Replacement of Australia's Collins Class Submarines

[SeanOhsee]

It isn't there right now but it could be if negotiations amongst the parties put speed and cost first. An Australian nuclear submarine line would be a white elephant once the order was complete while the US navy could use the added capacity as they are hard pressed with the current build rate and scheduled maintenance. A little headroom would be a welcome bit of insurance.

 

[jeffb]

Given Australia's troubles with keeping to major programs, or at least with investing sufficiently to maintain and build on them.

Examples please?

Lack of investment, especially on maintaining workforce for the Collins class upgrades and follow ons, as discussed elsewhere on this forum.

All six of the navy’s Collins-class submarines will undergo a $10 billion rebuild with the introduction of first of 12 new French Attack-class submarines now scheduled for 2035.

“It’s well overdue; eight long years ago when the government was elected, they were advised to make a decision on the life-of-type extension on the Collins-class submarines by mid-2015,” Mr O’Connor said.

“That was six years ago and the cost of the life-of-type extension would’ve been around $3-5 billion, that’s gone up to at least $10bn, if not $15bn, so major delays, massive timeline blowouts and expenditure blowouts on the future submarine program.

 

[uk 75]

In the short term at least the simplest option would be to re-flag an RN Astute and base it in Australia. The sub would then be able to cover East of Suez without deploying from the UK. Given how few Astutes we have, it avoids lengthy transit times. A joint RN/RAN crew would be no problem.
Adding 4 Australian Astutes to the build programme would merely put BAe back to the original number of Astutes the RN were supposed to get.
I didnt realise the US numbers were so tight.

 

[jeffb]

In the short term at least the simplest option would be to re-flag an RN Astute and base it in Australia. The sub would then be able to cover East of Suez without deploying from the UK. Given how few Astutes we have, it avoids lengthy transit times. A joint RN/RAN crew would be no problem.
Adding 4 Australian Astutes to the build programme would merely put BAe back to the original number of Astutes the RN were supposed to get.
I didnt realise the US numbers were so tight.

This is a good idea, do the Astutes have any 'special needs' that couldn't be serviced in Australia? Which does sort of raise the question of what happens if there's a reactor issue while it's deployed.

Indeed, numbers are tight. It might be that the easiest way to find more capacity is to invest in South Australian yards and build in Australia.

 

[zen]

As long as the beer is good and there's curry, the Brits will cope

The irony of Tomahawk purchase is in potentia, RAN could order some for tube launch to resupply an Astute as well. Which could open interesting possibilities.

 

[Josh_TN]

The Astute seems to be the only quick way forward. It seems like there is the bandwidth to build at least a few for the RAN. The US yards I think are just not going to be available with Virginia/Columbia. And building in Aus is going to take a long time for infrastructure to be set up. So an Astute or Astute like platform, initially built in the UK, possibly with additional units built in Aus (with some UK supplied systems, especially the reactor) seems like the quickest, lowest risk way forward.

EDIT: also the lower manning of the Astute would probably be very beneficial to the RAN.

 

[SeanOhsee]

As long as the beer is good and there's curry, the Brits will cope

The irony of Tomahawk purchase is in potentia, RAN could order some for tube launch to resupply an Astute as well. Which could open interesting possibilities.

There might be an issue with the former! There's a world of difference between a flavoursome English bitter and a freezing Aussie lager.

 

[uk 75]

I've never been to Oz (sadly) but I'm guessing that on most days there a cold one crosses the language barrier. That said I wouldnt put it past the RN to have English beer in an air conditioned environment.

 

[Josh_TN]

I've been - I don't remember finding many long pulls, which may be the main let down for Brits. But I suspect young sailors have a sufficiently...flexible...beer pallet that they will find what they need. Plus, some of the most chesty girls around with adorable accents.

 

[Flyaway]

US couple accused of selling nuclear submarine secrets https://www.bbc.co.uk/news/world-us-canada-58863678

I've seen rumours online on another forum that France is the foreign government involved in this who cooperated with the FBI to bring the would be purveyors of US nuclear submarine secrets here. If this is the case then the French governments anger over AUKUS becomes a lot more understandable.

 

[GTX]

Can Australia get second-hand nuclear submarines? The UK option | The Strategist

In case you’ve just arrived from Mars, the Australian government has announced it will acquire, with the assistance of the United States and United Kingdom, a fleet of nuclear-powered attack submarines (SSNs) that will be ...

www.aspistrategist.org.au

 

[H_K]

I've seen rumours online on another forum that France is the foreign government involved

Apparently not France. They issued an official denial. So my guess would be:

- India
- Brazil
- South Korea

Those are the only other friendly countries who might be interested in nuclear propulsion secrets. Unlikely to be a really close ally like the UK or Australia as the spies would have been really dumb to contact a country with intelligence sharing agreements with the US.

 

[jeffb]

Royal Navy nuclear submarine technology to be shared with Australia | Navy Lookout

www.navylookout.com

Some hurdles ahead...

There is a shortage of nuclear engineers and skilled engineering staff in general, with few people available to be seconded to Australia. The RN is also struggling to find and retain enough nuclear-trained watch-keepers for its modest submarine fleet. The RN should however be able to offer personnel exchanges, mentoring and advice to the RAN on its road to force generation. The US obviously has considerably more industrial capacity than the UK but is also not short of work, aiming to increase production of its Virginia class and about to commence the Columbia class SSBN programme.


Geo-politically the new AUKUS defence relationship makes sense on many levels and has potential benefits for the UK, further building on the export success of the Type 26 frigate. While SSNs are the desired apex predator of the seas, it would appear the Australians have committed to an even more costly, lengthy and demanding route to rebuilding their submarine force than before.

It would be nice to think you could add another two boats after Agincourt starting in say 2024 and 2026, but the new Dreadnought class SSBN's will probably have some impact on industrial capacity by then.

 

[Hood]

As I thought, Agincourt won't complete until late 2026/early 2027.
I think they'll be hard pushed enough to get the first SSN(R) completed before Astute's 25 years is up, life extension looks very much on the cards or another temporary force reduction circa 2038-40. Or maybe par for the course for the MoD will be to refit and refuel Astute costing millions then decommission her a year later...

There just isn't any slack on the UK side in anything, subs, build space or manpower. Short of sending RAN sailors to the UK I can't see what practical things we can do in the short-term. It feels very much like the Australians decided they wanted an SSN and the UK and USA did the handshakes but nobody really thought how this will work out in practice - hence the 18 month stage to mull over the options. But they are backed into a corner if it turns out SSNs aren't feasible within the medium-term.
(And before anyone suggests it, flogging second-hand 25 year old Astutes in 2040 to Australia is probably not a good idea.)

 

[Volkodav]

An interesting possibility relates to the way Sweden modernises their highly modular submarines, which logically will be how Australia modernises the closely related Collins as SAAB/Kockums is now working quite closely with ASC again. Basically they build completely new sections, fit them out, activate and test them, cut the old section out and weld the new section in.

If Australia follows this process then almost everything behind the escape tunnel will be new, with maybe some structural sections of the hull retained but new equipment fitted. Concurrently new auxiliary equipment, combat system equipment, accommodation etc. will be required, cutting the hull forward to withdraw and replace the relevant equipment rafts. These new rafts will be assembled, activated and tested before assembly into the boat, with the last stage being rewelding the hull back together.

Taking this a step further, if ASC / SAAB are fabricating new sections as part of the LOTE, they are not only efficiently upgrading the existing fleet, they are exercising their design and fabrication skills and........ (the is a very big, iffy, and).... they are more than half way to designing and building a Collins MkII.

Instead of building only six ship sets of propulsion sections, new diver lockout sections, new auxiliary and accommodation sections, they could build more and consolidate them with new build hull sections (weapons stowage, bow, sail etc.) and voila, new submarines.

These new boats, while not as advanced as the now dead Attack class, would still be world leading, with more life in them than the rest of the fleet. Their construction would not only preserve the skills at ASC, filling in the black hole until build on the SSGNs can start, but enhance them, as well as lead into the design and construction of an Australian SSGN, based on either a US or UK design but with Aust/Swede DNA as well.

Dare I suggest, such a boat could also be an option for export to a certain island nation?

Another thought is both the US and UK are struggling to build enough boat for themselves, could they actually farm work out to Australia to aid them in building their fleets faster? i.e., as with the F-35, Australia becomes a full partner, producing certain components, assemblies and sections for all three partners? The US currently shares work between EB and NG, each building sections for every boat, then supplying some of them to the other to consolidate and build the whole boat. Australia could join this program.

 

[Archibald]

Makes ton of sense ! Alas, that's now always the main criteria picked by a Gvt... unfortunately.
Clearly the Collins will need a massive MLU, because SSN don't grow in Australian trees (should I say, outback ?)

 

[zen]

An assurance here people are obviously beholden to is that RN spending and SSN numbers are a fixed quantity.
I would argue, and I bet Admirals are that RN SSN numbers have needed expansion for the last decade.

The capacity issue is directly down to spending priorities.
It us entirely possible to expand SSN numbers if the will is there.

Sharing a modular build with Australia is also highly achievable.

 

[Volkodav]

An assurance here people are obviously beholden to is that RN spending and SSN numbers are a fixed quantity.
I would argue, and I bet Admirals are that RN SSN numbers have needed expansion for the last decade.

The capacity issue is directly down to spending priorities.
It us entirely possible to expand SSN numbers if the will is there.

Sharing a modular build with Australia is also highly achievable.

The constraint will be reactors, can enough be built for the required SSN/SSGN and replacement SSBN fleets? As for hulls, all three partners have demonstrated that they can build high quality structures. Possibly, where there can be savings, optimization and accelerated production is in common systems, that can be used on a couple or even all partner designs going forward. i.e. the RN and USN replacement SSBNs are using a common missile compartment design.

Many auxiliary systems could be modular in nature and used across classes, possibly single sourced in a work share arrangement. some major structures could also be common. ship control and monitoring systems could be shared.

 

[zen]

Sounds a bit....Joint Combat Submarine??

Reactors is a interesting question. I'm guessing based on what I've read, but it could be they are assembled much like an interplanetary spacecraft. Slowly and with horrific precision.

 

[jeffb]

The constraint will be reactors, can enough be built for the required SSN/SSGN and replacement SSBN fleets?

I think the constraint is HEU. I forget the exact amount now but it's a significant amount for each reactor.

 

[Josh_TN]

I wouldn't have thought that would be the limiting factor over the timeframes we are discussing.

Maybe the new Iran deal can include buying their supply off of them.

 

[GTX]

I think the constraint is HEU. I forget the exact amount now but it's a significant amount for each reactor.

Australia could establish their own enriching capability. We do after all have approx 1/3 of the world's estimated deposits and already produce ~10% of the world's demand. Taking it the next step to enrichment is certainly technically possible...politically though...well that's a different matter.

 

[GTX]

Sounds a bit....Joint Combat Submarine??

I really like this idea. Having multiple locations able to build & service not only increases the capacity for all, it also provides enhanced robustness for the future.

 

[jeffb]

I think the constraint is HEU. I forget the exact amount now but it's a significant amount for each reactor.

Australia could establish their own enriching capability. We do after all have approx 1/3 of the world's estimated deposits and already produce ~10% of the world's demand. Taking it the next step to enrichment is certainly technically possible...politically though...well that's a different matter.

The Commonwealth Environment Protection and Biodiversity Conservation Act 1999 prohibits certain nuclear actions specified in s.22A unless a federal approval is obtained. It specifically prohibits nuclear power generation in s.140A (an amendment insisted upon by the Australian Democrats). The Act states that the Minister must not approve an action consisting of or involving the construction or operation of a nuclear fuel fabrication plant, or a nuclear power station, or an enrichment plant, or a reprocessing facility.

 

[jeffb]

So the technique for Uranium enrichment developed by Australians, can't be used in Australia...

The SILEX process was developed in Australia by Dr. Michael Goldsworthy and Dr. Horst Struve, working at Silex Systems Limited, a company founded in 1988. Their process was based on earlier methods of laser enrichment developed starting in the early 1970s, such as AVLIS (atomic vapor laser isotope separation) and MLIS (molecular laser isotope separation).

In 1993, the foundation of a set of principles for the separation of isotopes by laser excitation to enrich uranium were established by Goldsworthy and Struve at SILEX headquarters in Sydney.

In November 1996, Silex Systems Limited licensed its technology exclusively to United States Enrichment Corporation (USEC) for uranium enrichment.

Separation of isotopes by laser excitation - Wikipedia

en.wikipedia.org

 

[Hood]

I have pondered how the might get the reactors to Australia from the start.
Reactors are being built all over the world by foreign contractors I know, but there are probably few if any power station reactors that would simply be shipped complete.

So the options would seem to be:
a) Send the bits from UK/USA to Australia and assemble them there into the hull section - this would require the construction of a dedicated facility
b) build the reactor install it into a hull section sent from Oz to UK/US and then return it
c) UK/US build the reactor and the hull section and send it to Oz

The snags with b) and c) are that you're going to have to ship a large submarine section on a dedicated heavy-lift ship and protect it all the way from Somali pirates, South East Asian pirates, enemy special forces or state factions, terrorists or anyone else who might interfere.

In all these cases a facility will be required in Australia to load the fuel rods, so it seems like any construction programme is going to have to include a fairly expensive nuclear-industry installation in Australia. And handling the fuel means proliferation worries and certification in case any of those HEU pellets go missing.
Buying these reactors is not going to be like ordering up an S9G on Amazon and expecting it to come ready to plug in and play.

 

[uk 75]

My bet is that Australia will simply get RN boats and the RN will order replacements. I also think 5 is the most the RAN will get. But this will be offset by RN and US subs basing or deploying to Oz.
The US could do the same of course but the UK has done it before with conventional warships.

 

[kaiserd]

And which “spare” boats does the RN have that are available to loan/ transfer to the Australians, and aren’t required for the UK’s own defence purposes? And if there are some boats in this scenario then how does the RN justify (to the UK Government and to the wider UK public) needing replacements for them? When exactly are Astute classes vessels going to be replaced by successor vessels and be available for transfer, how reliable is any estimate when that might be, and what is their likely condition at that time?

If we were talking about an equivalent to a new post-Cold War peace dividend scenario in Europe (say a very marked reduction in tension with and threat from Russia) then a couple-of/decade reduction in UK SSN numbers (will awaiting successors) to the benefit of the of the Australian Navy may be doable/ acceptable/ realistic.

But as we’re not then it looks hard to see where these transferred UK subs are coming from; historic precedents (light fleet carriers etc.) related to genuinely surplus ships the RN didn’t need at the time and which were more useful for its purposes being crewed and paid for by the allies to which they were transferred to. And even a shared-crew/ co-operated Astute based in Australia would significantly weaken the RN closer to home.

Not sure the US Navy have any more “spare” boats for transfer but at least they have the overall numbers that if a political decision was made to loan a US boat to Australia it would have a much more marginal impact on US Navy capabilities and the boat would still be available and operating in a theatre central to US interests (but a largely peripheral theatre re: core UK interests).

 

[jeffb]

I have pondered how the might get the reactors to Australia from the start.

The reactors and turbine gear should be able to be constructed as equipment 'rafts' and be delivered for installation in hull sections prepared in Australia.

US manufacturers have accelerated their building processes recently by moving from building the Virginia Class in 10 sections to building it in 4. One of those sections will be the reactor and turbine section.

Apropos of nothing in particular, the Collins Class is already fitted with the AN/BYG-1 combat system that was developed for the Virginia Class.

Raft pics from HISutton

 

[Fluff]

The Collins are being refurbished, so plenty of time, as said before, everyone will squeeze up and will base a boat in aus, with aus crew in training. Across the US and UK fleet - and maybe Aus will send a collins to cover a UK or US commitment, somewhere.

With a will, it can be done. And I'd say there is a will.

And there will already be boats in that area, mostly US, but UK was there recently, so again, I'd expect to see the local boats being replened and repaired in Aus.

 

[UpForce]

I have pondered how the might get the reactors to Australia from the start.
Reactors are being built all over the world by foreign contractors I know, but there are probably few if any power station reactors that would simply be shipped complete.

So the options would seem to be:
a) Send the bits from UK/USA to Australia and assemble them there into the hull section - this would require the construction of a dedicated facility
b) build the reactor install it into a hull section sent from Oz to UK/US and then return it
c) UK/US build the reactor and the hull section and send it to Oz

The snags with b) and c) are that you're going to have to ship a large submarine section on a dedicated heavy-lift ship and protect it all the way from Somali pirates, South East Asian pirates, enemy special forces or state factions, terrorists or anyone else who might interfere.

In all these cases a facility will be required in Australia to load the fuel rods, so it seems like any construction programme is going to have to include a fairly expensive nuclear-industry installation in Australia. And handling the fuel means proliferation worries and certification in case any of those HEU pellets go missing.
Buying these reactors is not going to be like ordering up an S9G on Amazon and expecting it to come ready to plug in and play.

Yep.

 

[uk 75]

The sequence I suggest would involve one of the 4 Astutes in service now. This would be equivalent to keeping one RN boat East of Suez. Coupled with US, French SSN and NATO SSK that leaves enough to cope with the limited naval threat (as opposed to assymetric capers) posed by Putin.
The same would apply to the three on order. One would go to Australia.
A further batch of Astutes would then be worked in with the Dreadnoughts before the successor SSN for both RN and RAN.
The PLAN is a much more serious threat to British allies and interests than Putin's ramshackle fleet.
It would of course be much easier for the US but for the UK it would show we were serious about resuming a global role.

 

[GTX]

The Commonwealth Environment Protection and Biodiversity Conservation Act 1999 prohibits certain nuclear actions specified in s.22A unless a federal approval is obtained. It specifically prohibits nuclear power generation in s.140A (an amendment insisted upon by the Australian Democrats). The Act states that the Minister must not approve an action consisting of or involving the construction or operation of a nuclear fuel fabrication plant, or a nuclear power station, or an enrichment plant, or a reprocessing facility.

That doesn't really change anything. If the political will is there it will happen.

 

[NeilChapman]

From CRS R41129

"U.S. assistance to the UK on naval nuclear propulsion technology first occurred many years ago:
To help jumpstart the UK’s nuclear-powered submarine program, the United States transferred to
the UK a complete nuclear propulsion plant (plus technical data, spares, and training) of the kind
installed on the U.S. Navy’s six Skipjack (SSN-585) class nuclear-powered attack submarines
(SSNs), which entered service between 1959 and 1961. The plant was installed on the UK Navy’s
first nuclear-powered ship, the attack submarine Dreadnought, which entered service in 1963."

The US leases SLBMs to the UK. Part of the 'special relationship '. I mention this bc of the leasing agreement, not because I have any thoughts of the AUS considering SLBMs or ICBMs in any way. In fact, I believe this would be politically untenable in the Indo-Pacific.

There is plenty of precedent to provide US Naval Reactors life-of-boat nuclear propulsion to Australia.

There is also a possibility to lease new Virgina-class boats to Australia. Though it's been reported that Columbia-class equivalent to 2 1/2 Virginia-class in work effort the US has built 5 boats a year in the past. Adding another boat to an incredibly efficient, mature, production line is not out of the question.

The UK wants a new attack boat. It's more likely a new joint UK/AUS boat will be designed and built with US/UK tech. If BAE can get experienced design engineers to move to Australia that will help it look like AUS$ investment is staying local. Getting the yard up to speed will be more challenging.

It will be cheaper for the AUS to lease Virginia-class boats. The US would gleefully oblige. The UK will balk (they see AUS$ paying for 1/2 the design cost and expect build lead in UK) and the AUS political constituencies will want to build them locally even though it will be extremely challenging.

 

[jeffb]

The Commonwealth Environment Protection and Biodiversity Conservation Act 1999 prohibits certain nuclear actions specified in s.22A unless a federal approval is obtained. It specifically prohibits nuclear power generation in s.140A (an amendment insisted upon by the Australian Democrats). The Act states that the Minister must not approve an action consisting of or involving the construction or operation of a nuclear fuel fabrication plant, or a nuclear power station, or an enrichment plant, or a reprocessing facility.

That doesn't really change anything. If the political will is there it will happen.

Laws typically do change things I find.

Sure, the Parliament can change laws. Changing these particular laws however would require reopening and winning the nuclear power debate in Australia.

Good luck with that.

I suppose the government could slip a special amendment to the act through with some other legislation. Not a terribly democratic approach though.

 

[jeffb]

Australia to Build Eight Nuclear Submarines Based on Virginia-class Block V

The prime minister, Scott Morrison, announced on Thursday morning that Australia would be ripping up its $90 billion contracts with the French shipbuilder Naval Group and sign a new deal with the U…

www.globaldefensecorp.com

Don't know how accurate the above article is as it was posted only one day after the Australian SSN announcement and they don't quote their sources.

That said, I think an Australian design based heavily on the Virginia Class is a better idea for a couple of reasons:

1) It could greatly simplify and accelerate the initial build rate, getting boats in the water and operational sooner. From the outset, boats could have Australian built hulls. This has always been a central Australian condition and part of the reason that Australia wants their boats built in Adelaide. Basing the Australian SSNs hull design on Virginia's hull form means that the hulls could be populated with equipment modules that come, initially, directly from US Virginia Class manufacturers. Australian crews already operate with the AN/BYG-1 combat system, so indeed, whole Virginia command centers could simply be plugged into the design, vastly reducing the amount of testing and integration needed to certify the boat and allowing the simplified integration of US Sonar systems and weapons.

BAE is already supplying a number of systems for the Virginia Class, including the propulsors and VPM modules, further simplifying their integration into an Australian Virginia Class 'mod'.

BAE Systems to provide Virginia-class submarine propulsors for US Navy

google_ad_client = "ca-pub-4068738923530102"; /* Navy Recognition 468x15 link */ google_ad_slot = "6873402760"; google_ad_width = 468; google_a

www.navyrecognition.com

2) While the UK ship building industry is quite constrained capacity wise, the US one, based on a higher build rate, isn't (or not as much anyway having multiple suppliers for equipment modules).

3) Importantly, technically sensitive modules don't need to transit the Middle East or Southern Africa and the Indian ocean to reach Australia, instead coming directly across the Pacific from US ports.

4) Customizations to the internal layout that the RAN feels it needs to make (special accomodation sections etc) can be implemented from the start simply as locally built modules that can be integrated more easily during the construction process.

5) Training. The larger US fleet will allow more opportunities for Australian crew to gain experience on Virginia class boats, with Virginia Class equipment before deploying on Australian versions of same. Crew sharing generally becomes simpler (with the US) especially as the RAN already uses the Virginia's combat system.

6) The Virginia class design includes a large lock-out chamber for special forces deployment which is a priority for Australian subs.

7) Basing the design so closely on the Virginia Class would likely mean that Australian subs would be able to receive maintenance (and possibly spares) support at US facilities. Similarly, US Subs would more easily be able to receive maintenance and spares support at Australian facilities.

8) As Australian local manufacturing comes on line, more equipment modules can be sourced locally. But as a fallback, modules can be sourced from the US.

9) The higher number of US Naval facilities around the Pacific means more support facilities capable of supporting Australian SSNs.

 

[TomS]

3) Importantly, technically sensitive modules don't need to transit the Middle East or Southern Africa and the Indian ocean to reach Australia, instead coming directly across the Pacific from US ports.

There are no submarine manufacturing facilities on the US Pacific Coast. At minimum, they would have to ship via the Panama Canal.

The risks via either route would seem minimal. I'd expect shipments including sensitive items or any nuclear material to be escorted.

 

[GTX]

Can Australia get second-hand nuclear submarines? The US option | The Strategist

In my previous post, I looked at some of the issues involved in the Royal Australian Navy acquiring or leasing older nuclear-powered attack submarines from the UK to jump-start Australia’s own SSN program. In summary, ...

www.aspistrategist.org.au

 

[jeffb]

3) Importantly, technically sensitive modules don't need to transit the Middle East or Southern Africa and the Indian ocean to reach Australia, instead coming directly across the Pacific from US ports.

There are no submarine manufacturing facilities on the US Pacific Coast. At minimum, they would have to ship via the Panama Canal.

The risks via either route would seem minimal. I'd expect shipments including sensitive items or any nuclear material to be escorted.

Agreed, but it seems reasonable that the Pacific route would be inherently lower risk, even if shipments did come via Panama.

 

[NeilChapman]

Australia to Build Eight Nuclear Submarines Based on Virginia-class Block V

The prime minister, Scott Morrison, announced on Thursday morning that Australia would be ripping up its $90 billion contracts with the French shipbuilder Naval Group and sign a new deal with the U…

www.globaldefensecorp.com

Don't know how accurate the above article is as it was posted only one day after the Australian SSN announcement and they don't quote their sources.

That said, I think an Australian design based heavily on the Virginia Class is a better idea for a couple of reasons:

7) Basing the design so closely on the Virginia Class would likely mean that Australian subs would be able to receive maintenance (and possibly spares) support at US facilities. Similarly, US Subs would more easily be able to receive maintenance and spares support at Australian facilities.

8) As Australian local manufacturing comes on line, more equipment modules can be sourced locally. But as a fallback, modules can be sourced from the US.

9) The higher number of US Naval facilities around the Pacific means more support facilities capable of supporting Australian SSNs.

#7 If I'm not mistaken, US nuclear vessels must have maintenance work performed in the US. There is an exception for forward deployed ships but I'm not sure about nuclear powered vessels. It will be interesting to see if this agreement extends that opportunity to Australia. It would make sense for both US and UK vessels as well as other allies.

It would be a strategic advantage to have a shipyard with this capability 1/3 less distance than than the US mainland. A depot of shared spare parts and maintenance expertise.

#8 How much of the design would need to be shared? Who owns the design, GD/EB or the Navy? If GD/EB, would they need be the prime contractor?

The US has figured out that tweaks to a mature program is faster/cheaper/better than a new design. Hence Block V Virginia and probably VI and VII to shake out new tech. However, I could fathom a larger diameter boat should there be a technology or maintenance requirement for attack boats. That might be a reason to extend Columbia production once the boomer #'s requirement is met or at least build Virginia until the Columbia production line is mature.

If that tech requirement is now the UK would be in the know. My point being that the next gen US/UK/AUS attack boat may be more like Columbia than Virginia if that is the case.

What would require a larger diameter? I don't know. For a quieter boat? More armaments. Longer patrol duration? Faster, cheaper, better refit times bc equipment is not jammed packed. The Pacific is a big place. I could envision all the above.

Fourty year design life would be beneficial. Life-of-boat reactor is a no brainer with such a limited number to be procured. Electric propulsion is also a no brainer once the design is mature.

I'm not suggesting it would be the monster Columbia is going to be. Just potentially more like it than Block V Virginia.

#9 As I said, I believe nuclear powered ships/boats currently return to the US. Adelaide would be a boon. Perhaps by that time critical parts may be sent in 30 minutes by SpaceX Starship.