Sea Power: Operational CBASS service release imminent | ADM April 2013

Australia’s four operational Collins-class submarines are set to gain a welcome boost in capability over the next couple of months, with the widely anticipated service release of the upgraded Common Broadband Advanced Sonar System Heavy Weight Torpedo.

CBASS or, to give the weapon its full name, Mk.48 Mod.7 Advanced Capability (ADCAP) Common Broadband Advanced Sonar System (CBASS) Heavy Weight Torpedo (HWT), is being acquired under Project Sea 1429 Phase 2 and Australian operational service release is expected in the middle of the year. This will shortly follow on from US Navy release which is due to occur in the March/April timeframe.

An earlier version of the advanced software-driven Heavy Weight Torpedo has been in RAN service since being cleared by then-Chief of Navy Vice-Admiral Russ Crane in March 2010 but the latest version, known as Advanced Processor Build Four (APB4 or ‘Spiral Four’) represents the full operational capability CBASS weapon.

Sea 1429 Phase two
The Heavy Weight Torpedo being acquired under Sea 1429/2 is not via the usual foreign military sales (FMS) route, but rather as part of an Armaments Co-operative Project (ACP) with the US.

The ACP Memorandum of Understanding was signed back in 2003, renewed in 2009 and is current through to 2019 at this point in time.

The ACP allows collaborative development of the Heavy Weight Torpedo, which benefits both the USN and RAN. From an Australian perspective, it allows input into the development of the weapon to suit the RANs operational requirements, notably an enhanced capability in the littoral environment. Some of the software algorithms incorporated into the APB4 software have been developed by DSTO with Australia’s operational requirements in mind.

Because the US Navy only operates nuclear-powered submarines it does not have the capability to test the CBASS weapon against conventionally-powered submarines, and in the littoral environment. The opportunity to develop the weapon in conjunction with Australia and the Collins boats has therefore been of great benefit to both services.

The project is in parallel to the Collins Replacement Combat System project, Sea 1439/4A, and the ADCAP torpedo is not backwards-compatible with earlier combat systems. Four of the Collins fleet now have the AN/BYG-1 Submarine Tactical Control System (TCS) and the remaining two, HMAS Rankin (due to complete its Full Cycle Docking period towards the middle of next year) and Collins, which is due to complete the FCD Cycle in the mid-2016 timeframe, will have the capability once they re-enter service.

For the future this means that changes to the torpedo will have to be considered in the context of the TCS and vice-versa, but Air Vice Marshal Chris Deeble, Program Manager for Collins and Wedgetail and the man ultimately responsible for Sea 1429/2, does not see this as an issue.

“The ADCAP is not compatible with the older systems, but noting that it and the AN/BYG-1 are both under the auspices of the Armaments Co-operative Project, the US Navy will keep them both in lock-step,” he said. “While the two are related, the functionality improvements we are likely to incorporate into the torpedo software are not likely to have an impact on the TCS, but if there is increased functionality which will affect the system it will be handled through the two year software update cycle.”

Operational test and evaluation
The Spiral 4 ADCAP is still formally undergoing Operational Test and Evaluation but is currently in the data analysis phase, ahead of release by the US Navy Chief of Naval Operations sometime in the first half of 2013.

This version gained RAN initial operational release in March 2011, allowing OT&E to be carried out in conjunction with the US Navy testing program. It follows on from the Spiral One version of CBASS (APB1) which achieved operational release with the RAN in March 2010, having been in USN service since November 2008.

Operational testing of the broader CBASS capability has actually been undertaken in Australian waters since late 2005 and an early operational highlight was achieved in 2008 when HMAS Waller, the first Collins boat modified with the TCS and CBASS capability, sank the retired destroyer USS Fletcher with a Spiral One weapon during that year’s RIMPAC exercise off Hawaii.

Most recently, 16 Spiral Four CBASS firings have been undertaken in Australian waters in the 2011-12 period in support of OT&E.

“We’ve also had a number of submarines participate in exercises with CBASS as target submarines. Diesel submarines in the littoral environment is a scenario which the USN can’t conduct alone, so we have provided assets to act as target submarines,” explains AVM Deeble to ADM. “We’ve done a lot of work with DSTO and APB4, including the algorithms developed in Australia for the HWT. We concentrate on profiles which are important to us but which also contribute to the broader context of US Navy trials. So we get the benefit of both series of tests, but tuned to the way we anticipate the weapon will be employed operationally.”

Use of the Collins boats as targets has also seen the use of the US-developed Submarine-Launched Countermeasures Emulator (SLACE) system, a mobile countermeasures surrogate which allows testing against a threat submarine which can employ mobile countermeasures.

“I have to say that the collaborative program is working well and SLACE was a very successful part of that program in many respects,” AVM Deeble said. “It’s an autonomous mobile countermeasures emulator that is representative of regional threats. We have used it in the important work of developing tactics as well as torpedo testing.”

Australian testing contributes its results to the USN program under the ACP MoU, and therefore the local full operational release is expected to closely follow the USN service entry once all the data has been analysed. Australian operational release had initially been expected in early 2013 but this has slipped slightly due to recent disruption of the US Navy OT&E schedule caused by Hurricane Sandy.

From an Australian viewpoint, testing has gone well and has been boosted by the enhanced operational reliability of the Collins boats in recent times, which met every one of their exercise commitments in 2012 and enjoyed increased availability for test firings.

In the most recent RIMPAC exercise, HMAS Farncomb was involved in the SINKEX which sank the ex-USS Kilauea, using the Spiral One torpedo as part of the joint tactics development weapons reliability program.

“We’ve also undertaken a number of trials connected with exercises off the Northern Territory coast,” details AVM Deeble. “Those firings will now be fed into the OT&E analysis. That work has gone pretty well and as a result we don’t envisage any serious issues.”

Sustainment and future development
The final torpedo delivery to Australia occurred in January 2012 and so Sea 1429/2 is now transitioning from the acquisition to the sustainment phase.

Sustainment of the ‘back end’ hardware of the weapon, fuel cells, motor and the like has passed to the Explosive Ordnance Division (EOD) at the Torpedo Maintenance Facility at HMAS Stirling and overseen by the co-located Guided Weapons System Program Office – West. The facility will also perform the software upgrades to APB4 and beyond.

An Undersea Weapons Continuous Improvement Program has been developed to oversee both hardware and software developments in the future. In this context, responsibility for the seeker head and the ‘front end’ of the torpedo will remain within the Collins sustainment system.

“We used to have the sustainment funding in the CN 10 (Collins) budget, but we’ve recently transferred the funding for the torpedo itself to the EOD budget. They are looking after the ongoing maintenance of the missile and will perform the configuration management or software upgrades. We will retain, via the CIP, responsibility for looking at what changes we might want for the seeker head or software, which best fits that deeper submarine understanding,” AVM Deeble said. “We in the Collins program will remain part of the Undersea Weapons CIP through our sustainment funding to at least 2019 and probably beyond, if we sign an extension of the ACP MoU.”

The ongoing collaboration with the US under the ACP MoU will be the subject of further bilateral discussion in the 2015/16 timeframe.

“I think with decisions of a Life of Type for Collins and the transition to the Future Submarine, an extension is going to be a likely outcome,” predicted AVM Deeble.

The Air Vice Marshal also says he doesn’t see the Sea 1429/2 program being affected by the recent squeezing of the Defence Budget, at least in terms of the Spiral Four development.

“One of the biggest impacts on OT&E in Australia has been our submarine availability for firings. Having the right boat availability has really kept us on track in that regard, but there are no spending issues for us in the Sea 1429 context,” he said.

The fiscal problems currently being experienced by the US military is also not likely to have any impact on Spiral Four rollout, but may well impact the timetable for future software development. At this point in time however, that’s all in the future and very much unknown.

Should CBASS develop as planned however, AVM Deeble says he is already looking to the future. “The continued development spirals will look at addressing other elements of the capability,” he said. “The countermeasures that could be applied against a torpedo will continue to evolve and the shallow water capability of the missile is an area that we want to focus on, in particular to better meet the future operational needs of our submarines and the operating environment.”

For the immediate future however, Navy is looking forward to the roll-out of APB4 and a meaningful CBASS capability.