Probably No SSN-AUKUS Hull Building in Australia Till 2040s

 Hi Shawn. Regarding your 10/07/2024 9:04 PM comment: 

“I reckon that ASC could start contributing to the program early, perhaps by building hull modules for all boats in Osborne as a 'sub-contractor' while Barrow focuses on building the [reactor] rear half. Shipping by semi-submersible heavy lift ships should be no issue, though an AUKUS escort task force will be necessary.”

The problems with such a proposal are many:

INTEGRATING US COMBAT SYSTEM FOR AUSTRALIA'S SSN-AUKUS

BAE would need to fully design the whole submarine, hull and contents including integration of a future US combat system, which dictates hull dimensions, before the front hull could be constructed.

It is already a given that Australia will be using the future system, an evolution of the US developed AN/BYG-1 combat system, already used on the Collins. This allows current and future Australian submarines to interoperate with US submarines. The US being Australia’s closest ally. 

The combat system are the weapons, sensors, databases and other equipment used on current and future Australian submarines. These need to be integrated, after probably more than 10 years of intense UK and US  negotiations, within the Australian version SSN-AUKUS hull design. Taking even longer the US might use the combat system solution for the post Virginia SSN(X) which may only be designed by 2040.

See https://gdmissionsystems.com/shipboard-integration-and-combat-systems/tactical-control-systems   

“General Dynamics Mission Systems develops the Tactical Control System (TCS) for every submarine in the U.S. and Australian Navies. TCS ingests data from all of the submarine’s sensor and communication systems to provide a common operational picture. TCS provides sensor data fusion, target motion analysis, tactical situational awareness and command decision tools to enable the watch standers and commanding officers to execute their mission… General Dynamics delivers TCS as part of the AN/BYG-1 combat system which integrates the tactical control, weapons/payload control, information assurance and tactical network subsystems.”

For the hardware weapons portion of the new combat system Australia might use a new (post-Virginia) vertical launch system (VLS), not even invented yet. This may be configured for larger hypersonic missiles than the Tomahawk standard used in the Virginias. 

The post Virginia future SSN(X) Combat System which might be adopted for Australia’s version of the SSN-AUKUS may use taller US hypersonic missiles https://en.wikipedia.org/wiki/Long-Range_Hypersonic_Weapon (currently of unknown length/height). They may require a larger beamed SSN-AUKUS than the UK version SSN-AUKUS. 

See https://en.wikipedia.org/wiki/SSN(X)-class_submarine “The [US] Navy currently expects delivery of the first boat [SSN(X)] in 2042." This may dictate a later than 2042 design for the Australian version of the SSN-AUKUS. 

FUTURE REACTOR OF UNKNOWN DIMENTIONS

The height/beam of the rear-reactor hull dictates the beam of the front half of the hull. This means front and rear hull need to be sized and fitted together in the UK before any Australian work could be done producing front hull sections.

A future and different version of the PWR3 (probably smaller than the Dreadnought SSBN's) needs to be built to squeeze into a SSN-AUKUS hull. Or, taking even longer, even a totally undeveloped PWR4 of unknown height dimensions would need to be totally designed and completed before the SSN-AUKUS’s forward hull could be designed. 

See https://en.wikipedia.org/wiki/Rolls-Royce_PWR#Future

SUBMARINE WORKFORCE TRAINING AND SCARCITY

Australia retired most of its specialist Collins submarine hull building workforce more than 20 years ago. Australia has no experience building hulls for nuclear submarines. I understand the latter hulls (including their constituent sections) have much tighter tolerances than needed for the Collins. 

SSN-AUKUS hulls would also likely have to withstand deeper dives than Collins hulls. This might mean the pressure hull sections would be thicker and use different still alloys than Australia used for the Collins 2-3 decades ago.

A complete Australian hull building workforce would need to be trained up in Britain and/or British trainers come to Australia and/or a British workforce comes to Australia. But Britain has a hull building workforce shortage even for its through to 2040 Dreadnought SSBN project, let alone releasing large numbers of hull builder/trainers early for an Australian SSN-AUKUS hull building project. The UK has also had major problems keeping enough Astute SSNs operational which might be partially due to a shortage of submarine maintenance manpower.

See https://en.wikipedia.org/wiki/Dreadnought-class_submarine#Boats_of_the_class

The US also has severe submarine workforce shortages. Their highest priority is building Columbia-class SSBNs through to "2042". See https://en.wikipedia.org/wiki/Columbia-class_submarine This is partly why there are not enough workers for Virginia production, maintenance or repair or to work on the future SSN(X) project.

All pretty grim.