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cantclimbforsht
Jan 22, 2005, 4:13 PM
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I was at a gym the other day that put pulleys on the TR anchors. This made it so there was almost no friction at all in the system. My belayer who weighs about 20 pounds more than me got pulled up about two feet when I took a fall (not with a super tight belay, but it wasn't very loose either).
I even saw one girl who was belaying someone a fair amount heavier than her get her hand pinched in the atc and she dropped the climber. Of course it was the girls fault, but I don't think this would've happened if they had normal gym anchors such as having the rope go through carabiners or chains or around a bar.
This gym is basically just for little kids parties, so maybe less friction makes it easier when an experienced employee is belyaing a little kid, but the pulleys still seem like a bad idea. Is there any other reason for having pulleys? Am I missing something or is this just a stupid setup?
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kman
Jan 22, 2005, 6:57 PM
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In reply to: I even saw one girl who was belaying someone a fair amount heavier than her get her hand pinched in the atc and she dropped the climber. Of course it was the girls fault, but I don't think this would've happened if they had normal gym anchors such as having the rope go through carabiners or chains or around a bar.
Of course it was her fault...100%. This probably had nothing to do with the anchor.
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goober
Jan 23, 2005, 4:05 AM
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There is no advantage for using pulley's that I know of, even though I have seen it before. Friction is fundamental in belaying and is better when dispersed throughout the system, just like shock absorption should be. Ofcourse this system could have contributed to the girls hand injury by requiring more grip strength to lock off the brake hand (weight that was not absorbed through anchor friction), which she apparently did not have, thus pulling it into the device.
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cantclimbforsht
Jan 23, 2005, 6:23 AM
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one more idea that I forgot to mention:
Maybe the pulleys are meant to keep the ropes healthy? this is just an idea I had. It doesnt seem to make much sense though since I don't think your typical gym anchor messes up ropes too much.
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teamkonarider
Jan 23, 2005, 5:40 PM
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Sometimes gyms like to use what is called a sheer reduction plate. This is commonly mistaken for a pulley even by an experinced climber. They are the standard on ropes coureses. The benifit they provide is a wide rope bearing surface and dramatically extend the life of a rope. But, there shouldnt be much of a difference in friction.
Just my two cents
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easton
Jan 24, 2005, 3:07 AM
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In reply to: Sometimes gyms like to use what is called a sheer reduction plate. This is commonly mistaken for a pulley even by an experinced climber. They are the standard on ropes coureses. The benifit they provide is a wide rope bearing surface and dramatically extend the life of a rope. But, there shouldnt be much of a difference in friction. Just my two cents
This is true because some of them are basically a modified pulley. Put a bolt through the pulley and the housing somewhere out from the center, bammo, locked pulley. This gives a large radius for the rope to rest on, reducing sheer (duh) and creating more friction due to the larger area of contact. They work great on Challenge Courses, and the idea is sound for TR climbing.
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cantclimbforsht
Jan 24, 2005, 4:13 AM
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yeah, a couple of the anchors were like that. they looked like a regular pulley but there was something stopping it from spinning. but there were others (like the one where the girl dropped the climber) where the pulley actually spun.
I dont know, maybe they normally just have more experienced instructors belaying little kids so its not usually a problem for them.
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cracklover
Jan 24, 2005, 3:53 PM
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Yes it would make it much easier to belay little kids. No, it's not a good idea IMHO.
GO
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cchildre
Jan 24, 2005, 7:24 PM
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It saves wear on the rope and the gear. Friction on the rope should occour at the belay point on the ground not on the anchors. Any issue with belayers getting yanked off the ground, they should be anchored into the floor or some other secure point, pulley or not.
I personally think it is stupid to top rope through a pair for draws, beaners, chains. It can put major undue wear on the rope, especially if you give them any power assistance during their ascent. That is one mans opinion.
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