06 June, 2012

The Flying Crutchman : phantom no longer


While I had been  previously working on my paddleski, trying to turn it into a sailing canoe, I kept running into frustrating snags. A respite from the task has enriched my creativity and over the past two days I have tweaked my design by using the material I prefer:crutches. 

The joy of crutches

Second hand crutches can be had for cheap at Op shops and they are sturdy built devices made from layers of laminated wood, held together with bolts. Inch for inch they pack  a lot of useful properties for the would-be sailor (such as I). The curves especially are a handy engineering feature.

So when I designed my sailing rig I relied on crutches as my primary building material. 

Cannibalized. Sawn off here or there. Taped and bolted together. I know that there is always going to be plenty more where the last lot came from. 

To the mix add a couple of bamboo stems, a cheap single blade paddle to serve as a skeg and a tarpaulin trimmed to shape (lateen/settee) and maybe -- maybe -- I have the makings of a sail boat. 

When last I was  sailing the craft I learnt a lot about the forces in play under sail and the boat's limitations. I hope this time around I've solved some of the issues that were frustrating me then.

With this rebuild I've parred the rigging way back and made it much easier to attach and dismantle. Rigging for sailing should take no more that 3-5 minutes; and the fold -- the mast drops to the deck and the skeg folds back onto the beam-- makes for easy portage and to trim when the wind blows up.

The only complication is that I need to navigate with a single  blade paddle as a long double blade kayak paddle is difficult to maneuver when the sail is up and hard to stow on board when not in use. I could strap a double blade paddle to the mast stem  and carry it 'on board' there but  first I want to see how well I can paddle the craft with a single blade.

When the sail is up I won't need to paddle much -- only steer. But when the wind drops away completely...? I'll have to make do with the single blade to hand.

I also thought I'd need to drill another pair of hoes in the plastic hull but -- so far anyway, touch polyethylene -- I  discovered that the physics of  ratchet tie-ing ensures that the strongest grip ratio is dependent on the width of what's tied down. Both ratchets are designed to hold 300 grams which should be enough to hang onto my mast in winds up to 20 knots. (I hope so at least. Not that I'll be sailing in 20 knot blows as I hope to be heading for port well before then.)

Pumicestone Passage
But wind gusts being what they are...I still may rip the hull open if I'm unlucky and stupid. Nonetheless, even in sudden 20 knot gusts my old rig design held my mast aloft.

If the design takes off across the waters as I hope I'm thinking that it may make a nifty sail boat. While I may call it 'The Flying Crutchman' it won't be fast as it is too short and beamy to truly  'fly'.  The hull is a twin hull design which makes  staying upright a reasonably  stable business.

However, since I have added as much sail as I could fit aloft, if capsize is inconveniently frequent I can later easily add an outrigger and run it on the lee side (and swap it depending on the tack). But the twin hulls have their advantages in way of  not drowning and  enabling a carrying capacity of 130 kgm. This means I can load up camping gear if I want and head off for sleepovers along the Pumicestone Passage.

I'd never just paddle such distances as the paddleski isn't an easy pull through the water. Better to harness nature and rely on meteorology, especially as the prevailing winds here are coming from east to south east to south west. That means that travelling north -- tacking as required -- is very feasible. Coming home aint so easy but  against a south eastery it is possible to proceed even on a craft like this.