 10 years on the indigenous submarine building programme. The first two Type 1500 submarines Shishumar and Shankush were built in Germany by HDW in 1986 and the Shalki and the Shankul built at the Mazagon Dock Ltd, Mumbai in 1992 and 1994. The `crew rescue sphere' designed by the German Ingenieur Kontor Lloyd (IKL) design bureau in Germany can accommodate all 40 officers and crew of the IN's Type 1500 submarine. The sphere which is part of the central bulkhead divides the hull into two watertight sections and is accessible from two ends of the submarine. It has an oxygen supply for eight hours and can withstand pressures nearly as great as the submarine's maximum diving depth of around 260 metres. The Kursk is presently stranded on the seabed at roughly half this depth.

"Tt's very cramped in the sphere, but it has food and water and allows the crew to survive for upto eight hours without fresh air", says Commander Bhatla, who tested the sphere several times in the Arabian Sea in the early 1990s. However, this facility is limited to only the four HDW submarines in the IN's fleet. Naval officials admit that rescue facilities for the ten Russian Kilo class submarines are minimal. There is presently only one diving support ship in the fleet, the INS Nireekshak. The ship is equipped with two Deep Submergence Recovery Vessels (DSRVs) capable of taking 12 men to 300 metres. It is not known if this unique integral rescue sphere will be part of the design of the two indigenous Project 75 submarines, to be built at the Mazagon Docks by the end of this decade. The Project 75 is an indigenous versions of the HDW submarines.

There have been only two serious accidents involving the IN's submarines in over three decades of its submarine operations. The first occurred in the late 1960s when one of the newly acquired Soviet Foxtrot class submarines collided with a warship. The second was in 1989 when another Foxtrot class submarine accidentally surfaced beneath a warship. There were fortunately no casualties and the vessels involved got away with structural damage. After the loss of the US nuclear submarine USS Thresher in 1963 which went down with all its crew, several navies developed DSRVs following the US Navy lead. The US Navy currently has two DSRVs which can operate at a maximum diving depth of 1500 metres and can bring 24 men to the surface at one time. More importantly, these DSRV are air-mobile in Lockheed C-141 Starlifter transport aircraft and can be delivered to the scene of the accident by a special mounting on another submarine or by a special surface rescue ship. The Russian navy lost a significant part of its underwater rescue capability a few years ago when it scrapped two of its huge `India' class DSRV submarines.

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