31st August 2011, 06:43 AM
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#3 |
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Join Date: May 2011 Location: Victoria, Australia
Posts: 309
|  Re: Belay Loop on saddles?
Back country Beacon Quote:
The belay loop is the strongest part of the climbing harness, so why do so many climbers not trust it? It’s very common to see climbers backing up their belay loop with a separate piece of webbing or clipping their belay carabiner through the waist and leg tie-in points to avoid the belay loop. I’ve even seen some climbers cut the belay loops off their harnesses because they’re “old school” and never had a belay loop when they first started climbing. Although this has always been the case, fear over belay loops jumped off the radar when Todd Skinner tragically fell to his death after his belay loop failed. This had such an impact that backup loops are often referred to as Skinner loops. Unfortunately, most of the things that climbers do to skip the belay loop for extra safety actually makes the system more dangerous.
How Strong is the Belay Loop?
The belay loop is the strongest piece of the entire harness. You could not possibly generate enough force by rappelling or holding a big lead fall to cause a belay loop to fail. Not even close. For a harness to pass CE inspection and be sold in the United States, the belay loop must withstand 15kN (3372lbf) of force for three minutes. This is the minimum requirement. Most harnesses out there have a belay loop that holds somewhere in the range of 22-26kN (5000-6000lbf). What makes belay loops so strong is the way they are constructed. Unlike regular slings which simply have their ends sewn together, belay loops are wrapped in two or three layers and then sewn. This creates friction between the layers to keep them from slipping and unwrapping. In fact, the bar stitches on a belay loop are barely load bearing at all; it’s the sling itself that makes the loop strong.
Try this. Take a piece of webbing about 20-inches long and wrap it around itself until it creates a circle about the size of your belay loop. Now, simply wrap it with scotch tape where the bar stitching would normally be. Now try to pull it apart. Good luck. (a note for the lawyers: do not, under any circumstances, take this test to mean that you can repair your belay loop with tape.)
Actual belay loop webbing and scotch tape
Wrap the scotch tape where the bar stitches should be
135 pounds of short climber held with scotch tape instead of bar stitches
Why Are Belay Loops Not Trusted?
When harnesses replaced swami belts, they did not have belay loops. For this reason, a lot of climbers learned to climb without one, and they think that belay loops are just there to hold the leg loops to the waist loop. Lots of people see the belay loop is an “extra link in the chain.” Why would you want to add a single non-redundant piece to your safety chain? This is as far as most climbers get during the debate.
Skipping the Belay Loop:
An unfortunately large number of climbers clip their belay ‘biner through the harness’ tie-in points instead of using the belay loop. While this may seem like it adds redundancy, it actually creates off-axis loading. Carabiners are designed to be loaded from the top and the bottom. When loaded in the proper manner, most belay ‘biners have a strength rating of about 25kN. If you clip through the tie-in points, then the belay device pulls toward the front, in a third direction. This is known as off-axis loading and can weaken a carabiner to around 7kN. This is an unacceptably low number considering the force that can be created while holding a lead fall or even on a bumpy rappel.
The other method often used to bypass a belay loop is to clip a locking carabiner through the tie-in points where the belay loop already goes, and then clip another locking carabiner to that. Not only does this create the same off-axis loading as the method above, but it also creates a twisting force on the lower carabiner, which it was not designed to take. DO NOT DO THIS!
Misuse:
Besides bypassing your belay loop, there are a few ways you can misuse it in a way that compromises strength. First of all, never tie your rope in to your belay loop. The friction of nylon on nylon is a very bad thing and could possibly lead to failure in a fall or even during a lower that involves a lot of swinging around to clean gear. Of course, tying in correctly also touches nylon to nylon, but it holds the rope in a much more static position, and the tie-in points are designed specifically to deal with the friction. Plus, there are two of them in case one fails.
The other, and much more common, misuse is girth hitching a daisy chain or sling to your belay loop. When you do this, the sling tends to stay in the same place and rub at the belay loop when you weigh the sling at an anchor or even walk around the crag. Not only will this wear the loop (and sling) in a single place, but it also covers up the wear marks, so your loop may be more worn then you realize.
When Are They Unsafe?
There are times when belay loops are not safe. Everything wears out eventually, and it’s not any different for belay loops. Todd Skinner’s accident happened as a result of a badly worn belay loop. Your harness saves your life every time you fall or rappel, and it saves your partner’s life every time he falls. Do not take chances. Learn when to retire a harness, and replace it before it’s too late.
| This clip scares the be-jesus out of me... They are stong, check out the climber in the second part, 40ft + with one hell of a pendulam into those soft rocks. 
And the last fella.... doesn't get a tie in early enough.... |
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