From 8:25 in the US Defense Department video hereand above (of March 15) senior US Defense official, Dr. Mara E. Karlin (more biodata here) in answer to a question gives a lucid account that:
“Australia will get these [Virginia] subs in just about a decade. That is frankly faster than I suspect a lot of folks might have expected, when this whole [AUKUS] effort was announced just 18 months ago.
Australia will be purchasing a mix of new submarines and old submarines and right now it will be three with the potential for two more if needed.
As I noted earlier the cohort of folks looked at a wide range of different options and really came down with Virginia [as against preceding Los Angeles-class SSNs] as the right approach.
And Virginia Payload Modules [VPM on the future Virginia Block Vs] will not be a part of it [so no Block Vs for Australia]. The three countries saw that [block Vs with VPMs for Australia] didn’t make sense...[true]”
Dr Karlin then answers questions on sensitive submarine Information Sharing with the UK and Australia. And that US Defense has been consulting with the State Department [especially with the State Department’s International Traffic in Arms Regulations(ITAR) program and briefing Congress on this.
10:15 including "lowering the [transfer of US sensitive defense technology] barriers to working with them and information is just a piece of it…"
PETR COMMENT
Thanks to A on March 17, for finding the video above.
So Australia is getting 3 Virginias in the early 2030s and maybe 2 later. The five will be a combination of new and old.
Dr Karlin's advice on Block Vs just happens to coincide with my estimate of March 14 particularly about Australia not getting, or wanting, Block Vs. Block Vs will likely be semi-SSGNs having a heavy warload of 40 Tomahawks. Australia really isn't after SSGN-Block V land attack missile capabilities. Australia would avoid using land attack missiles against China.
By "old" Virginias Australia may get Virginia Block Is, IIs, IIIs or IVs.
Virginia reactors having a "Nuclear core life estimated at 33 years." is a crucial measure to keep in mind. Australia getting Virginia Block Is (commissioned 2004-2008) would be a risky proposition - as they may all reactor time out by 2041, which is likely before the first SSN-AUKUS is commissioned. The first SSN-AUKUS is likely to go to the UK RN for more experienced UK first of class testers and crews to commission.
The USN would probably not value Block IIs as highly as the later Block IIIs onwards. This is because Block IIs have 12 single Vertical Launch Systems (VLS) silos tailor-made for Tomahawk subsonic cruise missiles. Block II VLS cannot take significantly larger missiles or other types of warloads.
What the USN values more highly about the Block IIIs are that instead of single VLS they have 2 x much larger diameter multipurpose Virginia Payload Tubes (VPTs). Each VPT is capable of taking 6 Tomahawks, other much larger types of missiles (eg. 1 to 5 hypersonic missiles) or alternative loads like special forces gear or XLUUVs.
So Australia is probably looking at getting 3 x Virginia Block IIs. Looking at Virginia Boats in class the first Block II was commissioned in 2008 (likely to be decommissioned "reactor timed out" too soon in 2041).
It is likely Australia wants the 3 later Block IIs which were commissioned in 2011 (USS California), 2012 (USS Mississippi) and 2013 (USS Minnesota). These would time out around 2044, 2045 and 2046 respectively. The US may charge Australia significantly less for Block IIs than Block IIIs (or later Blocks).
It may be possible to get an extra 2-3 years of use if these Block IIs experience "more frequent intentional reactor shutdowns or slowdowns" when these three subs are tied to the wharf, while the RAN is training/transitioning to use these Virginias.
Alternatively, if one of the three above is labeled "new"-ish then it may be the last Block IV, USS Utah, which will be commissioned by August 2023.
Or if the US is talking really new for one of the first three we need to speculate on a not yet fully designed Block VI which could be an "Improved Virginia" of unpredictable capabilities and cost.
Then there is the issue of a possible two additional Virginias for Australia if the mainly UK designed SSN-AUKUS (was SSN(R)) program is running late. Lots of unpredictables in this "pick the Virginia" game.