Spindrift 2 is transformed for the Jules Verne Trophy

Interview with Antoine Carraz, head of research at Spindrift racing. He outlines the changes made to Spindrift.

Interview with Antoine Carraz, head of research at Spindrift racing. He outlines the changes made to Spindrift. 

What technical tools were used to calculate the potential improvement for a boat like Spindrift 2 and thus to decide which adjustments to make, such as shortening the mast?

By playing with computer software, we realised that we could make the boat lighter by reducing the height of the mast, while improving its performance. To calculate the theoretical speed of a boat, we use a computer-based velocity prediction program (VPP). This enables us to simulate the boat's speed depending on the wind's strength and direction in relation to the boat. But before using this, we carried out aerodynamic and hydrodynamic analyses of the boat with other specific programs that simulate tests on water or in a tunnel.

Have these tools changed much in recent years and particularly since the boat was designed?

Yes, they have developed a lot, especially thanks to improvements in computer performance. Before, we had to do tests in pools or wind tunnels. This was very expensive and complicated to do, whereas now we can get identical results digitally.

In what areas has technology developed most in recent years to support a project like Spindrift racing's Jules Verne Trophy attempt?

In many areas, but particularly the materials used to make the vessel – carbon and titanium – and the sails, which are much lighter and tougher than before.

Better knowledge of composite materials, particularly in view of their use in aeronautics, has enabled the weight of every part of the trimaran to be significantly reduced. Structural calculation software allows us to optimise safety factors and therefore to make the whole boat lighter. The materials are constantly evolving.

Are the gains you hope for in terms of speed and safety measurable and, if so, how precisely?

The speed improvements are first defined theoretically thanks to VPP, so we can make the main technical choices. During navigation, a control unit records all data for the boat, and engineers then analyse this to see the gains and make technical adjustments if need be. The measurement tools are highly sophisticated, giving an error margin of less than 1%.

How will a project like Spindrift racing's Jules Verne Trophy attempt support technological progress and facilitate subsequent innovations for recreational sailing?

Boats like Spindrift 2 are very much tailor-made and some systems will always be for competition only, particularly because they are so complex to use. But many elements, like the sail material, ropes and energy systems, will be used in a few years' time for recreational sailing.