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Is it usual in the Royal Navy for a ship to be commissioned prior to the completion of sea trials?


PR stunt for a visiting Australian politician.


Probably then related to AUKUS.


Is it that hard to re start PWR2 reactor production? And then start churning out a 8th astute or just the reactor parts with the rest to be fitted/ done in aus after relevant people have been trained in Barrow? Then do joint follow on next gen boats/new design.

Steve B

Yes, Rolls Royce spent £600m reconfiguring their factory in Derby from PWR2 to PWR3 production, not forgetting the standstill time whilst they did this. So you want to reinstate PWR2 facilities and then reconvert to PWR3?


If Australia is willing to pay to reinstate production of the PWR2 for their purposes, I don’t see why Rolls Royce wouldn’t do it. RAN gets the PWR2 while the RN gets the PWR3. It’s all about money, and Australia has it to spend.

There’s no reason that the RAN can’t get serial production of Astute class, modified with a US CMS and weapons, as long as they’re willing to pay for it.


Whe RR refuelled Vangard they delayed PWR3 production by 5 years. I don’t think they would have taken that decision if it was simple enough to run core production and refuelling capcity for both PWR2 and PWR3 simultaneously.


So Vanguard refuelling which started in Dec 2015 until Jul 2022- another almighty program stuff up. A 7 year period double the original estimate.

It seems that the delays at RR were because of a new core production plant was delayed. Vanguard ( which uses PWR2 as well) was used to put blame here as well.

All the while cores have still to be produced for PWR2 reactors going into Astutes …. as there is still 2 in final construction/fitout the ‘old cores’ may still be in production.

As is well known Rolls Royce has been promoting its new smaller modular reactor SMR design for electricity generation. I would assume it derives a lot from the submarine reactors as its central feature, so there seems to be a case of ‘ if there is a will there is a way’


Fella, the last two A boats are built, with said cores installed, so no more PWR 2 cores to be built.
All that is happening to the last two Astutes is fitting out work – ie cabling ,pipework etc and then setting to work/testing. It takes absolutely ages to conduct due to the miles and miles of stuff that needs fitting/connecting. There is not alot of space to work in, so you are limited by the number of people you can use.


Thats unusual, since they spent serious money on this extra capacity for Vanguard at least
‘ A further £150 million had to be spent on reactor infrastructure at Devonport and the Rolls Royce facility in Derby so as to retain the ability to manufacture Core H potentially, for HMS Victorious and the other two boats. ‘
thats was 2014 story. Core H was for the then latest PWR2 reactors

PWR3 has departed from previous practice to build a prototype at Dounreay and run it ahead of the in service reactors to give heads up on any problems.
But of course nothing can or could go wrong with PWR3 ?

Last edited 1 year ago by Duker

Sorry, should have made my last post clearer, should have said no more PWR 2 reactors to be built, not the cores ie Core H. Victorious might/might not get a new core, as you say would be Core H, that’s only really the fuel rods, not the entire reactor which has now moved onto PWR 3.


That was the nuclear cores [ CPC production facilities at Rolls Royce site, Raynesway Derby].
Should really be almost interchangeable ( he said jokingly) and the later larger PWR3 just has more fuel cell cores as being a bigger boat it needs more power too.
NAO report

‘For example, the Department undertook a wider project to determine what the future nuclear reactor core would look like. However, it started building the new CPC facilities without a clear specification of the core design and a full understanding of how the facility would be used. The initial facility subsequently turned out to be too small, contributing to the £146 million total project cost increase. Unforeseen events, such as the Department’s decision to refuel HMS Vanguard, also had time and cost implications for the project’

Talk about Barmy Army ?


In addition, PWR 3 is inherently safer than PWR 2, so to take a step backwards wouldn’t be the ALARP position and therefore wouldn’t get approval.


PWR3 however is based mechanically on the S9G reactor the US uses in the Virginia’s which have a smaller hull than the Astutes so not out of the question it could be made to fit even if originally designed for the Dreadnought.

Heck would take some wrangling but you could even slot a Virginia reactor in to an Astute hull.

Last edited 1 year ago by Watcherzero

I think this may now be the way forward for AUKUS – a modified Astute design hull with a US supplied S9G reactor. There was a major article in The Australian newspaper on Tuesday : “Australia to train 2000 workers for submarines”.

A quote:
Details about the AUKUS submarine are expected to be announced in the coming weeks in Washington. It is believed major sections of the first subs may be built in the United Kingdom as Australian workers gain experience in building the submarine, while the nuclear propulsion will be a self-contained modular nuclear power unit built by the United States. “

Personally if Australia could learn to build Astutes with some assistance from Barrow and S9G reactors, and the RAN finished up with eight, I’d be delighted.


I am excited to see, heard there has been some pushback in the US among politicians and the military to sharing nuclear technology with the Aussies separate to the other pushback on the US production rate being compromised further (they have had long delays in deliveries over last couple of years, build rate is now back on target but it wont close the couple of year gap that opened up). I am expecting they will order one or two Astutes from the UK (may be a one UK and one US scrounged from somewhere) as an interim capability to replace the Collins and for training and an understanding they will be part of the consortium on a common SSN(R)/SSN(X) design. With the SSN(R) design work so far in advance of the US work and its requirements being much closer to the Australian requirement I also expect that would form the primary basis of the common design while the US would also order a small run of a half dozen larger Seawolf like premium ships to supplement a fleet primarily consisting of the common design striking a balance between quantity and capability.

JJ Smallpiece

Ridiculous about 12 years from being laid down to sailing


That’s exactly the length of time the Tories have been in power




what has that got to do with how long Tories in power?


If that is indeed the case there is something seriously wrong with submarine building in this country!!


It seems that the Government(s)/Treasury have decided that to build continuously they can only afford a build time of 8-10 years. But have 3 under various stages of construction at once
The same ‘principle ‘ has migrated to frigate- destroyer build.

Even the major overhauls have been stretched out to be 2-3 x the usual 24 months plus

Last edited 1 year ago by Duker
Gavin Gordon

Has been in the past, of course. Nothing ‘seriously’ wrong if production kept at a constant drumbeat. BAES can ramp up if required by HMG. HMG may find inspiration forthcoming due to China / Russia making them an offer they feel disinclined to refuse. In the meantime increased cooperation with US (Australia?) is driving efficiencies – ‘improvising on the base riff’.

David MacDonald

And about 9 years for a Type 26.


Deliberately built slow so that the yard is in constant production and doesnt have the issue they had when they finished the Vanguards’s of several years of no submarine design or production and all the trained workforce spread to the winds.

Bloke down the pub

The best the Australians could hope for at the moment is for them to build dockyard facilities suitable for SSNs in the ports where they intend to operate and then for RN to forward deploy one boat with some RAN crew.


We don’t have the boats to do that. To have one boat deployed takes four boats. That is four for one. We will have seven boats. We will make it look like we have 2 boats but they won’t be operated at the tempo they were or they should be. Why should we pay for RAN defence before our own? We are constantly sending tax money to aid foreigners.

David MacDonald

I would have hoped we could do better than that now, particularly as the PWR2 is fuelled for life.


For ‘Life’ read as 25 years. HMS Astute was commissioned in 2010, so her reactor life started from then. She will need a replacement or need to be re-fuelled around 2035ish give or take.

Due to our lack of SSN’s those we have have/are being worked very hard. I dont really see her operating past 2035 without a re-fuelling.


Nah it will be chopped. I expect Astute to go as soon as the last A boat is commissioned.

As I said in the last thread if RAN does goes for SSN(R) I would hope that HMG invests Oz yards to increase production capacity. We need to get back to 12 boats.


Based on what? Last a boat should be with us by 2026/7, Astute should still have about 7/8 years life left in her. We won’t be building any SSN(R) class before 2030 at the very earliest anywhere.
Aus has many hurdles to overcome before they even start to build SSNs. Aside from all that, how far down the evolutionary design phase are we with SSN(R)? Probably a long way off a finalised version that could be put into production.
I believe that Astute will stay until around 2034/5, rather then a re-fuelling, will then be chopped with SSN(R) hull 1 replacing her. One lives in hope…


We shall see.


Theres supposed to be a special report out soon( done in 6 months) that Wallace commissioned to look at the submarine-destroyer/ frigate ‘balance’
At the moment ( once all 7 A class are in service) its 1 for 3 . Your desire for 12 is say 1 for 2


Yes. The 25 years is ‘ HEU fuel cores life’ ( at normal usage which probably starts from deployment ) not the hull life.
Talent was in service for 32 years and had how many refuelling’s ?


Sorry, no,use of the ‘core’ starts after having completed ‘power range testing’ in Barrow, with sea trials and continues through commissioning then into ‘in service’ just at a slower rate of usage. Astute has been using her ‘core life’ since 2010.

Talent has had at least 2 refuelling’s that I am aware of. The S-boats proved that 3 refuelling’s didn’t really work, so would be surprised if Talent had any more than 2 new cores.


Sub reactors dont even have to be powered up continuously, and Astute has done its fair share of tied up at the dock with the reactor cold. 3 months here and there over 25 years all adds up to maybe 30 years in service life for a core life of 25 years. Since PWR2 was a different design the 25 years maybe conservative estimate.
The army and RAF husband their planes and heavy equipment life like that
The Tank battalions make a good case study on that, when the last downsizing came the remaining tank battalions ( regiments as they get called when they arent) were increased in size by an extra squadron of tanks each . All the better to have half or something in storage while a limited number were used for day to day training….if its Tues it must be our squadrons turn to drive the tanks ?


I am actually aware that SM reactors aren’t powered up continuously, really I am! Broadly speaking, they are ‘shut down’ within 36 hrs of returning from sea until approx 1 week before they are due to sail again, give or take.

It is totally irrelevant how/what the other forces use/save their kit, RN SMs are designed to be used, and the small numbers that we have means that they are worked hard over the course of their lives, period.

A SMs ‘core life’ is governed by the amount of EFPH (Full Power Hours) its core has. HMS Dreadnought which had a Westinghouse reactor had on build a core with 10000 EFPH available to it (look up Westinghouse Nuc SM reactors), this effectively means that in the Full Power State the reactor would run for 10000 hours. Fortunately Nuc SMs spend very little time in the FPS, so, core life is extended beyond those hours automatically.

I have no idea what the core life of PWR2 is in terms of EFPHs, but, if
you flash up the reactor, you start eating into core life. The rate at which you use that life is governed by the Power state the SM is in and for the length of time it is in those various power states, ‘simples’ to quote a Meerkat.


Thanks for that useful information.
However our friend X says RN need 3 boats in refit/maintenance/work up to have 1 boat deployed ( and working hard)
Does that make sense in the way reactor time is run down ?


Well, if the SM is alongside for whatever reason the Reactor is shut down. It’s the use at sea that drives down core life. SM deployments are carefully planned generally well in advance, so the relevant authorities will know the state of all core lives as time progresses.

The maths is really simple, small SM force, more tasking equates to more core use=quicker OSD/re-fuelling required.


Yeah , and other cold war peak numbers are going to be matched by the Army and RAF


No. Why don’t you think a little bit before commenting? We don’t need a big army. 12 boats are a minimum. You have a very simple view of the world.


Just being submarine obsessed isnt ‘thinking’
The RN isnt facing a Russia with a massive sub fleet and a small surface fleet like the cold war years.
Nor did the RN have a proper carrier fleet in the late cold war era, which was paid for by reducing the surface and sub fleet.
Navy Lookout has done a story on getting more reliability out of Astutes in service so they can do better than the 1:4 ratio you talk about. Indeed the core life alone should save a whole 18 months- 3 yrs refuelling period. Did you think of that ?


Astute in service date was 2014 so 25 years is the middle of the 2030s
Agincourt estimated commissioning is 2026-27 plus in service maybe 2 years later


Honestly I don’t care.


Then why come up with a fanciful notion here and I quote
I expect Astute to go as soon as the last A boat is commissioned.’

Supportive Bloke

Astute is the odd one out and had a few design issues that the follow on boats don’t have. Some of which made it into the public domain.

That said she is still very, very useful for a different range of work such as SF insertions.

Given the shortage of subs I’d be amazed if Astute was prematurely withdrawn: just that she would have a different task profile.


I don’t think you’ll get 12 SSN(R), but with enough political pressure applied you might get 10.


Submarines are exceptionally complicated pieces of equipment.


That’s not right. Actually I think you need to check your sources. Unless you are confusing these with the V boats. Sorry, I know you like to post your comments all the time and don’t like anyone Questioning you but your comment here is just plain wrong. Cheers Phil currently in Plymouth.

Nigel Collins

A much-welcomed and timely addition to the RN fleet.

More required!

China’s navy has significant advantages over its US rival, including a bigger fleet and greater shipbuilding capacity, as Beijing seeks to project its power across the oceans, the head of the United States Navy said Tuesday.

Speaking at the National Press Club in Washington, DC, US Navy Secretary Carlos Del Toro said China “consistently attempts to violate the maritime sovereignty and economic well-being of other nations including our allies in the South China Sea and elsewhere.”

“They got a larger fleet now so they’re deploying that fleet globally,” he said, adding that Washington must upgrade the US fleet in response.

“We do need a larger Navy, we do need more ships in the future, more modern ships in the future, in particular, that can meet that threat,” he said.”

Last edited 1 year ago by Nigel Collins

Let some of these people eat their words;

 Reply to  Boris
 2 months ago

There is no critical UK interests in Asia that require military intervention or even possibility.
The lines of trade thing for a UK flagged fleet doesnt exist any more either
Geography not your strong suit then? or do you still think UK should be a global policeman
Let those Asia Pacific countries counter or accommodate China as they see fit.
Look at India they have actual real border disputes and conflict with China, does UK care that much and get tough on China ?
I think you are just getting hot and bothered over ‘words and reports’ and what ever the US does the UK must follow especially throwing lives and treasure into military action in remote places

 Reply to  Captain Mainwaring
 1 year ago

Who gives a monkey’s about the Ukraine? Why would Russia want to invade the Ukraine? What does it offer them that is worth risking a conflict that could possibly end in a nuclear exchange? Land? Russia has land. Resources? Russia has resources. Food production? Russia is the world’s biggest exporter of food. Manufacturing? Russia builds everything it needs and has China. So please tell me why does Russia want to invade Ukraine?

Nigel Collins

No mention of the poor-quality steel being used in their construction.

Sometimes people fail to see the bigger picture!


Did you learn all your tradecraft while in the Stasi and have indexed comments from a long time back for persons under suspicion.

As for Ukraine, a lot of people were wrong including me.
My reasons for thinking Russia wouldnt invade.
1)Historically ‘winning’ wars is much harder ( US can tell you that), so Russia could lose too
2) Ukraine is a very big country which would be difficult to conquer
3) Russias army isnt as good as Putin might hope ( another historical truth)
this is not hindsight , I used these reasons before 24 Feb 22


Old boy, to track traitor like you as a Chinese spy.
Anything on the net is never forgotten.

Last edited 1 year ago by Hassinger

Hardly . This isnt the place but Im averse to Chinas mercantile tactics and its notorious United Work Front activities.
The worry is armchair admirals like your good self.


US navy is always pushing for more ships, more resources, more carriers , more submarines etc. And it makes sense in that they as a policy have global reach and share the Pacific ocean with China.
RN doesnt have global reach as a matter of policy….they withdrew from ‘east of Suez’ in the late 60s and have only more recently moved back into the Gulf region permanently.


Last time I looked, the RN has had at least one escort and (until HMS Jufair opened) an RFA in the Gulf since the mid 80s. Which by my rudimentary maths is pushing forty years…….


not that far back, HMS Jufair closed in 1972 and was transferred to USN

‘In 2003 the Royal Navy reestablished a post in the Persian Gulf, with a new title, the UK Maritime Component Command. On 1 November 2015, it was announced that HMS Jufair would be re-established as a permanent Royal Navy base. On 5 April 2018, the UK Naval Support Facility was officially opened’
I know you hate this but its more reliable than memories

Last edited 1 year ago by Duker

What about the Armilla Patrol? Started in the very early 1980’s…


Of course . I was wrong


That’s the puppy. At least one and sometimes two DD/FF continuously (or near as) every year since.

Nigel Collins

Things appear to be changing in that regard it seems.

Worth watching!

UK’s biggest warship meets Chinese carrier in tense South China Sea


UK Aircraft Carrier warns Chinese Submarine that is hunting them in the South China Sea


Last edited 1 year ago by Nigel Collins

12 years to build one submarine. Bloody unbelievable.


Forgive the bone questions from someone in light blue but just picking the brains of those on the site:
Could the RN have asked RR to increase production run to have shore-based reactors at Plymouth & Portsmouth to be energy resilient and maintain uniformed workforce expertise?
Could existing submarine reactors be re-packaged to be deployable to a FOB situation.
Would militarised SMR designs be sufficiently compact to be used on surface vessels?