Page 234 - The Complete Rigger’s Apprentice

rated strength; the specific percentage will vary
from batch to batch. The best manufacturers,
notably MacWhyte Wire Rope and Carolina Steel
and Wire, test every run of their product. When
you buy wire, get the production number of the
spool it came from, then call the manufacturer’s
quality-control department for the breaking-strength
Figure 6-41T. The finished splice. figures for that production run. That way, you
can get precise numbers for your own destruc-
tion tests.
The parceling can be of friction or adhesive Swages and other mechanical terminals are
tape, with more lanolin applied to waterproof the almost universally rated as being stronger than
splice. If you’re going to serve with wire, use par- splices, but bear in mind that: (a) a rig’s design and
celing made from polyester bed-sheets or soft, light safety factors are based on the wire’s rated strength;
sailcloth instead of, or in addition to, the tape. The (b) the anti-fatigue splice will degrade more slowly
cloth parceling won’t get chewed up by wire service. than mechanical terminals will; and (c) mechanical
1
Use wire service of ⁄16-inch (1.5-mm) annealed terminals aren’t always as strong as their manufac-
stainless 1 x 7 seizing wire for stays with sail hanks turers claim. You might break a swage or two in
on them, or any other splices that receive a lot of your tests.
chafe, as from sheets. Chapter 5 shows how to go
about it. Otherwise, nylon seine twine of size 30–36 Possibilities
thread makes an excellent, inexpensive, durable The 1 x 19 Wire Splice enjoyed an all-too-brief
service. Paint a finished nylon-served splice with a vogue in the first half of the twentieth century, before
mixture of one-third black paint, one-third varnish, an expanding yacht population, high labor costs,
and one-third net dip (available at fishery supply and a shortage of skilled labor all conspired to make
stores) for a tough, resilient, handsome finish. swages and other terminals the preferred alterna-
Once you get the idea of the splice firmly fixed tives. But this splice just refuses to die. People seek
in your mind, turn out 15 or 20 of them for prac- it out for new boats, for born-again classics, and for
tice, to get the splice firmly fixed in your hands. cruising vessels of all descriptions. It isn’t likely to
When your work consistently looks good, it’s prob- dominate the market ever again. On the other hand,
ably consistently high in strength. But before you if a splice in 1 x 19 wire is possible, anything is.
consider using one, send a few of them off to be
destruction-tested. Wire rope manufacturers and Other Terminals
distributors in your area will know the location of If, after all of the above, you want to pursue other
the nearest testing facility. options, there are three main ones: swages, sock-
To test the greatest number of splices with the ets, and mechanical terminals.
least work, splice one end of each piece and have
the tester swage the other end. They’ll pull each Swages Swages are formed by inserting a wire
piece until it breaks and send you a certificate that into a steel cylinder, and then mashing that cylin-
says how much strain was on each splice when it der down, under tremendous pressure. The steel
broke. By comparing these figures with the wire’s of the cylinder actually flows into the interstices
ultimate strength, you can determine the strength in the wire, producing a terminal which, if done
of your splices. properly, is 100 percent efficient.
The actual breaking strength of good domes- There are two forms of swages: roll and rotary.
tic wire rope can be 5 to 15 percent more than its For roll swages, the cylinder is passed between two

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