Hi Arne,
wow, what a reply! Thanks for your effort and the sketch, this was really quick. I like the look of the junk rig on the Maxi 77. It really suits her :)
I agree with you about the hull shape being a good candidate. The rudder is quite large, but if necessary, the lateral area of the rudder could easily be increased.
Now that you already drew a sketch, I should mention some further design constraints and ideas: As both my girlfriend and me have to fit into the V-berth, I can't take away more space there to put in the mast. It would not be to much an issue for daysailing, but we want to sail around Sweden from April to Oktober next year, so would need any space under deck which is available...
The mast will be in a tabernacle, to quickly lower it. For this tabernacle, I am thinking of something special (but probably ugly...): It should be totally above deck, with no party protruding through the deck. This means, that one able transversal girder needs to be located above deck, which supports the bottom of the tabernacle. The top of the tabernacle needs then to be stiffened sideways, by diagonal beams. The whole thing would be mounted to the hull by only four screw, located at the toe rail (which of course will have to be stiffened from inside). I try to sketch some details next week or so.
By this rather radical design, there will be no space lost at all under deck. Of course this will increase windage on the bow as well as probably be not looking too yacht-like. However, I regard my boat as a work boat rather then a yacht.
Also, I want the front hatch to be usable.
For the mast position, this would allow the mast to be placed backwards up to the front hatch, so about 300-400 mm further aft.
About the sailing area: With the bermudan rig, the main sail has 10 m², the fock has 7.5 m², the genua I has 24 m² and the spinnacker has 50 m². This makes for a total SA of 34 m² with main and genua.
With the junk rig, I would like to increase the SA to about 35-40 m². She is not heeling that much due to the balast located in the bulb keel. Also I prefer to just be reefing earlier, and have a lot of sail in ligth winds. Also, according to your sketch this could be achieved by extending the sail more to the front, with the positive side effect of more mast balance.
Any thoughts on this preliminary ideas?
By now, it is all just ideas and sketches in my head. I will need to actually calculate the stiffness of this special tabernacle, and maybe readjust. However, my gut tells me the loads will be manageable.
Cheers,
Paul