Australia is facing significant challenges in recruiting and training sufficient naval personnel to operate its future fleet of nuclear-powered submarines under the AUKUS defense agreement, retired admiral Peter Briggs has cautioned.

The AUKUS pact, valued at approximately $368 billion, involves Australia acquiring three to five Virginia-class nuclear-powered submarines from the United States to replace its aging diesel-electric Collins-class fleet. The new vessels are considerably larger, requiring crews of up to 134 sailors—nearly three times the personnel needed for the Collins-class boats.

On Tuesday, the US Navy’s Virginia-class submarine USS Colorado arrived at HMAS Stirling, near Perth, for a month-long maintenance period. This visit aims to provide Australian personnel with hands-on experience in handling nuclear submarines ahead of the transition to domestic operation.

The Royal Australian Navy currently has about 230 personnel engaged in various stages of US nuclear submarine training. Approximately 145 of these individuals have completed nuclear training in the US and are now gaining experience aboard American nuclear-powered submarines. The navy anticipates that by 2030, around 400 Australian officers and sailors will be trained and ready to serve aboard the nuclear fleet.

Despite these efforts, Briggs emphasized the need to accelerate recruitment and training, stating that the submarine force will need to expand to around 3,000 personnel to meet operational demands. Currently, about 850 submariners are certified to operate Collins-class vessels.

In addition to scaling up personnel numbers, Briggs highlighted operational challenges stemming from the coexistence of two different submarine classes—the Virginia-class and the future SSN-AUKUS model, which is being jointly developed by Australia and the United Kingdom. According to Briggs, managing two distinct submarine types increases complexity in training, logistics, maintenance, and parts supply.

The Australian government has not publicly disclosed updated recruitment targets or progress reports on workforce development plans. Recruiting remains complicated due to the wide range of required specialist roles, encompassing trades from sonar operators to cooks and electricians.

Following its maintenance work, USS Colorado is scheduled to return in late 2027 as part of the Submarine Rotational Force-West program, which will see up to five nuclear submarines from the US and UK rotate through HMAS Stirling. This initiative aims to deepen Australian expertise and infrastructure for sustaining a nuclear submarine force.

Commodore Paul Johnson of HMAS Stirling noted that the docking period would be used to practice nuclear-related operational procedures. Officials assured that no radioactive material would be transferred during the maintenance and that nuclear scenarios would be simulated.

The deployment and presence of nuclear-armed submarines in Australian ports remain contentious. During Senate hearings last year, it was revealed that US nuclear-armed submarines could potentially dock in Australian waters despite Australia’s non-proliferation commitments. USS Colorado’s captain, Justin Reeves, refrained from confirming or denying the presence of nuclear weapons aboard specific submarines.

Built in 2018, USS Colorado arrived carrying conventional armaments, including torpedoes and payload tubes designed for additional weapons. Its journey from Pearl Harbor to Perth took two weeks, with a crew of 160 men and no women aboard.

Life aboard these submarines is demanding due to confined space and living conditions, which include triple-stacked bunks and “hot racking,” where sailors share limited beds by rotating sleep schedules. At times, sailors may even sleep in torpedo rooms when accommodation is scarce. Captain Reeves described the vessel as one “built for combat, not for comfort.”

Nuclear propulsion offers significant operational advantages, granting virtually unlimited range limited only by supplies such as food and toilet paper, making endurance periods measured in months rather than days or weeks.