H M Steele

Exercise 'Sorbet Royal 96' was designed to demonstrate NATO's submarine rescue capabilities. H.M. Steele reports from Norway.

• to demonstrate NATO's ability to respond to a submarine accident in north European waters and to execute a rescue operation;
• to rehearse joint operations of NATO and PfP units;
• to test the capability of Evenes Air Station and Bogen harbour to receive and despatch the American DSRV;
• to train and refine the procedures, equipment and rescue technologies used in submarine emergencies; and
• to enable all involved parties to train and gain experience in real-world conditions.

All operations were conducted under the control of the Naval Operation Centre at Headquarters Defence Command North Norway at Reitan outside Bodo.

Of the five submarines participating as DISSUBs in the exercise, four came from NATO countries: Kobben and Uredd from the Royal Norwegian Navy (RNoN); HrMs Walrus from the Royal Netherlands Navy; and FS Agosta from the French Navy.

In addition, Sweden (as a PfP participant) contributed HMS Gotland in the DISSUB role. The first of three new Type A19 submarines, Gotland was not officially accepted by the Royal Swedish Navy until July 1996.

Two exercise areas were used for 'Sorbet Royal 96'. The first, at Vestfjorden, was split up into two zones: a bottoming zone for DISSUBs at depths between 90-110m; and a waiting zone where support vessels remained until they received notification that the submarines were in their bottomed position.

The area was monitored by two fishery-protection ships from 0800-2300h in order to prevent any conflict between local fishing vessels and the exercise. Shipping traffic in the normal transit lanes was not affected.

The second exercise area, at Breivika just outside the Rasmund naval base in Ofotfjorden, was used for submarine replenishment operations (which took place in approximately 20m of water) using divers and the so-called "Newtsuits". The Newtsuit is a specially designed one-man deep diving suit with a constant internal atmosphere corresponding to the pressure on the surface.

Rescue systems and support units from Sweden, the US and the UK were deployed for 'Sorbet Royal 96'. In addition, Germany contributed the Drager Newtsuit.

Operating from its mother submarine USS Sea Lance for the duration of 'Sorbet Royal 96', the US Deep Submergence Rescue Vehicle (DSRV) Avalon (DSRV-2) arrived in Norway inside a C-5 Galaxy transport aircraft. With a rated diving ability of 1,500m, Avalon has a crew of between two and four (depending on the operation) and can rescue up to 24 persons in a single lift.

The UK Submarine Rescue Service, commercially owned, managed and operated by Cable & Wireless (Marine) Southampton and Rumic on behalf of the Royal Navy, deployed the manned rescue submersible LR5 and the remotely operated vehicle (ROV) Scorpio 45 aboard the Finnish chartered support vessel MV Nordica. A Submarine Parachute Assistance Group (SPAG) was also detached for the exercise.

The primary role of LR5 is to provide a rapid-reaction rescue capability ahead of the DSRV in north European waters, and to complement the US capacity in a large-scale rescue scenario: the mobilization of the DSRV and its operating crew by air - and preparation of the designated mother submarine - can take up to four days, whereas LR5 is at 12-hours notice for call-out.

In a typical rescue operation, LR5 would transfer technical and medical support specialists to the DISSUB along with any additional life-support stores which might be required. The submersible, which is capable of operating at depths down to 450m, would then commence a cycle of personnel transfers, evacuating up to nine persons at a time.

Primarily tasked with locating a DISSUB, the ROV Scorpio 45 can survey, inspect and mark the submarine and then transfer life-support stores (such as oxygen candles and carbon dioxide absorbent material) in special containers via the submarine's escape tower. Search-and-replenishment operations can be conducted down to the length of the umbilical (911m).

Sweden's submersible rescue vehicle, URF (Ubats Raddnings Farkost), was deployed with its support ship Belos. URF can operate at depths down to 460m, and can embark up to 25 persons.

Operating in conjunction with Belos, a dedicated submarine-salvage vessel, URF is the only system presently capable of saving personnel directly from a pressurized submarine. In such a situation, survivors from the DISSUB can be transferred, under pressure, from URF via airlocks to the compression chamber aboard Belos where they may receive treatment and undergo controlled decompression. Both DSRV and LR5 are capable of rescuing personnel at increased hyperbaric pressure, but would then need to transfer them to a suitable compartment in another submarine for therapeutic decompression. Improved transfer under pressure (TUP) systems are high on the shopping list for improvements to submarine rescue systems.

Operated from the Federal German Navy support ship Fehmarn, the Drager Newtsuit allows submarine maintenance and replenishment operations to be undertaken at depths down to 300m. Allowing the operator to retain 75 per cent of normal dexterity, the Newtsuit obviates the need for decompression and removes the requirement for special breathing gases (such as HeO2).

Two independent closed-circuit oxygen-supply systems provide life support. The full suit, including a back-mounted thruster pack with variable-pitch propellers, weighs 75kg.

Other support units participating in 'Sorbet Royal 96' included the French minehunter Clio and the RNoN diving support vessel Draug (both supporting clearance diver operations), the RNoN Valkyrien (supporting DSRV operations) and the Norwegian Coast Guard vessel Nordkapp (acting as On-Scene Commander).

Operations

The initiation of a search-and-rescue operation follows the expiry of the allotted Subnote (the system by which submarines advise of their transit routes and communication schedules) or as a result of an emergency signal from the DISSUB. Having located the submarine, recovery and rescue assets are then assembled in order to pick up survivors and undertake the rescue of crew members remaining in the submarine. This typical sequence of events formed the basis for Phase 1 and 2 of 'Sorbet Royal 96'.

Rescue and escape operations (practised in Phase 3 and implemented in Phase 4) were conducted using one of three methods: compartment escape (down to 70m); single-man escape (the Swedish gave a good example of this when six of Gotland's crew practised escaping using the UK's Mk 8 SEIS); and the use of a submerged rescue vehicle. The delivery of emergency life support in order to extend submerged survival capability was also practised using the various rescue vehicles, the Scorpio ROV and the Drager Newtsuit.

Additional operations included a C-130 air-drop of the British SPAG team (working in support of the single-man escape exercise from HMS Gotland), and submarine replenishment operations, conducted by French and Norwegian clearance divers using special supply containers. Meanwhile, the UK and Norway pioneered a method of injecting the support stores into Kobben, which is not fitted with a suitable tower, using ROV Scorpio.

A full debrief and analysis of Exercise 'Sorbet Royal 96' is due to take place in mid-September. However, initial reactions are understood to have been highly favourable, in all areas of command and control, interoperability, and the performance of the rescue assets and personnel involved. The next 'Sorbet Royal' exercise, scheduled for 1999, will be conducted in the Mediterranean.

All three main rescue vehicles used in this exercise (DSRV, LR5 and URF) are likely to reach the end of their operational lives within the next decade or so, as is the Italian MSM1(S) which was not deployed from La Spezia to Bodo on this occasion. ANATO pre-feasibility study was conducted in 1991-92 to assess the practicalities of a common NATO replacement submarine rescue system; the announcement of the contract for the feasibility study is expected at the end of this year.

* With contributions from Richard Scott and Paddy Ryan

The British SPAG team are air-dropped into Vestfjorden. (photos: H.M. Steele/Jane's)

The British SPAG team are air-dropped into Vestfjorden. (photos: H.M. Steele/Jane's)

The Swedish submarine rescue vehicle URF. (photo: Royal Swedish Navy)

The UK's LR5 manned submersible rescue vehicle is deployed from its mother ship MV Nordica. (photo: H.M. Steele/Jane's)

USS Sea Lance with DSRV-2 Avalon mounted aft. (photo: NATO)

Gotland diving in preparation for an escape exercise. The tender Draug provides support. (photo: H.M. Steele/Jane's)

Jane's Navy International Online (frequent updates + archive from 1995) US$ 795 UK STG 490 CD-ROM (monthly updates + archive) US$ 725 UK STG 445 Magazine : ISSN: 0144 3194 (10 issues per year) North / Central / South America US$ 180 UK UK STG 115 Europe UK STG 120 Rest of World UK STG 145 About online ordering (US$ price applicable to residents of North/Central/South America only)