Page 65 - Duane Raleigh - Knots Ropes for Climbers

Rope Testing

Many myths surround the UIAA, rope testing, and ropes. The most prevalent is that ropes with a
higher number of falls held are superior to ones with fewer. Some misguided people hold falls held
as the ultimate benchmark for rope quality and buy based solely on this deceiving number. Before we
go into why such claims are mostly rubbish, you

should understand how the UIAA drop test works. With single and twin ropes, a 176-

pound weight is dropped approximately 16 feet on 9 feet of rope that is tied off to the scaffolding. The

test sounds tame, but it's a bit like a hanging and is an eye opener when you see it. The snap on the
rope is appalling. You need witness only one such drop to reaffirm your faith in climbing ropes. The
test is so severe that it's nearly impossible to duplicate in real life, where the give in the belay, your
body, the runners on protection, your knots cinching up, the friction of your body grating down the
face, slippage through the belay device, and all the other uncounted and often unknown factors keep
the impact forces well below those generated in the lab. And the UIAA requires that single and

double ropes withstand five such drops. Twin ropes must survive twelve test falls.

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The strenuousness of the UIAA test assures that any passing rope is safe. Ropes that go beyond the

minimum requirements aren't necessarily stronger or safer or longer wearing.

About all you know for certain is that they can survive a good number of test drops and cost more.
And, unknown to most customers, the number of falls held as stated on the rope's hangtag is supplied
by the manufacturer, not the UIAA. A shady manufacturer can, for example, list a rope as an eight-fall
though only one sample held that number of test drops. The other samples might have held only six or
seven. Meanwhile, another

manufacturer could get the same results but list its rope as a six-fall. As a consumer, you have no way

of knowing who is conservative and who stretches the envelope. All you see are the numbers six and
eight. The UIAA doesn't care one way or another so long as the samples sustained five drops.

A more telling number than falls held is the maximum impact force. This indicates how much force a
rope is able to absorb. Since you and your protection feel the brunt of the impact force, the lower this
number, the better you two will be. The UIAA lists the

maximum impact force at 2,640 pounds for single and twin ropes and 1,760 for double

ropes. They do, however, allow ropes to stretch 45 percent of their length to absorb the force and do
not require the manufacturer to list dynamic elongation. Thus, it is possible to purchase a low-impact-
force rope that will, to your dismay, stretch like a Slinky when you drop onto it.

Oddly, the UIAA does require that a rope's static elongation be noted on the hangtag.

Static elongation is the amount a rope will stretch when you hang on it, as you do to rappel, jumar, or