12' Nuthatch Pram Sailing Version Plans PDF
After designing and building the 8ft Nuthatch Pram, I thought that a larger version of the hull would be a good fit in my series of stitch and glue boats. This is the finished design of the12ft"fishing" version, and I have a 14ft version in the early hull modeling stage. This design could even be lofted up to something around 20 feet or greater. The "Vee" of the keel would get even more pronounced on the forward sections of these larger hulls.
The main change in the10ft and this larger 12ft version of the Nuthatch Pram from the original 8ft hull, is the use of a curved arc along the bottom edge of the two side panels. On the 8ft hull, the bottom edge to the two side panels is a straight line. This was used to help in the lofting and construction process. The straight edge on the 8ft hull, also kept more hull below the waterline near the stern in this shorter version. Which in turn increased it's load carrying capacity, and increased it's stability. The larger hulls, from 10ft and up, have extra width and length to offset the need to keep the straight line on the chine seam. Plus the curve added to this and the other larger hulls, just makes the designs look better; with the smooth flowing (not quite parallel) curves of the chine and shear lines of the side panels. The curve in the side panels at the stern, also picks and lifts up the aft outside ends of the two bottom panels, and reduces the wetted area to improve rowing when solo in the boat.
This set of hull plans are mainly for those that wanted a sailing style hull, but it could be rowed and powered by an outboard motor too. This hull is mostly a stretched version of the 10ft version of the Nuthatch Pram, and has the plans and directions for adding the rudder, daggerboard, and mast partner. It differs from the "fishing version" only in the placement of the rear seat, and not having the beefed up transom, but you could install it for use with an outboard if you want to.
I have gone to using the "enclosed pyramid" (with watertight hatches) style of seating in all my designs for safety reasons. After reading a story with photos, dealing with the deep water self rescue of a brand new "traditional open interior" small boat design, and they couldn't empty out the water; I will no longer include drawings or instructions for old style wooden plank seat interiors. Your safety, and that of your family members is more important to me, than any negative comments about my non-traditional hull interiors. This hull as designed, has around 5+ cubic feet of extra positive flotation build into the enclosed pyramid seating. That's over 300 pounds of extra support, along with the wood in the hull; and you will have less water to bail out. The two handles or steps on the stern are there to help you or a loved one, get back in the boat again if needed. Always carry and wear, a life jacket adequately sized for you and your guests, and be sure they are in good condition at all times.
This is the first hull design that I have not built a prototype hull to test the lofting of the offsets and lines, but after tank testing the previously built 10ft Nuthatch Pram, and comparing that with it's launch photos; the 10ft Nuthatch Pram sat better than I though it would, and so this 12ft version should too. I have also found that there are very few "tweaks" that I have had to make to any prototype design while building. They have been in the 1/16" +/- range at a couple points during the lofting and curve smoothing stage, and usually dealing with the curved "arc lengths" between the mating edges of the side and bottom panels. I would expect no major problems for you during the construction of this boat.
Here are a couple of samples from the plans (click to enlarge):
Each set of plans comes with a printable paper model,
40 pages of colorful and concise drawings (samples above) and
a 53 page instruction manual - perfect for the first time builder.
Warren D. Messer