correction note: IUAA was changed to UIAA, brief dyslexic haze has passed.
There are a lot ropes on the market right now. With the advent of the sub 10mm rope, newer (second-generation) mountaineering or climbing ropes have appeared on the market. Are they safe? Are they safer? What is the definition of a safe climbing rope?
Rock climbing is still in its infancy when it comes to testing our gear. We all understand fall rating (fall factors and such) and we all understand ultimate failure forces (pull testing to failure and recording the force). However, is there a test that can accurately say “this rope X is without a doubt safer than this rope Y?”
Fall tests (UIAA)
The UIAA has a standardized test that all ropes must pass. Here’s a quick explination via shoo on Mountainproject.com
Essentially, the test involves dropping a large mass 2.3 meters above an anchor point, dropping it, and repeating this procedure in rapid succession until the rope breaks. The fall rating is the number of cycles the rope could withstand before failure.
In more detail, the rope is hung with the mass so that there is 2.5 meters of rope out, and raised 2.3 meters above a 5mm in diameter carabiner slightly above the anchor point. Altogether, this results in a theoretical factor 1.71 fall. The mass used is 80kg for singles or twins used together, and 55kg for half/double ropes tested individually.
So, in what situation would a brutal, factor two fall happen 5 times on any rope using 80 kg mass? Is this realistic?
This would have to be the set up: you and your friend go climbing. He’s at the anchor (bolts, presumably, as holding a multi-directional fall of this magnitude on cams would surely blow out the rock) and he ties you off on a knot to the anchor. He’s decided against belaying (would add slack, making the fall less brutal). He’s also used a knot that doesn’t slip.
You then proceed on falling (clean fall, no rock touching the rope) 15 ft (5m) into air, all while you now weight 170 lbs. You have obviously broken your ribs, back, spine, probably have some internal bleeding but you climb back up and do this four more times.
So what’s so dumb about this test? Well, it just shows nothing other than, “this rope can sustain brutal falls that basically never happen.”
The test is repeated five times on the same part of the same rope. Generally, climbing ropes outperform the base test, scoring instead 8-12 falls. Even the thinnest ropes on the market perform at 7-9 falls, generally.
What’s jarring, however, is this explanation from the same post on mountainproject:
The test also implies that ropes with higher fall ratings should be more durable. There is an argument to be made that the exact opposite is a more realistic conclusion. The core strands of a rope are typically what give the rope most of its fall holding capabilities. To increase the number of falls held, while holding materials and construction constant, one would add more core strands. The sheath protects the core. More sheath is more abrasion resistance. The vast majority of ropes are retired due to sheath damage, not core damage.
So, say you had a sharp edge, something the test does not test; your thin sheathed rope will sever immediately whereas your thick sheathed rope will not (correction: a sharp enough edge will sever any rope, a thicker sheath may add some resistance to sawing but ultimately cannot be the only consideration for safety). Unfortunately, sheath durability has no standard test so abrasion resistance is never shown on rope data.
Which is the safest rope?
Knowing that the UIAA has a flawed test for testing ropes, which is then the safest rope? Is the Mammut “Supersafe Evo”the safest (as they clearly have marketed this rope as being super safe)? Is there a brand that has ropes that are “less safe?”
Something that boggles my mind is that there is rarely an accident that has a rope being severed cleanly. In 2010, a climber died as his rope was sawed through from a sharp rock, killing him and leaving his partner stranded. A pendulum fall and a sling caused a sharp piece of rock to saw his line as he fell from a moderate pitch on this climb. Was his rope to blame? Absolutely not, ropes can be cut by all sorts of things (namely, sharp rocks and knives).
Other than this situation, personally I’ve had two experiences with ropes being cut: the first was during rockfall which cut a portion of our rope. We easily got around this by rappelling off someone else’s rope but could have tied our rope together if there had been a need for it. The second was from dogging on sharp rock and taking hard falls repeatedly. My rope started showing signs of abrasion after falling 10+ times on a route at the same spot, more or less, working the moves to get to the top.
What I’ve learned is thus there is no “safe” or “unsafe” rope out there. All ropes have to be used properly. Ropes can’t be used beyond their limits and their limits are clearly defined when you take a second to understand them.
Ropes will always catch your fall assuming you don’t cut them on a sharp edge. Ropes will need to be retired when they show visible signs of degradation. Ropes aren’t an excuse to do dumb things like place bad pro and climb stuff you aren’t ready for.
tl;dr all ropes that are rated by the UIAA are similar, none of them can be considered ‘safer’