The World's First Supercavitating Boat?

An anonymous reader writes "For decades, researchers have been trying to build boats, submarines, and torpedoes that make use of supercavitation — a bubble layer around the hull that drastically reduces friction and enables super-fast travel. Now a company in New Hampshire called Juliet Marine Systems has built and tested such a craft, and says it is the world's fastest underwater vehicle. The ship, called the 'Ghost,' looks like two supercavitating torpedoes with a command module on top, and can carry 18 people plus weapons and supplies. The company is in talks with the U.S. Navy to build a version of the ship that can guard the fleet against swarm attacks by small boats. The question is how well it really works, and whether it can be used reliably and effectively on the high seas."

Comments

So fast it outran the Link !

[sl4shd0rk]

http://www.prnewswire.com/news-releases/juliet-marine-systems-inc-announces-the-first-super-cavitating-ship-ghost-127461283.html

Re:So fast it outran the Link !

[aurizon]

Supercavitating is super noisy and very detectable by underwater ears.
The supercavitating transition layer reflects sound very well = also detectable.
at 300 to 500 miles per hour the immediacy compensates for the noise which makes it hard to localize, but you sure know it was around.

The Russian supercavitating torpdeo was very very noisy, but fast as stink...
It use decomposing Hydrogen peroxide as high power density fuel.
http://en.wikipedia.org/wiki/Russian_submarine_K-141_Kursk
http://en.wikipedia.org/wiki/VA-111_Shkval

Scientific American had article on the technology behind their paywall.
http://en.wikipedia.org/wiki/Supercavitation wiki refers to it and it can be found online...

Re:So fast it outran the Link !

[Sentrion]

1st: Radar cannot penetrate underwater and the part of the GHOST ships that are above water have the same type of design and material as the stealth fighter.
2nd: One of the goals of supercavitation is to achieve faster-than-sound speed underwater. Since sonar uses sound waves to detect objects, if you could travel toward a ship equipped with sonar you could reach them before they had a chance to detect you. Other ships would eventually detect you, but there would be such lag in detection that it would be extremely difficult to fire artillery, rockets, or torpedoes onto your position unless you traveled a straight or predictable path for a good length of time. The fact that the boat exists indicates that the torpedo technology is probably already on board US vessels - meaning that the US could sink just about any ship before the enemy even knew torpedoes where in the water.

If in fact the boat can travel up to 200mph it would be extremely difficult to track or follow without a high speed aircraft dedicated to this purpose. And such a plane would need to rely on visual contact with the vessel because it evades detection by radar. Methods to attack such a craft at max speed would be limited, such as flying right up to the boat and using visual sights to engage the vessel with machine guns, canon, unguided rockets, and/or optically guided missiles (where the pilot has to control the flight of the missile with a remote control and visually guide it into the target). Needless to say that many if not most of the "low tech" options, such as machine guns or rockets do not work so well at high speeds and many modern fighter jets aren't even equipped with such weaponry. The only modern type of weapon, the optically guided missiles, are very expensive.

At such high speeds though, I would hate to think what would happen if it were to hit a porpoise or sea turtle.

Re:So fast it outran the Link !

[alannon]

Re the 2nd: You realize the speed of sound in water is more than 4x of that in air, right? We can barely build a craft that can go that speed in the air, let alone water.

Re:So fast it outran the Link !

[Above]

I think we already have the perfect attack plane for this mission, the A-10. It can easily keep up, was designed to visually target, and would obliterate a boat like this in a few shells.

Re:Link, please?

[cachimaster]

Article has enough keywords to uniquely locate the original article

Re:A boat?

[gstoddart]

Since when is a 'underwater craft' referred to as a 'boat'? A USN Submariner friend of mine affectionately calls his submarine a 'boat' sometimes, but come on /.!

That's because

Submarines are usually referred to as "boats" rather than as "ships", regardless of their size."

A sub is always a boat. Navies have always called them boats, that's why your submariner friend calls it that.

You might not like it, but "boat" is the correct term.

Re:Link, please?

[Carnildo]

There's a difference between cavitation and supercavitation. Supercavitation takes those noisy bubbles that are destroying your propeller and extends them to enclose the entire vessel. This reduces the amount of surface in contact with the water, which greatly reduces drag, and all of a sudden you're rocketing along at 200 miles per hour and don't particularly care if people hear you coming.

Re:How long before Russia and China adopt the tech

[capnkr]

In addition, the claim is made by the inventor that the US Navy has no defense plan in place WRT small boat swarms, so his is the only solution. Wrong.

I can attest that is a blatant falsehood, and that our Navy does indeed train for exactly that sort of warfare. I don't think it is revealing any sensitive info to point out the fact that a certain well known, very-fast-boat manufacturer has an ongoing contract with the Navy conducting offshore exercises using 40-50' "attack" boats powered by twin or triple 250-300hp outboard engines. I've hung out many times with the guys running those boats, and they do not operate in any sort of "blacked out" manner. They use public and privately-owned marine facilities, and conduct operations in broad daylight within areas used by recreational offshore fisherman, so I am sure that the inventor is aware of them as well. These boats can easily run in excess of 70mph, and while they may be very high-dollar craft in the consumer market, they cost less than $500K apiece.

The one advantage his invention has over these conventional hulled boats (other than raw speed) is that this is a wave piercing design, which as stated ITFA is better for the health of those aboard. That said, I seriously doubt it has anywhere near the maneuverability of more conventional offshore craft such as those I mention above. The turning radius would have to be *extremely* large with that cat hull configuration, and even moreso at super cavitation speeds. And how large a sea state can it run in? Keeping that pod above water and waves at 200mph (or even 1/4 that speed) would be absolutely critical. Water being non-compressible, one good impact would likely render that platform unusable. So - it's very fast, but can't turn/maneuver for shit, and will primarily be useful only in areas where seas will remain relatively calm.

The inventor speaks glowingly about his $20-million-dollar-per solution becoming a multi-billion dollar industry. To me, knowing what I know about water craft, it seems to me as if he is selling the US Navy a marine version of TSA body scanners. Another Federal boondoggle...

Re:Link, please?

[phayes]

You are either confused or you didn't read TFA. This is a $10 million private sector development. Yes they are trying to interest the Navy/CG but were they really interested is would have been mentioned. If you want to beat on government spending go find a subject where the government is actually doing the spending.