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Pax Melmacia
Joined: 19 Nov 2004 Posts: 29 Location: Philippines
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Posted: Thu Dec 09, 2004 4:12 am Post subject: Being 'pinged' |
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Just like everyone else here, I've read quite a number of accounts by U-Boat survivors. The thing is they seem to have different accounts on the sound Asdic makes when it strikes their hull. Some say it sounds like pebbles on a roof. Others, a chain being dragged across the hull. Some say it's like a tuning-fork.
I imagine there's the sound of the pulse first, followed by its contact with the hull, but I'm just guessing here.
I've heard the pings on the subsims, but now I'm wondering if they're accurate. |
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Redwine
Joined: 10 Jan 2002 Posts: 1143 Location: Buenos Aires , Argentina.
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Posted: Thu Dec 09, 2004 10:31 am Post subject: |
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Yes i heard the same........
By casuality editing a ping download from the web, using equalizer, i found a effect wich change a little bit the sound of the ping at final of it when it hit the hull........ the ping finish with a "fried" sound.........
I do not know if it is excat real but reproduce that "change" you mentioned.............
I found the effect by casuality editing pings to hear them well at my sound system..................
I put a colection of rare pings from the web and edited at my signature............. |
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Catfish
Joined: 21 Sep 2001 Posts: 1248 Location: where the ocean meets the sky
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Posted: Thu Dec 09, 2004 1:57 pm Post subject: Pinngg... |
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Hello there,
i just read a book from a U-boat sailor ('Sharks and little fish') where the detection sound of the ASDIC was described as a 'tack' sound which increased it's frequency the better the destroyer's fix on the U-boat was. If the ship had the boat in it's detection beam (sorry for the transl., it's called 'Ortungsstrahl' in German), it was like lots of pebbles being thrown against the hull of the sub. This sound can be heard quite good in one of the first PC-subsims, 'Wolfpack'.
Greetings,
Catfish |
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Heibges
Joined: 26 Feb 2004 Posts: 681 Location: San Francisco, California
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Posted: Thu Dec 09, 2004 2:56 pm Post subject: |
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According to the Uboat Commander Handbook the Germans heard several differnent sounds from several different allied echo sounders.
deeper in tone that German S echo sounder
constant humming
ticking of clock
fluctuating tones between high and low volume
metallic blows on the ship |
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Vonotto
Joined: 07 Jul 2002 Posts: 551 Location: Alexandria, Va
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Posted: Thu Dec 09, 2004 5:42 pm Post subject: |
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Yes if you read the several accounts of the sounds then compare the dates you will see that people heard differents sounds in different years. This is due to upgrades and different equipment as it is introduced throughout the war.
The sound is also influenced by the depth of the sub and the amount of salt in the water as well as thermal layers.
If you scuba dive it is easy to understand all these. |
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Leif...
Joined: 25 Dec 2001 Posts: 241 Location: Sweden
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Posted: Thu Dec 09, 2004 5:46 pm Post subject: |
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I have never figured out how one can first hear the ping and then hear the contact with the hull. If you hear the sound then you are hit by the sound. What you don’t know, and can’t hear, is if anyone is listening in your direction and hears the echo.
Leif… |
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Lanzfeld
Joined: 10 Jan 2002 Posts: 1256 Location: Reston, VA
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Posted: Thu Dec 09, 2004 5:54 pm Post subject: |
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Very good point Leif.... :hmm: |
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Sailor Steve
Joined: 22 Nov 2002 Posts: 5433 Location: Salt Lake City, Utah
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Posted: Thu Dec 09, 2004 6:12 pm Post subject: |
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My guess is that the "ping" sound so common in movies comes from the fact that U.S. subs had active sonar themselves. Though not transmitting, the sonar reciever would actually translate the signal transmitted by the enemy, so they would hear a "ping". Any boat not having sonar equipment would only hear the sound waves bouncing off the hull, hence the "gravel" sound. |
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Torgen
Joined: 14 Sep 2002 Posts: 454 Location: Tampa FL
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Posted: Thu Dec 09, 2004 6:21 pm Post subject: |
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My father was a contractor visiting a US attack sub in Groton in the 70s, and the destroyer across the river went active andwas pinging the sub's hull constantly. My dad said it made a huge BONG! sound and damned near made everyone deaf. The CO made a *personal* visit to the DD, and the pinging stopped soon after.
Of course, the modern sonar are surely far more powerful and focused than the WWII era ones, and your usually not THAT close to one! :doh: |
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Redwine
Joined: 10 Jan 2002 Posts: 1143 Location: Buenos Aires , Argentina.
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Posted: Thu Dec 09, 2004 7:15 pm Post subject: |
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Leif... wrote: | I have never figured out how one can first hear the ping and then hear the contact with the hull. If you hear the sound then you are hit by the sound. What you don’t know, and can’t hear, is if anyone is listening in your direction and hears the echo.
Leif… |
The effect was described as a "vibration" or some thing after the ping finish............as if you ping a diapason, you heard the sound and after it finish you still hearing a small vibration...........
May be this "vibration" is present at same time as the ping but covered by the ping sound level and only is audible when the ping sound level down...............
But read some times about this "change in the sound at final of the ping...........wich is avery short time effect, as if there two sound wich finish "gap" by a small fraction of second...........
I never heard it, only read about it................ |
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Paximus
Joined: 07 Jul 2002 Posts: 44 Location: Miami. FL
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Posted: Thu Dec 09, 2004 8:39 pm Post subject: |
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This "gravel" or "pebbles hitting the hull" sound is what the author of Das Boot heard. Did the movie get it wrong? How does a ping turn into the sound of a bunch of pebbles hitting the hull for those inside the sub? |
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Sailor Steve
Joined: 22 Nov 2002 Posts: 5433 Location: Salt Lake City, Utah
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Posted: Fri Dec 10, 2004 1:49 am Post subject: |
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The "ping" is the tone generated by the sonar/asdic transmitter so the operator knows the signal was sent. If it bounces off of something the returning signal is translated by the machine into another tone. By listening to the difference in the tones a good operator can tell the approximate range to the target. The actual signal is supersonic-it can't be heard by the human ear at all. When the signal hits the submarine, the sailors inside are actually hearing the effect the supersonic signal has on the hull itself. Thus, no ping.
Of course I could be completely wrong on that. |
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shole
Joined: 28 Jul 2004 Posts: 130
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Posted: Fri Dec 10, 2004 7:52 pm Post subject: |
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supersonic?
i find that hard to believe |
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Sailor Steve
Joined: 22 Nov 2002 Posts: 5433 Location: Salt Lake City, Utah
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Posted: Sat Dec 11, 2004 1:22 am Post subject: |
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Sorry, I misspoke...er, miswrote? I meant Ultrasonic, as in higher pitched than the human ear can hear. Obviously sound can't travel faster than the speed of sound... |
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Drebbel
Joined: 10 Jan 2002 Posts: 6153 Location: Almost at periscope death !
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Posted: Sat Dec 11, 2004 8:21 am Post subject: |
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This is what my babylon says about it
Quote: |
- supersonic
adj. greater than than the speed of sound, ultrasonic
- ultrasonic
adj. having a frequency above the range of sound audible to the human ear (of waves, vibrations, etc.)
- supersonic
adj
1. (of speed) greater than that of sound in a given medium especially air; "the concorde is a commercial supersonic aircraft" [ant: sonic, subsonic]
2. having frequencies above those of audible sound [syn: ultrasonic]
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So it seems that both are the same in some instances. |
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