Remote island communities in the Pacific and elsewhere are being screwed by modern technology. Their sailing boats, sailing and boat building skills have been displaced by heavy, expensive fibre glass skiffs powered by expensive outboard motors requiring ever more costly fuel and maintenance. Many of these communities are at the forefront of the effects of global warming so have a strong interest in emissions free transport, both to lower emissions and to show what can be achieved.
A couple of years ago, a study was made of the problems surrounding this issue in the Marshall Islands. It was done in 2 parts. One was looking at boats for across the lagoon and near shore fishing. The other was for inter island travel (more on that later).
The priorities in the attached table are each multiplied by a score of 1-5 (5 is good) and the results added together to see how each boat fits the requirements.
We had a look at the requirements and designed a mini cargo proa which scored 569 out of a possible 605 and has been selected as one of 3 boats to build and test. The other 2 are a stitch and glue catamaran and a moulded cat for which they already have a mould. The next stage of the selection process includes comparing the boats and teaching selected local people how to build, maintain and sail the boats to a level where they can return to their villages and teach others, spreading across the Pacific and other remote island communities. This process will be assisted by the large budget that has been allocated to the project.
The hull shapes are box section with straight sheer and rocker with dimensions based around sheet ply. The bottoms, cockpits and decks are half a sheet wide. The sides are 2/3 sheet high. The windward hull is 3 sheets long, the lee hull, 4 sheets. There is one curve for the deck and bottom at the ends. This is drawn with a bent piece of stringer, cut and used as the master curve for the other 7 cuts. The result is not pretty, but it can be built with no setting up, levelling or measuring and no tools beyond a hand saw and some sandpaper, plus a small table saw if the timber and ply is not bought cut to size. The stringers are triangular so that they are easily glassed and sealed. The ply sheets are butt joined together, then the joint is glassed on both sides.. There are no screws (by far the main cause of rot in plywood/epoxy boats), everything is clamped with sand bags or spring clamps made from offcuts of pvc tube. All surfaces are glassed, then skim coated to ensure sufficient thickness of epoxy and long life. All up weight is about 500 kgs.
The boat has a capacity of 1,000 kgs/1 ton which can be people and/or freight. The 1 sheet of ply long cockpits are deep and self draining with seating along the edge. They are large enough for a cooler for fish or other fresh goods. The beam clearance is a compromise between wave impact, ease of getting on/off the boat and landing fish. The masts for the schooner rig are stepped on the beams near the hull and stayed to the ends of the boat. If a single sail is required, a third beam can be added to step the mast on. Unstayed masts are supported by a mast step on the bottom of the hull and the beams at deck level. An option is to include a small steering cockpit aft so the helmsman is not perched on the deck. The deck is slatted timber to make it easy to move around on and store stuff on.
Pacific Islanders know more about paddle steering and lateen sails than anyone else in the world, so that is what we chose for the proa. I am really looking forward to learning how these work in the hands of experts. Because of the shallow hull, we included a simple, tied on bidirectional leeboard to improve upwind performance, particularly when the boat is unloaded.
The beams are also timber/ply/glass/epoxy, the deck is slatted timber and the spars, leeboard and paddle are wood/glass/epoxy because that is what is available locally. Longer term, the skill level may be increased to include PET recycled foam and Intelligent Infusion for a lighter, cheaper, rot proof option. This will be even easier to build than the ply boats, but needs a bit more infrastructure.
In keeping with our philosophy of not selling anything we haven't tried, Steinar and I picked up the materials and a $100 table saw to build a mini cargo proa windward hull today. Progress on the build will be on the Building Blog page on www.harryproa.com. This is a garage build while my wife is away, not sure when the rest of it will be built, but one possibility is that I will sail it to Fiji and donate it to a village where it will be further assessed for suitability. Then in August/September I'm off to the Marshall Islands to teach the locals how to build and sail them and learn about traditional boats, rigs and navigation en route to, or perhaps from, the first Intelligent Infusion workshop in Maryland. Fun times.
Pictures of the boat and some more information on the web page soon.
__._,_.___
Posted by: Rob Denney <harryproa@gmail.com>
| Reply via web post | • | Reply to sender | • | Reply to group | • | Start a new topic | • | Messages in this topic (1) |
SPONSORED LINKS
.