Well you should be able to just set speed to 0 knots or all stop and you'll effectively disappear with the background sea noise. Or at least that's what I've been told.

2.5nm yea that seems quite far off. I believe I've detected a 4 knots diesel at lesser range than that. Are you sure you got it right? The diesels are supposed to be almost undetectable passively in RA more so in shallow noisy waters than in deep quiet waters.

Amazing :) I'm curious about how you guys bagged the 688, if more detail can be spared without breaking your vows to the country.

Is there a list somewhere that describes in very general terms what different kinds of equipment on both nuclear and conventional boats produce what range of tones?

Castout - The stories of the USN vs Gotland also come to mind too. Is there a way to get the AI to stop dead? Problem is I can't test the noise output of the Kilo when I'm controlling it. :)

I think even AI diesel subs are made to disappear at all stop. If you open the database, all diesel subs are made to have a passive noise level of 50 making them at 0 knots to be effectively undetectable passively. The noise of the diesel subs will be added as the screws rotate. The faster you move the more noise it emits.

Edit: I did one simple test and it seems that AI couldn't stop. And yea at 2 knots at 100 yards range the AI was detectable in the STA mode as a very thin line. while on 500 yards a 4 knots Kilo(not improved) was only detectable in the sphere ITA mode. I didn't check the towed array though. Mind you I did't check for maximum detectable range.

Many thanks for your comments Bubblehead Nuke, I knew you still had to run something even if at dead stop, but I didn't think it was so much and so noisy. Also, the point of something effectively obscuring background noise is something that I hadn't thought of! We live to learn... :up:

It's these things I love from subsim.com, you discuss and theorize with friends, suddenly a real submariner pops up and shares a piece of his knowledge, wow....I love subsim.com :up: :up:

yep, excellent points. How about coolant pumps? How noisy do you think they were? Lets say circa 1980's?

You know I can not get into that area of discussion, even in a roundabout way.


I can not even give you a rough list of the the constant running things that were NOT propulsion related. That stuff was on of those uber kill before reading type lists.

Way too much info for a sim.

WAY too much for general disclosure.

Either it is classified or not. Who is asking and for what reason has nothing to do with it.

The Complete Idiot's Guide to Submarines is an awesome source of info for these kinds of discussions but sadly the book is no longer in print and copies of it on Amazon range from $450 ~ $800! You should be able to check out a copy through an inter library loan.


With regards to reactor coolant pumps, the author says the pumps are car-sized and are quiet in slow speed but loud as freight trains in fast speed.

Hmm only an idiot would want to buy a book that costs $800.00 that clearly stated that it's intended for idiots.

First the book mocks your intelligence then you confirm it by buying the book at $800.00? :rotfl:I'll pass.

Those prices are crazy (hmmmm... my copy is in really good condition, lol)

The title aside (and I bought it when it was in print for $18.95US), it's written by Micheal DeMercurio and is an excellent read, definitely recommended for anyone interested in modern subs. Lots of interesting details you won't find in other books about nukes.

I would say more of a refrigerator in size.

As for the noise, I would say that is a little bit of an fudging on their part. They are a little quieter than that.

That book, from the parts that I have read, is a LOT more then an idiots giude. I'll bet it NEVER sees a printing again. It should have been classified NOFORN at the very least.

I'm feeling very lucky that I bought that book while it was still priced reasonably (read, at least less than US$100, a LOT less).

Anyway, IMO the book says a lot about American submariner(s), and for at least some of it, I hope for the US Navy's sake that "submariner" will be without the "s". For example, the sheer percentage dedicated to the reactor can't help but bring up memories of "Rickoverized" criticisms - the priorities of the average American sub officer...

As for his anecdote about their sub careening past a Russian submarine due to a gross operator error. He knows that there is little chance of the Soviet sub not hearing him, but when it doesn't immediately try and ram, he actually concludes that they somehow didn't. Apparently, this "Dmitri" was dumb.

I don't know, but based on the information provided, I can't help but think of this alternate scenario on the Soviet Vcitor:

BCh-7 officer: Comrade Commander, I have a target. American submarine, coming out of our shadow zone.

Commander: Damned American acoustic advantage! Did you get a print of him?

Bch-7 officer: Yes, Comrade, we have him on tape. Thanks to him we have a beautiful noiseprint of an American Sturgeon class submarine through its acceleration and deceleration cycle.

BCh-1: Comrade Commander, I have plotted an evasive course.

Commander: Watch officer, Execute the Evasive Drill.

Deputy Division Commander: Negative. Stay on your original course and speed. Remember, young Sergei, the American submariner is blessed with good hydroacoustic equipment and even better measures for reducing their physical acoustical field. However, they, not being good Marxist-Leninists, are cursed with their capitalist, subjectivist thought pattern. Therefore, if we stay our original course, the Americans will probably chew out whoever made that error, BUT they will think that they were undetected and continue to track us at their typical, dangerously close ranges, right in the supposed safety of our shadow zone of acoustical illumination. This gives us an excellent solution regarding the Target's Elements of Motion.

Commander: I understand, Senior Chief. (turns) BCh-3 will set up two TEST torpedoes for firing into the shadow zone of acoustical illumination. Adjust their initial courses so they cover our baffles from 1-4000 yards. That should be enough to cover the likely zone the American will be.

Zampolit: And that's why Communism will prevail.

DDO: That's good, Commander. Keep learning little lessons like this up the rest of this patrol and when we get back I'll recommend you for Independent Command. Then I'll be in your hair a bit less.

The 637's are razor blades now, so I am not sure that matters. But I do recall the russkies having very noisy coolant pumps.

While the 637's are razor blades a lot of things still carried overs into the more modern plants. Thus we do need to be careful. Even the old Nautilus info is still classified. I am more familiar with the 688 & 726 class of submarines. Particularly the engineering plants. The S8G plant design has a HEAVY influence on the newer boats.

However, the russian gear?? Yeah, they could be noisy, especially the early stuff. Older sonar guys used to complain that it messed thier ears up if they listened too long.

They had some fundemental design and operational philosophies that did not lend themselves to quiet plant operations. I am not saying they made junk. Far from it. They build some TOUGH stuff. It is that they have a different mission with different objectives.

Probably a futile question, but has anyone ever come across material discussing Russian/Soviet torpedo sonar sets? The UGST, being the latest in their arsenal, should (I had fondly hoped) be fairly good, but certainly in my games (playing with LWAMI and the 1.04 patch), it's nothing short of pathetic - just a moment ago no less than four UGSTs managed to miss a 688, even one which can have been no more than a thousand yards off the target (which was doing 35 knots) and was, supposedly, in passive mode went for an active decoy! 'course, I am assuming here that SCS modelled a difference in torpedo performance vis-a-vis detection and tracking between different torpedoes.

Come to think of it, any material on Russian sonar full stop wouldn't be bad. Even if it's in Russian.

Torps in passive mode as a general rule will not work against submarines in LWAMI, this is not a UGST thing.

This is a sign of our times,
it doesn't matter if it will be in print or not, with the internet you can be assured a :arrgh!: copy is somewhere awaiting to be downloaded. :rotfl:

I contacted the author at his website (http://www.ussdevilfish.com/index01.htm) and specifically asked him if the Navy had the book pulled from shelves and he replied that the publisher only printed a small number of copies on it's first and only run. I recall seeing it on the shelves at Border's years ago but thought nothing of it. Now I'm kicking myself for not picking up a few copies :damn:

As much as I HATE to admit it, but I have looked for a downloadable version of it. There are none to be found. I would HAPPILY pay the author for his work if I could find it.

That is what i recall too. It was our means of picking of Soviet Boomers, not so much the screw noise but the coolant pumps and other equipment that they did not have sound mounted and the noise transferred to the hull nicely.