Rope types and their falls explained:
1215 :: 27.01.2013
Disclaimer: This is a brief view of ropes and there fall catching capabilities and is in no way complete, there is a lot more to know and understand before jumping on the sharp end. This is compiled with my knowledge and experience and should not be taken as gospel. Do your own research and study and always climb within your abilities and only with full knowledge of all of your equipment.
Ropes for lead climbing should only ever be dynamic. You should NEVER lead climb on semi-static rope; any lead fall on semi-static will likely put you in hospital or worse.
There are three types of Dynamic ropes:
The most common, this rope is used as a single strand. It is best adapted to difficult routes which are fairly straight-line, easy routes without change-over belays, and where descent is not by abseil. It is in particular the rope for sport climbing.
A ‘rope’ formed of 2 strands used together of which the leader is tied into both but, unlike twin ropes, two seconds may each be tied into just one of the strands. The leader clips only one strand into each runner so as to reduce drag. Half ropes are recommended for mountaineering, wandering lines and long ascents where abseil descent is necessary. In addition they offer better protection against stonefall or falling on an arete; to limit the drag, and thus the fall factor, you can clip the strands separately
These ropes are always used with the two strands together, remaining parallel. Each climber ties into both strands and these are always clipped together. Its advantage over a single rope is that it allows for abseils as long as the rope. It is lighter than half rope but does not allow for separate strand clipping.
All dynamic ropes have to be tested for conformity to the Standard EN 892 in a test tower at a fall factor 1.77 (see below for fall factors explained).
Single and twin ropes are tested with a mass of 80kg. A single rope, must resist at least 5 successive falls, and both strands of a twin rope combined, must resist at least 12 successive falls.
2. Half ropes are tested with a 55kg mass on one strand. It must resist 5 successive falls. Why 55 kg?Because ropes which hold 5 falls with 55kg in practice hold 2 falls with 80kg, which has been allowed as sufficient security for a half rope which is not used to hold repeated falls on one strand.
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*Factor fall explained: Generally only possible in multi-pitch climbing and whilst on lead, the fall factor( f ) is the ratio of the height ( h ) a climber falls before the climber’s rope begins to stretch and the rope length ( L ) available to absorb the energy of the fall.
Confused? (Ignoring rope stretch)
a) If you climb 5m above a belay placing gear at say 4m and fall you will fall 2m (1m to the piece of protection and 1 more below it) on 5m of rope.
f = 2/5
f = 0.4 Not necessarily a bad fall.
b) If you climb 5m above a belay without any gear placement and fall you will fall 10m (5 to the belay and 5 more below it) on just 5m of rope.
f = 10/5
f = 2 A factor 2 is the worst kind of fall you can apply to a rope (and belay).
With factors in mind, always place gear or clip bolts as soon as possible when leaving a belay; it’s not the time to be thinking about running it out, not even just a little.
Acknowledgments: Beal Planet, Wikipedia.