‘Carbon bird’ still pushing the envelope
Posted on 24 February 2009
Written by Jim Flannery
l’Hydroptère hits a 61-knot peak before pitchpoling in speed trial, but setbacks are nothing new
Arguably the fastest sailboat in the world today, the French trifoiler l’Hydroptère hit 61 knots in speed trials, but the exhilaration of acceleration to more than 70 mph was short-lived because the 60-footer then pitchpoled.
Dumped overboard in a 45-knot gust, l’Hydroptère’s nine crew were stunned but not badly hurt — just sore, cut and bruised — in a tumultuous finale to a Dec. 21 speed run in a squall off Marseilles on France’s south coast.
l’Hydroptère lost its mast, rigging and some sophisticated electronics that monitor stresses and strains and help keep this temperamental beast from flipping at highway speeds.
Far from being discouraged, l’Hydroptère skipper Alain Thébault says he was elated at the speeds his vessel posted, describing them as “splendid feats. “With new records ratified by the WSSRC [World Speed Sailing Record Council] and speed peaks at more than 100 km per hour [54 knots], l’Hydroptère has greatly demonstrated her reliability and her performance potential,” he said in a statement, after towing her in to dry dock at Foselev Marine at La Seyne sur Mer.
Arriving at their speed base at Port Saint Louis du Rhône in October, the team trained while they waited for the Mistral — a cold, strong wind that blows off the south coast of France — to kick in and deliver conditions helpful to breaking some records. On Oct. 29, l’Hydroptère broke its own all-category nautical-mile record with an average speed of 43.09 knots (49.58 mph); then on Nov. 13 the trifoiler posted a speed of 46.88 knots (53.94 mph) across 500 meters, breaking the 500-meter record for craft with more than 300 square feet of sail. In December, Thébault set his sights on the outright sailing speed record of 50.57 knots (58.2 mph) set by French kitesurfer Alex Caizergues Oct. 4 off Namibia.
Winds on Dec. 21 were 35-38 knots with gusts of more than 45, and the waters off Napoleon Beach at Port Saint Louis du Rhône were a lot more roiled than they were for speed runs the week before, which made the sailing more difficult and more dangerous.
An unusually strong squall blew through, pushing the experimental sailing hydrofoil into overdrive and into a rapid acceleration to 61 knots. “The gust of wind was very violent,” Thébault said in a brief statement. “l’Hydroptère was in full acceleration at over 61 knots when she stopped and capsized.”
A chase boat plucked the stunned crew out of the water, but wind and seas were too difficult to tow the boat into port until the next day, when a crew towed it — upside down — from off Napoleon Beach to Port de Bouc a few miles away. There, a crane righted the boat so it could be towed on its hull to dry dock. l’Hydroptère’s crew broke for Christmas and New Year’s, but Thébault promised in a holiday message they would be back on the water in 2009.
Thébault , 46, is accustomed to the capsizes and dismastings and other setbacks that are part of the teething of an experimental craft. French sailing icon Eric Tabarly began experimenting with foil catamaran models in 1976 with help from aeronautical engineer Alain de Bergh and Francois Le- faudeux, an engineer with the French Navy Shipyards (DCN). In 1985, Tabarly passed the baton on to Thébault, who assembled a multidisciplinary team of engineers and negotiated partnerships with the European Aeronautic and Defense Company, builder of the Airbus; shipbuilder Alstom and its Chantiers d’Atlantique shipyard; and France’s National Center for Space Research to carry the project forward. The team developed two 1/15th scale models in 1987, and two years later tested a 20-foot model that carried a pilot.
In 1991, Thébault reported that the 20-footer was “unstable in roll, zigzagging, pitching, nothing works.” With ongoing backing from Tabarly, the team continued to test the model on the water and in tanks and wind tunnels, modifying it along the way. They launched the first full-scale prototype in 1994. It reached 39.7 knots on its first sail, but in 1995, during a run between Lorient and Belle Isle, France, the leeward crossbeam broke. In 1998, a metal fitting holding the foil to the beam snapped, causing the starboard foil to fall off and sending the design team back to the drawing boards again. In 2002, after 10 English Channel crossings, Thébault thought l’Hydroptère was ready to race and joined Tracy Edwards’ Maiden II in challenging the Round Britain and Ireland speed record, but again disaster struck. The windward beam broke. Then in summer 2005, l’Hydroptère’s port-side foil and crossbeam were damaged in a collision with a giant sea turtle at the start of an east-west trans-Atlantic record attempt.
Thébault says the challenge of l’Hydroptère has been to build a light boat (it weighs in at 6.5 tons) that can withstand heavy loads. Fifty-four sensors measure loads, stress, pressure, rotation and acceleration, and report to a computer, which sounds an alarm when any of these values become too high.
Information gathered from these sensors is stored and compared to the estimates of the Hydrop6, a 3-D flight simulator that helps l’Hydroptère engineers predict the boat’s theoretical behavior. The “carbon bird” went into a shipyard in October 2007 for modification for pure speed so it could challenge the 50-knot sailing speed barrier, equivalent to the aeronautical sound barrier.
The current version of l’Hydroptère rides on two 20-foot foils that are canted in toward the pod and attached to tough carbon-and-titanium crossbeams, which are in turn equipped with “shock absorbers” — nitrogen-filled pistons that cushion the vessel and keep the load on its foils under 28 tons. The pistons are similar to those used to reduce load on the Airbus A340’s articulating wing.
Designed to “fly” across oceans seven to 10 feet above the water with only its foils and an aft fin in the water, the racer is in some ways a cross between a boat and a plane. The boat begins to lift out of the water at 10 to 12 knots. The pilot then “flies” it with a joy stick with the aid of a navigation unit that gives the speed, angle of sail, real and apparent wind direction and GPS position of the boat, and an inertial unit that measure the boat’s roll, pitch, surge, yaw and speed with great precision.
Thébault is working on two new l’Hydroptères — l’Hydroptère.ch, which will be a research and technology platform, and l’Hydroptère maxi, a 100-footer that Thébault hopes will break round-the-world and ocean racing speed records. Both of these projects have been undertaken in cooperation with the Swiss banking house Messieurs Lombard, Odier, Darier, Hentsch & Cie; its charitable foundation, The 1796 Foundation; and the Swiss Federal Institute of Technology.
The race to break the 50-knot barrier has been intense. Paul Larson, a 38-year-old Australian, pushed his SailRocket — a 30-foot needle hull with a single nearly 25-foot cross beam with a sail on it — to 52 knots (59.8 mph) in a 25-knot wind Dec. 4 off Namibia before wiping out. The boat lifted off the water and started to fly, then flipped over. “I smacked down hard,” Larson reported. “Like someone big had full palm-slapped my helmet with all their might. I was out of that boat in an instant. I was a bit beat up and bruised ... but alright.”
Larson holds the 500-meter record of 47.36 knots (54.5 mph) for craft with 150 to 235 square feet of sail.
For information: www.hydroptere.com/_en
This article originally appeared in the March 2009 issue.