Everyone in this industry that uses ropes is familiar with the OSHA coined term “softener”. It is simply a form of padding placed between a rope and a sharp edge. This can be as elaborate as a $300 roller-edge-protector or as simple as layered cardboard. In climbing edges are often guarded with pads or jackets. Everyone using ropes is aware of the danger of sharp edges. After all: Ropes do not break. They are cut.
When I worked in a climbing gym, every so many months we would replace the ropes and destroy the old ropes before disposing of them. This involved standing on the rope, pulling it tight, and slashing it with a knife. The first few times you do this you are amazed at how easily even the burliest rope cuts when it is stretched tight. It gives you even more of an appreciation for protecting your climbing ropes when they have to pass over edges.
One of the terms I have not heard in this industry is DEVIATION. A deviation is simply when the rope is redirected by use of carabiners or pulleys. This is typically used to redirect the ropes for better access. But it can also be used in some instances to avoid sharp edges. When presented with having to hang rope over angle-iron, a better option for the rope is to hang it from a carabiner or even better a pulley. This decreases the chance that the rope will be damaged, and decreases the amount of wear on the rope.
When possible, a RE-ANCHOR can be used. This simply involves creating a secondary set of anchors in lines with the primary set. Depending on where it is located, a re-anchor could pose problems for the technician if they must pass it on the ropes.
This is an example of a simple single-deviation that could be used to avoid hanging rope over a sharp edge such as angle iron on a tower. It can avoid the use of a softener and also position the technician better for their work. A carabiner would better protect the rope from the edge. A pulley would further protect the rope.
Another use of deviations would be when an anchor is not in a useful position. An excellent example is rooftops. Many times, there will be one solid area to anchor ropes, but not in a useful place for the technicians. Here, deviations can be used to reposition the lines to the sectors that the technician needs to access.
The consideration here would be the directional forces being placed on the deviation anchor. Though the deviation may support the technician, it may not meet our guidelines for proper anchorage. In this situation the rigger needs to take in account for the angle of the deviation and the amount of force being placed on the rope system. In this example, a softener is still needed for the edge, but the ropes can be placed in a suitable position for direct descent, and far back from the edge to allow for safe access.
The use of deviations in a rope system opens up access opportunities for technicians and provides for a safer work environment. In instances where only aerial lifts or scaffolding were once considered, rope deviations would allow more freedom for the techs and faster turn-around times for completion. In instances where it is applicable, deviations can be used in place of softeners to help preserve rope-life and make access easier for the technician.