OPINION | The Royal Australian Navy should go hybrid to outlast a big war

The Royal Australian Navy’s (RAN) force structure of small numbers of warships and submarines is ill-suited to major wars. These vessels simply take far too long to build.

For the RAN to stay relevant to major warfighting, it will need to become hybrid, mixing big and costly crewed ships with uncrewed ones and ground-launched missiles. This simpler equipment can be built in numbers and, if necessary, at speed.

There are grim warnings of a possible major conflict in the Indo-Pacific that could include Australia. The RAN may be involved, but probably only briefly. Its combat power would diminish if ships were lost, since replacements would be unavailable.

The greatest weakness of modern navies is that they are being designed around highly sophisticated warships and submarines that, if lost in combat, cannot be replaced for years.

For example, the US Navy’s Virginia-class nuclear submarines take seven to eight years to build. While building conventionally-powered submarines is quicker, even the best-of-breed submarine builders, Japan’s, take four years.

Australia has instructive warship building experience. Each recently built Hobart-class destroyer took at least five years to build, with the forthcoming Hunter-class frigates expected to take seven years each.

Perhaps surprisingly, Australia’s shipbuilding experience during its last major war was comparable, if build time is related to tonnage.

In World War II, Australia built three Tribal-class destroyers and eight River-class frigates; these typically took two to three years to build. The Tribals were about a third of the Hobarts’ tonnage while the Rivers were about a quarter of the Hunters’ tonnage.

The United States achieved faster build times, but also with small ships. The US’s fastest average destroyer build time was one year for the Fletcher-class. A Hobart’s displacement is 3.5 times as great and a Hunter’s is more than four times.

The experience of both nations implies Australian warship build times will be lengthy even in wartime, especially given many imported components would be needed. Some, such as US-made missiles, could have a two- to three-year lead time.

Australia’s World War II shipbuilding effort was laudable but of limited value. Three quarters of the newbuild ships were not commissioned until late in the war, in 1944 and 1945.

Instead, the fleet with which the RAN entered the war gradually declined as losses mounted, albeit augmented by transfers from the Royal Navy. It lost 34 ships, most quickly in the first year of fighting Japan.

In 1942, the RAN lost two cruisers, four destroyers and a sloop (a small warship). Similar losses today would effectively remove the RAN’s surface warship fleet from a war.

Worryingly, a future war could have even higher loss rates. In 2022, the Center for Strategic and International Studies wargamed a naval war over Taiwan. One computer-modelled scenario simulated an attack on a large US Navy task force comprising two carriers, 29 cruisers and destroyers, and 10 attack submarines. All warships were either sunk or irreparably damaged. Of course, these are only estimates.

Even so, the dilemma facing smaller navies is clear. In a major war, losses can be expected, and these losses are unlikely to be replaced until after the war is decided. Most smaller navies today are likely to be of value only in a war’s initial phase.

Russia’s war against Ukraine reveals a solution. The Russian Navy quickly gained control of the Black Sea, bombarded Ukraine with missiles, and landed troops on Snake Island.

With its ships lost, the Ukrainians rushed anti-ship cruise missiles into service and developed a comprehensive range of uncrewed vessels (UVs). Over time, the Russian Navy lost a third of its fleet and was forced to withdraw from the Black Sea into well-defended ports. Russia’s losses include a cruiser, a frigate, a submarine, several corvettes and several landing ships.

Ukraine’s experience suggests smaller navies could progressively adopt hybrid force-structures comprising crewed and uncrewed elements. The Royal Navy already seems headed down this path.

In the RAN's case, crewed vessels would be used for such peacetime tasks as constabulary missions, including enforcing sanctions, and diplomacy involving flag-showing deployments. However, in a major war, the RAN’s crewed vessels would step back; their use would be carefully managed to limit attrition.

Ground-launched missiles and UVs would then step forward and provide the bulk of the RAN’s combat power, perhaps 80 per cent. Missiles and UVs could not undertake all the roles of the RAN’s crewed ships, but they would allow the navy to remain in the fight.

Being inexpensive, they could be numerous. Being small, they could be built much faster than crewed ships.

Functions would include surface and undersea surveillance, mine countermeasures, mine laying, hydrography, maritime and land strike, undersea warfare, carrying supplementary missile cells to increase crewed warship capabilities and, noting Ukrainian successes, potentially low-altitude local air defence.

Affordable, uncrewed vessels cannot fully undertake all the roles of a multi-billion-dollar destroyer or frigate, particularly in sea control missions such as merchant ship convoy protection. For such missions, uncrewed vessels could best complement crewed warships, making each more effective. Then a small number of available crewed warships could defend more convoys.

Uncrewed vessels are best suited to sea-denial tasks that prevent hostile ships and submarines operating freely in an area. Uncrewed vessels can be risked in offensive maritime operations well forward with crewed warships undertaking less hazardous defensive operations father back from the adversary.

Importantly, this hybrid RAN force structure could leverage growing Australian expertise in maritime autonomous systems. Australian industry could realistically be deeply involved in creating and then sustaining a hybrid RAN. Moreover, the necessary industrial base could be readily distributed across Australia and be designed to be capable of quickly expanding production rates in time of war.

In contrast, growing Australia’s single warship- and submarine-building facility in Adelaide would be impracticable due to complexity, size and workforce constraints.

Article reprinted with permission from the Australian Strategic Policy Institute's analysis and commentary site The Strategist.