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Supercavitation: Ultrafast Underwater Weapons
Peter Dyck writes: "According to this article, the world's major naval powers are developing the means to build entire arsenals of innovative underwater weapons and armadas of undersea watercraft able to operate at unprecedented speeds. This high-velocity capability - a kind of "warp drive" for water - is based on the physical phenomenon of supercavitation. The trick is to surround an object or vessel with a renewable envelope of gas so that the liquid wets very little of the body's surface, thereby drastically reducing the viscous drag." We've done a couple of articles about these weapons before, but Scientific American has good explanations and diagrams and some new information. If (when?) underwater guns actually come into use, it will change the entire nature of underwater warfare.
Especially more recent history
Bullshit. The past wasn't some happy place where people all got along, until people invented airplanes and poison gas and atomic bombs and ruined it all. The last fifty years have been the most peacful period in human history, and military budgets have always been funded even when other things couldn't be.
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The supercavitating projectiles are still going to have a hard time changing course.
A supercavitating torpedo or shell may be fast enough that a close-range opponent doesn't have time to dodge - even better, a supersonic weapon could hit your opponent before he heard it coming, since it would travel faster than both its own noise and a sonar return.
Disregarding that situation, supercavitating weapons are still useful as "engagement breakers", i.e. weapons that, even if they do not hit the opponent, force the opponent to abandon a favorable attack position and cut loose any wire-guided torpedoes he may have launched.
DES
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Oooooh. Underwater warfare! We're so scared. What are you gonna' do, kill all our fish?
Read the article again. The underwater missiles have the potential of scooting along underwater until they get to the coast, and then popping up and blowing away coastal cities, thus rendering any Star-Wars-style missile defense systems useless. Now, think about how just about every country has ships in the ocean that are permitted to come right up to our shoreline, and you'll realize that they don't even have to be that accurate in order to wipe out cities like DC, NY, LA, Miami, etc. Yes, you should be scared.
Of course, most of this can already be done on a smaller/cheaper scale by smuggling nuclear weapons aboard container ships, but this allows for a more timely attack, I guess.
What's your damage, Heather?
At high speeds, the inertia of the water is more important: Water has to move out of the way of the projectile, and return after it passes. Since water is hardly compressible, alot of water has to move.
The page written by Leonid A. Kharitonov that you linked states that the Russian government simply speculated on the idea of a failure of a secret new torpedo as the reason for the Kursk disaster, along with several other reasons. No mention of cavitation. So you are disseminating sensationalism and possibly misinformation by filtering out the rest of the page and submitting fourth hand knowledge (The Russian government - Russian reporters - Leonid Kharitonov - then yourself) to create fifth hand knowledge for the rest of the slashdot public.
A lot of people never read the links, you know...
There is a fine line between being a cultivated citizen and being someone else's crop. - A. J. Patrick Liszkie
One of the theories on what drives whales to mass beachings, other than the possibility of viruses; is underwater noise pollution. Its hard to imagine that an entire pod of whales would succumb to the same infection. Since these highly social(Eusocial?) beings depend on long distance communication through corridors of reflection; isn't this technology just going to drive them MAD?
What kind of impact would this weapon, or mode of travel have on intelligent aquatic life?
As usual, unless you are human; you have no rights at all.
The sinking of the Kursk may have been caused by the premature explosion of one of these "supercavatating torpedoes." This site has some good info.
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Here, let's spark one.
Super cavitating weapons would travel faster than the speed of sound, so it cannot be detected sonically.
The gas/water interface may be very radar noisy, so that might still work, I don't know.
A sonic attack, akin to a laser, should be able to collapse or deflect super cavitating weapons.
Focus the water waves/sound waves into a beam like weapon in the path of the super cavitating weapon, feed more energy into the bubble than it was designed to handle, and destabilize the cavitating devices capacity to create a stable bubble, forcing tail slap and mis-guides.
Or something as simple as 'ablative' armor, in which surface mounted explosives destroy the bubble and using the shockwave/water as a weapon against super-cavitating devices.
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Depends upon the nuclear weapon. :-) Seriously, a man-portable nuclear weapon could detonate and probably not inflict massive damage beyond the first row of buildings/hard objects surrounding the port. Fallout would be an issue, although weapons designers can minimize this to an extent - certainly not as bad as the apocalyptic impression spread by phrases such as that one. Remember that people in shelter's around Hiroshima ground-zero were relatively unscathed - and train service for the city was functional again in a few hours. Nuclear != Armageddon, just a particular type of weapon.
Highly recommended reading:
S. Glasstone & P. Dolan, The Effects of Nuclear Weapons, GPO.
Also, US Navy sonar will most certainly detect something appraching underwater at over 250mph (and maybe they could do something about it, or maybe not...) but if a nuke is hidden on a ship then the Navy very well may allow them to dock.
This is a big issue, and one that the Pentagon is familiar with (although navy brass tend to reject the notion that nuclear weapons will ever be used). In a recent wargame in which I participated, red team was able to do a ridiculous amount of infrastructure damage to the US with this very tactic. I'm told that there are systems in R&D for over-the-horizon detection of nuclear weapons... although I have no idea how that would work. For all I know, it's military vapourware.
It should be possible to detect inbound weapons travelling at >250mpg, the question is what to do about it once you've detected it (the exact same problem as with ballistic missiles). Shooting it down requires the existence of a pretty impressive infrastructure designed to stop that particular type of attack - and as you say, probably won't help against the shipping boat packed with explosives.
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However, they're not so dumb that they smoke cigarettes.
(And to the wales' credit, beaches don't have warning labels from the Surgeon General.)