Hi,
Rob's mention of using just a single crossbeam got me to thinking about how that would transfer all the heeling moment directly from the mast to the ww hull, which should reduce stresses on the lw hull. So, I drew up a version of sidecar with a midbeam that folds to trailerable width on the water (7.5').
It should also only need a 40' mast, since you don't really need to bury it in the lw hull much at all, so it will fit in a container without a 2 part mast.
The drawing is in Gardner's Layouts/Camper.
I do have some questions:
1) This requires the crossbeam to be pivot above the lw hull, including one of the rudder mounts (you would have to remove the actual rudder). I am thinking of a rudder mount like Aroha's. My question is how much freeboard does the lw hull need to practically mount the rudder? The more I give it, the higher the ww hull becomes, and the more windage it has.
2) The crossbeam is only about 2' wide at its maximum. Is that enough contact surface to deal with twisting on the ww hull as it meets waves at a different time than the lw hull?
3) I made the ww hull as short as possible, but the waterline beam is still 2', so I only have a 10:1 length/beam ratio. Would I be better off stretching just the hull portion out to 24-26 feet? It would add a bit of weight and windage, but would have a finer profile.
I am looking for a vote as to whether this is a practical design approach. It is back down in the size range where I have the facilites and confidence to try to build it myself. Just from the quick $10/sq ft rule that I have been using for budgetting, it looks to be about a $10K project, which could be a useful experiment to prove to my wife that the harryproa idea works.
- Gardner
York, PA