Hi guys
I have question about semi-static rope. I find that there are some people in gym are using semi-static rope for top rope belay. As we know that the fall factor for rope rope belay is very low, so if the belayer is keeping an eye very closely on the climber, then it is safe to use semi-stactic rope. But I want to know, if this kind of using are correct or not? Please let me know, thanks.
As a guess, based on having climbed with many 5 year old, with a low body weight not making any significant impact on a dynamic rope, I think the style of the rope is not so important. I mean, if you compare, a: An 80 kg parent belaying your child with a dynamic rope, or b: A 30 kg friend belaying your child with a static rope, the static example gives your child a softer fall. However, the might be official rules and recommendations that say the opposite.
I think the main reason why not more gyms are using semi-static ropes (EN 1891, often, incorrect, called static) is that people pull the ropes and use them fore lead-climbing, and that wouldn't be so good =).
In the EN 1891 norm there is a fall-test with 80 kg in a factor 0,3 fall. The impact-force is not allowed to be over 6 kN. In this fall you have both ends attached static, which isn't the case in top-rope climbing.
So you can do a quite long fall without any big risks for your body. But it will not be comfortable.
I think the best is to continue with the standard dynamic rope (EN 892). It will be more comfortable.
But don't be afraid of a bit slack on your semi-static, its softer than most people think.
I should not suggest you to use it only because of lower price. It will get stiff and not usable much earlier then dynamic rope, it will be harder to handle it and what was already said if someone will try to use it as belay rope it will be dangerous.
About Semi-static rope using in Gym