THE US navy wants to protect its warships with a system that will destroy incoming torpedoes by firing massive underwater shock waves at them. Posted on 10/07/2005 10:15:04 AM PDT by LibWhacker
THE US navy wants to protect its warships with a system that will destroy incoming torpedoes by firing massive underwater shock waves at them.
The ships would be equipped with arrays of 360 transducers each 1 metre square - effectively big flat-panel loudspeakers - running along either side of the hull below the waterline. When the ship's sonar detects an incoming torpedo, the transducers simultaneously fire an acoustic shock wave of such intensity that the torpedo either detonates early or is disabled by the pulse's crushing force, according to the Defence Advanced Research Projects Agency (DARPA), which is funding the project.
But these are no ordinary loudspeakers: instead of having a membranous diaphragm that can vibrate in response to a range of audio frequencies, each of the devices has a ram-like cylindrical metal armature at its centre. This is projected outwards by electromagnets at very high speed, producing a shock wave. The array can be fired as many times as needed.
When the six rows of 60 transducers on each side of the ship fire at once, the cumulative action should generate a "destructive pressure pulse capable of disabling an enemy's torpedo", according to DARPA.
Exactly how the system works is shrouded in military secrecy. But by making a speaker several times larger than the wavelength of the sound wave required, a tightly focused beam can be produced in front of the speaker. This is because beam width is partly determined by the aperture of the source - a bigger loudspeaker focuses sound in a smaller area. (New Scientist, 9 September 2000, p 38). And the combined size of the array makes for a very large speaker indeed. This focusing would allow the array to precisely target incoming torpedoes. In addition, the beam can be steered in different directions - probably by slightly altering the phase of the applied signals - a technique that is widely used to steer radio waves using side-by-side antennas. So torpedoes homing in on the ship's wake from many directions can be targeted (see Diagram).
So far, the system's developers, Anteon Technologies of Fairfax, Virginia, and BAE Systems of Farnborough, UK, have only built one transducer. But encouraged by software simulations that show the array should work, they plan to press ahead with a one-quarter-scale test rig.
If it reaches the stage of testing in the open ocean, however, the developers are likely to come into conflict with marine biologists. They have evidence that whales blasted by frequent acoustic signals from submarine or ship sonar appear to develop symptoms of decompression sickness, and die. (New Scientist, 11 October 2003, p 10).
But neither DARPA, Anteon, nor BAE Systems was willing to respond to questions about the array's proposed energy levels and any threat to marine mammals they might pose.
Non-stealthy Ping!
Interesting post and interesting research. I, for one, would like to see a whole lot more research in stopping IEDs that are killing troops now as opposed to some possible future naval battle. Too bad we can't get some lobbyists and congress critters to go on patrol in Iraq. Maybe something might get done then.
UH-OH! Now we get to hear from the "Save the Whales" crowd!..........oh, goody!........
"The ships would be equipped with arrays of 360 transducers each 1 metre square - effectively big flat-panel loudspeakers - running along either side of the hull below the waterline."
I think "yoots" of today already have these installed in their pimped-up street racers...
Better a dead whale than dead sailors and a sunken ship. But I know the liberals won't see it that way.
I would sure hate to be a good guy anywhere near, when this happens...especially submerged.
I suppose that if the IEDs were as noisy and easy to see coming as a torpedo, they would make something to get rid of them. Very hard to find something both random and passive...until it explodes.
Or a sound idea.
Rocking good news!
Now, apply the thing to vehicles in irak with the effect of rendering roadside IED inert. I for one would love to see a "unified field generator" that swept the sides of the road out beyond the max effective range of those IED, and blew them in place ahead of the convoy. Then apply it to low flying aircraft, effectively detonating all electrical and non-electrical blasting caps (a crapload of suprised bombmakers!)
Woo Hoo!!
Top sends
Truer words never spoken.
Sounds like this could be used as an offensive weapon, too and the enemy's sonic defense couldn't stop it.
It is no secret that the larger the speaker, the better the bass response. I think that these "speakers" will be very low audio frequency.
Don't forget...'save the divers', also.
"I suppose that if the IEDs were as noisy and easy to see coming as a torpedo, they would make something to get rid of them. Very hard to find something both random and passive...until it explodes."
Not necessarily. An electric blasting cap takes less than a third of a volt to 'go.' When using them, radios are strictly verboten. Non electric caps are more stable, but susceptable to shock. Seems to me there could be a way to send enough RF and or shock ahead of a column to settle the hash of an IED.
Just a thought.
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I think they used to use these kind of speakers at Who concerts...
Modern torpedoes are really, really big.
One Torpedo into a Burke or Tico could kill in an instant more servicemen than IEDs in Iraq kill in half a year.
Interesting idea. I wonder how hard it would be to build a shock resistant torpedo.
UH-OH! Now we get to hear from the "Save the Whales" crowd!..........oh, goody!........
What? What? What? I can't hear you, my ears are ringing......
Great idea. Now wait till we find out that the technology is only manufactured in China, so we have to buy it from them.
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