Two remarkable kiteboats aim to break the world sailing speed record
In 2012, the race to create the fastest sailboat (or the fastest sailing boat) was on. In the end, Vestas Sailrocket II, an inclined rig hydrofoil designed in Great Britain, set the new sailing speed record with such a big leap that the competition cooled down for a few years.
Now, a Swiss team and a French team (SP80 and Syroco) hope to set a new world sailing speed record and become the fastest sailboat in the world.
The competitions will take place in 2022. Both teams believe they can break previous records with their remarkable kiteboats – targeting top speeds of 80 knots (92 mph / 148 km / h). If this speed is reached, it will be really very impressive.
The current world sailing speed record was set by an Australian named Paul Larsen, who recorded an outrageous speed of 65.37 knots (75.23 mph / 121.06 km / h) aboard the Vestas Sailrocket II. The video below shows the exciting record race.
However, Larsen used a sail on a mast, and these two teams use kites instead. The teams are convinced that kites are better than sails because when they generate a lot of power from a sail connected to a mast attached to the hull of a boat, the boat can tip over. The higher the power, the better the chances of throwing. This means that even a massive catamaran design can tip over.
In addition, the kites are much more difficult to control, a key challenge for both competitors. But, on the bright side, body roll can be taken out of the equation entirely, allowing kiteboats to harness a lot more power. Here are the competing models:
Unlike many fast sailboats which “fly” out of the water on hydrofoils, the SP80 boat from the Swiss University of EPFL stays in contact with the water. Here are two reasons for this:
- First of all, the team will bring it to dangerously high speeds, where flipping is possible if the wind passes underneath and lifts the front.
- Second, the phenomenon of cavitation – water turning into vapor as it passes rapidly over the foils – creates so much drag and instability that hydrofoil boats are relatively limited to around 100 km / h (62 mph).
It will therefore be an 8 m (26.2 ft) long trimaran, in the shape of a futuristic high-speed VTOL plane, with its two stabilizers giving it a “wingspan” of 6 m (19.7 ft ) for stability.
The large kite of the SP80 is attached to the back of the boat, and there is a curved sheet embedded in the water to balance the high power generated by the kite. For this, the team used a triangular form of “vent” designed to dig an air pocket in the water behind it as it glides through the sea at high speed, thus eliminating the instability of cavitation caused by a regular leaf shape.
These will perform poorly at slower speeds, but have proven to be excellent in high speed motor boats capable of running up to 350 km / h (217 mph). Unlike ordinary foils, they do not impose any theoretical speed limit on the ship. To get the SP80 up and running, the team could launch the kite from a motorboat or a floating platform.
The EPFL team explains the SP80 in the video below.
French Syroco’s Speedcraft is completely different. It is a “weightless boat” that looks like a harpoon fish flying over water. One side of this spear is a thin wing leading to a submerged hydrofoil and the other, just in front, are the ropes leading to the kite. The hydrofoil performs steering tasks and opposes the pull of the kite, standing in the water.
Although the design looks simple, it does have its challenges. For example, as speed increases the hydrofoil will pull strongly against the kite, creating high pressure on one side of the foil and low pressure on the other. When the pressure becomes low enough, the water around it will vaporize, causing the phenomenon of cavitation – the speed limiter on all previous hydrofoils.
Surprisingly, Syroco is counting on it. “We won’t even try to avoid cavitation. Instead, we’ll work to make it stable. We have to achieve a super cavitation regime, ”the team explained. The idea is to produce a similar pressure field near the surface of the foil, which will form a stable vapor pocket that will not close and create vibrations and shocks only well behind the foil.
To achieve this, the team turned to numerical simulations of fluid dynamics. They took a standard cavitation sheet designed by NASA in the 1950s and modified it into 400 different designs. Each was then subjected to approximately nine hours of simulations on a single HPC system with 9,216 processing cores. The result was a design that the team are confident will perform 50% better than the original. From there, the team aims to optimize the geometry to improve performance by an additional 50%.
The Syroco team describes the Speedcraft in the video below.
Prepare for the challenge
Both teams have completed their prototypes and have already performed tests on the water. They are currently building and perfecting their final boats. The two plan to break the world sailing speed record in 2022 – but Syroco is aiming for the middle of the year, while the SP80 team is aiming for the end of the year.
Both designs are impressive, very innovative, with excellent crews and substantial resources backing them. It’s very exciting ! Who do you think will win?
If you’re interested in hydrofoils, you might want to watch high-speed hydrofoil racers compete in the first E1 series, scheduled for 2023. The E1 is like Formula E, but with boats, and it’s described as an electrified version of the F1H20 racing series motorboat.