On a dry salt lake deep in the remote west Australian outback, a British engineer is preparing for the ride of his life – powered by nothing but the wind.
Richard Jenkins hopes the perfect gust will blow his high-tech buggy to 120mph and into the record books. If he succeeds, it will mark the end of a decade-long quest for the wind-powered landspeed record. It would also convince him that a greater goal is within reach: by swapping the wheels on his craft for ice skates, and windswept Australia for the frozen wilderness of North America, Jenkins wants to go faster still, and become the swiftest naturally propelled human on the planet.
Jenkins is currently making final preparations for the landspeed record bid at Lake Lefroy, 300 miles from Perth. Heavy rain has delayed the effort, but a suitable window of dry and windy weather is expected to open within days.
His craft borrows technology from Formula One racing cars and has more in common with an airplane than a sailing ship. While conventional land yachts have a flexible sail, this vehicle has a rigid vertical wing, which generates thrust in the same way as a conventional aircraft wing produces lift. Combined with its streamlined shape, this allows the craft to travel at up to six times the speed of the wind.
Jenkins said: "Top speed is actually quite scary. The structure and tyre grip is all at the limit, so keeping it in a straight line under full control takes full concentration."
Trials in 2007 had to be aborted because of difficulty harnessing the immense power generated in even light winds. On a Nevada salt lake in 2005, Jenkins lost control at 106mph. "The winds out there are much more unpredictable, and in search of the perfect gust, I sailed into a pretty violent wind and dust storm. I lost steerage and span for about a quarter mile. Stopped when I hit the scrub on the edge of the lake." To achieve the high speeds, the craft does not travel straight downwind but at an angle.
The existing record of 116.7mph was set in 1999 by the American Bob Schumacher in his "Iron Duck" craft. Jenkins says he has already beaten that twice, in practice runs on the 3000m tarmac runway at RAF Waddington in Lincolnshire. His claimed speed of more than 120mph remains unofficial because there were no independent observers. In 2002, Jenkins officially clocked 113mph there, enough to set a new British record. The world record needs to be set on a natural surface, which rules out the UK.
He said: "I have tried every year, with different vehicles in different continents, but it is a tough challenge. The previous record holders spent five years on standby, waiting for the perfect day, and they live there, in the desert. If you have to travel overseas, assemble a team, the vehicle, official observers and a film crew, for ratification purposes as required by the Americans, and the perfect wind, it takes many attempts."
This month's attempt will see Jenkins race the fifth version of his wind-driven vehicle, which was originally called Windjet, but has now been renamed Greenbird, as a nod to Donald Campbell's Bluebird, under a sponsorship deal with UK renewable energy firm Ecotricity. A second seat has been fitted, to allow Dale Vince, Ecotricity's managing director, along for the ride.
Vince said: "Campbell made his record attempts in what historians will look back on as the golden age of fossil fuels. Fast forward 80 years and we are coming to the end of the age of fossil fuels and the dawn of the age of renewables. The Greenbird symbolises this historical watershed." Ecotricity says it will incorporate some of the craft's design into its wind turbines.
The weather at Lake Lefroy is expected to allow record attempts until the middle of next month. On a good day, the team could make up to 40 runs, covering more than 200 miles.
Because the craft is optimised for top speeds, it is relatively slow off the mark and can take 40 seconds to reach 50mph, more than twice as slow as a Robin Reliant. Acceleration beyond that point is more rapid, and it can reach 100mph in just another 10 seconds.
From September, the team's attention will switch to running the craft on ice. Despite wild pre-war claims for speeds as high as 140mph, the generally agreed record for an ice yacht is 80mph.
Jenkins says, in theory, ice should be a lot faster than land, and that 150mph is a reasonable target. "But my experience on land tells me it is all much harder than you think. It is not out of the question that there may be a fundamental reason why it is impossible to travel fast on ice due to the skate-ice interaction at high loads and speeds."
A speed of 150mph would be tantalisingly close to the ultimate speed record for an Earth-bound non-motorised human, which was set at 156mph by the Italian speed skier Simone Origone in 2006. Free from the surly bonds of Earth, the Austrian speed skydiver Alexander Diem reached an eyewatering 313mph during a jump in 2007.