Are Falls Held or Breaking Strength More Important In a Rope?
Falls held and breaking strength are both important, and ideally a rope will do well in both areas, but there is a lot more to selecting a rope than simply weighing those two factors.
MARRIAGE MADE AT ROPE FACTORY
Which is more important, the number of UIAA/CE falls a
rope can hold, or how many kiloNewtons it can hold? —climbboy via
rockandice.com
Choosing between those two is like choosing between good
looks and personality. They each have benefits, but ideally you get
both.
While falls held and tensile strength are important and
sound sexy, they are just two of the many bits of data you should factor
into your rope-choosing decision. Consider that ropes don’t break; they
wear out and can also be cut (for a cold dose of reality, read the
Accident Report on page 22). The number of falls held and breaking
strength don’t necessarily make a rope more durable or tougher, or even
mean that it will hold more real-life falls, which are never close to
the CE drop test, a savage ordeal that if you were somehow able to
replicate in the field, you’d see Jesus.
Consider that unless your rope sustains a core shot you’ll
climb on it until it reaches a fuzzy cattail-like state that has you
rightly questioning its reliability, and you’ll retire it then. The
number of falls the rope has held … well, who can even remember?
The more important number on a rope hang
tag is “maximum-impact force.” This is the maximum number of
kiloNewtons a rope transmits onto the top piece of pro in a fall.The
more important number on a rope hang tag is “maximum-impact force.”
This is the maximum number of kiloNewtons a rope transmits onto the top
piece of pro in a fall. Lower numbers are, of course, preferred to
higher numbers, especially if you like to climb above teeny nuts.
Ropes can achieve a low maximum-impact force a number of
ways, but often it’s by stretching. The more a rope stretches, the lower
its impact force. This is a double-edged sword. Low-impact force is
nice, but if the rope stretches so much you hit a ledge, it’s not so
nice. For that reason, also pay attention to “Dynamic Elongation,” which
tells you, in a percent, how much a rope will stretch. The perfect
playmate is a rope with a low dynamic elongation and a low
maximum-impact force. Don’t waste my time!