For more than 30 years, Arbor Age magazine has been covering new and innovative products, services, technology and research vital to tree care companies, municipal arborists and utility right-of-way maintenance companies
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TRAINING TRAINING & EDUCA& EDUCATION ROPE AND ROPE TOOLS By Michael "House" Tain Rope and rope tools are a part of every tree care professional's daily world;and,in most cases,are the most vital components of the job.After all,any type of tree work would be pretty difficult to accomplish with- out something to climb on,rig with,or lift up/lower down on.As with any tool,understanding the strengths,weaknesses,and care of ropes and rope tools will go a long way toward making sure they are used safely and efficiently by all crew members involved. Construction Ropes can be broken down into five basic types: three strand, 12 strand solid braid, 16 strand, 12 strand hollow braid, kernmantle, and double braid; and, as can be seen in the accompanying table, each has specific properties and abilities that may make it more or less suitable for a particular task. ROPE TYPE CONSTRUCTION Three strand Twisted, all strands bear load Twelve strand Braided, all strands USES Lightweight natural crotch rigging Climbing and/or natural solid braid bear load, no core/ crotch rigging solid in middle Sixteen strand Braided cover, cover Climbing and/or light- strands bear load Double braid Braided core/cover, both bear load, rope within rope Kernmantle Typically a braided weight rigging Rigging with blocks/smaller diameter climbing lines Climbing and/or rigging cover over a core that where smaller diameter bears majority of load and possibly more static line is needed Twelve strand Braided, all strands 12 Arbor Age / May/June 2012 hollow braid bear load, hollow in slings/eye and middle Rope tools/rigging eye Prusiks A rope tool, in this case an endless loop, used to create a footlock Prusik for ascent. Although all these constructions may be present on tree care worksites, the most common are 16 strand, double braid, and 12 strand hollow braid. Ropes of a 16-strand construction form many of the common climbing lines; and are designed so that the braided cover carries the majority of the load with the core simply ensuring that the rope stays round for functionality.This construction of rope is fairly easily spliced, though it can also be industrially stitched to create an eye or other desired rope tool.Double-braid ropes were typically built and used for rigging applications, but within the last decade several popular double-braid climbing lines have become available.A line of this construction is a rope within a rope, consisting of a braided cover over a braided core; and, as such,both components must work together to provide maximum strength. Double braids may also be spliced,though it is a more involved process due to the two "ropes"involved;and may also be industrially stitched to create the desired effect.Twelve strand hollow braid is commonly used to create a variety of rope tools due to the ease with which it is spliced. Many rigging slings,eye and eye Prusiks,and other rope tools are created from this construction,but,due to its relatively loose braid and tendency to flatten, it is unsuitable as a climbing or rigging line. Choices There is a wide variety of newer fibers available with desirable char- acteristics such as heat resistance and extreme strength.However, rope selection should always be based not on what the "latest and greatest"rope can do, but on what the crew needs it to do. For example, typically a rope with incredible strength numbers for its diameter is also going to have very little elongation or stretch.Therefore, while it'll certainly han- dle that big load that gets dumped into it by the crew, it'll also directly transfer all that energy of force right up to the rigging point where the www.arborage.com