In response to TDUA's well argued comments of August 29, 2023.
I agree. Given the work practices of Osborne Shipyard the Life Of Type Extension (LOTE) with expensive upgrades, may cost more than A$2 Billion and 3 years for each of 5 Collins. HMAS Collins herself may be cannibalised for spare parts as many parts have been out of production for more than 15 years.
The A$10 Billion (or more) LOTE submarine budget will also be occurring over the period of A$150 to 200 Billion being spent on the Virginia purchase, infrastructure upgrades (eg. an East Coast Base) and training of 1,000s of nuclear technicians/scientists/submariners/shipbuilders/officials in the late 2020s and 2030s. This is for up to 3 Virginias in the 2030s and maybe 2 in the 2040s. The LOTE + Virginias will form a huge distortion of Australia's defence budget, with likely reductions in non-submarine weapon systems across the Australian Defence Force.
Also, I see the hull life (immersed contraction and expansion cycles) of each Collins as a finite limitation that might only give each Collins 8-9 years of life after their LOTEs.
Instead 4 new SSKs would be a hedge against any understandable US decision not to deliver any Virginias. This decision will likely be USN and Congress driven over concerns about improved and more numerous Chinese SSNs and SSBNs threatening the American homeland.
The efficient Netherlands has similar long range, large SSK, submarine requirements as Australia.
Better for Australia (than the LOTE) would be leveraging information (including pricing) from the Netherlands thorough Walrus Submarine Replacement Program to select 4 TKMS, Naval Group or Saab designed SSKs. This Dutch selection program that began in 2014 would makeup 10 years of lost time in Australia. Australia could demand the same pricing for 4 Osborne built SSKs as Dutch built Walrus replacements. This would work as a ceiling on excessive pricing by foreign contractors, shipbuilding unions and Australia wide suppliers generally, that gouged the Collins build and the terminated Attack-class build.
Even if those 4 SSKs (each good for 33 years) were built at Osborne this would be a better solution than 5 LOTED Collins (only good for 9 extra years).
Australia has always had very few available Commanders and crew to man our subs. This scarcity is unlikely to change. Hence the diminished number of 4 SSKs (each with 52 crew) makes more sense than an unviable 12 SSKs (envisaged for the Attack class) or 3 to 5 Virginias (each with 135 crew).
In any sub-choice scenario 10 Anduril GHOST SHARK XLUUVs could also complement an Australian submarine force for the ongoing intelligence gathering tasking and even, in a run-up to war, smart-mine laying.
So, while so many in the ALP leadership and RAN are true AUKUS believers, they need to hedge in favour of new SSKs against the substantial chance the US won't deliver the vaunted Virginias.