Thursday, January 22, 2009

Ketch or Yawl?

With all this mast inspection and analysis over the last week, we discovered what we hope is our "last surprise" with the rigging. It turns out the mizzen mast that came with the boat, is in fact for the yawl configuration, NOT the ketch rig. Here are the dirty details that led to this discovery. Too Short
  • Comparing the mast length to the original factory drawings for the ketch and the yawl reveals that it is too short for the ketch. Ketch configurations had a keel stepped mast with no spreaders, yawls had a deck stepped mast with a pair of swept spreaders. The mizzen mast in possession is too short by about eight to nine feet.
  • The beginning of the sail track is too high. It starts at about 7 feet from the bottom. This would give a sail with a luff dimension way too small for the ketch.
Can we use this Mizzen Mast? Recall from recent posts that we pretty much decided to stick with the original masts. But this discovery throws all that into question (again). First thought is to step this mizzen and use it anyway, but, even deck stepped, it is too short by about three feet. Is that a significant difference in terms of sail balance? I am not sure. To use this mizzen will require significant modifications: extending the sail track, grinding off welds, fitting a pair of spreaders, and splicing in some height (requires finding a matching extrusion). Also, chainplate placement would need to be revisited. Sounds like a lot of work for such a small mast. What about the Main Mast? The main mast matches that of the original ketch configuration. Fifty feet tall. The yawls, according to the drawings, had the 55 foot mast with double spreaders. So, it appears we got the right main mast for a ketch (whatever "right" means by now). What to do now? One could say "switch to a yawl!" That presents problems: it would require moving the main mast aft, and to do so, with the current layout as built, would result in a compression post in the face the moment you stepped forward of the galley. Nevermind the main mast is too short for the yawl. Another problem: I hate the look of the the yawl. What we are likely to do: seek professional help. The "designer" kind I mean (we got that "other" kind already covered). Thanks in Order One Last Mystery I'll finish this post with one last mystery that maybe you readers can help solve. Below is a picture on the spreader bracket from the main mast. Immediately to the right is bolted a double-holed tang where the two inner stays are attached. There is a single holed tang immediately to the left. What do you suppose that is for? Too close to the spreader to be any standing rigging leading downward. Even downward and aft! I see no evidence of a need for such attachment point on any drawings. Its not for the staysail (attachment exists higher up). Perhaps something to do with external halyards? anyone?
From Building a Westsail 42: Mast and Rig


The Incredible Hull said...

Ref the mystery. Running backstays is all I can come up with, but it should be higher up to counteract the staysail.

The Incredible Hull said...

Just to add to your misery, have you considered a sloop or cutter rig. The sloop would require along boom but it may be feasible. The Whitby 42's evolved into the Brewer 12.8 which was a cutter. The mast was moved aft, which might or might not be a major undertaking.

rj said...

Yeah, we considered a sloop/cutter way before this. Same problem. Compression post is too far aft and would get in the way walking forward.