sonar sounds

[caspofungin]

what does real active sonar actually sound like? I've read books where it's described as a rasp, or gravel on the hull (eg das boot). Is the characteristic ping just a figment of hollywood imagination?

[sdfiddler]

I've served on a US SSBN for almost 4 years (USS Rhode Island), and I've heard active sonar from DDG's, CG's, SSN's, CVN's, etc at the USN's testing and training ground Andros IS, Bahamas. Active sonar kind of sounds like a really annoying single bird chirp. Think of it as a high pitched sound that seems to climb up 3 steps like one note followed by 3 or so individual higher pitched notes. I'm not sure what the old WW2 Active sounded like, but I know that lying in my rack in the off wath time, Active from a surface combatant would wake me up as you can hear it through the hull very clearly and distinctly! Hope this clears it up! Go Navy beat Army!

[urseus]

Im reading Das Boot, and ive read elsewhere also that it sounds like gravel/rocks against the hull.

Hollywood and this game sound nothing like that.

PING PING PING

Rocks against a hull would sound like a merky tapping scratching/sand sound.

[MuscleBob.Buffpants]

I would agree with sdfiddler, I was on an anti-submarine frigate and whenever they had the whale killer running it was nearly impossible to sleep through the noise (the sonar dome was midships, just below my cabin). It's not so much loud, as really piercing.

[OakGroove]

M.Dv. Nr. 906 (U.Kdt. Hdb.) lists some different sonar impulses as observed by U-Boat crews;

- constant chirping sounds
- sounds likened to ticking of a clock
- sounds likened to short metallic hits against the hull
- swelling and ebb away tone

Here an example for the chirping sound:
http://www.hnsa.org/sound/soundinthesea/track32.mov

[sdfiddler]

That sound sample sounded like the us AN/BQR-6 Naval Fathometer than a ping from a surface combatant. But the sound sample sure was cool! Brought back all kinds of great memories of standing RADAR watch on the surface for hours on end, and getting bored with no contacts for several hours, and having the fathometer watch turn the volume up so you can here the "Ping" of the fathometer! Go Navy beat Army!

[compressioncut]

I am an active, serving sonar operator and can tell you that actual "pings" are not figments of anyone's imagination. I would imagine that most WWII era active sonars would have used the classic ping, but there were many different models of sonar developed and installed, and the allies were always looking for a bigger advantage, so you could have heard anything I suppose. But again, most would have been of the pinging type, probably using a continuous wave (single frequency) transmission, which sounds most like a tuning fork.

This page http://www.jproc.ca/sari/ details the sonars fitted to a particular Tribal destroyer during the war. Parts 1-4 are what should interest you.