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View Full Version : Bug or was it really like this on US subs??


William516
04-05-07, 11:06 AM
Well thanks to some clever modders and forum posters, I have found out how to work my sonar and radar. There was a thing in the forum not long ago about sonar not working at periscope depth. I didn't believe it at first but now im finding the same thing.

Was this really true that a Submarine was deaf at periscope level with all engines shut off etc. I know in SH3 we had hydrophone and sonar contacts at periscope level with no problem.

Has this issue been addressed already or is it in the works. The files for SH4 are not as easy to play with as SH3. Seems like a whole different animal not to mention there is so much stuff left from SH3 in the files I dont know what to touch.

Thanks for any help

William

SKurj
04-05-07, 11:13 AM
yet active sonar ping (range estimate) works at PD and above...

Snowman999
04-05-07, 11:16 AM
Was this really true that a Submarine was deaf at periscope level with all engines shut off etc.


It is not true. USN submarines routinely used passive sonar at PD to track and classify targets and to monitor torpedo performance. The sound heads were on the keel.

Sailor Steve
04-05-07, 11:19 AM
Was this really true that a Submarine was deaf at periscope level with all engines shut off etc. I know in SH3 we had hydrophone and sonar contacts at periscope level with no problem.
First off no WWII sub was stable enough to sit at periscope depth with the engines off; it would start to either rise or sink fairly quickly. Try the NYGM 'Anti-Hummingbird Mod'-it works like real life.

That said, periscope depth is a grey area. Hydrophones have problems with surface distortion, and a destroyer can't hear (or ping, for that matter) an aircraft carrier, and its propellors are as deep or deeper than a sub's at periscope depth (well, maybe not quite that deep but still...). On the other hand I've never heard of a sub hiding at periscope depth, so I would say they could hear things there.

Platapus
04-05-07, 11:28 AM
In real life, I do not believe that passive hydrophones were useless at periscope depths but I can understand that they would be more effective at a lower depth.

The surface water disturbances, being closer at Periscope Depth would drown out any distant noise easier than when deeper.

Nothing obfuscates a topic like a good analogy.. and the following is nothing like a good analogy.:huh:

If you were to stand in a room with a fan and a person talking and you were far away from the fan you could hear both the fan and the person talking.

But when you are close to the fan, the fan noise (which has not changed) drowns out the person talking (who has not changed their volume). Your ability to hear (collect sound) has not changed either, you are just hearing more of the fan than the person talking. In this example you would not say that my hearing does not work near a fan.

I think the same analogy pertains to passive hydrophone collection at periscope depth. It still works just fine, it is just that now the hydrophone is closer to a constant noise source and thereby can't pick up the lower strength signal from the ship.