Hydrofoils... do plans exist.????

[Biofish]

My brother and i were discussing our trip from France to England the other day.. We decided against the Chunnel and went via boat. The trip was about 45 minutes and to my surprise as i looked down the bow, we were on a hydro. The ride was exceptionaly smooth and enjoyable. He then questioned me about the availability of plans for a two ski hydroplane boat in the 20ft. range with a outboard. I told him i had seen smaller "racing" type boats with hydros but never a "cruising" or "ski" boat. Anyone know of any that have been built? I have not checked all the WB plans yet, but i would figure i would have allready heard about it if it existed.

rob

[ 04-11-2002, 10:06 AM: Message edited by: Biofish ]

[Bernadette]

Biofish, we saw hydroplanes at the Sydney Classic and Wooden Boat Festival. If you don't have any luck on your side of the pond perhaps we can help with a contact for the club that was represented at the show?

[Iceboy]

Biofish, I belive that you are looking for hydrofoil plans. Not hydroplane plans. I would suggest a Google search. JimmyM

[Biofish]

Yeah... you are correct.. When i was thinking about smaller hydro's ( which are called hydroplanes) i didn't think of changing the term with larger boats..which i suppose would use the "skis" and would be called hydrofoils. I did a google search and most of my results came back as models... with no plans for boatbuilding in the larger range... wouldn't a cabin cruiser hydrofoil be great for this?... of course the engine would probably be huge and expensive.

Rob

[Ian McColgin]

When I was in college in the '60's one of my engineering profs was developing sail powered hydrofoils. We had a gas. Had one 40' cat with ladder type foils that could really scream.

Yachting caught us up on the lee hull foil, flying the weather hull and all of it's foils. Looking cool.

Second shot has us in the midst of the cartwheel that resulted when the bow foil collapsed. The astrix in the air over the rig is me, violently airborn.

The third shot shows up standing on the inverted wreckage.

There are now a couple of commerciall made little sailing hydrofoils set up to be handled as proas that look like a gas.

For power boats, in smaller boats the foils can be made to work in flat water but the boat itself is too small to get up above waves, so they don't make it as useful cruisers.

In larger sizes, the power inputs to get up are huge and generally need gas turbins coupled with high ram jet drives. Once up, you just want to go fast so the biggest use of foils - economy - doesn't really happen except sorta with the ferrys.

Fully immersed piercer hulls that the boat can get up on are more economical and far easier to engineer.

Bolger and Payson, if memory serves, made a modified foil, it was really a canard, to get sternwheeler to plane. It worked till they hit a tug boat wake and the canard collapsed.

The biggest problem is engineering, just to get the wing to stay with the boat. But when it does fail, there's nothing like a high speed water bounce . . .

In short, yeah, there's plans but none that anyone will sell since there are interesting liability problems. But innovative people who can figure stuff out for themselves can make a homebuilt that at least will keep them tinkering and otherwise not underfoot. . .

[brian.cunningham]

try the The International Hydrofoil Society at http://www.foils.org/

a great source for history and papers on designing a hydrofoil craft.

also the pioneer of the voyaging hydrofoil
http://www.foils.org/dak.htm
http://www.foils.org/willi4.jpg

[Vern D]

When I was a "boot" in the Coast Guard in '77, I spent a brief time in the C.G.Academy Hospital in New London CT. After I had surgery, I was able to walk around the grounds and check things out as I healed. I observed the cadets cruising around in a Hydrofoil. The hull was a 13' boston whaler, the foils were welded Aluminium. The power plant was an outboard, looked like a 40hp or so Johnson or Evinrude, modified in length...like a double long shaft. That modification wouldn't be all that hard. Lengthen the vertical shaft and add another center section from a short shaft engine??? I've often thought it would be a blast to build one, but the thought of flying headlong over the bow cooled my jets.
There is also a foil that one can sit on and get towed by a ski boat. Somehow, you can adjust the angle of the foil to raise out of the water. Never have gotten a good look at one, so I'm not sure how the thing works. Seems simple though.

Would still like to do one.
Good Luck.
Vern and Jake (the wonder dog)

[ 04-11-2002, 10:08 PM: Message edited by: vernd ]

[PaulC]

You could build your own from these plans:

http://www.geocities.com/janmartin_1999/sam.html

[Memphis Mike]

I prefer "Cypress Garden Dog Bones" myself.
Best darned hydrofoil ever made.