Thank you for your answer, sir.
So there are better Kilos and worse Kilos and between the better ones and Lada there is no serious difference, at least not on the quieting levels?
SSKs
- Thread starter zoolander
- Start date
So there are better Kilos and worse Kilos and between the better ones and Lada there is no serious difference, at least not on the quieting levels?
gf10012, forgive my ignorance here, I dont have any access to SSK info beyond what is available from open sources. Are you saying that older Kilos are not as quiet as many assume them to be? What about the latest version of the Kilo, in terms of noise reduction how does it compare to current generation Western designs like the Scorpene and Type 216?
Off-topic but I would be very interested on hearing some opinions on 2 questions I have.
1. Wouldn't larger the size of ocean going SSKs [Oberon, Kilo, Upholder, Collins] compared to boats designed for littoral work [Type 206, Gotland, Scorpene] place them at a disadvantage when operating in the littorals? There was a report a few years ago in Janes about the RN adopting an experimental blue scheme on one of its Trafalgar to make it harder for it to be spotted from the air when operating in shallow waters.
2. With regards to new SSK operators, which are purely brown water/littoral navies, would it not make more sense, from a training prespective to source their boats from navies like Germany and Sweden which have years of littoral SSK operational experience rather than a country like France which is an all nuclear sub operator? What I have in mind here is the Royal Malaysian Navy's 2 Scorpene's and the training given by DCN. Can it not be argued that even the Russian navy would have more littoral sub experience to share with customers rather than France?
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Well i can say that india, that wanted like 24 subs!!!, the first batch they have gone for its the scorpene, i think before the kilos (that they also seem to want), and the scorpene they are getting the technology transfer also, for own production, i dont know and doubt they do the same with the kilos, so like they are making a preference for the scorpene isnt? Because of littoral issues or because noise issues or other reason...?
In terms of littoral presence of those different types of subs, i think any sub is big enough to be discovered in that littoral depth by sight for ex., i dont think it makes difference, the thing if it is bigger is that it reflects more the active sonar waves.
Cheers.
oh good grief.
physical size has got little to do with whether a large sub is physically more detectable than a smaller sub.
the russians, americans, french and RN have shown this time and time again.
there are any number of examples from RIMPAC where active sonar has not been able to detect subs in proscribed boxes.
so in an environment where partial prosecutions occur the active sonar searches have failed.
it does make a difference - and significantly
it would help if you didn't make sweeping statements and try to pass incorrect assumptions off as fact.
this is a serious forum - lets not pollute it with assumptions presented as factual insight.
Apart from from-air systems to find subs in littorals, you have the sonar and if they dont find in littoral exercises like rimpac a smaller sub like Sturm refers, probably a slightly bigger sub wont be found by the sonar anyway (recall Sturm is referring to collins and similar sizes vs scorpene and similar sizes).
Probably in littoral points, to be detected by the sonar it depends more on the irregularity of the submerged terrain, or the lack of horizontal depth where the sonar waves needs to expand, rather than on the subs size, considering that the irregularity its enough big.
what are you on about? anything can be found by sonar depending on a number of conditions - it is an urban myth to say that larger subs are easier to find than smaller subs. It depends on context. RIMPAC includes subs ranging from 1200 tonnes to nuke weights. All get a run.
where do you get this nonsense? certainly not from people who are submariners or those who actually work with UDT.
Well, if we classify "water" as part of the "submerged terrain" and classify thermal gradients and certain ambient noise generating systems as a "irregularities"...
Yeah, i know ... he means hiding between underwater mountains and canyons. This is not the movies. You avoid those because otherwise you will crash into them. And unlike the movies hitting anything including the ground underwater tends to be something you want to avoid, because if you're not dead afterwards, your future job will be peeling potatoes.
That i've got from a submariner whose dive officer managed to crash their sub into one by failing to account for current drift btw. Oh yeah, and unlike certain other tiny subs of the same class, theirs was easily found during an attack run on a US carrier. Size doesn't matter.
Yeah, i know ... he means hiding between underwater mountains and canyons. This is not the movies. You avoid those because otherwise you will crash into them. And unlike the movies hitting anything including the ground underwater tends to be something you want to avoid, because if you're not dead afterwards, your future job will be peeling potatoes.
That i've got from a submariner whose dive officer managed to crash their sub into one by failing to account for current drift btw. Oh yeah, and unlike certain other tiny subs of the same class, theirs was easily found during an attack run on a US carrier. Size doesn't matter.
[Mod Edit: Text deleted. Irrelevant, unfounded and unlikely speculative statements on sonars with no reputable links deleted.] but i dont confirm, its another idea from me.
I didnt say that is easier to find a bigger sub than a smaller as a fact for every situation, i said that if your sub is bigger it has a bigger sonar firm, but anyway a slightly smaller sub will be detected in the same way because it is already quite big, comparing scorpene´s vs collins.
[Mod Edit: Your above statement is typical of the irrelevant, unfounded and unlikely speculative posts that you have a habit of making. If you have nothing valuable or logical to say, try reading other posts instead. This is your last warning. Take heed and learn to post links to support your bold statements.]
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Todjaeger
Potstirrer
What on earth do you mean by a sonar firm? Do you mean an acoustic signature?
When it comes to submarine design at a basic level, the difference between a large submarine and a small submarine in terms of size is that one is larger than the other. A larger submarine does not automatically have a larger acoustic signature just because it is physically larger.
In point of fact, a larger submarine might well have a smaller/lower acoustic signature than a much smaller submarine of comparable technology, just because some of the signature/noise reduction methods work better or are only available on larger submarine platforms.
I would strongly recommend a bit of further reading on the topic prior to making additional posts, as the assumptions having being made are frequently wide off the mark. The fact that many of them seem to be presented as facts as opposed to (incorrect) assumptions just makes the situation even worse.
-Cheers
I you take into account those reduction methods and they work enough then yes i can accept that equity or even inferior signature, but in terms of the same technology used in both sizes of subs, the active sonar firm or active acoustic signature, will be more or less proportional, you can have also anechoic tiles in both sizes.
But in the case of the scorpene vs collins it is 1700 tn vs 3350 tn, so almost the doble, almost twice in tonnes but in measures: 66 mts long vs 77 collins, 5 or 6 vs 7 collins beam, and 6 vs 7 or 8 vs collins draught, so anyway the scorpene would be big enough, for me.
StevoJH
The Bunker Group
On a bigger hull, for arguments sake. The larger the hull, the more space you have for sound dampeners, so a Collins could have "bigger" or more effective sound dampeners then say a U209.
By the way, volume and surface area/dimensions do not increase in proportion to each other.
The larger your submarine, the more volume you are going to have relative to surface area.
SA:V ratio is very high in small things, like for arguments sake a tennis ball. Now take a Basket ball (which is larger), and the SA:V ratio is going to be a lot smaller. If you want to test this yourself, you should be able to find the mathematical formula's for surface area and volume of a sphere on wikipedia or google.
By the way, volume and surface area/dimensions do not increase in proportion to each other.
The larger your submarine, the more volume you are going to have relative to surface area.
SA:V ratio is very high in small things, like for arguments sake a tennis ball. Now take a Basket ball (which is larger), and the SA:V ratio is going to be a lot smaller. If you want to test this yourself, you should be able to find the mathematical formula's for surface area and volume of a sphere on wikipedia or google.
"Certain ambient noise generating systems" maybe affects the passive sonar that is searching the sub, but i dont think affects the active sonar, or not much, because this are crashes of waves into the hull of the sub, and the reception of a rebounce.
Todjaeger
Potstirrer
As I understand it, at a basic level you are correct on what an active sonar does. A 'ping' or sound pulse is emitted into the water, and the kinetic energy of the 'sound' wave will propagate through the water, coming into contact with different things which can reflect, redirect or absorb some or all of the portion of the wave which comes into contact with it. It would be worthwhile to reread ones physics books, or at least the chapters covering the propagation of a wave through different mediums.
Now water, all on its own, can have differing impacts on a 'ping' depending on the temperature of the water, salinity (or other material dissolved or suspended in the water) and I suspect that water pressure also has an impact. In the case of something like a submarine, which would likely have a number of things included to mitigate the effectiveness of active sonar in searching for the sub.
So again, it gets back to it depends on what is used to mask the presence of a submarine, not the size of the submarine itself determing how difficult or easy it is to detect.
As an example (and please keep in mind, I know this is only a crude illustration of the concept) but consider two different types of motor vehicles, both powered by internal combustion engines. A Harley Davidson Fatboy, and a Toyota Prius. As mentioned, they are both powered by internal combustion engines, but which one would have a lower acoustic signature while driving. If the determination was made by size alone, and that a small vehicle is quieter than a larger one, the motorcycle would have a smaller signature and make less noise. However, the Prius, being a car, has a system in place to muffle to sound of the engine so it would likely be significantly quieter than the Harley.
-Cheers
This is getting ridiculous..
Can we not have this thread deteriorate on the basis that people who have no idea how UDT such as Sonar and ASW actually works make claims about what it can and cannot do.
This is not going to turn into an "ASW for Dummys" thread because it will not be allowed to deteriorate further. We will not let what is a serious subject degrade into another nonsensical debate
Those in the know are not going to publicly correct some of the assumptions made in here - but I for one am sure as hell that we are also not going to let it travel down a path where claims are made and presented as fact just because someone wants airplay.
All future rubbish will be deleted without warning
Can we not have this thread deteriorate on the basis that people who have no idea how UDT such as Sonar and ASW actually works make claims about what it can and cannot do.
This is not going to turn into an "ASW for Dummys" thread because it will not be allowed to deteriorate further. We will not let what is a serious subject degrade into another nonsensical debate
Those in the know are not going to publicly correct some of the assumptions made in here - but I for one am sure as hell that we are also not going to let it travel down a path where claims are made and presented as fact just because someone wants airplay.
All future rubbish will be deleted without warning
Since I don't know anything, I would like to hear the explaination on the statement that sonar detection is independent of the size (surface area) of object.
To me that sound counter-intuitive.
Let's set up a lab experiment:
In the first experiment, we have:
One plate of a material with surface area A, placed in a (very) big pool of water and we use a sonar to detect it.
In the second experiment, we have:
One plate of the same material but with surface area 2*A, placed in the same (very) big pool of water and we use the same sonar to detect it.
I would think that we will get twice the reflection of the sound wave(s)/pressure wave(s) of the sonar in experiment two than in experiment one.
Can somebody enlighten me?
Todjaeger
Potstirrer
Unfortunately, no. The people whom are 'in the know' are not in a position to give any real solid information, largely due to the sensitivity of the subject material. The entire topic is something that can really only be discussed in a circular fashion.
In the case of the experiment listed above, I would need to go back and dig up my physics books to determine the information. However, this sort of example does not corelate with submarines. Largely because subs are themselves composed of different materials, and with different sub designs the materials used and the impact such materials have upon the acoustic signature will differ. And discussion on what materials are used are for what I hope would be obvious reasons, not named or mentioned.
-Cheers
Grand Danois
Entertainer
Yes. Which aircraft is the stealthiest? The B-2 is a much larger aircraft than older F-117 and the newer F-35, yet it is considered to have a much smaller RCS on all parameters. Why? Because it's possible to use a different technology set on the larger object: think rafting, dampening, propulsion systems, anaechoic tiling, shaping, etc...
B&S This is an ordinary physics question.
Everything else equal, I think it does.
Let's try another experiment (requires a brickstone house)
Go out in your garden place a brickstone in a suitable distance and shout at it.
Turn around and shout at your house's brickstone wall.
Which action do you think produces the greatest echo?
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