Page 157 - The Complete Rigger’s Apprentice

Figure 5-17. Figure 5-18.

this problem is the addition of another wire, running
from the base of the spreader to the rail, where the
first wire is also attached. The new, more equitable
diagram that results is Figure 5-17. Figure 5-19. A perfectly balanced rig for Syrinx—
Next, since there remains a long length of except that the backstay and jibstay are hanging in
unsupported mast above the spreaders, we’ll add midair. Bringing them inboard (dotted lines) would
a third, intermediate wire to take the strain there too greatly reduce sail area.
(Figure 5-18). The staying angle without a spreader
is only 10 degrees, about as narrow as we can safely
go. Have to do something to improve this before and the lateral load imposed by the sail, as well as
we’re done. imposing a compression load of its own. At the deck,
Meanwhile, things are sufficiently evolved to see the mast partners provide one last lateral support
that the mast and all the wires have become inter- before the mast compression load is finally delivered
dependent, creating a system for delivering strain to the keel. Every time you add a wire, you must
to the hull: The upper shroud takes a portion of the balance it against all the other wires and the mast so
sail’s lateral load at the masthead and delivers some that no one part of the system receives a dispropor-
of it to its base, but also “drops” some of it off at tionate amount of strain.
the spreader. The lower shroud picks up the spread- So far we’ve assumed that the sail’s load will
er’s lateral compression load, some of the mast’s only be imposed laterally, as in the original staying
compression load that was imposed by the uppers, diagram. If this were the case, we could now proceed

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