Skilling & Training: Rescue Remora style | ADM Sep 2010

With an Australian-based submarine rescue system now operational for the first time in nearly four years, attention is turning both to the recommissioning of the RAN’s trouble-prone Remora rescue vehicle, and to its eventual replacement.

Julian Kerr | Sydney

The 16.5 tonne Remora sank in 140 metres of water about 40 km north of Rottnest Island in December 2006 when one of the two cables connecting it to the mother ship snapped during preparations for Exercise Black Carillon, a RAN submarine rescue exercise conducted in the Western Australian Exercise Area.

Two crew remained trapped in the Remora for 12 hours before it was lifted to 15 metres below the surface by the secondary cable, which broke in heavy seas after both men had been assisted from the vehicle.

Remora then spent four months on the seabed before being recovered by the US Navy’s Supervisor of Salvage and Diving, restored in Vancouver by its Canadian manufacturer, and returned to Australia in August 2008.

Meanwhile the LR5 deep sea vehicle was contracted by the Defence Materiel Organisation (DMO) from James Fisher Defence of the UK to cover the non-availability of the Remora.

Information elicited by a Senate Standing Committee in February 2009 established that the Glasgow-based LR5 was on 12-hour notice of embarkation to Australia, but was unlikely to be on site over a disabled submarine in less than 80 hours.

Rear Admiral Boyd Robinson, head of the maritime systems division in the DMO, told the committee the LR5 could have been pre-located in Australia, but this would have cost “several million dollars or more”.

Coincidence or not, four months later the LR5, the central element of what is now known as the James Fisher Submarine Rescue System (JFSRS), arrived at Henderson in Western Australia under exclusive contract to the RAN.

Defence says James Fisher has the necessary measures in place to satisfy the 12-hour emergency callout requirement.

Some dedicated operating personnel are located in Perth; others would be required to travel from overseas (probably from Singapore, where the company operates a submarine rescue capability for the Singapore navy).

According to Defence, the intention is to return Remora to service by late 2011 in order to achieve Operational Release in early 2012, prior to the expiry in May of that year of the LR5 contract.

Although the refurbished Remora vehicle has undergone harbour trials and was recertified early in 2009 by Det Noske Veritas as suitable for operation until January 2018, the A-frame Launch and Recovery System (LARS) remains out of service undergoing redesign to mitigate the shortcomings that led to the loss of Remora in 2006.

Both Remora and the LR5 require a suitable mother ship, with the prime requirements being adequate deck space to embark the rescue system and sufficient deck strength to mount the LARS.

The contracted Defence Maritime Services (DMS) ships Seahorse Standard and Seahorse Spirit are capable of supporting both systems and cover the highest-risk areas in South Australia and West Australia where submarine post-docking trials take place.

Given the wide geographic area covered by RAN submarine operations, the navy’s submarine rescue operating concept encompasses cooperation with other rescue-capable nations in addition to air transportable rescue systems such as Remora/LR5, and the ability to mobilise those systems on commercial vessels of opportunity.

A register of suitable vessels and their locations is maintained by the NATO-sponsored, funded and manned International Submarine Escape and Rescue Liaison Office based at Norfolk, Virginia.

Defence says each portable rescue system has its own unique deck mounting arrangements which are generally welded to a vessel’s cargo deck.

Mobilisation of a rescue system to a suitable commercial ship is expected to be achieved in less than 36 hours due to the modular design of the systems.

Harder than it looks

This is no easy undertaking.

Preparing the DMS ships for rescue contingencies involved strengthening their decks to accept a downward force of more than 1,000 kilonewtons (comparable, according to DMS, to carrying 60 average cars on an area the size of a ping pong table).

Additionally, ‘deck stools’’ weighing about three tonnes each and made of high grade steel up to 50 millimetres thick were designed and manufactured for attachment to the ships as required to provide the interface between the LARS and the deck.

DMS says the JFSRS can be fitted to either of its ships within 24 to 36 hours, and it has two 10-man, 10-hour shifts on call 24 hours a day ready to mobilise for a rescue emergency.

The arrival in-country of the JFSRS enabled the RAN’s first submarine rescue exercise since 2006 to be held in March, having been delayed from late 2009 due to a combination of submarine availability and the need to complete a step-by-step Demonstration of Capability.

In this case, risk management was complicated by the need to prove the new system and its support, with the four-year gap meaning most Defence personnel in key positions had little or no direct experience of participating in previous Black Carillon exercises.

For the same reasons the exercise did not involve a speed of deployment element so as to ensure the mobilisation was conducted in a deliberate and graduated manner to prove that the JFSRS and support ship interface were suitable for the task.

The culmination of Black Carillon saw the LR5 complete five trips to HMAS Waller, bottomed at an undisclosed depth in the Western Australian exercise Area.

One person was transferred by the LR5 from the submarine to the support vessel as final proof of the capability.

While the JFSRS system can operate in up to sea state 5, the significant wave height at the time of transfer was two metres.

The Remora is a remotely-operated rescue vehicle built about a diving bell, while the LR5 is a free-swimming mini-submarine.

This means the skills required to operate the systems are different, although many of the capabilities needed to launch, recover and maintain the systems are similar.

The Remora is powered and controlled from the mother ship by a pilot, navigator and dive supervisor via a 914 metre armoured electro-fibre optic umbilical, with room for one operator/attendant and six survivors.

Maximum rescue depth is 540 metres in a three-knot current, and the vehicle can mate with a disabled submarine lying at angles of up to 60 degrees.

By contrast, the 22.5-tonne LR5 can accommodate 16 survivors as well as its normal submersible crew of pilot, co-pilot and systems operator.

Maximum rescue depth is 400 metres in a current of no more than 1.5 knots, with endurance of six to 10 hours.

A mating angle of 45 degrees has been demonstrated, and 60 degrees is claimed.

In addition to the LR5, the JFSRS includes a Scorpio remotely operated vehicle (ROV) equipped with a sonar, a depth measuring system, tracking transponders and four video cameras.

A manipulator installed on the front of the ROV can be used to clear debris from the submarine’s escape hatch.

The ROV can also fit an underwater telephone and a radiation monitor, and be used to deliver life support systems to the submarine.

After rescue, survivors are taken to the surface and transferred under pressure to a hyperbaric chamber.

Remora is lowered on top of an RAN 36-person deck compression chamber to effect the transfer, while the LR5 goes nose-in to a portable 10-person Type B recompression chambers, a number of which have been provided by the Royal Navy for use with the JFSRS.

Training under pressure

Pressurised escape training is mandatory for all new RAN submariners to give them the skills and confidence to attempt escape from a submarine at depths up to 180 metres should rescue not be possible.

Requalification in either pressurised or unpressurised escape training is then undertaken every three years.

The pressurised training normally carried out at in the 20 metre deep water column at HMAS Stirling has not taken place there since May 2008 following a contractual dispute with then-provider ASC.

Since then more than 200 submariners have received their pressurised submarine escape training in Canada – a situation Defence says will continue until instructors being provided by new contractor Underwater Centre Fremantle complete a comprehensive training and assessment period.

Meanwhile a Request for Proposal under Project Sea 1354 Phase 1 for a Submarine Escape Rescue and Abandonment System (SERAS) to replace the present Remora-based system closed last November with seven responses.

First pass approval is anticipated in the second quarter of 2011 and second pass in 2013.

Lieutenant Joel von Thrum RAN, the project desk officer in Capability Development Group, told ADM the intention was to include a ROV in the system and to continue to rely in the main on a register of commercial vessels of opportunity to host the system.

While neither rescue vehicles, ROVs or hyperbaric chambers were new technology “it’s the bits that connect them that are the challenge, and that’s in engineering rather than high-level electronics,” he commented.

Another focus – within budgetary limitations – would be on increased interoperability with the submarine rescue systems of other nations, particularly transfer under pressure arrangements.