Replacement of Australia's Collins Class Submarines

[jeffb]

Possible interim SSK..

Subs taskforce mulls new Collins before nuclear boats arrive

Defence Minister Peter Dutton has held talks with his Swedish counterpart, at which Australia’s future submarine program featured heavily.

www.afr.com

Defence officials are weighing up whether Australia will need a new conventional submarine to avoid a capability gap while the navy waits for a fleet of nuclear-powered boats to be delivered.

This could include building an updated version of the navy’s Collins-class submarine in Adelaide by the government-owned shipbuilder ASC with support from the submarine’s original Swedish designer, Saab Kockums, according to multiple sources.

Navy chief Mike Noonan has left open the possibility of carrying out a second life extension to the Collins-class submarines, but sources said the price difference between refurbishing an ageing submarine and building a brand new diesel-electric boat based on the Collins but with more modern systems would be comparatively small.

Explain to me again how all this is better than buying French subs?

 

[Forest Green]

Explain to me again how all this is better than buying French subs?

Cheaper?

 

[Archibald]

Explain to me again how all this is better than buying French subs?

Cheaper?

I though Australia had pissed the Swedes (and Germans ?) twenty years ago, as they presently pissed the French ?
Nah, just kidding. Seems the anger has subsided, and the Collins ended as fine boats. But how ironic is all this ! Back to the Collins, after all these years...

Navy chief Mike Noonan has left open the possibility of carrying out a second life extension to the Collins-class submarines, but sources said the price difference between refurbishing an ageing submarine and building a brand new diesel-electric boat based on the Collins but with more modern systems would be comparatively small.

(facepalm) So the answer to the question of replacing the Collins, is
a) MLU Collins
or b) new Collins ?
(bangs head against a wall)

-----------------

By this point I'm reminded of that old song "She told me to go whistling on the hill..."

"Elle m'a dit d'aller siffler là haut, sur la colline..." (yes, yes, lame pun entirely assumed...)

View: https://www.youtube.com/watch?v=2fkWJmtQk8c

Briefly summarized: the song tells about a guy in love with a girl, but every times, she dodges him and he is left like an idiot... and on and on it goes...

"J'ai attendu, attendu, elle n'est jamais venue" (I waited and waited again, she never came...") ROTFL

Drats, this should be the Collins affair official song.

 

[jeffb]

So essentially, Australia won't have SSNs till 2040+.

The Collins life extension won't cover the gap till then so either a second life extension or a whole new SSK build 'based on' Collins.

The Attack-class submarine was a planned class of French-designed submarines for the Royal Australian Navy (RAN), expected to enter service in the early 2030s with construction extending into the late 2040s to 2050.

And again, the French could have been approached about supplying Barracuda SSNs instead. Either option would have provided Australia with state-of-the-art subs, delivered in time to minimise life extension costs on the Collins class.

Crazy.

 

[MihoshiK]

So essentially, Australia won't have SSNs till 2040+.

The Collins life extension won't cover the gap till then so either a second life extension or a whole new SSK build 'based on' Collins.

The Attack-class submarine was a planned class of French-designed submarines for the Royal Australian Navy (RAN), expected to enter service in the early 2030s with construction extending into the late 2040s to 2050.

And again, the French could have been approached about supplying Barracuda SSNs instead. Either option would have provided Australia with state-of-the-art subs, delivered in time to minimise life extension costs on the Collins class.

Crazy.

The Barracuda SSNs were only an option if Australia wanted to be completely reliant on a country on the other side of the world for frequent refuelings, because building nuke infrastructure in AUS is still a no-go.

In other words, not an option at all.

 

[jeffb]

So essentially, Australia won't have SSNs till 2040+.

The Collins life extension won't cover the gap till then so either a second life extension or a whole new SSK build 'based on' Collins.

The Attack-class submarine was a planned class of French-designed submarines for the Royal Australian Navy (RAN), expected to enter service in the early 2030s with construction extending into the late 2040s to 2050.

And again, the French could have been approached about supplying Barracuda SSNs instead. Either option would have provided Australia with state-of-the-art subs, delivered in time to minimise life extension costs on the Collins class.

Crazy.

The Barracuda SSNs were only an option if Australia wanted to be completely reliant on a country on the other side of the world for frequent refuelings, because building nuke infrastructure in AUS is still a no-go.

In other words, not an option at all.

10 year refuellings are not 'frequent'. People need to stop thinking that because the HEU S9G and PWR2 power plants have 33 year lifetimes means they don't require servicing, maintenance or repair, because that's bullshit.

If Australia is serious about owning and operating SSNs, then they need to have the engineering and scientific resources to maintain and repair them, even if they are S9G or PWR2/3 models. If they don't then they're not really in control of them, are they?

So the no Australian nuclear infrastructure story has to change, will change, and significantly, unless Australia is signing up to be completely reliant on a country on the other side of the world that isn't France.

 

[Archibald]

As a matter of fact, France must be the one and only country on this goddam planet proposing non-nuclear variant of its SSN. There is no such Astute, Virginia, or Seawolf variants.

All this because of the Agosta and Scorpène before the Attack class.

Agosta-class submarine - Wikipedia

en.wikipedia.org

The irony being, many people were frustrated to see the Agosta going away in the 2000's, and no Scorpène nor "Attack" procured, just to back the Rubis & Barracudas at far lower cost... the French Navy is operating on a shoestring budget, and the future isn't very bright.

 

[Deleted member 2278]

10 year refuellings are not 'frequent'.

Cracking your boat open like an egg every 10 years really isn't a great selling point. Sorry.

 

[Archibald]

10 year refuellings are not 'frequent'.

Cracking your boat open like an egg every 10 years really isn't a great selling point. Sorry.

Maybe it is the reason why French SSNs have two crews and thus spent a huge amount of life time at sea.

There must be a tradeoff there.

 

[Deleted member 2278]

Yeah I'm sure they'd have unrivalled availability, right up until they have to sail half a world from their home port to have their guts splayed out for how many months? I'm pretty certain availability might drop slightly then.

 

[starviking]

10 year refuellings are not 'frequent'.

Cracking your boat open like an egg every 10 years really isn't a great selling point. Sorry.

I thought the French SSNs had a hatch for refueling, but I could be mistaken.

 

[Deleted member 2278]

10 year refuellings are not 'frequent'.

Cracking your boat open like an egg every 10 years really isn't a great selling point. Sorry.

I thought the French SSNs had a hatch for refueling, but I could be mistaken.

I was speaking somewhat figuratively but suffice to say, a refuelling is a non-trivial exercise however it is accomplished.

The builds would have to be staggered in such a way that no two boats fell due for refuelling at the same time. Fine for the initial fleet build-up, you can do with the time but perhaps a pain for the later boats?

Another thing would be the post-refuel working up. The boat would probably have to stay local to the yard for some while afterward (weeks, months?). Not really much of an asset to Australia if it is working up in the Med or N Atlantic. Again, a bit of a pain really.

Life-of-the-boat cores are defo the way to go!

 

[jeffb]

Life-of-the-boat cores are defo the way to go!

Again, it doesn't get you out of the need for nuclear maintenance and repair facilities in Australia, operated by Australians. In theory, to be a truly sovereign capability, Australia would have to be able repair, fabricate and fuel their own reactors.

Cracking your boat open like an egg every 10 years really isn't a great selling point. Sorry.

Don't be sorry, it's a trade off.

The French chose a different design that used commercial [actually LEU](not weapons) grade nuclear fuel. This meant that French nuclear subs had to be refueled more often but this was made easier by building the hull with special large hatches that could be quickly opened for the once every 7-10 year refueling then sealed again.

The French approach requires two 6 month refuelings over a 30 year lifetime. In exchange you get substantially lower costs (from using the same fuel as in civilian reactors, thereby greatly simplifying sourcing & disposal).

No Australian SSNs based on US/UK SSNs till 2040, Collins class life extensions 1 & 2 or a new Australian(?) evolved Collins SSK.
With the French, brand new SSKs by the 2030s and potentially SSNs before 2040 with only 1 Collins class life extension.

It's going to be very interesting to see what comes out of the 18 month review they've announced.

 

[Fluff]

Very messy, but perhaps both UK and US could manage 1 more boat each, and with some horsetrading of global responsibilities, get 2 boats the same to Australia, on long term loan, eventually they come back to the home navies, who run on their old type by a couple of years, so the new design presumably with more commonality across all 3 navies, goes to Australia first.

We need to see this as a 3 way deal, the existing fleets need to be pooled, along with operational tasks. So build an extra Astute etc if we order the bits now it shouldnt delay the new design by much, and they seem to be building at least 2 boats at a time in Barrow.

 

[H_K]

10 year refuellings are not 'frequent'.

Cracking your boat open like an egg every 10 years really isn't a great selling point. Sorry.

It’s a lot easier than you think. The French SSNs do refueling as part of normal refits, through a specially designed hatch. It doesn’t take that long.

The whole refit lasts 18 months, of which only a small part is the refueling. The French subs require fewer and shorter refits than the Virginia SSN refits (2 year refits every 6 years!)…. so if anything it’s the Virginias that are going to need to be constantly pulled off from operations.

The builds would have to be staggered in such a way that no two boats fell due for refuelling at the same time.

Nope. This problem wouldn’t exist as the refueling can be done in the same yard that does regular maintenance. It doesn’t require the original builder’s yard. (The French SSNs are built in Cherbourg but refueled in their home port of Toulon). There is some special infrastructure (a moving shed) but that’s it.

 

[Deleted member 2278]

This problem wouldn’t exist as the refueling can be done in the same yard that does regular maintenance. It doesn’t require the original builder’s yard. (The French SSNs are built in Cherbourg but refueled in their home port of Toulon).

Is there a free bus between Cherbourg and Oz I don't know about?

Frankly, it doesn't matter how you sugar coat it, it's a bug not a feature!

 

[jeffb]

Very messy, but perhaps both UK and US could manage 1 more boat each, and with some horsetrading of global responsibilities, get 2 boats the same to Australia, on long term loan, eventually they come back to the home navies, who run on their old type by a couple of years, so the new design presumably with more commonality across all 3 navies, goes to Australia first.

We need to see this as a 3 way deal, the existing fleets need to be pooled, along with operational tasks. So build an extra Astute etc if we order the bits now it shouldnt delay the new design by much, and they seem to be building at least 2 boats at a time in Barrow.

Yeah but why? What does AUKUS give the US and UK? All that hassle, depriving themselves of very expensive SSNs just so Australia can have them?

 

[Fluff]

Very messy, but perhaps both UK and US could manage 1 more boat each, and with some horsetrading of global responsibilities, get 2 boats the same to Australia, on long term loan, eventually they come back to the home navies, who run on their old type by a couple of years, so the new design presumably with more commonality across all 3 navies, goes to Australia first.

We need to see this as a 3 way deal, the existing fleets need to be pooled, along with operational tasks. So build an extra Astute etc if we order the bits now it shouldnt delay the new design by much, and they seem to be building at least 2 boats at a time in Barrow.

Yeah but why? What does AUKUS give the US and UK? All that hassle, depriving themselves of very expensive SSNs just so Australia can have them?

Strategically it gives them a foil to chinese Naval expansion, i.e. Chinese carriers.
If the subs fly an australian flag, it removes the 'reasonable' chinese complaint that UK are US are sticking their nose in where they are not involved.

And my plan wouldnt deprive anyone, both countries extend their existing design by 1 boat. Gives more time for design work on the next boats, as well.

 

[H_K]

Is there a free bus between Cherbourg and Oz I don't know about?

Frankly, it doesn't matter how you sugar coat it, it's a bug not a feature!

For what it’s worth, here’s the mobile refueling shed used to remove the nuclear rods in Toulon. The RN has something similar in Faslane. You pull the rods out at the beginning of the refit and then normal maintenance work can continue inside the sub. At the end of the refit the process is reversed. Wouldn’t be too hard to build such a shed in whichever yard the RAN is planning to use for maintenance.

From there the rods go to a temporary storage pool and then would be prepared for transport by ship back to France for reprocessing (similar to how civilian nuclear plants around the world ship LEU rods around).

Finally, irrespective of whether a refueling is required or not, there will always be periodic nuclear maintenance required, even on a US or RN SSN. The French subs handle this with a simple access shed that can be dropped in by crane… easy.

 

[H_K]

I thought the geographical distance betwixt France & Australia and the difficulties in transporting even mildly radiological material even short distances would speak for itself.

Nuclear fuel is shipped around the world all the time, literally every day. By truck, by train, by ship… there’s a whole civilian industry around this. For example, Japan has been sending fuel back and forth halfway around the world to France by ship for decades.

That’s the beauty of using civilian LEU instead of military grade HEU. This eliminates most of the challenges of standing up complex domestic infrastructure. Ever wonder how tiny countries such as Belgium, Sweden and Switzerland can have civilian reactors? They’re much smaller than Australia. All the hard work of processing and storing the fuel gets outsourced to France (or some other large nuclear country) via a supply & disposal agreement.

 

[Deleted member 2278]

....and I would still rather a life-of-the-boat core were it up to me. Thank you.

 

[Archibald]

Is there a free bus between Cherbourg and Oz I don't know about?

A bus I don't know, but as far as flying distances are concerned...

Yeah I'm sure they'd have unrivalled availability, right up until they have to sail half a world from their home port to have their guts splayed out for how many months? I'm pretty certain availability might drop slightly then.

Perth to Cherbourg: 9,054 miles
(and Great Britain is only a little farther to the North, perhaps 100 miles)
Perth to San Diego: 9,374 miles

Distance calculator - Calculate the distance online!

The popular distance calculator calculates distances in kilometres between any locations and coordinates, providing route planners, interactive maps, and information.

www.distance.to

How about that ? I'm pretty certain availability of Astutes, Virginias, or Barracudas might match, or pretty close...

 

[Deleted member 2278]

Astute to it's reactor: 0m
Virginia to it's reactor: 0ft

How about that?

 

[Hood]

That’s the beauty of using civilian LEU instead of military grade HEU. This eliminates most of the challenges of standing up complex domestic infrastructure. Ever wonder how tiny countries such as Belgium, Sweden and Switzerland can have civilian reactors? They’re much smaller than Australia. All the hard work of processing and storing the fuel gets outsourced to France (or some other large nuclear country) via a supply & disposal agreement.

Yeah but what happens if the EU, say, in 2048 bans all imports of radioactive waste into the EU?
Its unlikely but environmental laws do change.
I'm not sure the overly filled Sellafield pools are necessarily a good long-term answer either.

....and I would still rather a life-of-the-boat core were it up to me. Thank you.

Still only a theoretical sell-by-date tag though, nobody has run either of these cores under a full life cycle of operational conditions. They may well use up more core life than planned.
Anyhow all this is mute because the Australians keep talking about building mature submarines and we all know Astute (certainly) and Virginia (possibly) will be out of production before the 2040s, certainly the same goes for the reactors and current cores.

As for interim SuperCollins; good luck!
It took 13 years to build 6 submarines, all of them were late (18, 22, 27, 31, 21, 41 completed months late respectively).
Let's say the 18 month review happens, let's estimate it takes another 6 months to agree a deal with Sweden not to mention time needed to make any upgrade design changes, checking all the suppliers are still in business and able to supply identical or similar mechanical and electrical parts.
So laying down isn't likely before 2024, one sub lays down per year while six years to build seems the average Collin-build time. That gets the first SuperCollins in the water in 2030, the last in 2037, if all goes reasonably well and achieves the same build rate of the Collins.

Sure that's a bonus over the Attack-class build rate but the French were looking at a deal for twice the number of submarines.
I suppose if the RAN felt it could double its submarine manpower and crew 12 SSKs by the 2070s then there is no reason why it couldn't crew 6 SSKs built during the 2030s and 6 SSNs built during the 2040s & 2050s.
But it would have to be a mixed fleet until the 2060s-2070s assuming SSN production continued with a second dozen replacing the SuperCollins as they reached 20 years old (maybe for onward sale?).

 

[Deleted member 2278]

Still only a theoretical sell-by-date tag though, nobody has run either of these cores under a full life cycle of operational conditions.

Perhaps but it does avoid a nasty hull penetration.

 

[Hood]

Perhaps but it does avoid a nasty hull penetration.

I have no idea (as its classified obviously) but I suspect the Astutes would still have what is called a 'refuelling plug' in place. I can't see BAE Systems having not put a refuelling hatch in.

 

[GTX]

Folks, play nicely or deal with the consequences.

Please also keep on topic!

 

[GTX]

Right now there is a lot of speculation and opinion here and very little, if any, facts. Until there are some facts (probably not for months at least) it is all speculation and opinion. No-one here has access to what else is in the AUKUS treaty that underpins Australia's SSN aspirations/plans and until more is released we probably won't. It has already been stated that this process will take at least 18mths:

Nuclear Powered Submarine Taskforce | About | Defence

Nuclear Powered Submarine Taskforce

www.defence.gov.au

 

[jeffb]

The whole refit lasts 18 months, of which only a small part is the refueling. The French subs require fewer and shorter refits than the Virginia SSN refits (2 year refits every 6 years!)…. so if anything it’s the Virginias that are going to need to be constantly pulled off from operations.

That's interesting, I couldn't find any Virginia class refit details. So all things being equal they'd be in refit for years 7-8, 15-16, 22-24, a total of 6 years. After that they are (most likely) decommissioned.

Strategically it gives them a foil to chinese Naval expansion, i.e. Chinese carriers.
If the subs fly an australian flag, it removes the 'reasonable' chinese complaint that UK are US are sticking their nose in where they are not involved.

Do an additional 8 boats (eventually) really foil Chinese Naval expansion plans though, whatever those plans actually are?

 

[H_K]

interesting, I couldn't find any Virginia class refit details. So all things being equal they'd be in refit for years 7-8, 15-16, 22-24, a total of 6 years. After that they are (most likely) decommissioned.

Each Virginia SSN is planned to have 4 major overhauls (called EDSRAs or DMP… depot maintenance period), the first one after ~8 years then the next ones after ~6 years. Each is supposed to last 20 months but historically has lasted 2+ years.

So the first overhaul would be in years 9-10, #2 overhaul in years 17-18, #3 in years 25-26, and #4 in years 33-34, for a total service life of ~40 years.

It will be interesting to see if the core can last that long. There are also shorter regular maintenance periods at more frequent intervals.

 

[jeffb]

interesting, I couldn't find any Virginia class refit details. So all things being equal they'd be in refit for years 7-8, 15-16, 22-24, a total of 6 years. After that they are (most likely) decommissioned.

Each Virginia SSN is planned to have 4 major overhauls (called EDSRAs or DMP… depot maintenance period), the first one after ~8 years then the next ones after ~6 years. Each is supposed to last 20 months but historically has lasted 2+ years.

So the first overhaul would be in years 9-10, #2 overhaul in years 17-18, #3 in years 25-26, and #4 in years 33-34, for a total service life of ~40 years.

It will be interesting to see if the core can last that long. There are also shorter regular maintenance periods at more frequent intervals.

I'm not seeing a huge advantage over the French design with refit/refuels every 7-10 years.

 

[Pioneer]

So essentially, Australia won't have SSNs till 2040+.

The Collins life extension won't cover the gap till then so either a second life extension or a whole new SSK build 'based on' Collins.

The Attack-class submarine was a planned class of French-designed submarines for the Royal Australian Navy (RAN), expected to enter service in the early 2030s with construction extending into the late 2040s to 2050.

And again, the French could have been approached about supplying Barracuda SSNs instead. Either option would have provided Australia with state-of-the-art subs, delivered in time to minimise life extension costs on the Collins class.

Crazy.

I think it's clear the LNP neither intends to explain its hats on, hats off logic when it comes to this whole submarine debacle, the time and money that's been lost and wasted.....
Then again, the complacency of the general Australian public has empowered them to do so.
A radio commentator I listened to right says 'why is Defence the only portfolio/agenda that is not open for questioning or true accountability?'
Saying this, I listened to a Professor of Economics the other day, he was talking about how Australia has literally pissed it's Resources Boom for the last 30-years up against the wall with very little to show for it (I'll find his name and link to the interview if anyone is interested). My point here is I can't but help seeing we're doing the same with Defence........

Regards
Pioneer

 

[Volkodav]

So essentially, Australia won't have SSNs till 2040+.

The Collins life extension won't cover the gap till then so either a second life extension or a whole new SSK build 'based on' Collins.

The Attack-class submarine was a planned class of French-designed submarines for the Royal Australian Navy (RAN), expected to enter service in the early 2030s with construction extending into the late 2040s to 2050.

And again, the French could have been approached about supplying Barracuda SSNs instead. Either option would have provided Australia with state-of-the-art subs, delivered in time to minimise life extension costs on the Collins class.

Crazy.

Yes but you still need to deal with French companies then, a thing best avoided in my experience.

 

[Volkodav]

That’s the beauty of using civilian LEU instead of military grade HEU. This eliminates most of the challenges of standing up complex domestic infrastructure. Ever wonder how tiny countries such as Belgium, Sweden and Switzerland can have civilian reactors? They’re much smaller than Australia. All the hard work of processing and storing the fuel gets outsourced to France (or some other large nuclear country) via a supply & disposal agreement.

Yeah but what happens if the EU, say, in 2048 bans all imports of radioactive waste into the EU?
Its unlikely but environmental laws do change.
I'm not sure the overly filled Sellafield pools are necessarily a good long-term answer either.

....and I would still rather a life-of-the-boat core were it up to me. Thank you.

Still only a theoretical sell-by-date tag though, nobody has run either of these cores under a full life cycle of operational conditions. They may well use up more core life than planned.
Anyhow all this is mute because the Australians keep talking about building mature submarines and we all know Astute (certainly) and Virginia (possibly) will be out of production before the 2040s, certainly the same goes for the reactors and current cores.

As for interim SuperCollins; good luck!
It took 13 years to build 6 submarines, all of them were late (18, 22, 27, 31, 21, 41 completed months late respectively).
Let's say the 18 month review happens, let's estimate it takes another 6 months to agree a deal with Sweden not to mention time needed to make any upgrade design changes, checking all the suppliers are still in business and able to supply identical or similar mechanical and electrical parts.
So laying down isn't likely before 2024, one sub lays down per year while six years to build seems the average Collin-build time. That gets the first SuperCollins in the water in 2030, the last in 2037, if all goes reasonably well and achieves the same build rate of the Collins.

Sure that's a bonus over the Attack-class build rate but the French were looking at a deal for twice the number of submarines.
I suppose if the RAN felt it could double its submarine manpower and crew 12 SSKs by the 2070s then there is no reason why it couldn't crew 6 SSKs built during the 2030s and 6 SSNs built during the 2040s & 2050s.
But it would have to be a mixed fleet until the 2060s-2070s assuming SSN production continued with a second dozen replacing the SuperCollins as they reached 20 years old (maybe for onward sale?).

The Collins Class LOTE will almost certainly include new, fully outfitted, tested and certified hull sections, i.e. the method the Swedes use to upgrade their subs. The old sub comes in, the hull is cut, old section is removed, sections being retained are striped and refurbished, then the entire boat is rewelded with the new sections in place.

Additional new sections, identical to the LOTE sections, are fabricated, assembled tested and certified on this hot line and consolidated with new build sections of the same function of the retained sections on the LOTE Collins, but new design, to deliver a new submarine. ASC is the design authority for the Collins, Kockums is the original designer, and EB is the technical consultant (as the were for Astute and S80 remediation's). That's a hell of a lot of technical capability, experience and knowhow.

End result, five or six LOTE Collins and several new build boats of similar design using LOTE sections plus new (old) sections.

 

[jeffb]

I listened to a Professor of Economics the other day, he was talking about how Australia has literally pissed it's Resources Boom for the last 30-years up against the wall with very little to show for it

“Australia is a lucky country run mainly by second rate people..."
- from Donald Horne’s "The Lucky Country"

 

[zen]

I think the UK may yet spring a surprise and offer an Astute from the RN on permanent detachment/transfer to the RAN.
There are more than enough NATO assets to deal with Putin's still moth eaten fleet. A reduction in Astute numbers would be more than offset by the practical and political benefits.

My own theory is we hand one over and build two or more, likely PWR-3 based evolutions.
The whole build rate for SSNs in the UK is massively slowed down to keep it ticking over.
It would actually benefit designers and builders to evolve the design, learn lessons and gain more experience.

Though to be strict here, the Australians could see which way the wind was blowing decades ago and could, and should have jumped in on Astute or Virginia back then.
This whole avoidance of nuclear propulsion is a product of the triumph of domestic political beliefs over hard facts.

 

[Moose]

interesting, I couldn't find any Virginia class refit details. So all things being equal they'd be in refit for years 7-8, 15-16, 22-24, a total of 6 years. After that they are (most likely) decommissioned.

Each Virginia SSN is planned to have 4 major overhauls (called EDSRAs or DMP… depot maintenance period), the first one after ~8 years then the next ones after ~6 years. Each is supposed to last 20 months but historically has lasted 2+ years.

So the first overhaul would be in years 9-10, #2 overhaul in years 17-18, #3 in years 25-26, and #4 in years 33-34, for a total service life of ~40 years.

It will be interesting to see if the core can last that long. There are also shorter regular maintenance periods at more frequent intervals.

I'm not seeing a huge advantage over the French design with refit/refuels every 7-10 years.

I don't know Naval Group numbers, so let's have a look at the USN: A simple refit with minimal modernization, common with earlier 688s, can take 20,000-60,000 person days of labor. The EDSRA for the VA is aimed to require a out 200,000 days of labor, though right now the shipyard workforce issues are stretching that number, becuase it contains considerable modernization work.. The refueling and refit of a 688i requires something like 450,000 days of labor. So, aside even from the discussion of materials costs and costs of making/keeping a shipyard refueling-capale, and without a breakdown of costs to train and maintain the refueling workforce, one can see a bit of the premium paid to refuel versus refit.

 

[jeffb]

As you say, it's difficult to say without Naval Groups numbers. You'd think that the refuelling 'premium' would be reduced fairly significantly by its inclusion in the standard refit process though.

 

[jeffb]

This whole avoidance of nuclear propulsion is a product of the triumph of domestic political beliefs over hard facts.

To be fair, the original plan for Collins wasn't to build a sub capable of cruising the worlds oceans at will, it was to build a sub capable of defending Australia and her sea approaches.

 

[uk 75]

If the UK and US still had conventional submarines in service I suspect the RAN would have chosen one of them over the Scorpene for much the same reason it bought the F111C in the 60s.
The RAN has always assumed that it would fight alongside the RN and USN in a major war.