Shiver Me Timbers

redneck joe

Supreme Mariner
Joined
Mar 18, 2009
Messages
10,200
From the Economist:




A new type of motorboat takes to the water in disguise

Using foils to travel faster through the water
Print edition | Science and technology
Aug 30th 2018
| PLYMOUTH

A STRANGE craft has been seen darting around Britain’s south coast recently. It has been causing something of a sensation among local seafarers, not least because it is painted in “dazzle” camouflage. This is composed of a series of geometric shapes and was used on vessels in the first world war to make it difficult for an enemy to estimate a ship’s speed and heading. A similar bit of subterfuge was behind the paint scheme on this mystery boat. But rather than dodging artillery shells or torpedoes, this dazzle was designed to make it hard for competitors to see details of the hull.

That is because the vessel was a prototype of a new type of craft called the R35, developed by Princess Yachts, a producer of luxury motor yachts. (Fittingly, the company’s base in Plymouth is near the naval dockyards that did much of the wartime dazzle painting.) But the secrets behind the boat’s hull will be available for all to see when the first production R35 is unveiled at the Cannes boat show, which opens on September 11th. Its most obvious feature is a pair of retractable hydrofoils positioned near the rear of the hull.

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Hydrofoils have long been used on marine craft, such as ferries, to raise the bow so that the boat skims along the surface of the water. This reduces drag which means a boat can travel more quickly, and it smooths out the ride over waves. The most extreme use of the technology occurred in the 2013 America’s Cup yacht race, when the contenders introduced hydrofoils to lift their hulls completely out of the water. These yachts appear to fly above the surface. The R35 takes a different tack, by deploying its foils to keep itself in the water.

The thrill switch

Racing yachts and speedboats are a bit like high-performance cars. Just as a vehicle designed for the racetrack can prove ungainly when driven slowly around town, boats that are honed for speed can be difficult to handle when pottering about, and vice versa. The solution in the automotive world is a system that lets a driver easily adjust the setting of things such as the suspension, throttle and steering response. On a typical high-performance car today you can flick a switch to “comfort” for a trip to the shops or “track” for a blast around the Nürburgring.

A similar switch can be found at the helm of the R35. It provides options for “comfort”, “sports” and one for safer handling in rough seas. Unlike most previous craft using fixed foils, those on the R35 are constantly adjusted. They remain retracted at slow speed, as when berthing in a marina. Out on the ocean, the foils deploy as speed increases. Sensors detect the position of the boat in the water, and a computer calculates 100 times a second the ideal angle at which the foils should be set to lift the bow and reduce drag. The foils also ensure that the stern remains in the optimum position in the water to improve thrust and handling. And, as both the port and the starboard foils can be adjusted independently of each other, the R35 can “lean” into a fast turn, making it highly manoeuvrable at speed.

The use of active foils means it is easier to control the boat and more comfortable for passengers, says Paul MacKenzie, Princess’s director of product development. The company worked on the project with BAR Technologies, a firm set up by Ben Ainslie, who is leading Britain’s attempt to win the America’s Cup, which next takes place in 2021. Pininfarina, an Italian design house famous for supercars, styled the craft. The boat is also unusual because it is made from carbon-fibre composites, which means it is both stronger and 25% lighter than it would have been if constructed from fibreglass, the material mostly used for leisure craft.

All this makes the R35 a bit of a supercar among boats. The foils, plus twin V8 Volvo Penta petrol engines, take the boat to 50 knots (92.6kph). It also comes with a supercar price tag: around $1m, depending on specifications. Kiran Haslam, Princess’s marketing director, says the active foils could be scaled up for use on larger marine craft. But he won’t say more. Watch out for more dazzle off the south coast.
 

robert graham

Admiral
Joined
Apr 16, 2009
Messages
6,908
Heck, old Alexander Graham Bell was one of the fist hydrofoil guys up at Bradours Lake in Nova Scotia....he held the speed record for a while!....
 
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