jopj

February 17, 2009

THE CHANNELS

Channels are in a nautical sense the ledges projecting from a sailing ships side to spread the shrouds and to keep them clear of the gunwales. Its an alteration of obsolete chain wale. It seems that channels in the nautical sense are now also obsolete. Time is passing. I use them however, because I hope to be able to lean my mast 30 degrees side vise. That will achieve a few things like giving the boat more stability when the mast is to windward.

Theoretically, placing a lead weight on the mast top would increase stability even more.

In light wind the mast can be made to lean to lee stopping stopping the sails from flapping as gravity will keep them down.

Also more sail area can be projected to the wind and the sails will be lifting instead of pressing the boat down. Also bringing the sails to windward will give her lee helm. Keeping them to lee will give weather helm.

A tilting mast gives a sailor many possibilities to experiment with his rig.

However it has been a time consuming job with many different operations. I started by gluing a piece of Divinycell to the hull. I fixed it with wooden jigs.

(click on the pictures to make them bigger)

Then I put some glass fiber below were the metal fitting was going to be.

Then I put a shelf to fix the metalfitting

Here is the metal fitting and I measure how much unidirectional glass I will need. Al the glass work is done with NM-epoxy. The pipe (wrapped in Marstr├Âm tape for release) is to hold down the UD-fibre.

Here is the result.

Now I am building up the shape with more Divinycell. Vertical athwartships pieces of glass is inserted between to make the structure rigid to avoid pealing.

Lead weights are employed to compact it and squeeze out any voids.

The final product have a lot of gluing surface and in theory should be good for twenty tons pull. A fair margin of safety even for Cape Horn.

Here are all six channels looking aft. I only really need the two forward ones but the other strong pints are good to have when experimenting with different sail sets and for lifting the boat. The aft one is for yuloh work. They give a place to put a foot athwartships and a place for the rope.

Here is a view from aft.




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