| |

Sailing a Canoe on Crutches I : The Mast

When I began the process of converting  my cheap plastic 'paddleski' (sit-on-top kayak/canoe) to sail I wanted to construct the rigging from a few simple readymade materials which could be  easily replaced.

So I created my sail rig by using:

  • Bamboo for the mast and spar
  • Second Hand Crutches
  • Polytarp
  • Zip ties
  • Stretch Cord

I sweated over everything and kept  fiddling with my options, but in the end some solutions seemed to work quite well.

I based my sail design on that outlined in William Mantis' little book, The $50, 5 Hour Canoe Sail Rig.

Mast Step 
I supported the mast  by a set of crutches and lashed them to the bamboo.  I dropped the two arms of the crutch either side of the kayak carry handle. The bridge  in the crutch  for  the armpit rest became  the pivot  for the mast so that I could raise and lower it.  I held this in place by  a off cut of wood. I supported the boom by adhering it to some webbing. My mast is 3  metres long. The paddleski is 2.4 metres in length.
Mast Step
Mast Upright
Since the mast is supported upright at approximately 45 degrees, I ran more crutches from a thwart I ran across the hull. I attached this to the mast by inserting a steel rod through the bamboo and the already existing holes on the crutches: I used two crutches  aligned together for extra strength.

I held the mast to the crutches by twining  through a stretch  cord. The base of the paired crutch arms sat on the thwart in a pair of socks made from webbing. This isn't the best solution, but it gave me any opportunity to adjust my design before I arrived at a permanent fix. (Maybe a better solution would be to make the crutch arms and the thwart one triangular unit which is then attached to the hull rather than have two separate attachments each side of the hull for the crutch arms.)

Since this was a temporary and provisional build, everything was held in place with Zip ties.
Steal Rod Through Bamboo Mast and Crutches
Stretch Cord Strapping
Mast Lowered to Deck
Since I didn't want to drill new holes into the plastic hull I was limited to what attachment came with the craft. I also didn't want to over stress any attachment point so that I'd do the paddleski a structural injury. The rig has been out in 15 knot winds without damage to itself or collapse. There is some lateral give  -- some flex -- but nothing that sabotages the harnessing of the wind nor  is cause for capsize. Despite the strength of the breeze or its direction the mast  stays  in rough centre line of the craft.

That's because the struts running up from the hull give the mast adequate structural support upwards  and laterally, and the meteorological forces are  spread between the two connecting points on the mast.The join between the crutch arms and the mast functions as a lever -- like  the bridge on a seesaw.  The stretch cord lashing the struts to the mast are adequate to the task of holding the rig in place against upward lift or side push and pull so long as the base of the mast is anchored to the hull. Raising or lowering the mast is an easy business of unwrapping the stretch cord and unhooking the struts from the rod. Raising the mast and setting sail takes less than two  to three minutes.

The crutches on which the mast rests hold the structure firmly in place as though they were  custom made for the task, especially as  the crutch arms curve inwards when attached at the gunwale.

Reefing  can be done very easily while seated by lifting the boom to the mast and throwing around the boom rope to tie the boom to the mast. 


Post a Comment