Tuesday, April 14, 2009

Proa Model

OK, so here's the model proa I made.  Its made in 1:10 scale, the real boat would be 4.8m long and 2.7m wide overall.

Not so amazing in itself, but there are a couple of things I was trying to prove.  Firstly, I wanted the hull form and rig to closely mimic the White Heron, a Kiribati sailing canoe that is on display a the New Zealand National Maritime Museum in Auckland.  Secondly, I wanted the design to be a modern translation, in plywood, with very simple shapes to minimize the need for complex lofting and also to use the fewest possible number of sheets.

I have a CAD drawing of the panels required to make the waka or main hull.  It is possible to fit them all on 3 standard 1200x2400mm sheets of plywood, and I think 6mm ply would be sufficient for the job.  The outrigger (ama) could be fashioned from a 100mm square fence post, 2400mm long by sawing crude point and then refining the shape with a coarse sanding wheel on an angle grinder.  The spars could be akas (beams holding the ama) could be bamboo and the same possibly for the mast, but the spars I'm not sure on at the moment.  To scale they are 4.5m long, sop probably scarfed and laminated softwood is looking the most likley.  Softwood stock would also be required for gunwales, gluing battens and the mast and spar steps.  The sail would be poly tarp.

Now the only problem is, I can't attach the PDF file I created from the CAD drawing, its a limitation of blogspot that I can't post attachments that aren't photo or video file types.  This means I'll have to add more dimensional information before publishing them as jpegs, to allow others to lay out the panels.  The great thing is, the shapes are so simple that I could almost manage a written description of each piece instead.

I'm not sure I'll ever build the real thing though.  I've gone through the shunting process in miniature and its easy to imagine a disaster trying it for real at sea.  I think the next step will be to develop a smaller version of the hull, 4 metres length at most, and equip it with a tipping Gibbon's rig.

Thursday, April 2, 2009

Boats and Boat Names

The kayak doesn't really have a name. I have jokingly referred to it as 'Bullseye' and the double that is to come as 'Double Top' in reference to the design name of Dart and the cult but awful British darts quiz show. I don't think kayaks are boat enough to bare a name though, but that's not the case with subsequent builds.

Currently I have half-hatched plans for a 16' 3-ply sheet proa. I've got a model made that proves the shapes I have designed end up looking like a boat of sorts, I've just the rigging to add. Because I intend to make this boat for very little money, most of the materials will be sourced from large DIY outlets, and so I thought the name 'Big Shed' appropriate. I'd like to have this in Maori, or even better, what ever the native tongue of the Marshall Islands is, but I'll have to be careful to get a good translation and not rely on Internet tools of questionable validity.

Since starting the model, I've been thinking about the difficulties of shunting the real thing (changing the end of the main hull at which the sail is tacked and changing the direction of travel while keeping the outrigger to windward). One solution is to go for a sail with no lower spar and the upper spar hoisted from its mid-point. Such a rig is tipped from one end to the other and is called a Gibbon's Rig. I think it would suit a smaller, single-handed proa and would have to be called the 'Funky Gibbon'. I think it would have a large silhouette of a brachiating gibbon painted on the polytarp sail just for good measure.

These are side projects. I really want to get going on making a dinghy over the winter so I can learn to sail in my own boat. I've decided on another Selway-Fisher design, the Rhum. It will be light enough to trolley down to the beach, can take a small outboard for a spot of fishing and can be rigged with a Gunter rig, similar to the UK Mirror dinghies. It will need a name and I've been thinking along musical themes. I've been looking through song names by my favourite bands to some up with something less in jest than the proa names. Likely candidates are 'Hope', 'Spindrift', 'Red Barchetta' (but only if I paint it red, which is unlikely because its a notoriously difficult colour), 'Working at Perfekt', 'Born of Frustration', 'Anthem', 'Earthshine', 'Beautiful Machine' and 'Pacifier'.

'Pacifier' is likely to be reserved for a bigger boat, should I not like the name it comes with. I like the idea of its relation to Pacific, as in the ocean and the calming affect that messing about in boats tends to have. Rather than building a camp-cruising boat, I'm on the lookout for a good trailer-sailer with sleep-aboard accommodation for 4. This needs a bit of preparation work, firstly I need to learn more about sailing (hence the dinghy build) and secondly, I need to prepare a space on the driveway; more landscaping work.