[WIP] Soviet Campaign (North Atlantic 1984)

[Doctor Haider]

Hmmm. Let's take a look to the well known picture from Polmar.
According to it Alfa should be roughly equvalent to Permit class in basic noise level (but Alfa is still more noisy when running at 40 knots of course). Also even early Akula is slightly less noisy than the Sturgeon class, which is still in service in 1984.

Also I've seen the exact meaning of the Charlie class noise level in the Russian sources. There it's claimed to be equal to 110 Db in the audible part of the sound spectre (at top speed). But this information seems to be doubtful to me.

[denis_469]

Originally Posted by Doctor Haider

Hmmm. Let's take a look to the well known picture from Polmar.
According to it Alfa should be roughly equvalent to Permit class in basic noise level (but Alfa is still more noisy when running at 40 knots of course). Also even early Akula is slightly less noisy than the Sturgeon class, which is still in service in 1984. The Charlie class is not on the scheme but it should be somewhat less noisy than Victor I.

It is western point of view. Not need think, that it is really proprotion. So it is data most secret now.

[Doctor Haider]

Originally Posted by denis_469

It is western point of view. Not need think, that it is really proprotion. So it is data most secret now.

Yes, but it's better than nothing.

[suitednate]

Shouldn't the Charlie classes have anti-ship missiles and a VLS? I'm not seeing missiles for them when loading them out.

[JhonSilver]

Originally Posted by Doctor Haider

Let's take a look to the well known picture from Polmar.

it's propaganda.

671rtm MUCH less noisy, a little more than 688.

971 Akula was less noisy then 688 Fl.0

And Skipjack noiselevel was about 150dB
according to Tom Stefanick data 1987

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Consider that Americans tend to overstate the secret characteristics and the Russians on the contrary are understated.

[FPSchazly]

Ships don't emit constant levels of sound across their speeds, though, so what does "a Skipjack makes 150 dB of noise" really mean? It's a very simplified graphic, and as the axes don't have units, should be interpreted as such. A graphic like this can't show that diesels are quieter at low speeds but louder at high speeds than a nuke boat.

[JhonSilver]

Originally Posted by FPSchazly

so what does "a Skipjack makes 150 dB of noise" really mean?

According to this American chart 1987, the noise level of Skipjack was in the range of 150-172 dB.
Permit is from 137 dB.
- 133 db. (Later reduced to 129 dB)

Old diesel subs (613, 641) from 127 dB (138 full speed). Kilo - 115 dB.
Sierra - 115 dB.
Alfa full speed - 165 dB (so on 5 knot must 129 db, surprize)

In general, it is clear that the developers adhered to this data, but apparently the skipjack came out completely unplayable

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sorry bad english

[aaken]

Originally Posted by JhonSilver

According to this American chart 1987, the noise level of Skipjack was in the range of 150-172 dB.
Permit is from 137 dB.
- 133 db. (Later reduced to 129 dB)

Old diesel subs (613, 641) from 127 dB (138 full speed). Kilo - 115 dB.
Sierra - 115 dB.
Alfa full speed - 165 dB (so on 5 knot must 129 db, surprize)

In general, it is clear that the developers adhered to this data, but apparently the skipjack came out completely unplayable

------
sorry bad english

And to be honest the estimates of self noise tend to have relatively high spread between different sources.
I don't know at what speeds the 1987 chart indicates the self noise. Other published work, especially on SSBN tend to predict much lower noise. For example Yankee in 1987 chart is predicted 150 db at speed unknown. Paper below predicts 135-140 at 4kts.
On older boats difference in prediction seems larger. Hotel for example in 1987 chart is predicted 160-170 db, paper below predicts 140-145 at 4 kts.
https://fas.org/spp/eprint/snf03221.htm

[JhonSilver]

Originally Posted by aaken

to be honest the estimates of self noise tend to have relatively high spread between different sources.
I don't know at what speeds the 1987 chart indicates the self noise.

Absolute values have no differences for game purpose.
We need to display the relative noise in the game conventions more correctly

This diagram of topics is interesting because it correlates both American and Soviet boats.
Whereas in different studies data are usually given either for some or the other, while it is not known in what specific conditions.

[aaken]

Originally Posted by JhonSilver

Absolute values have no differences for game purpose.
We need to display the relative noise in the game conventions more correctly

This diagram of topics is interesting because it correlates both American and Soviet boats.
Whereas in different studies data are usually given either for some or the other, while it is not known in what specific conditions.

If you are familiar with dangerous waters, I took a look at the units database, specifically the Lwami mod database (since it had more units compared to original dangerous waters and had become widely used). I based the reworked self noise values in the soviet campaign mod on this.
In particular, the DW selfnoise value multiplied by 2 should pretty much correspond to CW selfnoise. What is different is that in DW each unit can have a noise increase/speed, whereas in CW all enemy units have same noise increase/speed.

[Doctor Haider]

Originally Posted by JhonSilver

Alfa full speed - 165 dB (so on 5 knot must 129 db, surprize)

It's very compact submarine with single reactor suite. It should be relatively quiet on creep electric motors.