After the ESTEREL-M and Futinet & Futinette, here is the same design concept applied to the RG65.
To recall the guide lines.
1st - the initial idea was to reduce the construction weight of the hull by simple narrowing the Deck ( nobody is on board anyhow !)
2nd - the narrow deck do also stay away from water level when the boat is tilted.
3rd - When the boat is tilted, the leeward side appear to be a sort of vertical immersed wall that should contrast the drifting
Looks great Claudio. I’m interested in making a wooden version of this boat, specifically set up for a mast aft wing sail? Will this work for this design?
Hi Jim,
Every hull can sails, so far the CE is falling at the right place.
Tuning is generally searching the best position.
Similar RG65 was already subject in this forum for a so called “Delta Rig”
The above sketch is still under design evolution, was just introduced as an example to explain only the criteria used.
Cheers
ClaudioD
With the Prismatic of 0.60 these hulls should be particularly performing with medium/high winds.
NOTE : The displacement is kept rather low, but a small vertical stretching will increase the draft and consequently the displacement.
1mm variation close to the Water Plane is equivalent of 55.5cm3 or grams of fresh water
have you had a chance to extrapolate the data on the size and shape of the Panels on the hull. Since its a hard chine design. I woudl think that with any easy to print out shapes, one could almost go framless and start tacking together the panels and they would pretty much shape themselves??
Yes of course, high aspect ratio produce better lift and efficiency, sailing in clean airs, but suffer also of lateral stability since the CE is higher unless larger bulb is used increasing the overall weight… as always compromise and again compromise …
Between the last rig and the gaff rig there is about 27% higher CE. The gaff rig will sail better with wind increase. Off course this is theory and with the use of thumb is another story!
ClaudioD
Hi Marc,
imo is too deep and producing deeper wave !
After all the immersed cross section is very similar !
Of course one could try a compromise, but for the time being I have choosen 28mm instead of 36mm
Cheers
ClaudioD
-Dear “Claudio” I would like to ask you about polyhedral hulls: when the boat heel, and flat side is horizontal to the water, what is the effect on sailboat glide? *
Glide. - (I do not know if I use the correct term)
Hi Alberto,
it may not become an horizontal flat panel, but in case is, it could produce a little lift to gain a couple of mm at the LWL level, but at the same time the wind will push down the boat, so at the end one may compensate for the other, or at least is what I can suppose theoretically !
Cheers
ClaudioD
As usual, a beautiful looking design. I will have a go at making this boat, once it is out of the furnace and cooled nicely. Is the design sufficiently advanced for you to advise what materials and building techniques are likely to be appropriate for this boat?
Hi Jim,
the last published version (h) is the one I could retain for construction. The reversed bow , if required, can be adapted with a balsa bloc.
According to rough estimation :
1128g - 700g bulb - 85g rig - 105g electr. - 80g hull/deck - 50g fin&rudder = 108g left for internal supports, paints, etc.
Now the total available weight for the Hull/Deck is in the order of 80/100g
Without going into calculations, the solution retained is with Glass/Epoxy 2x100g laminated on a plug.
Up to you to find other solutions.
Couple of pictures of Fuxia-65 and Trap-65.
Note that the Esterel-65 design is supposed to be lighter due to the narrower deck and no deck line tripes.
