Utilizing Span Rigging to Create Rigging Points
Avoid Climber's Limbo
Many times when rigging down limbs and logs, we as climbers can get into situations where we wished we had a rigging point where one doesn't exist ' a climber's limbo. Personally, I've had many instances when I wished I had a rigging point where one doesn't exist to aid me in getting material into the only open area around, or so branches wouldn't have to swing near me in tight quarters. One rigging technique I've found that has worked very well for this situation is Span Rigging. Span Rigging consist of using the tree you are in and another tree to create a rigging point, as well as a slight mechanical advantage for lifting or moving brush.
Setting Up Span Rigging
Let's start with the set up. The first thing that needs to be accomplished is the installation of a block and rigging line in the adjacent tree. One thing to keep in mind with setting this block is that there will be an increased load and, in some situations, a side load on this rigging point. Make sure you choose a substantial rigging point for this block.
Once the adjacent tree is set and you are in the tree to be rigged down, the rigging line can be tied to this tree in a high and substantial rigging point with a running bowline. A bight of this rope can be run down to the limb you are planning on removing. Next, install something like an Omni Block Sling on the limb and clip it into the bight of the rigging line. When the working end of the rope is pulled, it will create a slight mechanical advantage depending on the angle created by the legs of rope.
Now when the limb is cut it will move to the center point or apex between the block and running bowline. Since the Omni Block is moving along the rigging line, most times this takes quite a bit, shock out of the system ' if not all of it. If limbs are tip-tied in this setup, they can easily swing slowly until they are equalized between the two points.
From personal experience, this technique actually decreases the load on the tree with the running bowline tied to it because there is no block in that tree to increase the load on the rigging point. The best way to help illustrate this is to always remember that pulleys and block are force multipliers when rigging. The running bowline tree sees far less movement when rigging out logs in this setup as well, which can be highly beneficial when rigging in compromised trees or dead trees. As we all know, a good rope guy can be even more beneficial in those situations as well!
Share Your Experiences
Have you ever used Span Rigging on your jobs? I personally love it because of the reduced load on the tree I'm in and the ability to get wood and brush away from me. I'd like to hear your thoughts on this as well as some of your experiences with it! Shoot us some of your thoughts in the comments below!