WHY THIS MATTERS IN BRIEF
By reducing the water friction ships and torpedoes can reach speeds that even make even the fastest cars look slow by comparison.
Some boats are fast, especially when they fly like the latest generation of sail boats, and some boats are really fast – fast in a way that makes even the P1 racing boats look tame. And the “Ghost” stealth boat might be the most exciting, and impressive, innovation in marine technology since the submarine. Fast, agile, and mean-looking, this diminutive little vessel could be the answer to blue-water fleet protection and SPECOPS – especially as it has a top speed of 70 knots, or 80mph, or 130kmh.
That is, of course, if the US Navy actually buys it… and this incredible speed is all thanks to its design and super-cavitation technology which blows air across its submerged nacelles to lower water resistance and drag to achieve those speeds. And that’s the same technology that the Russians have used to develop a torpedo with a top speed of over 200mph, and that militaries around the world are eyeing as they try to develop supersonic submarines. But back to the story …
The “Ghost”, or the Juliet Marine Systems Ghost, is a highly advanced reconfigurable SWATH stealth-capable warship currently under development for the US Navy. The vessel’s design enables it to travel over water at a fraction of the friction experienced by conventional vessels.
This provides it with impressive manoeuvrability and speed on the water. Capabilities that would prove essential to countering small, highspeed vessels like motorboats.
The vessel is also said to have a very small radar signature owing to its incorporation of advanced technologies and physical form.
See the ship in action
According to Juliet Marine Systems, the Ghost can be used for a variety of missions including force protection, special operations, and intelligence, surveillance, and reconnaissance roles. It could also be used for civilian duties, including, but not limited to, high-speed maritime ferry or taxi services, offshore oil rig supply, or even as a pleasure craft.
The inspiration for the Ghost came from a perceived need to provide a means of protecting US Navy warships and personnel in both deep and shallow waters following the bombing attack on the guided missile destroyer USS Cole in 2000. The Cole was refuelling at Yemen’s Aden harbour at the time, and during the attack a small motorboat, packed with $500 of explosives was able to penetrate the USS Cole’s defenses and detonate midships.
This caused a gaping 12.2 m (40-foot) wide hole in the USS Cole’s hull, killing 17 sailors and injuring many more. After an FBI investigation, the attack was discovered to have been organised and carried out by terrorists from the Al-Qaeda terrorist network.
The Ghost’s hull is 18.9 m (62-feet) long, and of an angled, faceted design that has more in common with stealth-capable aircraft than waterborne vessels. Empty, she weighs in at 6.4 tonnes and has a range of between 563-805 km (350-500 miles). Her design also makes minimal use of windows, to further reduce the radar signature.
It has an overall stout shape, when viewed in profile, and the forward sections are well-slanted. The bridge of the Ghost has a 5 cm, 2 inch, thick ballistic windscreen behind which her two crew, a pilot and co-pilot, operate the craft.
The Ghost’s most standout feature is its dual-strut super-cavitating pontoons, or nacelles, that are known, technically, as a Small Waterplane-Area Twin-Hull, or SWATH for short. Control at high speed is achieved by using a series of gyro-stabilization and over 20 underwater control surfaces to maximize the craft’s agility.
This is all computer-controlled in much the same way that electronic control systems are used to prevent cars from slipping on the road at high speed. This enables microsecond calculations and corrections to be made without the need for human input.
The vessel is also capable of operating in wave heights of up to 2.4 m, 8 foot.
When traveling at less than 8 knots, the ship sits in the water up to its centerline, with its two 3.7 m, 12 foot, struts submerged, parallel to the water’s surface. As the craft accelerates above 8 knots, the hull can be lifted out of the water by bringing the two struts closer together.
This, along with its super-cavitation technology, which is explained in the video, enables the Ghost to skim over the water’s surface. Her hull is constructed using aluminium and stainless steel, making her particularly lightweight and corrosion-resistant.
The angular shape of the hull is inspired, in part, by stealth capable aircraft like the veteran Lockheed F-117A Nighthawk stealth fighter. This makes the vessel virtually invisible to radar detection.
A central cargo hold can be used to carry either cargo, weapons, or passengers which can be loaded and unloaded using a single hull door.
Propulsion is provided using a pair of 1,342 kW (1,800 horsepower) gas-powered turboshaft engines incorporated at the end of each of the boat’s struts. Future models may replace these engines with a pair of General Electric T700 turboshaft engines.
The location of the boat’s engines, fuel, and most of its computer systems in its nacelles also offer the vessel some added protection, as they are mostly protected by the water around them.
The boat is expected to take on some similar duties to attack helicopters, by intercepting illegal shipments and incoming small attack vessels, once equipped with the right weapons and other technologies required for such roles.
For example, it is envisaged that she could be equipped with 20 mm cannons for anti-surface warfare, or rockets like the BGM-176B Griffin missiles, or Advanced Precision Kill Weapon System rockets. Rocket exhausts could be vented into the water column through the struts, dramatically reducing the vessel’s heat signature in combat, too.
The vessel could also be equipped with a variety of electro-optical sensors, radar, sonobuoy launch tubes, sonar, and fore/aft torpedo tubes. It could also, conceivably, be equipped with a towing boom for mine-hunting sonars using systems like the Raytheon AN./ADQ-20A.