Thursday, February 19, 2009

16-18' "Sit in" High Performance Dingh, - using on deck movable ballast

I have always wanted to sail a boat like a 2.4 Meter but with much higher performance. I suggested a concept years ago and wonder if anyone else has any thoughts on how to make something like this work.

As I envision it the wing+ballast is supported by trapeze wires-side to side movement would not require a whole lot of effort....

Just as a rough illustration here is a picture of a Melges 24 model fitted with a "trapeze power ballast system". The battery was part of the sliding ballast and that could be done on a full size version.

The idea I had was to use a molded "wing" that would have ballast slide inside it to give large RM-similar to a two handed dinghy where one of the crew is on a trapeze. The ballast could be moved by hand, foot power or electrically. The boat might have a small fixed keel. The ends of the "wing" would be slightly larger in section to provide extra buoyancy. Each side of the wing would be supported by a "trapeze" wire making moving the whole wing(and the ballast inside it) fairly easy since it all moves horizontally.

The "wing" on the model is just two carbon tubes that form a track for the ballast to slide on. To me, a molded wing
on the fullsize version would have a number of advantages including lower aerodynamic drag, buoyancy and it could be built with a slight curve.

The idea is to sit in the boat like a 2.4 meter but plane early and fast.

Tuesday, February 10, 2009

photos of the first prototype

You can't keep secrets for long. And before it hits the interweb, here it is ... the first production prototpe of the peoples foiler on its first test sail. With yours truly at the manual controls.

Just after this photo was taken, she got up and foiled for the first time, but the camera ran out of film.

This photo is on another test flight just prior to take off. At this point I was just about to engage the manual controls. It is a shame that the camera went flat just after this photo was taken.

On this photo you can clearly see the bouyancy pods working their magic and allowing a lot more power to be carried than a MOTH.

Saturday, February 7, 2009

Bi-foiler with "Power Foils", idea that MIGHT add more "High" to Performance

One of the great advantages of a boat like the Hobie trifoiler, Rave or Dr. Sams new Osprey is that that dual wands operate independently allowing the boat to develop all its own RM without input from the crew. Hydroptere and every surface piercer I know of develop RM differently by increasing the separation between the center of lift of the main foils and the boat CG as it heels(leeward foil develops an increasing amount of lift). Hydroptere uses movable ballast as well.

I've been toying with the idea of a hybrid: a "bi-foiler" that uses retractablesmall foils in each buoyancy pod-primarily in heavy air upwind. The point would be to increase the RM of the boat boosting upwind speed. The foil would be deployed in such a way as to hold the boat at a designed angle of veal heel along WITH crew participation. A target might be to add 50% to upwind RM and that would require a foil(actually one foil each side-only one used at a time) about half the size of a Moth mainfoil.

Disadvantages include the fact that two foils would be required and the additional weight. The gains could be appreciable, allowing a substantial increase in SA.

In light air the foils are retracted but the boat still has all the extra SA. So the gains would be not only upwind in heavy air but downwind in every condition and upwind and downwind in light air due to the extra power.

Takeoff would be significantly earlier than a "normal" bi-foiler....

Bradfield and Ketterman have already proved that the extra drag of a third foil is more than made up for in moderate to heavy air by the virtually unlimited rm available with their system. I think that it would be ideal to have these "power foils" able to be deployed without an altitude control system-a preset angle of incidence might work.

What do you think?

Monday, February 2, 2009

International 14's

Most people probably know that the 14's are using a rudder foil that supports 25-30% of the sailing weight of the boat. What some people don't know is that the FIRST two person bi-foiler in the history of the world was an International 14 sailed in 1999 within months of John Iletts first sail of his foiling Moth.

Many people may not realize that this first foiling 14 also used MANUAL altitude control using a twist grip tiller operating the flap on the rudder foil.

Another first for David Lugg and Alan Smith who developed this boat.