Friday, November 17, 2017

Here We Go Again



Some time ago I kicked around the idea of rigging Autarkia as a Gundalow typical of the sort that plied the Piscatauqua River in the late 1800's and early 1900's.

The idea keeps coming back to me for the following reasons:

The rig lowers in seconds to get under bridges - one simply lets off the block and tackle at the base of the yard, and the counter-weighted rig slowly descends with a gentle pull on the back-stay.  Shoot in under the bridge and haul the yard back up.  That is it.

Also, we will be making many trips downstream from Mission, and the rail bridge is right in the way.  Without a dipping rig we will have to cross the river and get the bridge swung.  If we go upstream, our destination is likely Harrison Lake via the Harrison River.  Two bridges to deal with there, and the highway bridge requires a wait of up to a week.

This type of rig points into the wind better than a junk rig but it does not reef easily or quickly like a junk.  I've been thinking about that though.  The fact of the matter is, winds here are very light - if we get them at all.  I think in any case a crazy rogue gust can be dealt with by letting go the sheet and lowering the rig.  It isn't like we simply have to keep sailing - we have a motor.  Even with a junk rig - for us there will be a learning curve and we will have to figure out how to use the rig properly in any case.

The stub mast and yard can be made from steel.  The yard would be sections of Schedule 5 and 10 pipe telescoped and welded together.  I have hundreds of pounds of tire weights I can cast into a counter-weight for the base of the yard.

The biggest job will be to sew a sail but unlike a junk sail with batten pockets and such, it will go together faster.  I will have to use proper sailcloth, and borrow a better suited sailmaking sewing machine than my Granny's Singer Featherweight but no big deal.  I also bought a copy of The Sailmaker's Apprentice and have been reading it voraciously - so I think I can do it.

One unconventional thing I may do is to attach the yard to the top of the stub mast with a fabricated U-Joint of sorts, rather than chaining it up there in the traditional fashion.  Since the stub mast will only be six feet off the fwd cabin top keeping it greased and maintained will be easy, and there will be no rubbing or chafing. Still thinking that one through.

I've done some of the engineering and calculations for the pipe sizes, and have figured out how much counter-weight I need at the base of the yard, but will post those details later on should I proceed with this route.

As a matter of interest, the folks at The Gundalow Company have been quite helpful.  Please check them out.

I have not been very active blog-wise as of late, like many of the fellow bloggers I like to follow.  It is simply life.  Gets in the way sometimes :-)

On a last note, I made a change to the wood stove installation aboard Autarkia.  I lowered down by a foot and replaced the flue with insulated pipe.  The stove works better now and also heats the nether regions more efficiently.

Here's a pic:



4 comments:

  1. Hi Alan,

    Gundalow Rig looks very practical for you. It looks to me like two or three sets of reef lines could radiate from the tack, forming a series of smaller triangles... lower mast until the foot is brought down to its target height.

    Or a Bermudan reef might work until motor time... tie a line around the clew end of the sail, a few feet fwd, reducing the area and spoiling the draw. Definitely quick and dirty, but effective.

    One thing I don't see is what would prevent the heel from swinging off the centerline. Do Gundalows have a prevention system?

    Dave Z

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    1. Great to see you back Dave!

      I think that the heel is supposed to swing of the centerline. It really is more of a big yard than a mast - and so is allowed to wing out. I've played around a bit with some dowel models just to get a feel of the stresses and where they occur. With a running backstay that can be adjusted, as well as a block and tackle on the heel to counter the tension we can wind up with a spar that is quite a bit lighter than what an unstayed mast would be. We wind up with three lines to deal with - the running backstay, the heel block and tackle and of course the sheet. Captain Matt of the Piscatauqua has told me that they do use a set of transverse block and tackles on the heel to prevent the yard swinging around at the dock and at anchor by virtue of powerboat wakes - something he says was not a problem in times of yore and therefore not part of the traditional rig.

      All in all I am very intrigued with this and as time goes by feel more and more it is the way to go. For us - here - and the type of sailing and use we will have for her.

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  2. Funny, I was looking at biplane rigs for a cargo hauling sailing vessel. (Think 45' pram). I was thinking roller furling but that would bring the center of effort too far forward when reefed. If I could tilt the mast backward at the same time I was roller reefing, the center of effort would more or less stay the same. (And we could go under bridges). May I ask where did you get the information that the gundalow rig goes to windward better than a junk? And thank you for all your interesting posts.

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    1. Thanks for the compliment. I don't remember exactly where I read it, but it was more along the lines of a Lateen sail going better to windward rather than a Gundalow specifically...

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