R Class foiler-the boat has foiled!

R Class foiler-the boat has foiled! Here are some numbers:

Hull weight 63lb(29kg) plus a min. of 20lb(9.1kg) for rig and foils(probably not possible at this weight)=83lb ready to sail(nice if you can do it!)

Sail Area upwind: 140 sq.ft.(13sq.m)

Hull beam at wl(ESTIMATE) 3'(.9m)results in a L/B ratio of 4.33/1

crew ESTIMATE=320lb.(145.5kg)

sailing weight=403lb(183.2kg)

W/SA=2.87

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This ratio would allow the boat to foil upwind but in marginal conditions /light air it probably would foil after the Moth,RS600FF,M4 and Foiling 18. To bring it to the 2.558 number of the Moth either SA would have to be increased to 158sq.ft(14.7 sq.m) or the weight would have to be reduced to 358lb.(162.7kg)-leaving a 275lb.(125kg) crew.

A probable negative factor that would suggest lowering the W/SA number further is the sloop rig
Another negative factor suggesting a lowering of the number even further is the relatively wide hull at the waterline(compared to the ideal).

This boat could foil well downwind even in light air-in heavy air downwind it would need a smaller much flatter spin.

It could foil upwind in all conditions a Moth with a 180lb crew could as is. But light air /marginal conditions performance would be improved if the negative factors above are addressed by less weight and/or more upwind SA.

If only it had pods, a sliding seat, manual control and dual midship wands.

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crime against humanity

There is a rumor on the blogosphere that a 16' foiler, described as a "Monster Moth" by Phil S. exists and I don't have any details.



It is a crime against humanity to keep the fantastic development work he is doing to himself. Please-for the sake of all thats good and holy-please can someone ante up with the story and ideas! The only other alternative will be to send the foil police to deal with the situation.

Ok, perhaps I'm being too "demanding"-yeah, thats it. So how about posting the pictures and info one week from tomorrow? Is that ok? Thanks.

Kiting is kiting-sailing is not kiting-kiting is not sailing.

The magical 50 knots barrier fell as the outright sailing speed record fell twice in 24 hours at the Lüderitz Speed Challenge over the weekend, with French kitesurfer Alexandre CAIZERGUES recording the fastest speed of all at 50.57 knots, subject to ratification by the World Sailing Speed Record Council (WSSRC). - sailing.org

If a kiteboard is a boat then so is a waterski-absolutely ridiculous! A "boat" has to support it's load with buoyant lift at rest. But nothing can take away the kite guys accomplishment-so far(if ratified) it appears they hit 50 first-congratulations. But it is NOT a sailboat record-it is a kiteboard record.
And a kite is not a SAIL-it is a kite! In the same way an airplane is not a helicopter!

A kite can be moved independently of the"craft" it is powering to increase apparent wind enhancing power. A kite produces much more vertical lift than a sail. There is no "put-down" of kites or kiteboards in what I'm saying: it is a recognition that these two forms of harnessing wind power ARE different and should not be confused with each other in my humble opinion.

A kiteboard-carries one person only when moving -requires wind close to or higher than its top speed.
hydroptere-carries 11,000 lb of carbon + 8 people at 52knots in wind significantly less than its top speed.And it carries the same load at zero knots!

So I sent of an email and got this interesting reply from John Reed:
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Dear Doug,

The categories which can make attempts on sailing speed records are decided
by ISAF.The WSSR has no responsibility to decide whether kites can claim
the outright record.

Regards,

John Reed
Secretary to the WSSR Council
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Guess I have to raise hell with ISAF. Right.... time for another email.

"I'm curious why ISAF considers kiteboarding to be "sailing" ? I think what the kiteboarders have done is phenominal but how can it be placed in the same category as a sailboat speed record?
No way is a kite a "sail"; no way is a kiteboard a boat.
So what is the rationale?
Thanks!
Sail Fast,Doug Lord"

If you have a board that is not a boat and a kite that is not a sail and yet you want to be able to claim a "sailing" speed record?! Listen, what kites have done is tremendous-but they are not "sailboats" and do not deserve a "sailing" record!!

Kiting is kiting-sailing is not kiting-kiting is not sailing. End of message.

They REALLY don't know what they're talking about!!

The Bradfield planing wand has been around 8 years longer than the bow wand( which was copied from the Bradfield system) and can be adjustable-with the ratio of wand movement to flap movement completely adjustable with variations of the system including a wand clutch, adjustable bungee tension AND adjustable bungee responce.

Also, "cam" like adjustment set ups that allow variable RATES of flap movement for a given wand movement-and more-all developed by the Bradfield team years ago. And things like simultaneous fore and aft flap movement with 100% mixing adjustability, manual/wand instant switchback, manual only fore and aft systems,athwhartship angled midship wand pivot axis are being developed now(among other very interesting technical tidbits you will hear about in a while).

1) from seahugger mode to flap neutral the wand tip moves 62.5% of its max travel
2) from flap neutral to max flap up the wand moves 37.5% of its max travel

That gives much finer flap control from 10 degress flap down to 2.5 degrees flap up with much quicker reaction above 2.5 degrees up-something that is required on the Rave since the foil pulls down as well as up and is symetrical set with a 2.5 degree positive angle of incidence to the static(design) waterline.

So, you see, it pays to think(or at least check out the facts rather than guess) before you speak........

And,oh yes: a high priority on jumping with 100% successful re-entry.

the ultimate kickass 2 person boat

Many have tried and are trying to convert existing two person dinghies to foilers but have you ever wondered what a two person foiler designed from scratch as a replacement for,say, the 49er might look like?

Here ya go:
LOA= 18'(5.49m)-no gantry
Hull Beam@ wl=1.6'(.49m)
L/B=11.25/1
Beam OA= 6'(1.8m-includes very small buoyancy pods)
Allup boat weight=154lb(70kg)
Nominal Crew Weight=320lb(145.5kg)(twin trapezes)
Sailing weight=474lb(215.5kg)
Sail Area=185 sq.ft(17.2sq.m)(main only-reefable rig)
W/SA=2.56(equal to or better than Moth,same vicinity as M4,I14(Lugg),Foiling 18)
SCP/total weight= 45%
SA/ws hullborne and foil borne greater than or equal to Moth
Retractable foils

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Approx 50% of the hull/deck area of a 49er-less material-less cost
Approx 122lb(55.5 kg) less weight than 49er-less material-less cost
Approx. 44sq.ft less SA than 49er upwind. No Spin(light air code zero?)

---- With Manual controls and a retractable, sel-frighting K-Bulb, This boat could be MUCH faster than a 49er if carefully designed and engineered. And cost less.

The case for the midship wand

A midships wand is definitely better than a bow wand in flat water because it can be significantly lighter if the Bradfield system is followed.

In chop with a forward wand there is a delay between wand activation and the foil being where the wand was when activated of around a quarter second at upwind speeds in addition to wand response(bungy) lag. This intereferes with the ability of the forward wand to average it's inputs.



The midship wand has only bungy lag and therefore has a quicker and more reliable response to begining to average wand input resulting in a steady altitude and less of a likelyhood of dramatic flyouts from waves. This can be seen on the Rave video in the rapid movement of the wand which is noticeably more than on a Moth in similar conditions as best I can tell.

This is very important: Because the forward wand's center of lift(drag) is significantly displaced from the boats center of lift when flying there is another element added to the forward wand response and that is pitch coupling. This can add or subtract from the wands response-when it adds the boat flys out of a wave. That happens much less frequently with fewer consequences on a boat equipped with a midship wand where there is NO PITCH COUPLING whatsoever.

So the combination of the midship wand developing an averaging response quicker than does a forward wand and the pitch coupling common only with a forward wand explains very well the observed responses of both boats and seems to suggest that a well designed planing wand mounted midships might be an improvement on a monofoiler in every conditon.

At 22 knots there is no 'anticipatory' or 'reactionary' wand-just an averaging system with fairly rapid wand movement on a Bradfield system.

The bow wand would be subject to unanticipated moves due to pitch coupling as mentioned earlier. I'd bet that the midship wand would be -by far-best in these conditions.

The question about foil spray is one of the best yet. On the Bradfield system the wand is next to- not in line with -the foil and is not affected by the foil "spray" in any way. But in applying the Bradfield system to a bi-foiler the wand will need to be close to the center line and the foil wake and/or spray may or may not have some effect.

The Japanese Mothies are experimenting with an in line trailing wand system similar to the ones used for many years in human powered foilers(very successfuly). That type of wand does not have the power of a Bradfield type and yet has worked very well despite being located behind the vertical fin.I'd imagine that the Bradfield type would work well-I'll know before too long on my boat. It would be interesting to see three equal Moths rigged with the standard ,Bradfield type and Japanese type.

The problem with the bow wand seems to be that it can produce movements of the flap unrelated to the averaging of the wand.Depending on whether it adds to or subtracts from flap movement the average wand movement can result in unpredictable and sudden big movements of the flap.(Probably exacerbated with flexible wands)

This kind of pitch coupling can't occur in the Bradfield system because the wand makes contact with the water at the center of lift of the boat so there is no pitch coupling at all.

Unless the wavelength is so great that the boat contours the averaging occurs when the boat platforms and results in rapid wand movement(several times per second) while the boats altitude remains the same. In wave conditions where the boat is platforming the wand reacts multiple times per second and the forward wand anticipates nothing-in fact there is some reason to believe that in those conditions the separation between the center of lift of the wand and center of lift of the boat is not a positive thing at all-contributing to erratic behaviour. Flexible wands would tend to agravate the problem-both in averaging and with pitch coupling. Depending on whether the wand is a planing wand or not, conditions can make the ride feel like a bumpy road in short steep chop.

One thing all this recent wand study has done is reinforce 100 times over the fact that a manual system that mixes main foil control with rudder foil control will be superior in racing. Wand movement at multiple times per second reduced to virtually no movement! When the wand is averaging it is essentilly creating major changes in the lift coeficient of the foil rapidly and for no net change in altitude. This is a drag producing machine!

Manual control will be fairly hard to learn to race well but the potential savings are much greater that I thought just a few weeks ago.

You can't handle the truth

So every day I have some idiot telling me "pics or it didn't happen" or "you have never foiled". Well enough is enough. Just because I have never been seen foiling doesn't mean I haven't done it and here is the proof.



Why haven't I shown this before? Well the photo is out of focus, and blurry, and who wants to see an out of focus blurry picture?

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So now that people can't call me up on the 100% proven part, what will they say now?