Wing-Sail
Righto, let’s try and explain a little bit more about this wing so those of you who are interested know what I am referring to.
The wing for VESTAS Sailrocket 2 is comprised of seven separate parts... each with a specific role.
The wing was designed by the Sailrocket team but was largely the responsibility of Chris Hornzee Jones and Wag Feng at AEROTROPE. Chris designed our first wing. It is a much more powerful, efficient and complex beast that the first wing. We also expect it to be much more mildly mannered. Whilst the overall area is 22 sq/meters, the actual driving area is only 18sq/m i.e. only 2 sq/m larger than our first wing. It does however have a number of features which make it much more efficient and more stable. It is thinner than our first wing and has a ‘reflexed’ trailing edge which basically means the trailing edge has a slight return ‘ramp’ right at the back which stops the wing from going into a negative lift mode when it is sheeted out.
The main spar is a tapered, filament wound spar supplied by COMPOTECH. The ribs are carbon on 38kg Styrofoam (basically standard under floor insulation... buy it cheap by the pallet). The leading edges are 80gm glass on 5mm foam core or 200gm SP GURIT carbon at ±45 degrees on a 5mm foam core depending on what section they are. The all up weight is around 65-70kg. The wing is inclined at 30 degrees to match the inclination of the foil it opposes on the other side of the boat.
As we only need to sail in one direction, the wing is asymmetrical. It is set up for a starboard tack to suit Walvis Bay.
Some of the basic criteria for the wing are that it obviously needs to be powerful and efficient enough to drag our boat down the course at speeds over 60 knots. It also needs to be able to fit inside a 40’ shipping container. It needs to be practical to use and handle in a number of situations relating to on the course and simply getting back to the top of the course.
We endeavoured to make a wing that will allow us to tow the whole boat back to the top of the course without having to stop and lower it. This is in an effort to be able to get more runs in quickly and remove a process which is often risky in its own right.