With Air Warfare Destroyers (AWDs) coming on stream later in the decade and the Future Submarine and Frigate programs on the horizon, the Royal Australian Navy’s undersea warfare capability is set to receive a significant boost.

Nigel Pittaway | Melbourne

The configuration of the AWD, in terms of weapons and sensors, is of course well known and the government has announced what equipment it prefers for Future Submarine, but what capabilities will it actually bring and what does the future hold for undersea warfare in the ADF?

The key to modern undersea warfare is, like the other domains, not just about who has the fastest or biggest platform or most capable weapons system.

According to Captain David Mann, the Director of Navy Capability Requirements and Analysis, it is the establishment of battlespace awareness in a complex underwater domain, the ability to exploit that knowledge and the capability to effectively and efficiently employ weapons.

“From that perspective it has become apparent that only a layered and multi-faceted approach to combining major systems, tactics and planning will support the operational intent and the capacity to employ those weapons,” he noted to ADM.

So, more than just the weapons themselves, capabilities either now being introduced, or in the pipeline, across the ADF will combine to provide the ‘knowledge edge’ in the underwater battlespace.

Trying to predict what the future will look like with regard to undersea warfare isn’t easy but recent events in the South China Sea for example, have indicated increased emphasis in the littoral environment. CAPT Mann also predicts a growing complexity, affected by a range of disparate sources.

“Things such as the growth in the size of merchant vessels and also the growth in numbers of such vessels will impact on the complexity of the surface environment from a submariner’s point of view,” he said.

“The size of some of those ‘mega ships’ could possibly alter the approaches to harbours and ports, which will mean increased activity in those areas as well.”

The prediction of increased resource exploitation will also see increased military presence in the region, to bolster maritime security and guarantee that shipping lanes are kept open to free trade.

“I think the elevated demand for minerals and resource metals will see an associated re-invigoration of underwater mining and the subsequent use of remotely controlled vehicles to extract these resources,” CAPT Mann added.

AWD
The principal underwater weapon to be employed on the RAN’s Hobart-class AWDs will be the EuroTorp MU90 advanced lightweight torpedo, launched from torpedo tubes mounted within the hull of the vessel. In addition, the Lockheed Martin/Sikorsky MH-60R Seahawk Romeo helicopters now entering service will also be armed with the Raytheon Mk.54 Light Weight Torpedo (LWT).

"The delivery of an ASW system, combining long range sensors, a layered defence and a return to a towed and dipping sonar capability is consistent with the trends of our allies."

More than the weapons though, both the AWD itself and the Romeo have an integrated suite of sensors which will also integrate into a broader ADF capability, provided by platforms such as the Boeing P-8A Poseidon maritime patrol aircraft and Northrop Grumman MQ-4C Triton unmanned maritime platform, operated by the RAAF.

The Romeo has re-introduced a dipping sonar capability to the Navy, lost when the Sea Kings were converted to the maritime utility helicopter role several decades ago. They are equipped with the Raytheon AN/AQS-22 Airborne Low Frequency Sonar (ALFS), which is highly regarded by the US Navy.

“The AWD has an integrated sonar system, combining a hull-mounted sonar with a variable depth towed array system and integration of aircraft and sonar systems into the same operational area, provides a high performance, flexible submarine detection capability which is also combined with a torpedo detection system and obstacle avoidance capability,” CAPT Mann said.

“The delivery of an ASW system, combining long range sensors, a layered defence and a return to a towed and dipping sonar capability is consistent with the trends of our allies.

“The Hobart integrated sonar system also has identified growth paths and there is also the possibility of incorporating anti-torpedo defence systems in the future.”

Future Submarine
Although the capability requirements for the Future Submarine to be acquired under Project Sea 1000 are unknown, the General Dynamics AN/BYG-1 Submarine Tactical Control System (TCS) and Mk.48 Mod.7 Common Broadband Advanced Sonar System (CBASS) Heavyweight Torpedo (HWT) combination has been announced as the preferred weapons system.

Captain Geoff Wadley, Navy’s Director, Submarine Capability notes that this will provide commonality with the US Navy, Australia’s major ally in the region, but also provides future growth opportunities – critical in modern times of rapid technological advancement.

“Given the long life of the platforms from a submarine perspective, it’s critical that we have mechanisms in place that can keep pace with technological change,” he detailed to ADM.

“The Mk.48 CBAS HWT and the AN/BYG-1 TCS are both jointly developed with the US, so we have the benefit of leveraging off the might of their research and development efforts and also influencing the direction of their future development to ensure that it embodies both their and our operational needs.”

Unmanned vehicles and the future of undersea warfare
Included in this rapid technological change is a similarly rapid increase in computing power and the development of new construction materials, which both CAPT Mann and CAPT Wadley see as delivering an evolution of weapons and sensing capability.

“Things like the big data and the capacity to process an inordinate amount of information and the ability to prove hypotheses now that we didn’t have the computing power to prove in the past, we can now use to our advantage,” CAPT Mann explained.

Some examples of this change are the development of non-acoustic detection techniques, such as the ability to detect minute changes in the ocean surface and the use of laser and/or LED technology.

From a weapons standpoint, the US Navy is looking at a Common Very Lightweight Torpedo (CVLTT) or ‘anti-torpedo torpedo’, which may be deployed from a surface ship, or possibly even a large unmanned underwater system.

“We think these future direction technologies could make the underwater domain less opaque than is the case at the moment, using active and passive sonar systems, though that is balanced by the same technology supporting the increased stealth of underwater vehicles,” CAPT Mann said.

“The combination of those advances in technology and increased congestion has the potential to make some littoral areas more hazardous to manned submarines and may support the push for increased unmanned technologies.”

Navy is already closely following unmanned technology through the Navy UAS Development Unit, which has recently hosted shore-based demonstrations of the Insitu Blackjack and Schiebel S-100 Camcopter UAS, together with a range of EO/IR and Synthetic Aperture Radar sensor packages. Navy has recently acquired two Insitu ScanEagle deployable systems to continue its UAS development program.

Other applications for unmanned technology in the near future include a deployable mine countermeasures system and a role in the rapid environmental assessment capability, but further technologies are already under consideration by Australia’s allies.

Wave gliders which can be used to deploy smaller versions of the towed array sensors are expected to offer up to two months
endurance in the next couple of years offering a new dimension in underwater persistent surveillance.