New Speed Sailing Contender

From Multihulls Digest and SA: http://www.wiebel-sailing.com/index.html

[pkoken]

I don't see how this is going to beat a sailboard. You have taken a very pure sailing craft (sailboard) and added lots of complexity to it.

An interesting craft, but I don't think it is going to set records.

[PortTacker]

Over the years every time I've seen a sketch for one of those wings that can be trimmed partly or mostly horizontal, I think "What's gonna keep it from lifting off at speed?"
The video of the crash of Sailrocket was such an event - even my non sailing friends who saw that vid said "Seems like they would have seen that coming."

[robherc]

Seems to me like they'd do better with a higher-area sloop rig...or better yet with a large wing sail. I can see where they're gaining more righting moment by making the sailboard into a tri, but by tripling the planing surface area/friction, you're gonna need a lot more sail too.

[Munter]

Lots of computer generated images doesn't really make a contender. More like a dream for the moment. Lets see a prototype or demonstration boat actually moving before they start making claims like "solved in six dimensions". As you in particular would know Doug its a piece of piss to design something that has record breaking ratios - its something completely different to actually go out and build it and make it work...

[BWD]

Usually at SA they have a saying, "pics or it didn't happen."
>>All the pics are fake. Either fake or doctored.
No numbers, but they solved all the equations... whatever.

If it's real, put up a youtube clip of it keeping up with a moth, cat or board. Or a tleast some gps junk.

[tom28571]

Originally Posted by PortTacker

Over the years every time I've seen a sketch for one of those wings that can be trimmed partly or mostly horizontal, I think "What's gonna keep it from lifting off at speed?"
The video of the crash of Sailrocket was such an event - even my non sailing friends who saw that vid said "Seems like they would have seen that coming."

Well, like it or not, that is the way that the eventual records will be set. Minimizing drag is the sine qua non of speed sailing. Air drag is important but hydro drag is what keeps water sailing way behind ice boats in the speed race. The only way to minimize hydro drag is to take both skin frictional and and induced drag to a minimum. The inclined airfoil is the way to reduce both of these.

Control of lift would be automatic, just like in the foiler Moths, but with spoilers on the sail like in a sailplane. These ideas go back over 40 years, waiting on someone to make it work. Crashes are inevitable if you are going to get to the edge.

I agree that these guys are just making noise right now. A bit overbearing noise at that. Their boat doesn't look like a good one either.

[johnelliott24]

Someone had a sailboard based boat like this design with a suspension a few years ago in England. Does anyone know how that boat did? I only know of it because it was momentarily shown in a video clip. There was also a huge catamaran sailboard effort a few years ago.

I have attached sailboards to a rig a few times with limited success. Right now I am working on foiling but do plan to try replacing the foils with short planing surfaces on a suspension -- sort of light MI with springs.

One problem I see in this design is that there is no ability to adjust lift. A sailboarder can constantly adjust the lift in the rig so that the fin is just about all that is in the water. This boat will have to remain in the water too much to go very fast. I'll be it will be like an I-14 on a reach. Another problem is that this design has no suspension, but maybe it is OK for ultra-flat water. A sailboard rider uses his legs as a suspension whereas this design will plow the boards into each wave.

[Gary Baigent]

Slightly off topic but still relevant - has anyone done research on windage reduction and drag on multihulls comparing the differences between open net or closed trampoline (sail cloth or Lumite type) infill areas between beams. Or going further, the difference between the usual D shaped beams prevalent on most multihulls to tear drop wing shaped beams - with the following void covered areas - which is the better? With multihulls becoming closer to aircraft than to conventional yacht design, these are areas where gains in aerodynamics surely can be made, reduced drag, greater speed. Or maybe we don't have any trampolines at all, like Tabarly's pioneering trimaran Pen Duick 1V, where the crew tight roped across bare alloy tubes or semi circular mainsail tracks.

Gary, you might like to read Bill Beaver's CSY Symposium paper-he goes into aerodynamics quite a bit finding aero drag surprisingly high upwind. It's directly related to Moths but they have tramps and speeds similar to multihulls.