French pedal-powered champion Stéphane Rousson is developing a scull water bike aimed at breaking the 30-year-old world record for the fastest human-powered jet-ski. The first prototype has been built and tested on water.
The long-standing record was set on October 27, 1991 by the Decavitator team at the Massachusetts Institute of Technology, when Mark Drela rode the boat on Boston’s Charles River for a 100-meter run and clocked 18.5 knots best operating speed (21.289 mph).
The idea for the project arose out of a 1988 chat between MIT students Marc Schafer and Bryan Sullivan on a flight back from Greece as part of the Daedalus team, Helped set the world distance record for human flight. Submitted a proposal and received seed funding from MIT.
The original intent was to make riding fun for anyone, but with the announcement of the $25,000 DuPont Award in 1989, the focus changed – and since then, the goal has been to be the fastest man. After several redesigns and performance tweaks, Drela took a recumbent position on the pedals of the final 22 kg (48.5 lb), 6.1 m (20 ft) single propeller hydrofoil design and set the speed record.
In late 1992, the Decavitator team returned to the water again in an unsuccessful attempt to break the 20-knot barrier. However, no one else was able to surpass the top speed of 18.5 knots, and the Dupont Award went to the MIT team. This record has not been broken so far.
Stéphane Rousson I first met him at the Paris Green Air Show in 2010 when he took over Le Bourget Air & Space in his Zeppy airship Exhibition hall of the museum. He also revealed plans for a pedal-powered personal submarine called the Scubster, which went on to win a Bethesda Innovation Award at the 11th International Submarine Competition in 2011, but a crowdfunding attempt was unsuccessful.
Modeled after the propulsion systems used on airships, Rousson chose a two-propeller setup for the Aeroster to improve performance and ultimately speed. In fact, the 3-meter (9.8-foot) diameter propeller in the first prototype was “recycled” from the Zeppy itself. They’re off-center relative to the cockpit to improve airflow, but don’t currently counteract yaw and roll forces, which is on the to-do list along with aerodynamic improvements and mass tweaks.
The frame is made from “a mix of recycled materials from my garage, like old carbon bike frames, multi-ply tubing with carbon socks on them,” and the carbon fiber tubes that support the struts. The Zeppy nacelle was also repurposed for the Aeroster prototype, meaning the pilot assumes an upright position rather than the prone position of MIT’s record-setting hydrofoil.
While this means a high center of gravity and greater drag potential, riders do benefit from improved visibility and more natural balance. Russen told us he hopes to improve the aerodynamics of future prototypes by installing fairings and improving the seats.
Each propeller is independent of the other, but they all spin at the same speed (about 200 revolutions per minute), and the steering is controlled by adjusting the position of one propeller relative to the other. At this point, a chain connects the crank to the propeller drive mechanism, but Russen hopes to switch to a lighter, more durable belt as the project progresses.
The prototype’s frame is attached to 4-meter-long (13-foot) floats, but the goal is to extend it to 6 meters (about 20 feet) and reduce the weight of each float to 3 kilograms (6.6 pounds), plus Install oscillating hydrofoils for better performance.
It’s still early days for the project, but prototypes have already been launched and speed tests will take place in the coming months. Russen still has a lot of work to do before his record-breaking attempt — including losing some weight to pilot the craft himself, or getting a lighter rider aboard — and is currently looking for a funding partner to help Move things forward. Meanwhile, the brief video below shows the man himself testing mobility.
source: Stephen Rousson