AC 36 Foiling Monohulls

[OzFred]

I think there's a fundamental problem with foiling monohulls in close quarters match racing. In order to foil, you need to have a light weight boat, powered up. To get power, you need beam to generate righting moment. A multihull provides the righting moment within the max beam of the hull(s). Most (the Moth being the rare exception) existing foiling monohulls allow the foils to extend outboard of the beam of the hull. This is manifestly unsafe for match racing - think Ben-Hur style chariots.

One way around this problem might be to ensure the foils stay within the max beam of the hulls, and give the monohull the beam of a multihull. This could mean a cross between Mark Pivac's Moth design that Brett Burvile sailed in the Perth Moth World's in 2000, and the KZ1 big boat from the 27th AC in 1988.

Doesn't this lead to a Blue Arrow configuration (about 1988), which is pretty much what the Pivac/Burville Moth did? Though Blue Arrow was termed "foil stabilised".

It pretty much precludes close match racing too.

 

[schakel]

I think the 80 million automobiles sold each year that can all potentially have electric or hybrid engines are a hugely greater incentive to produce lightweight batteries than a quadrennial sailing competition with half a dozen (extraordinarily expensive) boats. ;-)

I agree with you on that one but: Even more aplication of for instance Lithium Polymer Batteries might lead to a higher performance of the kanting keelers monohuls.
Main concern is the 100 % foiling tack that the "old" ac 50 did have. There are still enough highly effective power trainers like in team ETNZ, they are able to fill these batteries with enough power to ensure a fast swing from left to right and backward of the kanting keel. It's proven technology on the VOR's.

 

[Doug Lord]

NZAC ONE-----my initial conception of how the design could work:

1) I don't much like the bow but the idea was to make it a bit safer for anyone working up there.

2) Both foils pivot in their own pivoting trunk to retract-they could also slide up if required.

3) This type of foil doesn't need to be constantly adjusted-very rarely adjusted since it is a surface piercing foil

4) Only one mainfoil and the rudder T-foil in the water providing lift--plus the keel providing lateral resistance.

5) Didn't have time to draw it but the flared section of the main hull is relatively short in a F& A direction to keep weight down.

 

[Gary Baigent]

Doug, did you take note of the minuscule area of support in the deck/gunwhale area of your sketch for the hard working and high forces produced by the long foils?

 

[CT249]

A small wind turbine or water turbine to charge an electric or mechanical acumulator is nothing new on sailing yachts.

If it's small, is it going to be able to power a canting keel through a tacking duel?

Electricity for communication, illumination and safety that is generated by a small turbine is one thing. After all, electricity for those three purposes is common in even the simple sports like running, kayaking. But a turbine big enough to generate enough power to move tonnes of lead back and forth is arguably another.

 

[schakel]

If it's small, is it going to be able to power a canting keel through a tacking duel?

Electricity for communication, illumination and safety that is generated by a small turbine is one thing. After all, electricity for those three purposes is common in even the simple sports like running, kayaking. But a turbine big enough to generate enough power to move tonnes of lead back and forth is arguably another.

I think the AC so far has strongly suported mandriven energy suply as in my post number 47.
AC 36 Foiling Monohulls https://www.boatdesign.net/threads/ac-36-foiling-monohulls.59160/page-4#post-814235
Exept for the 2 dogfights simply because they were too big to be handled without engines.

 

[Doug Lord]

Doug, did you take note of the minuscule area of support in the deck/gunwhale area of your sketch for the hard working and high forces produced by the long foils?

====================
Yes.....

 

[Dolfiman]

Dear Doug,

Super to brainstorm on the concept , just to contribute here attached is a variant whith closed loop foils, for structural reason : you avoid a cantilevered assembly and its usual disadvantages (high flexure/torsion efforts at the root, low frequency of the first eigenmode of vibration, which can be excited by the waves encounter frequencies or by vortexes). The design can be lighter (for a same lift) and likely cheaper. From the hydrodynamic view point, foil + keel are 3 surface piercers instead of 2 in your concept, so yes more drag but also more stability I think.

 

[Doug Lord]

Dolfiman, you might consider a way to retract the foils(see the pivoting foil on my sketch) and I'd review the angle of heel the boat apparently has when foiling. I would plan on a canting mast on my version-same with your boat? Interesting idea!

 

[Gary Baigent]

====================
Yes.....

<removed>
Your creation would snap its foil connection areas like pieces of dried toast.

 

[Doug Lord]

This was a sketch, not a design. However, I used my 56 years of sailing, boatbuilding and design experience to estimate that the foils could easily be supported in an all carbon structure similar to what I showed.

Look at the space available for the head of a very long foil on the Quant 23-not much different than NZAC. Both the Quant 23 and NZAC foils would support about 80% of the boats weight.

 

[michaeljc]

Still trying to anticipate the new AC design. Forget foils for the moment. Hows about a wide beam planing hull - 50 ft +. Bring back in the spinnakers. Feasible? Oddly, the Volvo boats were mentioned at one point as though there should be some kind of connection. I cannot imagine what that may be

 

[schakel]

Why not the following idea integrated with the new monofoiler?

Might be a winning idea? If Guillaime Verdier integrates this, the cup might look much more interesting.

 

[Doug Lord]

NZAC One revised:

LOA 78'(changed from version one), Beam 59.5'
1-no canting keel

2-retractable foils by pivoting

3- foils don't need to be "flown"-they are automatic

 

[Konstanty]

If it's small, is it going to be able to power a canting keel through a tacking duel?

Electricity for communication, illumination and safety that is generated by a small turbine is one thing. After all, electricity for those three purposes is common in even the simple sports like running, kayaking. But a turbine big enough to generate enough power to move tonnes of lead back and forth is arguably another.

The inclined canting keel has potential energy. Before the lee ho canting keel has potential energy. On the lee ho canting keel go down. Potential energy of canting keel transforms at energy of hydraulic acumulator. After lee ho this energy + little added raises up canting keel.