SolidWorks image of SWIFTWOOD

[brian.cunningham]

What I've been up to.
http://members.aol.com/swiftwood/swiftwood.jpg

If the pics doesn't work, just follow the link in my signature.

I'll post more pics as work progresses.

BTW
Merry Christmas

[michigangeorge]

What a great name Brian!

[JimD]

Somehow I didn't realize it was going to be a schooner :eek: How are you going to manage all that sail from a kayak cockpit?

[Paul Pless]

Jim, and to think that sketch doesn't even show the gollywobbler!:D

[brian.cunningham]

What a great name Brian!

Thanks :)

You can single hand a schooner, quite a few forum members take their big schooners out single handed. You just need to run all the lines to the cockpit.

Here's a page on Bolger Single Handed Schooner
http://duckworksmagazine.com/04/s/projects/schooner/index.htm
http://duckworksmagazine.com/04/s/projects/schooner/boat24.jpg
though you may want to run multi-colored lines
http://duckworksmagazine.com/04/s/projects/schooner/boat5.jpg

What's really going to complicate it, is that I'll also have to hike out whenever all the canvas is up! ( the nets are not show ), and being able to put it together and take it apart.

If I move the middle beam forward, or just run two beams, I can have a 'dashboard' to run everything from.

[Milo Christensen]

Brian: It's good to see you back.

[Stiletto]

Seconded.

[brian.cunningham]

Again, thanks.

Some updated pics.

I'm using 3 foils and 3 rudders. Why so many? When healed, the kayak will be just kissing the water. They're also angled. This way they provide lift just like a hydrofoil. If I can get going fast enough, then that's just what I'll have. :)

You can see I also changed the central aka (crossbeam). I'm hoping this will keep the spray out of the cockpit. Though when all the canvas is up, I'll actually be hiked out to where the V is, 6ft out and 3ft above the waves. I'll really only use the cockpit when paddling.

Some stress analysis pictures
http://i242.photobucket.com/albums/ff87/swiftwood/aka_V_monocoque_lip_2.jpg

COE for the sails
http://i242.photobucket.com/albums/ff87/swiftwood/sail_COE.jpg

[ewan]

hi, i discovered the fulmar 19 the other day and then the windrider rave and they brought to mind your project. i am quite intrigued especially if i can base the central piece around a functional double kayak.
i am wondering how you design the foils, (the rave has t-shapes like a hydrfoil moth, yours are angled like the l’Hydroptère) and will they need a specific speed to raise you up.
lastly, is there a site that goes into multi hulls and foils along the lines of your project that you can recommend perusing.
regards ewan

btw; i don't mean to suggest that i was not impressed by your design until after i saw the others.

[Keith Wilson]

The tiller linkage is going to be interesting, since the axes are in different planes, and getting the proper angles on all three (or maybe only two out of three at any one time?) seems like it would be important. Cables in housings (like bicycle brake and shift cables) perhaps? You'll have to deal with lubrication and corrosion, but that's manageable. Will you be able to retract the foils for shallow water? OTOH, if it works as planned, you'll be going fast enough that you should probably stay a LONG way away from shallow water. :D

Why the third (aft) crossmember? To give you someplace solid to mount the rudders? Sheet forces? At first glance, the beams look larger than they need to be, but maybe not. Is there a functional reason for the very high arch, or is that for looks?

I presume you've calculated the displacement of the outer hulls and are sure one of them will hold the whole thing up?

This looks like a really fun project.

[P.I. Stazzer-Newt]

If you really want it up on foils, then seek out and read "Icarus The Boat That Flies" by James Grogono - it contains what is probably the most complete and accessible account of the early days of sailing foilers.

What boke and why, what was tried but failed, which others worked and which did not - all worthwhile stuff.

[brian.cunningham]

I've updated the design after feedback in another thread.
How wide a paddle slot in the aka nets? (http://www.woodenboatvb.com/vbulletin/upload/showthread.php?p=1483689)
Project has grown just a little from my 1st design.

This shows the original batwing sail rigged design with sliding akas (crossbeams), alongside the current gaff rigged design.

http://i242.photobucket.com/albums/ff87/swiftwood/side_by_side.jpg

The 3rd beam was to 1) help take the loads 2) give me something to hike out on. Since I've found some lightweight netting, I'm trying to do it with just 2, since it will help me save some weight.

Most of the information I have on hydrofoils came from the International Hydrofoil Society
http://www.foils.org/
There's several ways to set them up. The Rave & l’Hydroptère use active foils, you can also use self stabilizing ladder foils.

Swiftwood is really a foil stabilized boat rather than a true hydrofoil.
Take a look at the Open60's and you'll see what I mean. They use sickle shaped foils that retract like leeboards. But, I need to be able to run in the shallows, or more important for me, where there's lots of lobster pot lines! So mine are more like leeboards.
http://www.sailingscuttlebutt.com/photos/06/gitana/5.jpg

Some more good pics are here http://www.thetransat.com/
I saw them up close when they finished in Boston, the variety of steering mechanisms was really interesting!

Despite the angle in the rudders, they'll all share the pivot about the verticle axis. Otherwise, as ewan pointed out, I'd be changing the angle of attack as I steered.

As with the Open60's, the beam also matches the length.

The curve in the beams is for wave clearance.
http://www.thetransat.com/dbimages/600x400/Foncia_finish_2536_BS.jpg
http://www.holopunicanoes.com/tahiti2005/images/3steerH5.jpg

Right now wieght is a driving force behind the design. I've got 620lbs displacement in the amas(floats) right now, I may wind up raising their decks to get more, but I'm trying to avoid that. Most of the Open60's run about 200% displacement, I'm pushing 100%. I could easily do it with carbon fiber crossbeams, but I'm trying to stick with wood. I want to see those curved beams all varnished. :)

[Keith Wilson]

Despite the angle in the rudders, they'll all share the pivot about the vertical axis. Otherwise, as Ewan pointed out, I'd be changing the angle of attack as I steered.If the angled outer rudders pivot about a vertical axis (vertical to the world - parallel to the masts) the tips will move fore and aft quite a lot as you steer. Only one of the outer rudders will be in the water at speed, right? That means the force of the water on the rudder will tend to push it backward - might put a lot of force into the steering linkage? You could model the pivot axes in SolidWorks easily enough, and wiggle the rudders back and forth to see what happens. It looks like the force of water on the rudder will make her want to bear off if the pivot axis is vertical and on the centerline of the outer hull. OTOH, maybe I'm misunderstanding completely - will the rudder pivot axis be in the plane of the rudder?

My first impression would be that the rudders need to be straight up and down (or maybe even angled out on the outer hulls), but maybe I'm missing something.

[jlapratt]

Brian,

Are you using the finite element analysis of SolidWorks to develop your scantlings? It seems that this would be a much more accurate process than older calculations and rule-of-thumb guesstimates.

Jeff

[brian.cunningham]

You raise a good point. If the pivot axis is all the way outboard, then yes, the rudders won't be self-centering or balanced. Which would explain why the Open60's have verticle rudders. But I want the balance of having a foil at the back.

The other option would be to drop a separate steering rudder, that could also act as a brace, but that would also add drag.

[P.I. Stazzer-Newt]

Right now wieght is a driving force behind the design. I've got 620lbs displacement in the amas(floats) right now, I may wind up raising their decks to get more, but I'm trying to avoid that. Most of the Open60's run about 200% displacement, I'm pushing 100%. I could easily do it with carbon fiber crossbeams, but I'm trying to stick with wood. I want to see those curved beams all varnished.

Are you saying that the boat has a Mass/Weight of 620 lbs?

With or without crew?

I have tried paddling a 1000 lb boat, using a canoe paddle, this can rapidly lead to a complete sense of humour failure.

[Keith Wilson]

The rudder can't really be a foil - at least not one that supports a significant amount of the weight of the vessel - without transferring that load through the steering linkage into the tiller. Visualize a force on the centroid of the rudder pushing sideways, equal to the lift generated by the foil and you'll see what I mean.

[P.I. Stazzer-Newt]

The rudder can't really be a foil - at least not one that supports a significant amount of the weight of the vessel - without transferring that load through the steering linkage into the tiller. Visualize a force on the centroid of the rudder pushing sideways, equal to the lift generated by the foil and you'll see what I mean.

It can, and commonly has been, in almost everything built from 1972 onwards. The classic approach is to use an Inverted "T" foil. - See Philfly, Icarus, Seafly and countless foiler moths.

The thing I'd most like to see is a full analysis of the "Monitor" data.

[Keith Wilson]

Ah, of course; you can tell I'm not very familiar with what's been done and am trying to work from first principles. Let me revise to: The outer rudders as shown above can't be foils without putting the lifting load into the steering. In general you want to avoid this - as one does with a T-shaped rudder, where the lifting force is taken by the rudder pivot mechanism, and is separate from the steering.

[brian.cunningham]

Are you saying that the boat has a Mass/Weight of 620 lbs?

With or without crew?

With crew, me, 420lbs for the boat, 200lbs for me, or 400lbs for the boat and 220 for me. Depending on how many pizzas I've eaten. :D

Monitor's rudders as foils, 3 post setup, mine is a 4 poster.
http://www.foils.org/monitor4s.jpg
more on monitor
http://www.foils.org/monitor.htm
This one has a video
http://home.worldonline.nl/~hbsmits/monitor1.htm
The ladder foils are self-stabilizing at the cost of drag.

I'm leary of the 3 poster setup. If the boat heals enough, either the central foil will come out of the water, or the boat will pivot and on diagonal axis though the leeward foil and the rudder.

Also with no floats, there's no righting moment until the boat is moving. And gusts would be an issue.

[P.I. Stazzer-Newt]

The two foils illustrated at the rear of the outriggers - are the sort of mistake that vanished from aircraft design sometime before 1910 - since then you almost always find a pair of load bearing wings (or vertically stacked set in the case of bi-planes or tri-planes) and a controlling tail assembly.

Icarus 2 had a "flying tail" rudder with up/down and left/right.

Monitor derived the torque/righting force from incidence control of the main foil sets - mediated by tension in the shrouds - clever.

[brian.cunningham]

Except for the fact that this is a boat that heals in water and not an airplane. All hyrofoils have a load bearing rudder. Most of the modern ones are active t-foils as pointed out.

What happens when the boat heals enough to pull the central rudder out of the water?

What I'm hoping to do is get it balanced. And then use the split sailing rig to steer with the sails.

[P.I. Stazzer-Newt]

...

What happens when the boat heals enough to pull the central rudder out of the water?

....

With an inverted T this simply does not happen - as the stern starts to lift, the angle of attack of the lower portion of the T - goes negative - and rise is contained.

[brian.cunningham]

Ah, negative lift. I thought that's what they were doing.
The ladder type foils can't do that, so you need to hike out.
http://www.foils.org/gallery/williwaw.jpg

Sounds like that's what I should shoot for. That way I can avoid hiking out.
l’Hydroptère uses a computer feedback loop.
Rave uses float levels.

[brian.cunningham]

Here's the boat with 3 poster T-foils.

http://members.aol.com/swiftwood/swiftwood.jpg

In this photo you can see another idea I've thought of, but dismissed as a bad idea.
Full airfoil winged akas.
http://i242.photobucket.com/albums/ff87/swiftwood/Swiftwood_wing_T-foil.jpg
This would help in both aero to lift the boat out of the water, and drag.
Why wouldn't I want to use them?

1) weight
but I can conquer that by using fabric, rather like kayaks and bi-planes of old.
2) if the air gets up under it, the boat could do a back flip.
This actually happens on lightweight catamarans with solid fabric decks, rather than nets.
Perhaps active controls on the foils could help control this.

3) Wave collisions
If you look at the previous designs, I'm using a triangular design. The forward aka has the point facing down so any waves are kicked down to cut down on spray. If I invert a true airfoil, then the force would keep the boat in the water and not up on the foils.

[brian.cunningham]

I guess you could call this one "full race mode"
Single full wing akas, fabric covered.
http://i242.photobucket.com/albums/ff87/swiftwood/Swiftwood_fullwing_foil.jpg
Also a change of foils, easier to make kick-up style.
Since this one covers all the structure underneath, I could concentrate on strength to wieght. Making the crossbeams simple I beams.

[brian.cunningham]

Ice case your wonder why I'm doing all this analysis instead of building. I waiting for it to defrost :(

It was 70 last Wed, then it snowed another foot :eek:

[brian.cunningham]

Well the good news is that the boat is finally thawed out.

The bad news is that I'm not in NE at the moment.
Another contract has pulled me accross the country.
But this should get me the $$$ for its completion.

[Daniel Noyes]

Hi Brian
I see your immages with the air foils, have you been to Dave Culp's speed sailing page. I havent' been recently but he has had a number of kite powered boats and plans done by the designer of the trifoiler for a flying boat riding on self adjusting wings instead of foils. I dont' know that it ever sailed. the hull was strip planked, also as an asside i believe yellow pages endevour world speed record holder also has a good amount wood in it's construction.
happy designing
Dan

[brian.cunningham]

Hello,

Consulting jobs have kept me away from home, but more there's been alot of progress this last week!

All three of the 18.5ft by 3 ft beams are coming together.

http://i242.photobucket.com/albums/ff87/swiftwood/08-28-08_1507.jpg
http://i242.photobucket.com/albums/ff87/swiftwood/08-28-08_1807.jpg
http://i242.photobucket.com/albums/ff87/swiftwood/09-02-08_1230.jpg
http://i242.photobucket.com/albums/ff87/swiftwood/09-02-08_1234.jpg
http://i242.photobucket.com/albums/ff87/swiftwood/09-03-08_1619.jpg

[brian.cunningham]

more ...

http://i242.photobucket.com/albums/ff87/swiftwood/09-03-08_1621.jpg
http://i242.photobucket.com/albums/ff87/swiftwood/09-04-08_1259.jpg
http://i242.photobucket.com/albums/ff87/swiftwood/09-04-08_1300.jpg
http://i242.photobucket.com/albums/ff87/swiftwood/09-04-08_1626.jpg
http://i242.photobucket.com/albums/ff87/swiftwood/09-04-08_1706.jpg

More photos are my website:
http://members.aol.com/swiftwood/

Or you can go there directly here:
http://s242.photobucket.com/albums/ff87/swiftwood/

NOTE:
I'll go back later and fix the images links to point to my new site.

[brian.cunningham]

More progress pics

http://i242.photobucket.com/albums/ff87/swiftwood/09-06-08_1518.jpg

http://i242.photobucket.com/albums/ff87/swiftwood/09-06-08_1517.jpg

http://i242.photobucket.com/albums/ff87/swiftwood/09-10-08_1705.jpg

[brian.cunningham]

More progress

My mold seemed to work nicely
http://i242.photobucket.com/albums/ff87/swiftwood/09-15-08_1552.jpg

You never have enough clamps

http://i242.photobucket.com/albums/ff87/swiftwood/09-16-08_1339.jpg

Time to start adding a 3rd dimension
http://i242.photobucket.com/albums/ff87/swiftwood/09-21-08_1545.jpg

http://i242.photobucket.com/albums/ff87/swiftwood/09-23-08_1625.jpg

http://i242.photobucket.com/albums/ff87/swiftwood/09-23-08_1531.jpg

A little "gentle persuasion" being used to align the panels

http://i242.photobucket.com/albums/ff87/swiftwood/09-23-08_1616.jpg

[brian.cunningham]

Well that may be it for a while.

Unfortunately it's getting cold at night.

Too cold for the epoxy to cure.

So unless it warms back up, I may have to put the project to bed until spring :(