John,

I think that perhaps a length of 10 metres is a little too big. It's no accident that in the Western yacht racing world, the Folkboat and the J24, for example, have developed large fleets in many places. The very name, "Folkboat", points the way - what you are aiming for is "A boat for the people". Boats of this size are easier to own and to manage, in all respects, maintenance, mooring etc being so much less than for a 10 metre boat. Yet they are more fun for short-distance round-the-cans weekend racing than a bigger boat. I suggest that you aim for a 7 or 8 metre boat that looks like a junk, but takes full advantage of all the advances in naval architecture that have been made over the last century. Small is beautiful, less is more, as Annie would say.

Much as I like the soft wing sail, it doesn't seem appropriate for this boat, since you are aiming to revive interest in China's maritime heritage. I think the rig type should be recognisably derived from a traditional planform, if it is to be a one-design rig; but actually, I would suggest that the hull should be one-design, and the rig should be restricted. That is, set a maximum area and a few other rules, and then encourage development.

The Hull no.1 was mainly meant as an exercise in using the QCAD program. Although this program was great for drawing sails, I found it to be a struggle to draw a boat with it. However, its limitations (read: my limitations with it) keeps me from drawing complicated lines which would be difficult to build. After all I had home-building in mind, and as far as I can remember, I never got better than a “Good” (= C?) in carpentry at school.

The design was to emulate the narrow and heavily ballasted Folkboat, but with a bit longer waterline. In addition, the trapeze sections and flaring topsides should give additional hull stability, so the ballast ratio was reduced to just below 50%. The Hull no.1 is still of moderate beam (2.1m in wl.), so I think it needs an outside, ballasted keel of some sort.

The keel I have drawn is only 1.10m deep with a horizontal sole. I thought it could be made from a flat steel plate with a flange at the top to fit with the hull, and with ballast from iron, lead or concrete (less good) bolted to the lower end. This keel may not be the fastest, but would make the boat easy to handle, both afloat and ashore. It will not need an expensive cradle when being laid up ashore, just a 'chain cradle' as the one I fitted to my ‘Ingeborg’, recently.
Any other keel type could be chosen, including one of 0.8m draft with a centreboard fitted inside it (no cb. trunk inside the hull).

The rudder is meant to be a big one, possibly deeper than the keel, and thus of some sort of swing-up type.

Arne

Hi John

A while ago I made my first CAD design study for a junk, being 7.00m in the waterline. As you can see I went for a pram type, as I think these hulls should make good sailboats. The boat is meant for plywood construction. As it mainly consists of circular arcs and straight lines it should be easy  and quick to build. Any keel or rudder could be used, but with at least 1000kg ballast. An ordinary JR (sloop) of some 35 - 40sqm should be good. Later some boats could be fitted with development rigs; wings, aerojunks, split junks and wotnot.

Just a thought.

Arne