The Pentagon’s weapons buying system is notoriously flawed. In truth, much else about the Department of Defense is screwed up as well—the place cannot even be audited, and hasn’t been for decades (which is against the law). But, for the moment, let me focus on one issue. That is the ridiculous situation that unless a service issues a requirement, you cannot do business with it.
But what if the service does not know it has a requirement because what is proposed is so innovative? There is the rub.
The Ghost is a privately developed, stealthy, stable, hydroplane—which which is propelled by two 62 long tubular foils each housing a 2,000 horsepower gas turbine engine driving two propellers (making four in all). It’s the brainchild of self-made millionaire, and inventor, Gregory Sancoff.
In case you missed the point, ‘stealthy’—in this context—means it won’t show up on an enemy’s radar. Unless seen with the Mark I eyeball (a British Army expression) it will be invisible.
Big sea. Little boat. Little, invisible, very fast, unusually stable boat. Minimal drag means fuel efficient. Stable means good weapons platform and vastly less fatigue. Pirate un-friendly. Highly automated so easy and inexpensive to operate. Ideal for littoral (coastal) operations—the Navy’s more recent area of concern (Appreciate that traditionally, the U.S.Navy, with its aircraft carrier groups has been deep-water focused) . Minimal crew required. Scalable if you want a bigger invisible boat—or, perhaps, a ship.
By Pentagon standards, developed for ridiculously little money at quite extraordinary speed—and, so far—without government funding.
The propellers are in the front—so, in effect, the Ghost is pulled through the water. Why did no one think of that before?
Supercavitation—creating bubbles which offer little resistance—minimizes drag. This is what Wiki says about it.
An object (black) encounters a liquid (blue) at high speed. The fluid pressure behind the object is lowered below the vapor pressure of the liquid, forming a bubble of vapor (a cavity) that encompasses the object.
Supercavitation is the use of cavitation effects to create a bubble of gas inside a liquid large enough to encompass an object travelling through the liquid, greatly reducing the skin friction drag on the object and enabling achievement of very high speeds. Current applications are mainly limited to projectiles or very fast torpedoes, and some propellers, but in principle the technique could be extended to include entire vehicles.
Among other benefits, the phenomenon makes craft more fuel-efficient and more stable for shooting at targets. The Russian military, Sancoff learned, had built a supercavitating rocket-powered torpedo, which traveled at 200 knots, roughly four times as fast as American weapons. But the torpedo was difficult to steer. The problem, he realized, was that the propellers were pushing from the back, rather than pulling from the front. “If you push a pencil across a table, it’s very hard to keep it going straight,” Sancoff explains. “If you pull the pencil, it’s easy.”
The following is an extract from the Business Week story.
Matte gray, with the chiseled angles of a Nighthawk stealth aircraft,Ghost doesn’t look like a boat. Its 38-foot main hull is designed to travel above the water’s surface, propped up by two narrow struts, both 12 feet long and razor-sharp at the front so they can cut through ocean debris. Underwater, each strut is attached to a 62-foot-long tube that contains a gas turbine engine. Hinges allow the struts to move up and down like wings. While parked, or traveling through shallow waters, they can be extended to the side. In deeper waters, at speeds of eight knots or higher, they can rotate downward to lift the hull into the air, eliminating the jarring impact of waves.
Four propellers positioned at the front of the tubes are powered by the two 2,000-horsepower engines. They pull the craft and, with the help of air funneling down through the struts, create a gas bubble around each tube—an effect known as supercavitation that can reduce drag by a factor of 900. In short, Ghost makes a bubble and flies through it.
“It’s such a smooth ride, you can sit there and drink your coffee going through six-foot swells,” says Gregory Sancoff on a recent trip to the hangar. A self-made millionaire who started a string of medical technology companies, he’s looking up at Ghost, grinning. This is his baby. Sancoff came up with its design, leased the ramshackle hangar, and built the vessel entirely on spec. His 18-person startup, Juliet Marine Systems, has invested $15 million in the project.
Ghost, Sancoff says, could be used as a kind of “attack helicopter of the sea”—conducting coastal defense and anti-terrorism missions and protecting massive naval vessels from swarm attacks by armed speedboats. Built from aluminum and stainless steel, the vessel is nonmagnetic and difficult to target using sonar. “We came up with the name Ghost because the boat is intended to have no radar signature at all,” says Sancoff. “With Ghost, you can get into denied-access ocean areas and loiter for 30 days with the fuel on board. You can listen to cell phone conversations, you can monitor what’s going on, you can launch operations and leave, and no one knows you’re there.” He adds, “That’s not something the government can do right now.”
In the face of budget cuts, Defense officials have asked companies to fund more of their own research, which is why Juliet Marine personnel are surprised they haven’t garnered more interest. Juliet Marine hopes things will change if the craft breaks the commercial SWATH speed record of 31 knots. So far, Ghost’s top speed is 29 knots, but Curcio says 50 knots is within reach, roughly the speed of Mark V boats, a formerly popular mode of transport for Navy SEALs that was discontinued in 2012.
I’ll be surprised if the Ghost doesn’t achieve more than 50 knots. Given minimal drag, fuel consumption—relative to the speed—should also be low.
What is the significance of supercavitation on a larger scale?
Hot-rodding aircraft carriers? Super-fast oil tankers? Bubble, bubble, boil, and trouble! The implications of that boggles (bubbles?) the mind.
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