Why are SSBNs so Quiet?

[Bellman]

I wonder how realistic it is when we have missions with a SSN acting as an escort to a SSBN ?

Surely not when they are covert ?

[TLAM Strike]

Well SSNs aren’t a close escort but they do defend the areas SSBNs operate in.

[Kapitan]

yes thats what some of my missions were defending SSBN's but i never acctualy knew where the SSBN was only a rough area (about 300 miles x 300 miles) so big area to get lost in

ive only trail an SSBN three times once i smashed into one and the second time was kinda sucsessful and third was 100% sucsess

the SSBN i smashed into was an america ohio called rhode island and the second one i tracked was also an ohio unknown one

the third was a chinease xia so i could stan off about 3 miles so that wasnt to much of a problem

[Bellman]

Just thinking about mission design possibilities for SSN escort of a SSBN.
But if I think of power projection over large 'support' areas this wont translate to a scale suitable for DW.
So perhaps, although unrealistic, for gameplay I am stuck with closer-in escort.
Maybe this is a natural for an under-ice setting.

Perhaps a damaged Red SSBN limping home through straits with Ak/s escorting and Kilo/s in waiting
near the home port pursued by Blue FFG and sub/s. :hmm:

[Kapitan]

tis possible but an FFG against a force of say 4 submarines well that would be deemd suicide

it would be better if subs do all the persuing but in saying that the harbours are constantly patroled so the chance of getting a blue sub in is minimal

a while back K114 tula smashed into a berg while on a mission under ice a small fleet was assembled to bring her home this included an udaloy destroyer a krivack two grisha 3 nanchuka 2 victor 3 submarines a kilo and akula

and that was to bring one submarine home so the notion of getting in firing range of a crippled SSBN returning to port could well be a one way mission but it has to be tried

bellman give it a go and id like to try it out

[zma]

From a realistic standpoint, perhaps a noisy SSBN (such as Xia) would benefit from an SSN escort? I mean, if you don't have an advantage in stealth, you might as well have a friend close, right?

[compressioncut]

SSBNs are physically quieter because the hardware necessary to quiet machinery is quite large. There's simply not enough room in an SSN for all the decoupling technology used in SSBNs. That's the main reason the Rubis/AMYTHYSTE class is generally louder than the much larger LA/Trafalgar/Akula. The Han also shares the same problem, in addition to its overall low-tech.

Originally Posted by TLAM Strike

Well SSNs aren’t a close escort but they do defend the areas SSBNs operate in.

Sure they do, but not continually. If you detect more than one LA and there's no carrier in the area, you can be pretty sure there's an Ohio there, too. That's about the point that the Americans get a little uptight and tell you that you're restricted from tail ops.

[Bellman]

Yes I rather saw the FFG as part of a full Blue group pusuing a Red escort group and the relevant action beeing
a sideshow in an ice channel (charnel !)

I have already designed two scenarios featuring different aspects of these situations - neither of which
fully satisfies me. I shall combine the best (?) of each and hope to produce an interesting challenge.

So the clash of the titans (above) has lit a creative spark..............................I hope.

[PeriscopeDepth]

Compressioncut, could you comment on how loud modern SSKs are compared to modern SSNs assuming both are at lower speeds?

Thanks, I understand if you can't.

[Kapitan]

from one of the guys here told me that the german 212 and 214 diesels are quieter than any modern US navy nuke wether thats true i dont know

[OKO]

Originally Posted by Kapitain

from one of the guys here told me that the german 212 and 214 diesels are quieter than any modern US navy nuke wether thats true i dont know

modern Diesel electric are ALWAYS quieter than SSN
from a long time now, certainly even before you born.
And that's why there is lots of discussion about this new kind of threat in western HQ.
Even a KILO make less noise than a "modern" nuke, even it's an old diesel/electric plateform now.
And these diesel electrics are really cheaper than nuke.
So, at this time, the main question of nuke owner is : how to counter the proliferation of modernised diesel/electric, so difficult to detect and so efficient for their missions.
With AIP system, these diesel can now stay under water, without snorkeling for weeks, making them nearly indetectable (detectable only with active sonars).

Main constructors and sellers of diesel/electrics are now Germany and France.
India just confirm they bought 6 French Scorpene this week (to counter the Agosta sold -or produced under licence- to pakistan ... by France ...), Chili has receive their first Scorpene 1 month ago.

With time, there is lots of new diesel plateform, far more efficient than previous generation, coming at sea.
"The sub of the poor countries" is becoming now a big part in naval strategy

[compressioncut]

Originally Posted by PeriscopeDepth

Compressioncut, could you comment on how loud modern SSKs are compared to modern SSNs assuming both are at lower speeds?

Thanks, I understand if you can't.

A modern SSK would be much quieter at low speed than an SSN, generally speaking. It has no need of constantly running, noisy equipment like a nuc (reactors and associated gear). They also do not have the complicated mechanical drivetrains of the nucs - it's a propeller pretty much directly attached to an electric motor, without any big, noisy reduction gearing and whatnot. Also, due to their size, hull resonance sources are much less likely.

I have no idea how much quieter the new gen (T212/214, Scorpene) SSKs will be than the current crop.

Originally Posted by OKO

With time, there is lots of new diesel plateform, far more efficient than previous generation, coming at sea.
"The sub of the poor countries" is becoming now a big part in naval strategy

Yes, that is why the US leased the Swedish Gotland, and why every sim- and actual ASW exercise over the past few years has been versus an SSK. Even when an LA is participating, it's normally as a "sim-Kilo." I can't recall the least time I saw a "sim-Akula" or "sim-Oscar."

That said, supposedly, modern SSKs are still quite detectable via advanced arrays like the TB-29D, in a dual-stream setup as on some SURTASS ships.

And not all AIP systems are that quiet, even though they obviously do increase underwater endurance. Stirling and closed cycle diesel are quite noisy, as I recall. I don't remember what MESMA is forecast to be, but the German fuel cell setup is definitely silent.

[Kapitan]

if and when i can get some info on the new lada i could start posting but that is a big big if and i mean big

[Amizaur]

Originally Posted by OKO

modern Diesel electric are ALWAYS quieter than SSN
from a long time now, certainly even before you born.
And that's why there is lots of discussion about this new kind of threat in western HQ.
Even a KILO make less noise than a "modern" nuke, even it's an old diesel/electric plateform now.

I will agree completly that they ARE quieter at stop. But not neccesarily ALWAYS quieter when running. Of course, when you put proportionally same amount of money and same technical level into SSN and SSK - the SSK will be quieter ! But not every SSK is on the same technical level as modern SSNs. For example Type-212 boat may be as quiet as Seawolf (if this was design goal!) and at stop probably even quieter with no doubt from me. But not a Kilo. From available data (and Kilos are quite old now) whe know that when running, they are on about same level of noise that Akula class. Of course they become much quieter than Akula at full stop. But again Akula is not most recent quietness standard... Kilo Improved at 3kts are said to be quieter than 688I. At full stop probably quieter still (sad we can't simulate this in DW).
But Seawolf is said to be about 10dB quieter than 688I. So are SSKs always quieter or not ? I think - they usually are. If build for proportionally same money and technical level, they are quieter.

But in case of Seawolf we maybe ask ourselves a question - so there is an SSK boat for few dozens million $ - it's very quiet. It's quieter than SSNs, even though less expensive. Probably as quiet or quieter when slow, and really quieter at stop.

But then - if you spend $ 13 BILLIONS !!!! - could you for this money design an SSN (for $ 4.4 Billions for a piece) as quiet as best SSK ?? :-) IMO it's possible :-)

Is the Seawolf cost-effective ? I think no :-) But it is real. And can it be as quiet as best current SSKs running at 3kts ? I think that for THAT money - it can Of course those best current SSKs, if somone spend few billions $ on them could be quieter at full stop

[Orm]

OKO, I could say that Kapitain is in some way right about French SSN and SSBN noise level. Amethyste/Rubis –class subs have had always a very bad reputation, as they are quite noisy and slow (25 knots, not very fast for SSN). But, as for the new Triomphant-class SSBN, it got a serious boost in underwater technology and indeed is very quiet. The same seems to be for the new Barracuda-class SSN that will be somewhat a “European Virginia�.
One thing more, as a French and as a former sailor, I have always think that French military ships were not up-to-date compared with other European and North American navies. For example, the lack of CIWS onboard makes them very vulnerable to SSM and the new Aster missile is still on development. Also, we know how expansive and inappropriate (too slow, too short, not very liable…) was the commission of the Charles de Gaulle carrier.
At least the new Mistral command and control ship was just commissioned and seems to look “modern� and very useful for this age of conflict.