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Sonic Torpedo Defense
dylanduck writes "How do you defend a ship against torpedoes? According to the US Navy, you line the hull with loudspeakers and blast the incoming missile with such a devastating blast of sounds that it explodes." When asked about the possible ecological effects on marine life the military had no comment.
When asked about the possible ecological effects on marine life the military had no comment.
We care... why? My guess is that a large sonic blast is going to be a lot less harmful than a torpedo detonating. But that's just me.
We need to be cautious, as Britney Spears at 200db could have a devistating effect on the entire oceanic ecosystem.
To get best results they need gold power cables at 1000 for each speaker :)
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Reading TFA, the concern is not over the effects of sonic blast vs. sinking ship.
The concern is the effect of open-water testing of the sonic blast against simulated or dummy threats in the ocean.
Exploding drummers weren't included in the final test data.
Actually, being an acoustician, I would be willing to bet that they would use a phased array of loudspeakers. With the correct phasing of the speakers, some pre-determined "point" in the water could be driven to very high sound pressure levels, while the remaining ambient noise, while still loud, may not be all that dangerous. This would occur as a transient excitation from the various loudspeakers propagates away from the source and coalesces at the point in the water where the torpedo is located, the point where a very large pressure spike is generated. There are plenty of smart researchers in the navy and I have my doubts that they would use anything other than a phased array. And by the way, this is the same methodology that they use to destroy kidney stones.
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the principle behind this tech is the same as most when it comes to military planning: It's better to have it and not need it, than it is to need it and not have it.
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> This is like shooting down missles with lasers; just make a shiny
> missile and the light bounces off without damaging it.
Utterly ineffective. At intensities high enough to be useful the electric field of the laser pulse rips electrons out of the surface of the target. This creates a plasma which absorbs more energy from the pulse, explodes, and blows a piece out of the surface. It makes no difference at all what material the target is made of or how it is polished. This effect has been experimentally verified.
It's also how LASIX works.
> You can probably render the sound blast torpedo killer worthless
> just by skinning the torpedos in cheap appropriately sound
> absorbing material. Perhaps a derivative of foam or rubber.
Failed freshman physics, did you?
Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
I am a former sailor in the US Navy, my particular job was working with the Aegis weapon systems. Just because the system is installed on board doesn't imply that it gets used during a simulation or exercise. We have missiles and guns but very rarely ever fire a live round during training. We have electronic counter measures but those do not get set off either. Why waste the equipment and materials if they can be simulated via computer instead? But then how do you know the stuff works? Every bit of equipment has a planned maintenance schedule that is closely followed. This includes tests based daily, weekly, monthly, yearly etc. They are also very aware of the potential dangers, more so than you that is clear. The Navy is very careful about operating withing specific guidelines when it comes to the environment, they observe all of the whale habitats along the US costal waters and any other environmentaly sensative areas.
Just about anyone with a relatively big boat has to repaint the hull with antifoul paint every couple years. Not really that nasty, now, it's simply marine paint mixed with a bunch of (correct me if i'm wrong) aluminium dust. The older stuff used primarily copper, which had a few adverse effects on sea life.
Apparently some of the Cajuns down south use cayenne pepper, and they claim it works the best, but hey, to a cajun, cayenne pepper's good for damn near anything.
The navy these days has actually been using some pretty wierd coatings for ships, although mainly subs, in order to reduce friction.
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Oh, right. Because we would *hate* to have a loud noise in the ocean instead of thousands of gallons of fuel oil or a ruptured nuclear reactor from a sunk ship.
Brought to you by the same retards who nixed nuclear power for environmental reasons, forcing the country to depend on burning coal.
I'm 90% sure I know what this is for. I'm not a naval warfare specialist, but I am a scientist with an interest in these things.
In the 1990s, the Russians developed the prototype for what would later be termed the Shkval or Squall supercavitation torpedo. Knowing the Russians, the Chinese probably have them too.
Cavitation is a phenomena where a body moving through the water pushes the water out of the way so fast that it creates bubbles around the object (fast = lower pressure = water vaporization = bubbles). You may have heard of propellers cavitating - that's where small bubbles of water vapor form then burst on the low pressure side of a prop blade, causing lots of noise and even damage to the blade when they implode.
Supercavitation, on the other hand, is an intentional phenomena where a blunt-nosed object is shot through the water, creating low pressure vortices on the sides. Air or exhaust gases are injected into these vortices, creating a static "bubble" around the object that drastically reduces friction - perhaps up to an order of magnitude. You have to fire these things at about 50mph or greater to start the supercav effect going, effectively "handing off" the bubble to the torpedo, which then sustains it.
The numbers on these torpedoes are incredible: we're talking about a 300mph torp carrying a 460lb warhead with a range in excess of 7000 yards. That's the tame version - others carry nukes. In other words, carrier-killers.
Supercavitation torpedoes, as you can imagine, are incredibly noisy and easy to detect - you just can't get away from them because they're so fast. This sonic projector essentially sends a high-energy single pulse through the water directed at an incoming torpedo. That pulse probably wouldn't be able to crack a torpedo - you'd probably need on the order of 250-500PSIG overpressure to do that, (scuba tanks contain 2000PSIG regularly). You wouldn't be able to detonate the high explosive, because you need a wavefront speed above the detonation velocity, which for C4 is about 7000m/s (much slower than the speed of sound in water, 1482m/s).
I don't have the time right now to spin the equations, so I could be wrong.
However, you would be able to disrupt and dissipate that bubble around an incoming supercavitation weapon with a high-energy sonic pulse. Break that bubble, and the torp stops dead in the water because it can't reform the bubble around itself. If it mistakes that sudden stop for a ship hull - boom.
'Be always mindful, even when ditch-digging.' --D. T. Suzuki