if there was a new GWX RPM chart, would you use it for hydrophone hunting?

[DrMilton]

I don't know if GWX uses different rpms than stock game. I certainly use rpm identification. I find it quick and efficient. What I haven't found is a chart for warship rpms, only merchants. Anyone knows anything?

[robbo180265]

If someone wants to make it - I'm all for it

[RawRecruit]

I'd be interested in learning how they used hydrophones for speed, direction, etc, but I wouldn't use it in game proper. When I play, I'm the captain and I have crew whose job it is to listen...

[Corsair]

Originally Posted by RawRecruit

I'd be interested in learning how they used hydrophones for speed, direction, etc, but I wouldn't use it in game proper. When I play, I'm the captain and I have crew whose job it is to listen...

You should try to stand behind the hydrophone yourself from time to time - depth around 20m and all stop - preferably with good headphones. You would be surprised how many targets you would find that your crew never hears...

[Rykaird]

Originally Posted by Corsair

You should try to stand behind the hydrophone yourself from time to time - depth around 20m and all stop - preferably with good headphones. You would be surprised how many targets you would find that your crew never hears...

I have a pretty good "chief" in there too, well decorated and experienced, and I have made a habit of this when I submerge. I hear ships all the time that he misses.

[Dantenoc]

Maybe determining a target's exact speed by rpms is a bit too much, but a training mission to help us differentiate the sound of an aircraft carrier from that of a tugboat would be very much apreciated... specialy when your attacking a convoy and have a hard time telling which of the sonar contacts corresponds to that big and juicy tanker. :hmm:

[LukeFF]

Originally Posted by Dantenoc

Maybe determining a target's exact speed by rpms is a bit too much, but a training mission to help us differentiate the sound of an aircraft carrier from that of a tugboat would be very much apreciated... specialy when your attacking a convoy and have a hard time telling which of the sonar contacts corresponds to that big and juicy tanker. :hmm:

Seconded

[raduz]

Originally Posted by DrMilton

I don't know if GWX uses different rpms than stock game.

It does. And if there was a " GWX hydrophone hunting mod", it would definitely use the stock game propeler sounds.

Originally Posted by DrMilton

What I haven't found is a chart for warship rpms, only merchants. Anyone knows anything?

Yes, there is a british ASW RPM chart by Greyrider. You can find it here:
http://www.subsim.com/radioroom/showthread.php?t=86508

nevertheless, there are no american warships and remember, you have to replace the GWX propeler sounds by the stock ones if you want to use the chart.

[Jimbuna]

YEP ...I'd be interested in that

[DrMilton]

Originally Posted by raduz

Yes, there is a british ASW RPM chart by Greyrider. You can find it here:
http://www.subsim.com/radioroom/showthread.php?t=86508

Thanx, I will try it.

[raduz]

Originally Posted by DrMilton

Thanx, I will try it.

you are welcome, go ahead

[Sailor Steve]

I'll have to recheck my books, but the RPMs listed on that chart have nothing to do with real life.

The fact is real submariners tried firing without visual contact, and failed every time.

[raduz]

Originally Posted by Sailor Steve

I'll have to recheck my books, but the RPMs listed on that chart have nothing to do with real life.

The fact is real submariners tried firing without visual contact, and failed every time.

why do you think so? let me quote greyriders discussion on this topic :

Originally Posted by Redwine

Mmhh... :hmm: I think so that was not the method in that age.

... in WW2 age, the periscope was used to determine range.

I am not sure they can determine propeller turns/min in that age, plus they need the data about how many knots per turns is corresponding to that ship. I think so they had not that data in that age.

Originally Posted by greyrider

i hate to say this, but redwine has given you wrong information, this method was used by american submarines in ww II.
propeller pitch was known then as it is now. TMA is a more modern way now. but not then.
below is taken from fleet submarine.com, which is all about wwII
fleet submarines of the american fleet.

http://www.maritime.org/fleetsub/

How to take a turn count
1. Train the hydrophone directly on the bearing where the prop beats are loudest.

2. Turn the prop-count detector ON. It may bring out the beats more clearly. (If it does not, turn it OFF.)

3. Notice whether the beats are accented or unaccented. Accented beats go CHUG, chug, chug (three-bladed propeller)-or CHUG, chug, chug, chug (four-bladed propeller). Unaccented beats go chug, chug, chug, chug, chug.

4. Get in rhythm with the beats by pumping your arm up and down. If there is an accented beat, let your hand come down with every accented CHUG -or if the beats are all the same, on every chug.

5. Count the number of times you pump your hand down in 15 seconds.

6. Multiply this count by 4 to get the number of rpm (revolutions per minute). Report the rpm immediately. For example, if your 15-second count is 24, the rpm will be 96, and you will report: "JP, turn count is ze-ro nines six. Good count." If the beats are so rapid that you are not sure of the accuracy of your count, report: "Poor count."

7. After you have reported, make sure that the prop-count detector switch is OFF.

as you can see, it was used in ww II.

http://u-boot.realsimulation.com/

[Sailor Steve]

Originally Posted by raduz

why do you think so?

Because Americans did NOT use that method during the war. They trained to use it before the war, and found that when they tried it in actual combat they failed miserably, every single time. Read Blair's Silent Victory. I can't get at my books right now, so I can't quote you chapter and verse.

As to the game, I still haven't been able to look at the library's copy of Conway's, but if I remember correctly a British Tribal class destroyer at flank speed is turning something like 220 RPM, which is 3.67 times per second, which is impossible to count accurately. The game has them turning much slower, so as with a lot of other mechanisms the game lets you do something they couldn't do historically.

Unfortunately, Greyrider gives a link to the homepage for The Fleet-Type Submarine, but not the specific page. I can't find it anywhere.