October 29 marks another significant leap in Australia’s journey to acquire a sovereign capability to operate and maintain conventionally-armed, nuclear-powered submarines from HMAS Stirling.
Together with our AUKUS partners, Australia has the responsibility for coordinating, supporting, and delivering a significant package of maintenance work on Virginia-class submarine USS Vermont (SSN 792), which arrived at HMAS Stirling today for the Submarine Maintenance Period (SMP).
USS Vermont includes 13 Royal Australian Navy personnel in the crew of 134. These are from the cohort of officers and sailors who have completed the rigorous training in the US.
The SMP builds on last year’s milestone, when Australian personnel participated in the first-ever maintenance of a US conventionally-armed, nuclear-powered submarine on home soil during the 2024 Submarine Tendered Maintenance Period.
This year’s SMP involves a larger and more complex package of work that more closely reflects the type of maintenance will be required when Submarine Rotational Force – West begins operations at HMAS Stirling in 2027.
Unlike the previous maintenance period, this year’s work is being carried out without a tender ship – meaning Australian personnel are taking on even greater responsibility for executing complex maintenance activities on site. This will be a significant achievement and a reflection of the progress in upskilling the Australian workforce.
During this maintenance period, ASC will have an active role supporting work streams, including the provision and operation of pier temporary services and other support services like scaffolding.
Working alongside US personnel from Pearl Harbor Naval Shipyard and Intermediate Maintenance Facility (PHNSY & IMF), 19 ASC International Military Students and a further two from Raytheon and Thales are currently being trained at PHNSY & IMF.
They have returned to Australia for the SMP to help deliver the majority of the maintenance effort. This will contribute to sovereign technical uplift and facilitating knowledge transfer in line with an agreed phased capability plan leading up to the 2027 Initial Operational Support (IOS) milestone with the commencement of Submarine Rotational Force – West.
To further assist with the SMP, 22 Royal Australian Navy Fleet Support Unit personnel have also been training at the Pearl Harbor Navy Shipyard since June 2025, along with eight Royal Australian Navy clearance divers who will work alongside PHNSY Divers throughout the SMP.
The visit of USS Vermont is not only a practical training opportunity, it is also a critical moment to test and strengthen Australia’s nuclear stewardship systems, drawing on the deep operational experience and world-leading safety standards of our AUKUS partners.
Australia, the United Kingdom, and the United States share a long-standing commitment to the safe and responsible operation of nuclear-powered vessels. For nearly 70 years, these principles have enabled trusted naval operations, and our navies are working together to reinforce them here in Australia.