Astute Class Attack Submarine (SSN) (RN)

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SKB
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Re: Astute Class Attack Submarine (SSN) (RN)

Post by SKB »

bobp wrote:HMS Audacious has departed Barrow for the Clyde. She is the fourth Astute class submarine.
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(Photos: https://www.nwemail.co.uk/news/18361602 ... es-barrow/ )

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Name: HMS Audacious
Class: Astute Class SSN (7 boats)
Pennant number: S122 (4th of 7 boats)
Ordered: May 2007
Builder: BAE Systems Submarine Solutions
Cost: £1.492 Bn (budget)
Laid down: 24th March 2009
Naming Cermony: 16th December 2016
Launched: 28th April 2017
Sponsored by: Lady Elizabeth Jones
In service: 2021 (delayed)
Status: Began sea trials 6th April 2020

Surfaced Displacement: 7,000 to 7,400 t (6,900 to 7,300 long tons; 7,700 to 8,200 short tons)
Submerged Displacement: 7,400 to 7,800 t (7,300 to 7,700 long tons; 8,200 to 8,600 short tons)
Length: 97 m (318 ft 3 in)
Beam: 11.3 m (37 ft 1 in)
Draught: 10 m (32 ft 10 in)
Propulsion: Rolls-Royce PWR 2 nuclear reactor, MTU 600 kilowatt diesel generators
Speed: 30 kn (56 km/h; 35 mph), submerged
Range: Unlimited
Endurance: 90 days
Test depth: Over 300 m (984 ft 3 in)
Complement: 98 (capacity for 109)
Sensors and processing systems: Thales Sonar 2076, Atlas DESO 25 echosounder, 2 × Thales CM010 optronic masts, Raytheon Successor IFF
Armament: 6 × 21 in (533 mm) torpedo tubes with stowage for up to 38 weapons: Tomahawk Block IV cruise missiles, Spearfish heavyweight torpedoes

UKD
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Re: Astute Class Attack Submarine (SSN) (RN)

Post by UKD »

Considering that the Astute class are designated for the anti-shipping role, wouldn't it be a force multiplier to equip them with quality sub-launched anti-ship missiles?

Defiance
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Re: Astute Class Attack Submarine (SSN) (RN)

Post by Defiance »

Aside from funding and ROE concerns, blasting missiles out of the sea makes your undetectable asset pretty darn detectable against any sort of capable adversary

That's not to say they aren't useful, because they are, but i'd sooner fit them more ubiquitously to the surface fleet IMO

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Re: Astute Class Attack Submarine (SSN) (RN)

Post by UKD »

Surely firing torpedos does exactly the same thing though and puts your right next to the enemies ASW assets?

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ArmChairCivvy
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Re: Astute Class Attack Submarine (SSN) (RN)

Post by ArmChairCivvy »

Defiance wrote:blasting missiles out of the sea makes your undetectable asset pretty darn detectable against any sort of capable adversary
A good objection as they tend to be vertical launch. India is extending the sub-launched Brahmos missiles range from 290 to 500 km, so a quick turn from vertical flight could leave the adversary knowing just the rough sector (on detection) as to where the missile originate from?
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Re: Astute Class Attack Submarine (SSN) (RN)

Post by Scimitar54 »

SKB Wrote “ Class: Audacious Class SSN (7 boats)

If only she were the first of a class of 7! That would give us 10 x SSN (with the 3 x Astute Class)

I admire your audacity, but of course you must have meant Astute, rather than Audacious. :mrgreen:

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ArmChairCivvy
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Re: Astute Class Attack Submarine (SSN) (RN)

Post by ArmChairCivvy »

Maybe a VLS payload module is secretly being welded to the back of the conning tower - voi la! A new class has come into being; and would explain the delays, too

I am v much wondering about this combined (larger) hall for Astute and Dreadnought builds. Sure, trades can work more efficiently, in waves thru the parallel - now I am exaggerating of course, let's make it 'somewhat' - builds.
But: the bottleneck has been building the reactor cores... will that change?
Ever-lasting truths: Multi-year budgets/ planning by necessity have to address the painful questions; more often than not the Either-Or prevails over Both-And.
If everyone is thinking the same, then someone is not thinking (attributed to Patton)

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Re: Astute Class Attack Submarine (SSN) (RN)

Post by Scimitar54 »

Well it got slower (to the present rate), so it should not be impossible for it to return to a quicker pace, given the will to do so that is. :mrgreen:

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Re: Astute Class Attack Submarine (SSN) (RN)

Post by Defiance »

UKD wrote:Surely firing torpedos does exactly the same thing though and puts your right next to the enemies ASW assets?
Potentially, although ideally they will not be aware they are being fired upon until they detect the incoming torpedos

Putting it into an tactical context, throwing at best 6, more likely 4 (assuming you might want a decoy and a torpedo ready just in case - you're vulnerable when you set up to launch missiles) anti-ship missiles out of an Astute in a salvo doesn't seem worth jeopardising the location of your prime ASuW asset. This is especially stark when our SSN numbers are so few; why give away their position for such a low Pk?

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Re: Astute Class Attack Submarine (SSN) (RN)

Post by Aethulwulf »

It also depends how close to the surface target a submarine can get before being detected. If the answer is many 10s or even 100s of km, then a sub-launched anti-ship missile may be your best bet. However, RN sub captains like to get close enough for visual contact with the target in their periscope. At that range a torpedo is deadly.

Its the difference between an assassin choosing to use a sniper rifle or a knife.

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Re: Astute Class Attack Submarine (SSN) (RN)

Post by ArmChairCivvy »

Defiance wrote:why give away their position for such a low Pk?
The USN has modified Tomahawks to be usable against moving targets (ships) from a great distance, i.e. targeted using other assets.
- let's add the Indian bragging about Brahmos, both surface and sub launched, without any evidence for the first bit: 7x as deadly and 3x as fast
- will that modify the Pk calculus?
Ever-lasting truths: Multi-year budgets/ planning by necessity have to address the painful questions; more often than not the Either-Or prevails over Both-And.
If everyone is thinking the same, then someone is not thinking (attributed to Patton)

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Re: Astute Class Attack Submarine (SSN) (RN)

Post by Defiance »

ArmChairCivvy wrote:
The USN has modified Tomahawks to be usable against moving targets (ships) from a great distance, i.e. targeted using other assets.
- let's add the Indian bragging about Brahmos, both surface and sub launched, without any evidence for the first bit: 7x as deadly and 3x as fast
- will that modify the Pk calculus?
If you want something to throw AShMs in the air to be targetted by someone else, it's probably cheaper/easier to do it from a surface vessel and to allow the sub to do something more useful in its role IMO - so putting it in a UK context I would rather make sure we get weapons onto T45/T26.

As for BrahMos, the threat of massed supersonic anti-ship missiles have been a problem since the 70's so I personally don't think it changes the price of fish too much

(There is a question around how much reaction time do you gain from, say, F-35 on CAP up-threat due to the signature of Su-30MKI, and how much does this offset the minimal reaction time due to speed of the missile. I would also be keen to know how far a Su-30MKI can lug a BrahMos prior to launch considering it's so huge it can only carry a single missile on the centre station - I might mess around with these in CMO to see what comes up, it's a fun piece of software despite its issues in places)

The debate between supersonic/sub-sonic when it comes to ASuW is still ongoing and we're seeing that with our own FCASW discussions with France. I personally don't have an opinion which is better, what seems to be more important in attacking ships is volume, attacking from multiple directors and overall EW tricks to complicate the picture.

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Re: Astute Class Attack Submarine (SSN) (RN)

Post by ArmChairCivvy »

While we are lucky if we can keep our SSN numbers steady, for PLAN and USN it looks like they are starting to spiral up:
https://news.usni.org/2020/10/12/chines ... rd%20Brief

The metric in that is:
- China 5 under construction at any time
- US wants 3 out of "the factory gates" every year
... those two measures probably translate to "abt the same" - whereas we will take a break in favour of the boomers
Ever-lasting truths: Multi-year budgets/ planning by necessity have to address the painful questions; more often than not the Either-Or prevails over Both-And.
If everyone is thinking the same, then someone is not thinking (attributed to Patton)

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Re: Astute Class Attack Submarine (SSN) (RN)

Post by Scimitar54 »

Whereas we should probably have interleaved Astute & Dreadnought builds. :mrgreen:

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Jensy
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Re: Astute Class Attack Submarine (SSN) (RN)

Post by Jensy »

Scimitar54 wrote:Whereas we should probably have interleaved Astute & Dreadnought builds. :mrgreen:
Considering the amount of R&D and investment required for Dreadnought, I'd be curious what the opportunity cost of ordering three more as SSGNs, with a reduced missile payload (4 or 8 tubes) would be?

HMS Astute will be reaching the end of her 25 year reactor life in the early 2030s, I can't see the appetite, or funds, for another submarine programme in the middle of Dreanought deliveries.

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ArmChairCivvy
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Re: Astute Class Attack Submarine (SSN) (RN)

Post by ArmChairCivvy »

Jensy wrote: I'd be curious what the opportunity cost of ordering three more as SSGNs, with a reduced missile payload (4 or 8 tubes) would be?
I had the same thought but implemented the other way round, on extra Astute hulls. Then started to ponder whether something that has been developed for fat and slow (silent) boomers could simply be dropped on top of the sleeker(?) hunter-killers designed to 'go fast'?
- studying the Virginia class payload module dimensions could provide some pointers
Ever-lasting truths: Multi-year budgets/ planning by necessity have to address the painful questions; more often than not the Either-Or prevails over Both-And.
If everyone is thinking the same, then someone is not thinking (attributed to Patton)

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shark bait
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Re: Astute Class Attack Submarine (SSN) (RN)

Post by shark bait »

Jensy wrote:HMS Astute will be reaching the end of her 25 year reactor life in the early 2030s, I can't see the appetite, or funds, for another submarine programme in the middle of Dreanought deliveries.
Exactly, looks like a life extension is on the cards.
Jensy wrote:I'd be curious what the opportunity cost of ordering three more as SSGNs, with a reduced missile payload (4 or 8 tubes) would be?
Sounds totally reasonable. My suggestion would be to cut all the tubes out and use the Virginia Payload Module instead, plus maybe an inline dry deck shelter.

The cost of developing nuclear plant means something similar to this has to happen.
@LandSharkUK

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ArmChairCivvy
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Re: Astute Class Attack Submarine (SSN) (RN)

Post by ArmChairCivvy »

shark bait wrote: The cost of developing nuclear plant means something similar to this has to happen.
Which plant did you reference? Switching Astutes (midstream) to the new one was a big issue due to the delay assessed,
- are you thinking that the one in production would not be a fit with Astute hulls?

Interesting to see how France will assess the costs:
- 3 of the old ones, to propel the carrier
- or 2 bigger ones, to be developed (... risk being a cost; of course only if A. you can assess risks, and B. are trying to put the two alternative costs on an equal basis)
Ever-lasting truths: Multi-year budgets/ planning by necessity have to address the painful questions; more often than not the Either-Or prevails over Both-And.
If everyone is thinking the same, then someone is not thinking (attributed to Patton)

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Re: Astute Class Attack Submarine (SSN) (RN)

Post by Pseudo »

Defiance wrote:Aside from funding and ROE concerns, blasting missiles out of the sea makes your undetectable asset pretty darn detectable against any sort of capable adversary

That's not to say they aren't useful, because they are, but i'd sooner fit them more ubiquitously to the surface fleet IMO
UKD wrote:Surely firing torpedos does exactly the same thing though and puts your right next to the enemies ASW assets?
And given the different ranges that you'd be launching AShM's and torpedoes from, I'd have to wonder if it's pretty much a no score draw as far as the detectability of the boat is concerned.

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Re: Astute Class Attack Submarine (SSN) (RN)

Post by ArmChairCivvy »

Pseudo wrote: pretty much a no score draw as far as the detectability
I would argue against that, exc. if one has persistent satellite surveillance - or something like Zephyr following the CTF - to cover the vast areas beyond radar range
- if the missile goes high, early on, it gives up the cover of the Earth's curvature
Ever-lasting truths: Multi-year budgets/ planning by necessity have to address the painful questions; more often than not the Either-Or prevails over Both-And.
If everyone is thinking the same, then someone is not thinking (attributed to Patton)

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Re: Astute Class Attack Submarine (SSN) (RN)

Post by dmereifield »

Interweaving Astute and Dreasnoughts would have been risky, could easily have seen the later Astutes being cut due to cost overruns and delays to Dreadnought

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Re: Astute Class Attack Submarine (SSN) (RN)

Post by ArmChairCivvy »

Yes, and not the only risk/
- run late on reactor cores?
=> will have to prioritise keeping the older boomers working (at sea)
Next priority: get the new ones into (literally) water before the old ones break down

End result, as per post above: fewer SSNs (Astutes) because you can't launch a boat without propulsion in it

Two designs, both (allegedly) good
- propulsion (not reactor) advances on Dreadnoughts
=> borrow for Batch2 Astutes

Astutes not 'potent' enough, to warrant the high cost
=> borrow, as suggested, from the Virginia Payload Module (hey-ho. the LibDems are not there anymore to say that launching a conventional missile from a sub will automatically cause WW3). They might be somewhere, but not in Gvmnt.
Ever-lasting truths: Multi-year budgets/ planning by necessity have to address the painful questions; more often than not the Either-Or prevails over Both-And.
If everyone is thinking the same, then someone is not thinking (attributed to Patton)

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Re: Astute Class Attack Submarine (SSN) (RN)

Post by Jensy »

ArmChairCivvy wrote: I had the same thought but implemented the other way round, on extra Astute hulls. Then started to ponder whether something that has been developed for fat and slow (silent) boomers could simply be dropped on top of the sleeker(?) hunter-killers designed to 'go fast'?
- studying the Virginia class payload module dimensions could provide some pointers
For me the appeal of a Dreadnought derivative, over an Astute with the VPM, is the upward potential number of SLBM tubes, say eight rather than the expected twelve. By the time the CASD Dreadnoughts enter service, there are likely to be all manner of things other than missiles to launch from them (loitering munitions/USVs/UAVs/etc)

With our very modest number of SSNs, I'd favour going even bigger with the next gen so as to maximise each's capability and allow the non-VLS equipped Astute class to focus on more conventional hunter-killer taskings.

Comparing the procurement costs of 12x Ohio Class replacements ($108.9bn) Vs 4x Dreadnought Class (£31bn):
https://crsreports.congress.gov/product ... R41129/179
https://commonslibrary.parliament.uk/re ... /cbp-8166/

I think we should be trying to get as much value out of what will undoubtedly be a world class platform, and seemingly a bargain compared to the US programme when taking into account the sunk costs that both programmes will have.

On a darker note, with the increasing likelihood of peer conflict, having a latent capability to increase our deterrence capability by 50% seems something worth considering.

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Re: Astute Class Attack Submarine (SSN) (RN)

Post by Scimitar54 »

Not if your conventional SSN type Dreadnought ends up being 50% more likely to be detected. We just need more conventional SSN, not more SLBM tubes. :mrgreen:

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Re: Astute Class Attack Submarine (SSN) (RN)

Post by Defiance »

If 12 Trident isn't enough to put someone off you'd probably end up needing orders of magnitude more rather than multiples

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