Prasun K Sengupta: Asian navies interested in DSRVs

PSK: Following the examples set by the navies of Australia, Japan, Singapore and South Korea, China’s PLA Navy has acquired its first deep submergence rescue vehicle (DSRV) that will be used for supporting its submarine rescue operations in future. The DSRV, an LR-7 (Photo 1), has been built by Rolls-Royce Marine and is currently being subjected to acceptance trials under the frigid, choppy waters of the Raasay Inner Sound, just a few miles from the Isle of Skye in Scotland. The PLA Navy is later expected to acquire another two such DSRVs, which will be based on board its three Dajiang-class submarine rescue ships.

DSRVs are typically designed for quick deployment in the event of an undersea submarine accident. They are transportable by truck, aircraft, ship, or by specially configured attack submarines. At the accident site, the DSRV works with either a mother ship or mother submarine. The DSRV dives, conducts a sonar search, and attaches to the disabled submarine’s hatch. Once the call to render rescue assistance has been made, the DSRV is quickly loaded on an aircraft or ship and sent, along with its support crew, anywhere in the world. Upon arrival at its destination, the DSRV is transported to the water and attached to the back of a mother submarine, which then travels to the location of the disabled submerged submarine and the DSRV detaches off the back and then travels to the disabled submarine, attaches to the hatch, transfers the submariners in distress and delivers them back to the safety of the mother submarine.

For fulfilling the PLA Navy’s DSRV contract, Rolls-Royce had put together a powerful team to support this project, including Perry Slingsby Systems Ltd, The Engineering Business Ltd, Babcock Design and Technology, Babcock Naval Services, Divex Ltd, Kongsberg Maritime Ltd, and Lloyds Register. The LR-7 features an all-steel, single piece hull, is ISO containerised for transportation and is fully certified to Lloyd’s Register, has an on-board fibre-optic umbilical data and communications link, has a four-man crew (Pilot, Observer, and two Rescue Chamber Operators), has a mating capability of up to 60o with rescue seat compliant with STANAG 1297, is operational in depths ranging from 20 metres to 610 metres, uses a ZEBRA advanced battery power system, and has an innovative full diver-less launch and recovery capability. The 10 metre-long, 27-tonne DSRV, together with a portable launch and recovery system, support and operating equipment and the optional transfer-under-pressure (TUP) system can be deployed within six hours of receiving the go-ahead. All equipment and personnel will be flown to the nearest mobilisation port for embarkation on a suitable military or commercial support mother ship. The complete mobilisation will take less than 18 hours and the mother ship will then sail to the scene where the DSRV will be deployed and dived to mate or dock with the rescue seat fitted around submarine hatches. The aim is to achieve a Time To First Rescue (TTFR) of 72 hours and then rescue the disabled submerged submarine’s personnel in groups of 15 to the mother ship, transferring them to the TUP system for decompression under medical supervision if necessary. The TUP system is fully autonomous, providing full decompression recovery and medical support.

Another Asian navy that is likely to acquire customised DSRVs is the Indian Navy, which already selected the Remora 2000 (Photo 2) remotely operated rescue vehicle (RORV) for its submarines by mid-2005, along with its launch-and-recovery system (LARS) and a fully integrated self-contained emergency life support system (ELSS) package, all to be supplied by Canada’s Ocean Works International of North Vancouver. The yet-to-be-signed contract, however, ran into rough weather two years ago amidst allegations of irregularities (i.e. kickbacks) during the contractual negotiations phase. The 20.6-tonne Remora 2000 RORV has a depth rating to 610 metres, can accommodate 18 men, can dry-transfer personnel under pressures up to 6 atmospheres into surface decompression facilities, and is designed for operations in Sea State 5 and transport in Sea State 6. The related surface decompression facility can treat more than 100 personnel. The entire Remora 2000 system can be air-transported for rapid deployment. Similar systems built by the same company are currently operational with the navies of Australia, Russia and Singapore.