Foiling Keelboat: 30'

Foiling Keelboat: 30'---radio controlled Moth with movable ballast

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The sketch shows "windward heel" with the canting keel deployed to weather.
I think the guy was trying to represent veal heel which can only occur when the boat is on foils. The idea of using the whole boat as ballast has merit and that is exactly what happens with veal heal without a system that moves the daggerboard and main foil athwartship. The advantage of veel heal is its simplicity and the fact that it can generate around 40% of the total RM developed by the boat.
The question the owner has is can veal heel be managed using sliding/pumped on- deck water ballast and movable crew or is it impossible to develop a system for moving on-deck ballast that is fast enough?
The proposed system, shown in the sketch, would use a canting keel( 90 degrees one side) plus some sliding/pumped water ballast as well as the sliding
daggerboard/foil.
I'm pretty much convinced that the water ballast system using Hydropteres system with pump backup can allow fast movement of the required water ballast. I think the sliding tank system may still be an option: the tank would slide on a track athwartship. One possibility for testing the system would be to convert a Moth into a radio controlled test boat. It would allow the electronic systems including a prototype autopilot( heel angle, altitude and heading) to be tested extensively. And it would resolve every outstanding question.

Pictures,L to R : 1-Owner sketch of sliding daggerboard/foil system, 2-36" microMOTH experimental RC bi-foiler,
Click on image:

 

Foiling Keelboat: 30'---Out 95

Several years ago a boat was designed called the Out 95. It was designed to eventually use lifting foils and to serve as a prototype for a much larger keelboat foiler. Haven't heard anything for a long time-and given the economic situation that's no surprise....

 

Foiling Keelboat / Out

More on the Out 95 "monomaran"-- see pdf below:

Specifications:
--LOA-9.57m / 31.4'
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--Beam-4.8m / 15.7'
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--Draft-2.13m / 7'
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-- Displacement- 900kg / 1980lb
a. Ballast-360 kg / 792lb
b. Crew 400kg / 880lb
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--Sail Area
a. Main + jib=602 sq'
b. main + jib top=817.76 sq.ft

-click on image-

 

Foiling Keelboat: 30'--- Version 4-Summary

Summary of Version 4 Foiling Keelboat tentative as of 7/15/11

Here are some elements of Version 4:

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. Adds up to 40% of the total righting moment. Manual/ electronic control of sailing angle/ altitude.
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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.

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

1) molded rack that includes water tankage with an 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 molded carbon-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(dihedral) 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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Elements of the Sail plan/ Profile include:

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.(rudder and cassete rotates-top of rudder becomes rudder after rotation)
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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)


Rough Sketches of the Foiling Keelboat:
-click on image-

 

I like the idea and drawings. Looks sleek. I hope it gets built. I just wonder on the feasibility of techno gizmos being able to keep it at the correct angle of veal heal. This seems very difficult to me.

Obviously when a boat that is upright or leaning away from the wind, leans further away from the wind the righting force goes up and the healing force from the sails goes down until it reaches an equilibrium. This is self correcting.

If a boat is already leaning to windward and a gust pushes it away from the wind, the righting force will go down and the healing forces will go up at the same time, accelerating the possible knock down. This sounds difficult to control with tech. But I agree it it will be faster if you can get it to work with gizmos. I would love to see a more detailed plan on how all this will be controlled on a large boat. On a windsurfer or moth its takes a long time to master. On a large boat the difficulty seems almost insurmountable at first but with enough money a lot is possible. I imagine a pump that could move water fast enough would be many horse power and require fuel to run adding a lot of weight. Has this all been calculated?

Good luck with it.

 

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Dennis, thanks for your comments. The design of the movable waterballast system has not been done, however because of work Julian Bethwaite did and that Team Hydroptere did there is high confidence it can be done. Hydroptere uses water ballast that is fed to the port or starboard ama from the leading edge of the rudder under dynamic pressure. In combination with a pump water may be able to be moved fast enough. My original idea, 5 years ago on the 60' Moth was to move water inside a sliding tank-that would definitely work with plenty of speed.
Julian Bethwaite devised a water ballast system for the concept boat below-that also might have used sliding on-deck lead( if Russell Coutts had prevailed).
As to holding Veal Heel electonically I'm convinced that is a piece of cake-electronic stabilization is used on all kinds of boats so the basic stuff is available now. Adapting an existing system shouldn't be too hard. Also, on a boat where a high percentage of wind force on the sails is due to apparent wind(boat speed), the effect of gusts is minimised a bit. Flying it manually is not out of the question.....I hope it gets built too-if not the current owner than another one somewhere else-its just a matter of time. Of course, it would help if the economy would turn around.

Picture-Pterodactyl-Bethwaites on-deck ballast concept boat. I've talked to him about this and he was convinced it would work.
click on image:

 

I imagine the the ballast system on Hydroptere is not working overtime at insanely fast speeds as it would need to for keeping a boat with veal heal upright. Their 3 foil design is inherently stable in that when the boat leans over more the righting force goes up on its own. Therefore I assume the ballast system just adds enough weight to counter the average force of the wind over a longer period of time in minutes not seconds, this does not have to be near instantaneous.

Sheeting angles could be made to react fast enough. Will this alone be good enough to keep it upright? Sliding ballast might be fast enough also. However I think it will be near impossible to use pumped water for instantaneous weight changes to keep the boat upright. A system that could move water fast enough would be far to heavy. Just take a look at what pumps are available and how much water they can flow compared to their weight and energy requirements.

Maybe you could use a lighter water pumping system (feed from dynamic pressure) to fill a movable ballast tank to suit the average conditions, then slide the tank to suit instantaneous conditions?

 

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There are lots of possibilities. One thing though-I think the requirement you mention for "near instantaneous" response is probably not the way it would be.
But designing for that requirement is probably a good idea.

 

Something needs to happen fairly quickly should the wind drop for a few seconds (which it does)

 

The design could work Doug, but it needs to be detuned a little so the movable ballast is not so large in volume and weight and the high sail area reduced - because it is pretty close to the edge design and shifting that ballast quickly would be very tricky, difficult to move fast, even if setup on rails across the widest beam of the hull. Dennis is absolutely right; you can't compare the ballast of spread out and stable? Hydroptere to your 30 foot ballasted Veal Heel mono. Perhaps if you had a powerful motor you would be able to shift ballast fast enough to not tip in to windward during a wind lull, or get knocked over to leeward in a hard blow.
Out95, Gordon Trower's Warbird and Mach 1 and Jim Young's Rocket Extreme, are previous designs, although not foilers, not far off your concept and they use movable intelligent ballast for power, actually the Flying 18's have been doing this sort of thing for many years; they even Veal heel before the term was invented.
Trower's Mach 1 and Warbird.

 

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Thanks ,Gary-only one bit of nitpicking: veal heel is only possible on a full flying foiler and ,as you pointed out those boats are not foilers.

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Gary, the sail area for version 4 is 530 sq.ft of upwind sail area. However, the Out 95 carries 602 sq.ft. of working upwind sail area and more for light air upwind. My SA is easily carried in 1.8-2lb per sq' pressure-not sure about the OUT95-I don't think it even has movable ballast other than the crew. The CE on my boat is substantially lower than that of the OUT 95 and probably has the capability of carrying max SA in significantly higher pressure than could the OUT 95.

 

This is just a brief summary of what I consider to be the critical elements to design, build and sail a foiling keelboat:

1- The best configuration is, without any doubt that of a bi-foiler: One foil on a daggerboard(keel) and one foil on the rudder.
--a. this configuration allows reduction of wetted surface in light air by partially retracting the keel and using a rotating cassette to invert the rudder removing the t-foil from the water.
--b. the configuration allows the use of veal heel to increase RM up to 40 %.
--c. It is the lowest wetted surface foiler configuration which helps for earlier takeoff.
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2- I'm convinced that using fixed lead ballast in a bulb at the intersection of the daggerboard/keel and main foil is a better solution than a canting keel for allowing self-righting and keeping wetted surface low.
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3- It is without a doubt true that electronics will or, at least could(and should) play a major role in a coastal/ offshore bi-foiler:
--a. an auto-pilot with additional functions for controlling veal heel(movable ballast and sheeting) and altitude,
--b. some form of radar/sonar(?) that can pick up partially submerged or low floating objects in time for them to be avoided. It is possible that Team Hydroptere has already developed such a system
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4- the boat(see 2 above) Must be self-righting! Crew assistance at the same level allowed on Open 60's may be ok.
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5- boat must float rightsideup, sideways, upside down
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6- Rig must be depowerable/reefable.
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7- Bi-foiler keelboats in this size range and smaller may be able to be trailerable.
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8-Safety considerations for this type of boat probably should be similar to those for multihulls-see example of safety regulations for multihulls wishing to participate in the Chi-Mac race below.


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Performance

Foiling keelboats are likely to extend the bi-foiler revolution in incredible ways.
Boat speeds may approach or exceed those of "foil assist" multihulls. Contrary to popular myth foils can improve seaworthiness and well designed keelboat foilers should be able to handle any condition that they are designed for. And well done designs using this technology should be able to compete with "normal" monohulls in any ocean race anywhere-as long as the recommendations above are followed/ incorporated.

 

Expecting to hear an update on progress from the owner shortly....

UPDATE: word is that "things are progressing nicely"....

 

Foiling Keelboat

It was noted in an earlier post that a foiling keelboat this size could be made trailerable. If so then the "racks" would have to be made foldable which will include considerations for the movable water ballast etc.
I brought up an idea in another thread that would be worth testing in a model
to determine its applicability to a boat like this. Some earlier "wing" boats such as the Moore 30 and Kiwi 35 have foldable wings-originally to facilitate trailering. I think it would be possible to develop a folding wing system that could be used at sea to secure for imminent extreme weather. If the engineering can be done within a suitable weight budget then the folded wing
would be likely to prevent a capsize and prevent a winged boat from turtling. In particular reference to this boat, since the racks are not solid wings and have a lot of dihedral the folding system might be redundant. This needs to be explored in model testing.

Below-very rough sketch of winged boat @130 degrees with +stability.
click on image

 

Doug,

One of the advantages of the wings is that they allow you to move the jib leads, and stays outboard. I am not sure how folding them at sea would work if you take full advantage of them.