The T-boats were designed to be refuelled mid-life - and were. A-boats are not so designed. Pain, grief and suffering.......

If HMG does commit to a class of 12 it gives the builder and reactor suppliers (I assume BAES Submarines and RR Submarines) much greater certainty which should be good for planning, processes, mamagement, recruitment, retention (of people and corporate memory). I hope they will learn from mistakes in the Astute programme.

Ordering a class of 12 for delivery at 18 month drumbeat gives 16.5 years that plus the work on development and construction implies that (assuming there is one) work on the follow on class should beginning as the last one commisssions.

ORAC, the T-boats' reactors could be and were refueled - the A-boats' reactors have full-life cores which will have been running for some time before commissioning.

Friday will be the 23rd anniversary of St Albans commissioning, highlighting the massive time gap between 23 and 26. One ray of hope coming out of yesterday's turgid pile of goodish (and also many worrying) intentions was:

I await the announcement of the carrier drumbeat ...






NOT;)

PS One does wonder where the are going to get all the lads and lasses to spend months cut off from social media while dodging sunshine crewing the 12 boats - maybe AI will help:ugh:

PPS Cross posted with N_a_B

The PW2 is based in the Virginia S9G with a reactor life of 33 years. That gives a bit of leeway over the planned 25 service life of the submarine for up to another 8 years - depending on when the reactor went critical.

Assuming Astute’s reactor went critical in 2007 when launched she should be able to manage until 2040 without refueling. Unknowns are radiation fatigue in pipes, build up of radon in the core and other, well, unknowns.

Problems with the earlier Virginia subs should be able to give advance warning of issues. USS Virginia was launched in 2003, so 4 years ahead of Astute.

Downside is they never built a prototype so the reactor in Virginia is the first of the type and everything about the life is an estimate.

That's not the case. PWR2 went to sea on the V-boats in the early 90s, well over a decade before the Virginia class. The difference between the V-boat PWR 2 and the A-boat PWR 2 is the core design. V-boats designed to be refuelled and when that happened fitted with the new core design (core H).

No they aren't they are a pwr2 designed for vanguards but modified with some of the technology concepts of the S9G to extend their unrefueled life. PWR3 is the first clean sheet design using the a S9G design concepts

They might have some wiggle room to extend service life of some them due to the fact that some of the early boats have seen sitting around for years waiting for maintainence

The S9G reportedly has a degree of natural circulation of coolant allowing a reasonable fraction of max power before coolant pumps need to come on.
Not sure what degree PWR3 has in this regard.

The ones used in the Ohio's and Sea wolf definetly have that capability, haven't heard anything about the virginia having that capability

The R-R site says it "has fewer coolant pumps" than PWR-2

The RINA say ".....circulation of the water may rely on natural circulation to eliminate noise and the power requirement that would be introduced by using pumps."

https://www.nuclearinfo.org/wp-conte...ns_no_date.pdf

is interesting.....................

Let's hope they both write any old crap - we are talking about weapons secrets here. I would rather remain ignorant

The UK has far too many subsurface assets around the country, not to cause us worry, if they are not protected

Its the 21st Century - everybody, especially the Navy and the contractors, publish all sorts of stuff that used to be considered "secret". Over 15 years ago a senior USMC officer lectured some of us and he said that anything on a computer would or could be public knowledge with 18 months. I reckon he was very far-sighted.

I can't imagine that the Russians and the Chinese don't have a pretty good set of blueprints and the Operating Manual (draft) of the PWR3 in hand already.

They may. They may not. but let's not send them some, just in case they don't

It's the stuff they DON'T publish that I would like to keep that way

Natural circulation isn't new. First used with S5G on USS Narwhal in the 60s.
I think you'd be surprised as to just how hard it is to get hold of actual classified info for submarines, as opposed to "stuff on t'interweb"

I was replying to Throat who seemed to be suggesting that my post was coming close to publishing secret info - it wasn't . It's all publicly available information easily found.

But, as we all know, not everything published, either conventionally or on the web, is totally correct nor is EVERYTHING published.

From what is available in the public domain, the Virginia’s S9G reactor was the first with “Convective Cooling” whereby the coolant fluid is able to pass through the reactor extracting heat and then rising vertically due to convection. The PWR3 is reported as having extensive technology from the S9G so it should also have this design feature. The S9G is reported to be able to generate sufficient power on Convective Cooling alone for the Virginia’s to achieve a comfortable cruising speed - higher speeds require the use of cooling pumps.

The PWR2 is an old design which doesn’t have this capability and it’s also considered to be outdated (less safe) in that it doesn’t have multiple cooling systems. For normal operations, the cooling pumps are running and, as most submarine captains want to have the ability to generate maximum power immediately, they run the reactor “hot” even when loitering at slow speed. In this situation on older submarines, the cooling pumps generate more noise than the propeller.

I have confidence that the AUKUS SSN (probably should be designated SSGN) will be a very good design utilising a lot of the technologies developed for the Dreadnought class and, with the British Government’s stated intention to accelerate the design and construction processes, this will also be a very good outcome for Australia. If the design is finalised earlier, construction at Osborne could start earlier which may mean that the acquisition of the 3rd Virginia submarine for the RAN would not be required. With what is happening around the world, we are definitely living in interesting times.

There is a surprising amount of detail in the public domain.
It's just a case of knowing where to look.
If you haven't already, I recommend reading The Silent Deep.
Fascinating account of the RN acquisition of the nuclear deterrent - and Cold War operations.

My point was not 'directed'

Since the SMO Russia has been focusing on undersea vulnerability of the Western end of Europe

An example - 70% of UK gas requirement comes from Norway via one pipe

We either need more pipes or protect that one very, very well.

I can see the 12 new subs being build - and quickly I hope

I can't but think the RN surface and ASW assets also require a boost in numbers

Fortunately the Russian Navy is about as good a shape as the Army and Air Force

I've always thought that we should have bought more Astutes (and less aircraft carriers)

There's also a clear need for more small patrol vessels to do the nitty gritty jobs that seem to fall to the Navy - and maybe stop having to use tankers & Argos as a fill-in

I can't see how you can protect pipelines tho' - the anwer is several methods of importing gas & oil - which we have to some extent.

Former firebrand Australian Prime Minister Paul Keating (who is now largely regarded here as an irrelevant, angry old man shouting at clouds) did have a rather amusing take on large surface vessels.“I always say to the American admirals, you know every great battleship went down in the first week at sea in the Second World War, the Bismark, the Tirpitz, the Yamato. I mean Churchill sent the Repulse to Malaysia and it wasn’t their first week at sea but their first conflict and they went down too,” Mr Keating said. “Just like these American carriers are going to go down when a nasty fight starts and I said to this admiral they all sound the same in the end. And he said what do you mean? “Glug, glug, glug, glug!”

Certainly not known for his military brain

Yamato was launched in 1941 fought at Phillipine sea, Leyte Gulf and Samar. Before they sent it on a suicide mission in 1945


Just on a curious note theres a guy on twitter who is south korean, while a bit nationalistic times, he has great information about korean defence developments, procurement and sales. He tweeted an interesting thing
Like WTF you cant tease us like that