Slipper, Real Soon Now!

Slipper proceeds toward completion in fits and starts. I must admit that my second attempt to design an original kind of boat has been a bumpier road than the design of Slider.  With Slider, everything was very conventional, except for the in-hull seating on a boat that small.  Even the unusual sprit-sloop rig was not new– James Wharram used the rig for his classic design, Hinemoa, many years ago.  Everything else was as optimized as possible… big high-aspect NACA section rudders and daggerboard, slender slippery hulls, lots of sail shape controls, and so forth.

Slipper, on the other hand, is a kind of Slider boiled down to the bare essentials, so that it could be light enough to cartop, and most important of all, irreducibly simple to sail.  The hulls are still under 50 lbs. each, the center deck is about 35 pounds, the rig and rudders add a little more, but each piece is light enough for one reasonably strong adult to handle.  The rudders are fixed, barndoor rudders, attached to skegs for strength and tracking.

The mast is stayed, because of the difficulty of using an unstayed mast on the crossbeam of an open deck cat, but I’m going to see if I can go boomless on the spritsail, so that the rig can be brailed up by freeing the sheet and hauling in the brailing line.  That would make setting up the rig very simple, since there would be no jib, and no halyards.

The most irritating aspect of the build has been figuring out a good strong simple way to attach the crossbeams to the hulls.  I was obsessed with using line to secure the beams, since I admire the kind of lashings used on certain Wharram designs.  But I was too proud to simply borrow Wharram’s idea of exterior lashing points, and besides, I wanted these hulls to look as graceful as possible, with nothing to break the sweep of the sheer.  There’s a feeling among some admirers of traditional boats that multihulls must be ugly.  Needless to say, I don’t buy it.  I don’t want to contribute to that perception, either.

But unfortunately, my first couple of ideas, while they seemed clever to me, turned out to be completely inadequate.  The first lashings could not be effectively tightened.  The second scheme allowed me to really crank the lashings tight, but unfortunately, the leverage of the mast was enough to pop the beam out of its position atop the bulkhead.  I’m still a little dubious about the current solution, but it is strong, very slightly flexible, and I can’t see how I can break it.  Each connection now requires the use of a 3/8″ stainless bolt.

As I say, I’m not completely happy with it, but there are other things I can’t wait to experiment with, so it will have to do for this iteration of the design.  There’s some extraneous blocking on the beams that can eventually go, but it’s only a pound or two, so for now it can stay.

First and foremost among those other things I want to see about is whether or not a dory-hulled cat can get to windward adequately without foils.  Slider is able to do fairly well with her board up, but her good deep rudders may have something to do with that.  So I’m going to try Slipper without any foils first, and then try the kind of horizontal foils popularized by such designers as Matt Layden and Bernd Kohler.  If either of those approaches proves adequate, Slipper will be a boat that can get to windward in less than a foot of water.

Currently I’m only short some rigging and finish.

So Slipper is going sailing.  Real Soon Now.