Rob,
After hearing about 48' containers, I experimented with lengthening the lw and ww hulls on a design I was working on that was just a bit too cramped in the harryproa 12m size. The thing that worries me is that I might have crossed a point where the weight/sq ft starts going up dramatically. The reason I ask is that harryproa weighs 800kg and rare bird weighs 3054kgs.
I checked your numbers for Solitarry (1.2lbs/sq ft for lw hull, 0.75 lbs/sq ft for ww hull) and found that it matched what I have been calculating also. My ww hull is 1250 sq ft (125 sqm) and the lw hull is 400 sq ft (40 sqm), so I am getting a combined hull weight of about 1500 lbs (700kg), which is probably a bit higher than harry. I am guessing at a total weight of 2500 lbs (1130kg). I would be fine with that, but Rare Birds' 3000kg weight scares me.
Do you think that you could build a flat panel version of rare bird now, with all that you have learned, that would weigh alot less than the strip planked cedar? Or should I be scaling up all the laminate weights because my righting moment is about 10 tonne-meters, as opposed to harry's 6 tonne-meters? I can see having to beef up the lw hull and the beams, but the ww hull isn't taking more load.
You know everything revolves around the weight, so if I screw that up then everything is screwed up. If i just assume that I have to double the weight of everything, then my sail plan doesn't work.
Any advice? Is there some other info you need to give me an idea?
- Gardner
Pasadena, MD
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