Top roping is the most common form of belaying that is done in the United States. Sport Climbers usually have an easy way to get to the top of the rock that they are trying to climb. They will use that way to set the rope system up.
At the top of the climb there has to be a solid anchor. Anchor failure is a problem that is easy to avoid as long as you are careful about your choices. Inspect what you are going to use as the anchor . Just because the guys right before you used it yesterday, it is not necessarily still solid. Also be wary of gear that has been left behind. If (and this is a big if) you use it, absolutely make sure that is is still good.
To create an anchor you simply wrap a piece of sewn tubular webbing around the base of the item that you are using for an anchor. Tie a loop knot in each end of the webbing. Then pull one end of the webbing through the loop of the knot on the other end. IMPORTANT: turn the webbing so the long end comes directly off of the side of the anchor. We want the webbing to tighten up on the anchor point and not put pressure on the point where it loops through itself.
You will need to find a handy backup for your anchor. This redundancy will at some point save your life. Keep this secondary anchor point within a 60 degree arc directly behind the primary anchor point. To see potential anchors, stand on the side of the anchor directly behind where your rope is going to be attached. Look 3o degrees to either side for a suitable anchor. Ideally it will be directly behind your primary anchor.
Tie another line (I suggest webbing over rope, it is easier to carry in and out and, personally I find it easier to work with), to this secondary anchor point, using the same method as before. Then hook it to the original anchor point with a carabiner. Hook it to the webbing or rope that is being used to tie the rope to, not the anchor itself.
This back-up anchor is intended to replace the original anchor if it fails.
Now that we have the anchor set-up and a back-up, we can look at hooking up the rope. You have two methods to do this.
1) You will attach a carabiner to the loop in the webbing. To this carabiner you will attach what is called a shear reduction device. This is a semicircular device with a track to thread the rope through. The diameter of the semicircle is in such a relationship to the diameter of the rope as to nearly eliminate the shear on the rope. Shear is the downward force that is erected on the rope when it changes directions from going up to going back down.
2) An alternative method of attaching the rope to the anchor points is to use at least two, if not three carabiners with the gates reversed. This means that when you hook and lock carabiner number one to the end loop of the webbing that is attached to the anchor, the gate is up and locked. Carabiner number two is hooked to the webbing with its gate facing down and locked. Carabiner number three is hooked to the webbing with its gate facing up and gate locked. This creates a similar effect of the shear reduction device.
Either method creates a pivot point for the rope to travel through as the belayer takes up the rope as the climber ascends and does the same as the belayer lowers the climber after the ascent is over.
Now we need to thread the rope through the pivot point of the anchor. Put the rope through the pivot point device (the carabiners or the shear reduction device). Let one end down the cliff face by lowering the rope, hand over hand. Stop when there is about ten feet of rope on the ground. Take the rest of the rope and get ready to throw it off of the cliff. Yell "ROPE!". If everybody is out of the area where the end of the rope will land is clear, they will yell to you, "CLEAR!". Then you toss the rope down to them.
This is the setup for top roped belays. This is the most common way to belay a climb. It does require that you have an alternate access to the top of the climbing route.
Remember: This blog is intended to assist you in understanding the concepts and skills needed to be a successful climber. It is not meant to replace professional instruction.
A Great source for rock climbing information is from the folks at The Climbing Harness Co.
Another useful guide to climbing can be found here
