Page 160 - The Complete Rigger’s Apprentice

but their location near the waterline presents spe- than the jibstay. By scaling off distances, we find
cial problems. a leverage advantage of 2.8 to 1, so the bobstay
First, the bowsprit. The jibstay at its end, with needs to be 2.8 times stronger than the jibstay. The
a staying angle of 64 degrees relative to the bow- bobstay is the most corrosion- and collision-prone
sprit, has an advantage in leverage over the bob- wire on a vessel, and much of the rig depends on its
stay, which has an angle of only 25 degrees rela- integrity.
tive to the bowsprit. It’s like pitting a long crowbar Lateral staying for the bowsprit is effected by
against a short one. As the dotted line shows, we bowsprit shrouds. No asymmetry here, but once
could increase the bobstay’s angle by attaching its again staying angle is at a premium, so we position
lower end at a point just tangent with the hull, but the chainplates to make the bowsprit shrouds just
this would make the stay much more vulnerable to about tangent to the hull. This has the added benefit
corrosion and to damage from striking objects in the of providing a “fender effect;” a glancing blow to
water, as well as contributing to drag. Better to keep a dock, another boat, etc., will be absorbed by the
its lower end above the surface and deal with the wires, rather than bashing the hull.
leverage inequality with a larger wire and stronger At the other end of the boat, the boomkin
end fittings. extends outward to pick up the backstay. The pres-
Figure 5-21 shows a diagram for determining ence of the rudder precludes a staying arrangement
just how much more strain the bobstay must endure like the bowsprit’s, so the two boomkin shrouds

Figure 5-21. Jibstay strain relative to bobstay strain.
Measure up the jibstay 1 inch, then draw a line par-
allel to the bobstay to intersect the bowsprit, and one
parallel to the jibstay to intersect the bobstay. The
resulting bobstay segment is 2.8 times as long as the
jibstay segment, thus the bobstay must be 2.8 times
as strong as the jibstay. A dolphin striker will reduce
this disparity.

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