Page 223 - The Complete Rigger’s Apprentice

Table 7. Splice Strength as Percent Rated Strength of Wire Rope

November 1, 1982, issue, fittings were measured THE 1 x 19 WIRE SPLICE
against the wire’s rated strength. Cast-Lok and Sta- MADE POSSIBLE
Lok fittings tested at 110 percent and 106 percent,
while the swaged wire broke at 95 and 105 percent In the days of hemp rope, if riggers wanted an eye
of rated strength. in the end of a line, they spliced or seized it there. As
The other six samples tested by O’Connor iron wire rope came to prominence in the latter part
were “improper” splices: an early splice of my stu- of the 19th century, riggers treated it pretty much
dent’s (made after only a few hours’ practice); 1 like hemp, splicing and seizing as they were used
x 19 splices with standard thimbles instead of the to doing. It was more difficult to hold and work the
solid or heavy-duty thimbles that should be used stiffer, tougher material, but they managed—once
with this construction; splices in old wire; and one they had devised some specialized tools such as rig-
sample made very short, so that the splices backed ging vises.
into each other at the middle. This group averaged With progress, iron gave way to plow steel, and
87.7 percent of the rated wire strength; technique plow steel (at least for yachts) to stainless steel.
and proper materials do make a difference. Wire construction was also changing, with the old
6 x 7 being replaced by 1 x 19 wire (Figure 6-39).
These changes were calculated to reduce (even if
only slightly) weight, windage, maintenance, and
stretch, to aid the performance of twentieth-century

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