Foiling Keelboat: 30'

[Cheesy]

This, yes that is a foil, yes it was designed years ago, yes it would be self righting

[Doug Lord]

Originally Posted by Cheesy

This, yes that is a foil, yes it was designed years ago, yes it would be self righting

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Is that a rudder foil or main foil? Any more info available on the boat?

[Cheesy]

Yip, its too heavy to foil, the foil is on the rudder, reasonably conservative sail plan, 300kg ish 3 or maybe 4 crew

[Doug Lord]

Originally Posted by Cheesy

Yip, its too heavy to foil, the foil is on the rudder, reasonably conservative sail plan, 300kg ish 3 or maybe 4 crew

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That doesn't seem "too heavy to foil"? How much SA?

[Cheesy]

60m^2
10.6m^2
24.5m^2

the 300kg is without crew

[Cheesy]

Nothing, it was designed to an old rule so it is obsolete before it (the design) was finished, pure vaporware

[Doug Lord]

Here are some elements of Version 4(tentative 6-17-11):

1) 100% self-righting to past 130 degrees. Lead keel ballast is not used for RM when on foils-it is there just to assure self-righting from a capsize or pitchpole. It is a compromise that seems appropriate for an ocean going monofoiler.
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2) Takes off(light) at 10 knots boat speed(6-8 knots windspeed)
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3) Takes off with full water ballast at 11.8 knots boatspeed. Reaches the drag bucket of a 63412 foil at 15 knots with full waterballast.
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4) Sail Area=530 sq.ft. @ 21' / designed for 1.8lb max pressure per sq. ft. before reefing/depowering.
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5) Main foil area 6.39 sq.ft./ 83 sq.ft. SA per sq.ft. main foil.
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6) Designed to sail with veel heel up to 30 degrees.
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7) Retractable rudder lifting foil.
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8) Lifting daggerboard/keel/mainfoil--allows wetted surface reduction as if main foil was retracted off foils/ facilitates trailering.
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9) Folding racks to allow boat to be trailerable.
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10) Potentially the fastest 30' keelboat ever to touch water on and off foils.

[Cheesy]

As many have said before, have a go at sailing something with similar numbers to what you have there.

With that sail area you will need a gorilla to trim, especially with the jib and main linked

Linking the jib and main on this is not a good idea, the main will have to dump a lot of power (the traveler will slightly mitigate this tough) and be constantly trimmed

If there is any significant weight in the bulb (50kg+) you will not be able to lift it under way without damaging the foil, also most places require it to be locked down.

To be even close to successful the rig and sails will have to be very dynamic, think 18ft skiff type of technology.

Im guessing that it will take a long time before it is faster around a course than something like the Shaw 7

[Doug Lord]

Originally Posted by Cheesy

As many have said before, have a go at sailing something with similar numbers to what you have there.

With that sail area you will need a gorilla to trim, especially with the jib and main linked

Linking the jib and main on this is not a good idea, the main will have to dump a lot of power (the traveler will slightly mitigate this tough) and be constantly trimmed

If there is any significant weight in the bulb (50kg+) you will not be able to lift it under way without damaging the foil, also most places require it to be locked down.

To be even close to successful the rig and sails will have to be very dynamic, think 18ft skiff type of technology.

Im guessing that it will take a long time before it is faster around a course than something like the Shaw 7

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Great comments, Cheesy-thanks. The keel would only be lifted in very light air. I think I have addressed keeping the foil ok from other experience.
Lots of new stuff here but I think it can be done-upwind foiling takeoff at 10 knots boat speed etc, etc.
Extremely fast movable ballast, and electronics to help where possible.
Hope it gets built....

[Doug Lord]

A new idea: how about sliding the entire main foil assembly athwartship to increase RM?

click on image:

[Paul B]

Originally Posted by Doug Lord

A new idea: how about sliding the entire main foil assembly athwartship to increase RM?

click on image:

That's funny!

[Doug Lord]

Originally Posted by Paul B

That's funny!

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No, it's a worthwhile suggestion by the owner to find extra RM ,possibly w/o using sliding ballast with less reliance on veel heel. It is being taken seriously but at this point ,as best as I can tell, it doesn't compare with the RM available thru veal heel and the simplicity and self-righting characteristics of Version 4.
However, he is concerned about moving the ballast fast enough and with managing veal heel. He continues to want to use a canting keel and perhaps some amount of water ballast. Also, he says the rule he will race under won't allow a fixed keel with 440lbs(though, he says, it will allow a canting keel with 440lbs) even with the buoyancy designed into racks that are molded as part of the deck. Even though that configuration is 100% self-righting thru 130 degrees.

[Paul B]

Originally Posted by Doug Lord

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No, it's a worthwhile suggestion

If you can't see why that picture (obviously not drawn by you) and your statement are funny then there is no hope for you.

[Doug Lord]

Rough sketch of Foiling Keelboat-:

Elements of this view of the Version 4 Foiling keelboat include:

1) molded rack that includes water tankage with and equal amount of buoyancy. The tankage is roughly located from the forward outboard portion of the rack to the aft side of the third seat.
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2) The helm-and to some extent the whole crew- is protected by a molded shield integral to the rack. The footwell for the helm is open-but screened on the aft side for quick draining. All seats are molded into the top of the rack/ seat. Lifelines surround every place the crew has to work.
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3) The tentative waterline beam for the "ideal" hull is 3'.
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4) The "techno" position(center outboard) is for the crew member that is the navigator, and "technology manager"-he/she controls the movable ballast system, altitude control system, and the master computer/ auto-pilot.
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5) The sheet position is aft and controls the mainsheet/jibsheet(single line with separate slot controls-), and the traveler, vang etc. The outboard traveller ends would be recessed into the molded rack- the center raised a bit.
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6) The cabin is fairly wide and long for such a narrow hull.
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7) The racks are tentatively set up at 20 degrees up which has many benefits including facilitating Veal Heel and increasing RM as the rack is immersed in a knockdown. Though the boat would self-right from at least 130 degrees if it were to turtle it might require the crew to flood a ballast tank. However, because of the dihedral to the racks and buoyancy in them this is probably unlikely.

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click on image for best detail-

[Doug Lord]

Here is a rough sketch of an inshore sailplan:
(more later)

Some features:

1) keel retracts forward of mast-allows large "footprint" for pitch stability. Keel can retract enough to remove the equivalent area of the main foil in very light air.
Similar to Mirabaud and Arc 21("shared lift").
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2) rudder retracts using unique system that gets the t-foil out of the water in very light air.
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3) Squaretop main and jib along with masthead buoyancy for inshore rig.
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4) wide circular traveler(see plan view)


click on image: