Shawn C. made some interesting comments on July 16, 2025. My response on submarines is:
The UK's Astute-class submarines have a record of low availability. This is perhaps because their PWR2 reactors have high pressure pipe issues that need frequent inspection and maintenance. Leaks are usually contained within the subs' reactor sections. https://en.wikipedia.org/wiki/Rolls-Royce_PWR#PWR2.
Wiki advises https://en.wikipedia.org/wiki/Astute-class_submarine#Propulsion_and_general_specifications
"A 2009 safety assessment by the [UK] Defence Nuclear Safety Regulator concluded that PWR2 reactor safety was significantly short of good practice in two important areas: loss-of-coolant accident and control of submarine depth following emergency reactor shutdown.[37] The regulator concluded that PWR2 was "potentially vulnerable to a structural failure of the primary circuit", which is a failure mode with significant safety hazards to crew and the public.[38] Operational procedures have been amended to minimise these risks.[39]"
Australia would be less able to maintain problematic Astutes (at Fleet Base West/HMAS Stirling or Osborne) than all the UK's 10s of Billions of pounds of inspection and maintenance facilities, developed over decades.
The UK has only 5 Astutes for the next 3 years. This is due to HMS Astute undergoing its first "decommissioning" and Mid Life Re-Validation Period (MLRP) in Devonport UK for around 3 years. The final Astute, HMS Achilles, will only be commissioned in 2028 or, more likely, 2029. So dividing the 5 commissioned Astutes by the naval Rule of Thirds yields only 1.66 Astutes being operational at any one time until 2028.
The 2 or maybe 1 Astutes' highest priority is Vanguard SSBN escort duties, in and out of Faslane. When all 5 commissioned Astutes are under maintenance (as has been recorded) US or French SSNs might escort UK SSBNs in and out of Faslane.
The emerging NATO First policy may keep Astutes in seas around NATO more than currently. Their North Sea and Arctic Ocean duties include shadowing Russian ships and submarines and collection of Russian land based intelligence. The UK may insist NATO First will not diminish non-NATO missions - but worldwide Astute and associated US SSN availability is already stretched.
See mentions of AUKUS here https://www.rusi.org/explore-our-research/publications/commentary/optimising-readiness-uk-astute-fleet. Also US SSNs are being shifted from the Atlantic to the Indo-Pacific against China in the above link. This is increasing the Atlantic workload for Astutes.
Between SSBN escort priorities the Royal Navy could perhaps spare one Astute for one month rotation every 2 or 3 years at HMAS Stirling. Ex submarine commander and continuing expert Peter Briggs reported all 6 Astutes are at times in dock. Their maintenance issues (often kept secret) may frequently involve their reactors. Chronic maintenance problems may mean no Astutes might come to Australia for more than 3 years.
I'm glad another expert, on July 29, 2025, agreed https://www.lowyinstitute.org/the-interpreter/debate/aukus-stress-test-alliance-pressures-australia-s-strategic-choices .
3 comments:
Hi Pete,
The RN held a decommissioning parade at Devonport Naval Base yesterday.
The last Trafalgar-class, HMS Triumph (S93) was formerly decommissioned and will enter nuclear recycling.
HMS Astute (S119) was decommissioned in the presence of her sponsor, Queen Consort Camilla and will enter MLU: https://www.navylookout.com/the-queen-visits-hms-astute/
Both Albion-class LPDs were decommissioned, and will be transferred to the Brazilian Navy. https://www.navaltoday.com/2025/04/07/uk-to-sell-two-albion-class-amphibious-ships-to-brazil/
Hi Shawn at 7/18/2025 6:39 PM
I reckon from https://www.navylookout.com/the-queen-visits-hms-astute/ of July 16, 2025 the UK commissioning system is strange.
So https://www.navylookout.com/the-queen-visits-hms-astute/ indicates HMS Astute has had "the end of the submarine’s first commission". It goes through "the formal act of decommissioning" of its first commission. Now HMS Astute "enters a £multi-million Mid Life Re-Validation Period (MLRP) in Devonport [UK]."
So, as you say, Astute enters an extended Mid Life Update (MLU) - maybe for 2 to 3 years? Then Astute may have 10-15 years operational life for its second commission.
So until 2028 or 2029 when Achilles is commissioned the UK RN will have only 5 or, at best, 6 rather low availability SSNs in all. https://en.wikipedia.org/wiki/Astute-class_submarine#Boats_in_the_class
This is a real come down when in past (Cold War) years there may have been more than 12 UK SSNs in commission with 40+ US SSNs in the Atlantic.
The Albions (in UK commission from 2003) may have been a delayed reaction to gaps seen in the Falklands 1982 marine landings. Not much use against continental Russia or China. https://en.wikipedia.org/wiki/Albion-class_landing_platform_dock . I reckon Brazil wants the 20,000 tonne Albions because they're BIG, even if their still of little use - and getting rusty :)
Cheers Pete
The failure of the RN submarine force is the most telling. There are no UK SSNs protecting the HMS Prince of Wales carrier group, in its July 2025 Indo-Pacific cruise.
In 1982 there were 11 UK SSNs and ~10 SSK available. Now there is 1-2 SSNs operational at any one time, with priority going to SSBNs.
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