Island Escape Entry #1: Skip Johnson

An entry for our Island Escape Design Contest

Island Escape Design Contest Entry #1 from Skip Johnson. (Get your entries in by February 20th.)

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Would that our intrepid adventurer was stranded with a good pull saw along with the leatherman.

Oh well, no use crying over absent tools, we have what we have and that’s it.

Some basic assumptions

1.   Our intrepid adventurer was stranded weighing 190# +/-, he will leave weighing 160#+/-

2.   The 200 miles will take somewhere between 4-10 days to complete.

From the above, first guess is craft will weigh about 200# and provision will add another 120#, primarily coconuts for food and fluid.

480# will require 7.5 cubic feet of buoyancy we have 4 cu ft of Styrofoam and somewhere between 0.5 to 1.4 cu ft of plastic bottles, call it 1 cu. foot. (it’s unreasonable to assume they are all 2 liter bottles).

On to boat design:

From the above we need another 2.5 cubic feet of buoyancy, call it five even for some freeboard.

Using 2” diameter bamboo will require 227 l.f. (where’s that damn pull saw?).

Actually the bamboo is tapered and it would be better to figure on around 300 l.f.

So how to arrange 300 l.f. of bamboo to make a one way 200 mile journey?

A proa naturally! Bear in mind I’m currently building my sixth proa and it may or may not be my last but it will almost assuredly be the last camp cruiser.

Around 20-24’ long takes ~ 12-15 pieces. At this point I’ve not put pencil to paper, excuse me while I sketch something out.

I’m back, the poor bastard’s going to have to cut more bamboo.

The basic hull will consist of a mat of bamboo bits with equal numbers of ~ 18’ pieces and ~12’ pieces tied together staggered in such a manner to make a 30’ long mat about 3 ‘+ wide tapered to almost nothing at each end. Everything tied together tightly in the middle 8’ or so and a little looser towards the end. All the tying done with some of the poly pro rope unraveled into 3 separate strands.

Mat to be rolled up over two pieces of the Styrofoam shaped into semicircular formers.

Float to be made from smaller pieces of bamboo formed up over some of the bottles, 2 liter if possible.

A frame mast from select pieces of bamboo per drawing.

Area between beams to be used for coconut storage (it’s a wet well, so coconuts don’t really count towards paaload).

Obviously our craft isn’t actually “watertight” in the conventional sense so sailing performance will be for a far heavier craft than would be first supposed. None the less, a similar sail from half a sheet of 8 x 12’ polytarp propelled my P52 proa regularly at 10 - 12 mph.

Hopefully one of the pieces of driftwood or some of the other errata would suffice for the blade of the AD scull shown. My experience with two of these sculls has been very positive and I believe our intrepid adventurer could easily manage 2 mph on windless evenings after the sun’s gone down.

One resource that’s really stretched in this scheme is the 100’ of polypro rope. Normally down and dirty rigging by yours truly uses a lot of trucker hitches. This project can’t afford such extravagances so I would use the eyelets and shoelaces from the shoes to tighten up shrouds and the like.

Netting should be used over top of hull to keep coconuts from be washed overboard.

Shelter from the sun is paramount, as our craft is travelling south the sail should provide shade in the morning and some shade would be provided in the afternoon by a screen made from scrap clothing fastened to the A frame mast and outrigger beams. The remainder of tarp left over from sailmaking would be used for cover if any rain was chilling. If not it would be handy to collect rainwater for drinking. •SCA•

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We’ll share Skip’s other entry soon. Other contestants remember the the 20th is deadline. —Eds