Estimating speed using prop revs.
 

I recently read in a tutorial that it was possible to estimate a vessels speed by counting it's prop revs.
Is there a table or chart to show this anywhere?

You can try this - for NYGM but may do for you too

http://www.subsim.com/radioroom/showthread.php?t=193770

Apart from that not seen one in a long time

Thanks bigboywooly,
Not sure I want to use this method. How would one know if the vessel had three or four bladed props in the first place? But I was intereseted in the technique.

you can here a change in the sound, like a -whump, whum, whum for a 3 blade, and whump, whum, whum, whum for 4 blades

Look here:

http://subsim.com/radioroom/showthread.php?t=186854

Canovaro, did you caluclate these times yourself or was it something from the kriegsmarine?

either way its impressive! i wonder how accurate it is as i often listen on hydrophones and try an estimate the speed.

many thanks:yep:

This was recorded in the game using SH3 ships, this is not real life stuff.
I created single missions with each ship at each speed.

Long time without seeing your posts. Good to see your still around.

Ken

I have to laugh at this, in a good way. It reminds me of trying to learn how different diseased lungs sound from a book. :D

I've toyed with the idea of making "training records" for GWX, along the lines of these databased US sonobuoy/SONAR sessions. (Warning: some racist content against the Japanese, due to the prevalent wartime attitude toward the enemy.) Still a valuable research source despite that.

The records would have probably covered identifying different propulsion types and speed via prop count. However, I scrapped the idea after realizing sound mods and ship adjustments will change the value of such lessons... and I can't speak German for that authentic touch.

Yes I've thought of this as well, you could make ogg sound files for in the grammophone folder. They sound like this:

"This is a small merchant type."
"chug-chug-chug"

So you switch between the grammophone and the hydrophone.