The use of elevated anchors, i.e. high directional anchor systems, is a mandatory requirement of NFPA 1670 for rope technicians. Having said this, it is impossible to discuss one facet of rope rigging and not address all the many other aspects at the same time. A rope system is like a living breathing thing; like any living thing, it is composed of many cells and body parts. Yes; these many parts are separate components, but without a realization of the whole body each component means little. This is the essence of the knowledge base that rope rescue technicians must try to ascend to.
When we study elevated anchors, we are usually addressing the extremely complex subject of edge management. In other words, how do we overcome edge trauma, and how do we maintain a coefficient of friction at the edge that best meets our needs? Furthermore, elevated anchors are just that…an anchor system. As with all anchor systems, we must have complete working knowledge of force vector analysis and resultant management. If this sounds like an overly demanding picture of years of advanced detailed study of an overwhelmingly complex subject… then good…we’ve made our point.
When approaching an unprotected edge, such as a mountain location or an industrial site that is void of hand railings or other reliable fall protection system, the elevated anchor system needs to be belayed into place using a single tagline. Once in place, leave the tagline connected to the system and tied off at a suitable anchor as a precaution against a dynamic event. A dynamic event could include any number of things like the surface of a mountain edge falling off, or even a mainline failure. Although the system belay would arrest the load, the mainline could possibly jam the high directional pulley and radically alter the resultant causing the tripod to topple over the edge onto the rescue package.
This stuff is getting very interesting. Gear is getting smaller and we’re getting closer and closer to the edge! It used to be the edge was something to stay away from… now we’re looking for ways to put anchors at or Over The Edge… (Yes… that was a plug for our friends. Check them out!)
By The Way… You can see it over at Rigging Lab Academy as well!
“A Confused Mind Will Always Say NO!”
The two-tension rope system is the primary system RLA teaches for lowering and raising rescue loads. The two-tension rope system provides a safer, and easier method of high angle rescue by eliminating fall factor and shock loading of components in the event of a failure.
Peace on your days!