Juliet Marine Systems "Ghost"
GHOST is a super-cavitating stealth ship which can achieve 900 times less hull friction than a conventional watercraft. It was developed to provide superior protection for US service personnel. It was built by Juliet Marine Systems.[1]
History
Inventor Gregory Sancoff had decided to focus on small watercraft following the attack on the USS Cole in 2000, after which he recalled saying: "Some yahoo terrorists in a cheap little boat and $500 worth of explosives can kill 17 sailors on a billion-dollar ship?" He also came across a 630-page U.S. Navy report on an exercise called Juliet, where the Navy attacked an enemy force of small, high-speed boats; after two days, the Navy had suffered over 20,000 simulated casualties. Sancoff gathered information on marine technology, including hydroplane racing boats and high-speed supercavitating torpedoes.[2]
In 2007, Sancoff founded Juliet Marine Systems, named after the Navy exercise that inspired him, and began work on a plywood hull mock-up at Portsmouth, N.H.. In October 2009, Sancoff's patent attorney received a letter from the U.S. Patent and Trademark Office, with a recommendation from the Office of Naval Research (ONR), enforcing a secrecy order forbidding Juliet Marine from filing its patents internationally or speaking about its technology; the secrecy orders were lifted in 2011. Prototype trial runs were conducted at night; the main hull section failed to lift out of the water on its first dozen runs, it first successfully lifted in 2011, reaching roughly 4 ft (1.2 m) high. Trials revealed the vessel's smoothness, traversing 8–10 ft (2.4–3.0 m) high waves without the crew feeling much seasickness, unlike those onboard an accompanying chase boat.[2]
In 2014, Sancoff declared he was "aware" of the Department of Defense's apprehension to working with startup companies. The Navy has a policy of only buying technologies of an announced interest and cannot procure a system without established requirements. In 2009, the Defense Advanced Projects Research Agency (DARPA) expressed interest in funding the Ghost, Sancoff rejected this to retain the patent rights. The ONR reportedly produced feedback declaring a lack of trust in the design. He also voiced concerns over potential theft of the design as the patents are publicly available, and repeated attempted to breach the company's computer systems. U.S. allies have expressed interest in the Ghost, and Sancoff has said he is willing to make a foreign sale.[2] In September 2014, the State Department permitted Foreign Military Sales discussions with South Korea about the Ghost.[3][4]
In 2014, it was reportedly offered to several nations including Bahrain, Qatar, Israel, Saudi Arabia, Japan, Taiwan, South Korea, and Singapore. High-level discussions were allegedly held with one nation interested in 25 Ghosts in a potential $300 million sale. Juliet Marine also offered a scaled-up corvette-sized Ghost 150 ft (46 m) in length during the U.S. Navy's re-evaluation of the Littoral Combat Ship program; costing about $50 million per vessel, it is six times cheaper than the $300 million per-ship cost of a Freedom-class and Independence-class littoral combat ship. One impediment to U.S. Navy procurement of the Ghost is a preference of senior leaders for large-hulled oceangoing vessels that can also perform inshore operations instead of smaller craft specialized for inshore missions.[2][5][6][4]
Design
The Ghost uses a dual-pontoon supercavitating hull, known as the small waterplane-area twin-hull (SWATH), to run at top speed through 10 ft (3.0 m) seas. It is gyro-stabilized, control is provided by 22 underwater control surfaces. Below eight knots, the Ghost sits in the water on its centerline 38 ft (12 m)-long module; faster than this, the marine aluminum buoyant hulls lifts the main hull out of the water by two 12 ft (3.7 m)-long struts, achieving full stability and reducing the amount of area resisting the water. Each strut is attached to a 62 ft (19 m)-long underwater tube that contains the engines. Four propellers are at the front of the tubes, which is more stable and allows for better control at high speeds; the propellers funnel air down through the struts, creating a gas bubble around each tube (the cavitation effect) for reduced drag and smooth motion. Propulsion on the prototype is provided by two T53-703 turboshaft engines providing 2,000 horsepower, there are plans to later adopt the General Electric T700 turboshaft engine. Since the tubes that contain the engines, fuel, and most computing systems are underwater, this lessens vulnerability because critical systems are protected by the water itself. The aircraft-style cockpit is outfitted with large windshields fashioned from two inch-thick glass; steering is provided via a throttle and joystick arrangement. The Ghost has achieved speeds of over 30 knots, and is being tested to 50 knots.[2][5][6][4]
It is called the Ghost because it is virtually invisible to sonar and radar detection through its aluminum and stainless steel construction, making it non-magnetic, its hull angles bare a resemblance those of the F-117 Nighthawk. It can perform several types of mission including anti-surface warfare (ASuW), anti-submarine warfare (ASW), and mine countermeasures (MCM): ASuW armament consists of the M197 20mm rotary cannon and launch tubes that expel exhaust downward between the struts of the SWATH hulls, concealing and dissipating the thermal signature of the launch for BGM-176B Griffin missiles and Advanced Precision Kill Weapon System rockets, with an electro-optical/infrared (EO/IR) sensor and radar; an ASW version could be equipped with an EO/IR sensor, radar, sonobuoy launch tubes, a dipping sonar, and four aft-firing torpedo tubes; an MCM version could be equipped with a towing boom to lower and raise two towed mine-hunting sonars, such as the Kline 5000 or Raytheon AN/AQS-20A. The current Ghost costs $10 million per copy, is crewed by 3-5 sailors, has an endurance of 3 days, and can be partially disassembled to fit in a C-17 Globemaster III for transport if needed. There is room for 16 passengers with two 6 in (15 cm)-diameter round windows in the hull. It is designed for fleet protection for navies with few blue-water needs but require a small and affordable craft in large numbers for near-shore maritime border patrol and defense missions.[2][5][6]
See also
References
- 1 2 3 4 5 6 This Stealth Attack Boat May Be Too Innovative for the Pentagon - BusinessWeek.com, 21 August 2014
- ↑ The Navy's New Patrol Boat Wasn't Made by a Long Shot Inventor - BusinessWeek.com, 23 September 2014
- 1 2 3 Shipbuilders Bet on Radical Hull Designs to Defeat Swarming Boat Threat - Nationaldefensemagazine.org, November 2014
- 1 2 3 Firm Offers the Ghost to Navy as a Versatile Combat Platform - Seapowermagazine.org, 28 July 2014
- 1 2 3 Littoral Combat Ship Will Be Modified, If Not Replaced - Nationdefensemagazine.org, August 2014