Page 334 - The Complete Rigger’s Apprentice

Of all the responses tried so far, the most work-
able has involved a sort of glorified gooseneck fitting
attached to the face of the mast three-quarters or so
of the way up. Shrouds, forestay, and running back-
stays attach to this fitting, which remains stationary
as the mast pivots behind it. The mast is further rein-
forced laterally with diamond stays, which, since they
do not attach to the deck, do not inhibit rotation.
This was the configuration chosen for Tum-
blehome, designer Scott Sprague’s sleek, fraction-
al-rigged sloop (Figures 8-11 and 8-12). (The dia-
mond stays are very small and do not show on the
drawing.) Sprague is best known as a designer of
heavy deep-sea boats like the Hans Christian line,
but when he went to design his own boat, he had
Puget Sound sailing in mind. He wanted to try
something “a little different—lighter, more chal-
lenging, and a lot of fun.”
Tumblehome’s wing mast (4 inches by 14 inches
3
at its largest, with an average wall thickness of ⁄4
inch) is a vertical-grained Sitka spruce work of art.
Here’s Sprague on its construction:
“Originally I was going to cold-mold the mast, but Figure 8-13. Diamond stays, shown here on a multi-
after studying the shapes and wall thicknesses, I con- hull, provide lateral support for a mast, preventing
cluded that for this spar solid spruce made the most buckling without being attached to the deck. This is
sense. The mast is really made a lot like a traditional ideal for masts with long unsupported lengths and
spar. Gluing was a bit of a problem since there was no narrow lateral cross-sections, notably on multihulls.
way to clamp the spar as you would a box mast, so
I made a series of female molds out of plywood and it a semi-stayed mast. Note: In the (many) years
set them up on a 50-foot workbench with a transit. since I wrote the above, wing masts have indeed
The mast was then glued up in two halves and flopped gained wide acceptance, with technical develop-
together like a giant submarine sandwich. Blocking, ments, fueled by many miles of all types of sailing,
halyard runs, wiring, and internal epoxy sealing were informing the design of masts and hardware. As of
all done prior to putting the two halves together. Let- this writing, Tumblehome’s particulars, while not
tuce and mayonnaise are optional.” completely archaic, are by no means cutting edge
Stayed wing masts are more popular on multi- any more, and should be taken as a primer on rig
hulls than monohulls, since the wide shroud angle considerations for rotating masts.
of the former makes for less mast compression.
Sprague widened his shroud angles by mounting Lyle Hess Gaff Cutter
the hinge fitting well down on the mast. This lim- To many people, the gaff cutter rig is not simply old,
its the size of the staysail, but with no backstay to it’s anti-modern. And yet, for eyes weary of balanc-
deal with, there’s room for a big, efficient, full-bat- ing out the high-stress details of the Bermudian rig,
tened main. Note that the section of the mast above the gaff rig is a marvel of engineering.
the hinge is unstayed; like an unstayed mast, it can Just think of it: no standing backstay, so no lim-
deflect to leeward in gusts to depower the main. Call itation on mainsail area. Sail shape controlled not by

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