Why are SSBNs so Quiet?

[Neutrino 123]

SSBN are reportedly very quiet, but why is this so? It seems to me in a basic analysis that they really shouldn’t be much quieter then SSNs of similar technology (though all sources say they are, so I would of course expect this to be true).

SSBNs have similar propulsion to SSNs, but they have a lower maximum speed. Approximately speaking, this implies similar machinery to the SSNs (this seems to be the case on cutaways I’ve seen, too…), but since the SSBNs are larger, they need more power to get the same speed, and thus, the machinery would generate more noise for the same effect. Presumably, this would be somewhat mitigated by additional quieting equipment. However, the storage space for the large missiles should limit the amount of space available for other things such as this, especially since the SSBNs usually have a larger crew and a fairly good torpedo armament, too.

In addition, the water noise flow that accounts for a portion of the BB noise (I am not sure how much, but this is something I would like to know…) would be significantly greater in the SSBNs.

…so, when considering the above, why are the SSBNs much quieter? Can they really fit enough quieting equipment to do this? If this is efficient, why not add similar equipment to the SSNs?

[Amizaur]

From what I know, the first boomers were SSNs with additional hull sections, they were as noisy as first SSNs or even more. But later they become specialised constructions. SSN have to be fast, somewhat maneuverable, have large torpedo armament, many sensors, it needs ALL those things. When 688 class was constructed, high speed had same, or maybe even higher priority as stealth. We can guess that if the requirement was not 35 but only 25 or 30kts, they could be even quieter.
Now they are in 2/3 filled with reactor and machinery, rest with armament, and people are packed in corners that left ;-)
SSBNs don't need speed and some other things, they need only one - quietness. They needs it to be able perform their task, and their task is to be undeteced. So they are build with this requirement in mind, specialised in that. Don't need very powerfull propulsion, they are larger but don't need to be fast. The shape is much more hydrodynamic than in first constructions.
And... in fact they are not that quiet :-). Most of them isn't. From all boomers, Russian ones are more noisy than same generation SSNs. Both Typhoon and Delta IV are more noisy than Akulas. Don't know about British boomers, if they are better than Trafalgars. The one and most famous quiet boomer is Ohio, and it was probably only one similar in quietness to best SSNs, at least untill le Thriomphant appeared, it is supposedly very quiet too. And it have to be, it's his main and only task. With improvements in sonars, noisy SSBN would simply not be able to perform his task good enaugh, or at all...

[Kapitan]

russian SSBN's are not as quiet because there getting old but also because the russian navy says they spend along time in area that cover noise one can only guess this is the artic ocean well its obvious the typhoon was specificaly designed to oparate under ice.

the new borey class is roumerd to be quieter than ohio but no one knows as of yet.

the british SSBN's are even quieter than the ohio's they trail pump jet propulsors and stay at around 5 knots most of the time (ramius can you confirm this please).

the trfalgar are very quiet also as quiet as seawolf in some cases and the new astute is supposidly as quiet as virginia.

the le triomphant is noisey a tad noiseyer than the deltas (french SSBN tech is behind) so they relativly ewasy to track and the XIA of china is about as quiet as a november class of the 1960's

[OKO]

Originally Posted by Kapitain

the le triomphant is noisey a tad noiseyer than the deltas (french SSBN tech is behind) so they relativly ewasy to track

this is not only wrong but also a stupid answer
you better don't talk about thing you don't know about
because you REALLY don't know anything about the latest and most stealth generation of SSBN made in the world (because it's just the latest...), called the triomphant.
You just confuse older generation with the new one.
Once more, update you links, you are 25 years late Kapitain ...


to improve your culture =>
http://www.netmarine.net/bat/smarins...a/caracter.htm

[Kapitan]

what one is what le tromphant or le inflexible ? i cant think what ones the new one and secondly if there anything like the rubis class then they are noisey

i know enought to get me by i know french submarines are noiseyer than most, british subs are only quiet because of american help hence thats why our SSBN's carry the trident rather than our own ype of missile like the french

if you read france is a little behind becaue it went the long way round

and the le triomphant is supposed to be the new one i know they still have at least one le inflexible about so probly thats what im confused over

as for stupid answer all answers can be stupid just takes brains to work it out some thing you obviously didnt quite catch oh well better luck next time

[Kapitan]

as for france having the latest build SSBN dream on the russians bough out there new one bigging of the year and its in service and conducting combat patrols

[OKO]

I think you better really dig a bit before saying stupid and false things, Kapitain ...
You look like a young naive guy, thinking he know better than every other people, when you have big HOLE of knowledge in some aspects.
Be honnest : you don't know anything about french submarine performance, so stop staying stupid things about it, and start to inform yourself.


thanks

[Kapitan]

:rotfl: OKO i have read things thats all i know i agree i have the whole and its mainly over french and chinease and pars of the american submarines but as it goes i do remember reading on many occasions from people like norman polmar stateing the french navy is under funded itself.

france isnt a bad navy there fleet is old but there building new as is every navy all the time.

as for rusty SSBN's there the best kept item in the whole inventory 17 SSBN's are active withing russia come this time next year three will pay off but the new build is not even a year old and there is already another three in some form of construction

my answers are from other people not realy myself my personal view of the french well not going to say here but they do need to have a major review of thier fleet oh and build new ships something they doing now yes.

janes has even said the french are behind britian and america by 3 years that not a big gap but big enough

[Stewy]

Oko, I don't mean to get into this flame war, because I really respect the French SSBNs, but I wanted to ask (quite innocently and respectfully) why does France still maintain SSBNs?

Given the current climate in France, and the world - who are France's nuclear enemies?

[Kapitan]

i spose you could say the same for britain but its kinda clear but i rekon i can give a rough bearing

franch maintain SSBN's becaue its part of the EU and allie of britain and europe if the need to go to war arrises france has its own WMD to protect itself rather than relying on britian or america to do it for them

am i right ? correct me if im wrong

[Molon Labe]

Originally Posted by Neutrino 123

SSBN are reportedly very quiet, but why is this so? It seems to me in a basic analysis that they really shouldn’t be much quieter then SSNs of similar technology (though all sources say they are, so I would of course expect this to be true).

SSBNs have similar propulsion to SSNs, but they have a lower maximum speed. Approximately speaking, this implies similar machinery to the SSNs (this seems to be the case on cutaways I’ve seen, too…), but since the SSBNs are larger, they need more power to get the same speed, and thus, the machinery would generate more noise for the same effect. Presumably, this would be somewhat mitigated by additional quieting equipment. However, the storage space for the large missiles should limit the amount of space available for other things such as this, especially since the SSBNs usually have a larger crew and a fairly good torpedo armament, too.

In addition, the water noise flow that accounts for a portion of the BB noise (I am not sure how much, but this is something I would like to know…) would be significantly greater in the SSBNs.

…so, when considering the above, why are the SSBNs much quieter? Can they really fit enough quieting equipment to do this? If this is efficient, why not add similar equipment to the SSNs?

I tend to agree that SSBNs will be very close in noise level to SSNs of the same tech level. All the quieting technology that can go into the boomer would have gone into the fast attack. The main reason the SSBN is reputed to be impossible to locate is because, unlike the SSN, it doesn't go looking for trouble. It just finds a huge piece of ocean and crawls at very low speed. You won't find her unless you run her over.

An SSN, on the other hand, has to transit all over the place to complete its tasking, and will often have tasking in such areas that are have military significance.

[Kapitan]

yeah thats true i didnt see rhode island till i smashed right into her

[OKO]

Originally Posted by Kapitain

:rotfl: OKO i have read things thats all i know i agree i have the whole and its mainly over french and chinease and pars of the american submarines but as it goes i do remember reading on many occasions from people like norman polmar stateing the french navy is under funded itself.

one more thing you don't know about :
under funded for SURFACED ship only
SSN AND SSBN are national priority and ALWAYS HAD along the years the appropriate funds, whatever the political side or budget problem
one more thing you better dig to understand better the real situation, then to understand better what you are talking about ...

Originally Posted by Kapitain

france isnt a bad navy there fleet is old but there building new as is every navy all the time.

except, at ANY TIME, for SSBN, so you made again a bad statment based on your lack of knowledge on this subject.

Originally Posted by Kapitain

as for rusty SSBN's there the best kept item in the whole inventory 17 SSBN's are active withing russia come this time next year three will pay off but the new build is not even a year old and there is already another three in some form of construction

my answers are from other people not realy myself my personal view of the french well not going to say here but they do need to have a major review of thier fleet oh and build new ships something they doing now yes.

you could talk about it if you knew what you talk about, Kapitain.
You showed me you just don't ...

approximation and generalization won't learn you much about this subject

Originally Posted by Kapitain

janes has even said the french are behind britian and america by 3 years that not a big gap but big enough

talking about SSN yes, until barracuda class comes.
concerning SSBN, well just think what you want to think
french one have 3 hulls for each motorised engine, a turbo pump for propulsion, and the most advanced embarqued technology.
Ballistic missiles are less powerfull fewer and have less range than US one (also UK, because UK rely on US for them ... opposite to french who have the entire tech under there control)
but we don't talk about missiles here, but stealth.
And anyway, only one of these SSBN can eradicate 90% of United States or Russian towns, so ...
I personnally think there are now dinosaurus from the end of the cold war.

And when you read the paper, the french one is the stealthy one.
Of course, boat are not made in paper, but your 'easy' assertion just show you are partial and bad informed.

[OKO]

Originally Posted by Stewy

Oko, I don't mean to get into this flame war, because I really respect the French SSBNs, but I wanted to ask (quite innocently and respectfully) why does France still maintain SSBNs?

Given the current climate in France, and the world - who are France's nuclear enemies?

This is an excellent question
Why ANY country maintain SSBNs ...
Isn't it a useless weapon now ?
Isn't it a DANGEROUS useless risk ?
Without SSBN, you can't have a nuclear holocaust for any reasons, just because there is no SSBN ....
But with SSBN, whatever the security you can use, you still have a risk something goes bad, for whatever reason (i don't want to mention or evaluate each of them ....)

Whatever you do, there is ALWAYS a risk as long as these dinosaurus survive.

You said, stewy, why does France maintain SSBN
why US, Russian, Chinese and UK still maintain them ...

because they was the fleuron of their navies ?
Because they just don't know what to do with them, and their crew ?
because these 5 countries are the 5 permanent members of the NATO security consil, and so think they have legitimity to do that ....... ?

the bad aspect of conserving these dinosaurus is they give legitimate revendication to growing nation for acquiring the military nuke : why them (older owner) and why not me.

But I also know our democracy, in west europe, were built without soviet invasion, mainly thanks to nuke dissuasion.

France was the latest to built SSBN at this date.
and our actual generation will work for the next 30 years.
I think this money could have been better used since the end of the cold war.

[Kapitan]

to date russian SSBN's

1) TK208 dmitri donoskoy
2) TK17
3) TK 20 severstol

4) K-496
5) K-506
6) K-211
7) K-223
8) K-180
9) K-433
10) K-129



11) K-407 Novomoskovsk
12) K-84 Yekaterinburg
13) K-64
14) K-114 Tula
15) K-117 Bryansk
16) K-18 Karelia

17) borey

as you can see 17 names and pennants now look up the list i can say the middle lot will all be gone by 2010 replaced by borey class which will number 12 hulls that is whats in service with the russian fleet

when i was saying french navy being underfunded i was meaning the surface fleet i do give them a hand because they have built the worlds smallest front line attack submarine.
as regards to the SSBN's i think they have two class in service cause they await a full hand over am i right (according to navy news)

and yes i knew the SSBN's are high priority for france i spent a week with a french family who showed me the area where you can see ships and submarines in france (long drive dont recomend it)

building a navy can be on paper or out in the yard when britain launched vanguard class 3 months after the last one came down the line plans were made to replace them in 2014 (apparently again navy news) fleets are forever undergoing changes be it minor changes like decor or major overhauls always changing hence why i said that

as like france russia is a submarine navy not surface ship navy they rely heavily on submarines there SSBN's are the best kept submarines in the fleet that is why when conscripts sign to the navy they always want to be assigned to a SSBN rather than SSN because of the better maintinance

third part i was asking a question are they rebuilding part of the fleet i know they got lafayette frigates but what else they building most of the ships are from the 70's and 80's and getting real old even my books dateing back to the 70's shows ships that are still in commission

3 hulls each motorised engine huh dont understand last part