Page 158 - The Complete Rigger’s Apprentice

to calculate actual pounds of strain for a given vessel, diate shroud can be made to guy both laterally and
choose appropriate materials, and begin construc- aft by moving its point of attachment to the hull
tion. But sailing imposes strains from all directions, aft. Happily, this also results in its staying angle
so the rig must be elaborated to suit. increasing from 10 to 10.5 degrees. The forestay
Starting again at the top, the lateral guying of leads from the same point on the mast as the inter-
the upper shroud is complemented by the fore-and- mediate, and since its forward pull is more than
aft guying of the jibstay and backstay. The interme- the intermediate can handle under some condi-

Aft-led vs. Lateral Intermediates

Intermediate shrouds that are led over the lower can make runners easier to use (see below), some
spreaders are maximally effective for lateral staying, designers opt for another tactic that is simpler and
to oppose lateral pull from the forestay, but they pro- cheaper than jumpers, and no work at all:
vide no aft staying to oppose the forestay’s forward 4 Aft-led Intermediates. By taking the intermediates
pull. To deal with this problem, designers generally off the spreaders and anchoring them a little aft of
adopt one or more of the following fixes: the mast, you can get them to function for both aft
and lateral staying. The drawback to aft-led inter-
1 Stiffen the Mast. With a small enough sail on it, mediates is that they don’t do either of their jobs
the forestay won’t generate enough force to deflect very well. They don’t lead far enough outboard to
a sufficiently stiff mast too much. But since this provide optimum lateral staying, and they don’t
means a lot of extra mast weight and an ineffec- lead far enough aft to provide more than trivial aft
tive sail, a more careful designer might choose to staying, because with even a minimal aft lead they
enlarge the sail, lighten the mast, and add: interfere with boom travel and add to mainsail
2 Jumper Stays. These stays project diagonally for- chafe.
ward at the height of the forestay (see Troubador What is worse, their staying angle is so shallow
in the design section). With sufficient mast section, that they add significant extra compression loads
and perhaps a little shaving of staysail size, they to the mast. So, once again, the mast must be
suffice to keep the mast in place. heavier and the staysail smaller.
3 Running Backstays. These stays make up well I believe that aft intermediates are attractive
aft, so they can oppose the pull of the forestay partly because people don’t realize how ineffective
much more efficiently than jumpers can. They can they are, and largely because running backstays
entirely replace jumpers, as well as allowing for can be so very hard to use. As typically config-
more sail and lighter mast. There is a runner on ured, tension is supplied by a block-and-tackle,
each side; the weather one takes the load, while usually 4:1. This configuration must be slacked
the leeward one must be released and taken for- away and taken up on every tack, a process which
ward, so it doesn’t interfere with the travel of the involves copious amounts of rope, and has blocks
main. swinging around at head height. And for all this
Racers sometimes take running-back virtues fussing, you get an anemic amount of purchase,
to such extremes that the mast can come down not nearly enough to tension the forestay when it
if an inattentive crew “blows a tack,” not getting matters (i.e., clearing a lee shore in a blow). That
a runner set up in time. More moderate rigs will is why, in our shop, we run a single-part runner
play mast stiffness off against sail size to get a safe through a single deck block, with a lead to the
stick. Good designers can dial-in these factors so weather winch. Now you have 40:1 or the like,
that cruisers can count on leaving their running instead of 4:1, plus runners that set up quickly
backs unused 70 to 80 percent of the time. and slack instantly. No blocks to hit you, no heavy
The same effect can be achieved by combining rigging flailing around and chafing the mainsail.
runners and jumper stays, once again allowing a The rope is Spectra until just above the block,
lighter and a larger forestaysail than would other- where a fat piece of Dacron is spliced to it.
wise be possible. The load on the deck block is higher by about
The drawback to jumpers is that they are 40 percent than with the older arrangement,
expensive to fabricate and install. The trouble owing to the angle departing the block, but this
with runners is that they require some effort on can be dealt with when selecting the block and the
the part of the crew. While a little careful planning anchoring hardware.

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