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 without 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.
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.
Twisted, all strands bear load
Lightweight natural crotch rigging
Twelve strand solid braid
Braided, all strands bear load, no core/solid in middle
Climbing and/or natural crotch rigging
Braided cover, cover strands bear load
Climbing and/or lightweight rigging
Braided core/cover, both bear load, rope within rope
Rigging with blocks/smaller diameter climbing lines
typically a braided cover over a core that bears majority of load
climbing and/or rigging where smaller diameter and possibly more static line is needed
Twelve strand hollow
braided, all strands bear load, hollow in middle
rope tools/rigging slings/eye and eye Prusiks
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 insuring 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.
A rope tool, in this case an endless loop, used to create a footlock Prusik for ascent. All photos by Michael “House” TainChoices
There is a wide variety of newer fibers available with desirable characteristics 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 handle 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 climber is typically tied in. As professionals, tree crews need to look beyond the “sales pitches,” and recognize how the rope is going to be used in their day-to-day work; and what they hope to accomplish with it safely. Something as simple as rigging out of a natural crotch can dictate which rope would be the best choice; and discovering that the wrong choice was made midway through the job is a hard way to learn a lesson, particularly if someone gets hurt in the process.
Rope tools are simply needed pieces of gear that have been created out of cordage through either hand splicing or industrial stitching. They are meant to accomplish a task in tree care operations that either would not be possible otherwise, or one that would be more difficult. They can also be created by tying appropriate knots to create the desired rope tool, but knots decrease strength dramatically in comparison to splicing or stitching. So, in general, a spliced or stitched rope tool is the better option. Whether it has been stitched, spliced, or tied, a rope tool used for rigging, even just once, is [ital>never<ITAL] P climbing.
An eye and eye being used to create a rope “grab” on a rigging line.Endless loop
One of the simplest rope tools, an endless loop is created by securing a length of rope or cord back to itself. The loop can then be used in a variety of ways in climbing and rigging: girthed around a trunk or limb providing an anchor point or foot hold, or wrapped around a single or doubled climbing line in a variety of ways it provides a means of attachment to the line for both climbers and other loads. This tool’s primary limitation is its lack of adjustment; it has to be exactly the right length for most applications.
These tools are most commonly created from 12-strand hollow-braid cordage, but some are available made out of double braid. They have a large eye in one end, and are particularly useful in attaching rigging blocks or devices to a tree. A timber hitch or a cow hitch with a better half are the best knots to use to attach an eye sling to the tree. Whenever possible, the use of connecting links should be avoided in dynamic rigging situations with them. A bowline tied in an old piece of rigging line may look similar to a spliced eye sling, but this hand-tied eye sling is a recipe for disaster. Beyond the possibility of the knot working loose through multiple loads, the sharp bends created by the bowline will reduce the original strength of the rope by at least 40 percent, meaning it will fail at the most inopportune of times.
A rope tool in action, footlock ascent on an endless loop.Whoopie and loopie sling
These rope tools are adjustable in nature; and are most often constructed from 12-strand hollow-braid ropes. The whoopie has a fixed eye on one end and an adjustable eye on the other, and is an excellent choice for attaching lowering devices and the like to a tree. Its adjustability allows it to adapt to a variety of diameters, which makes it the efficient choice. The block or device should be connected to the fixed eye, which has been passed through the adjustable eye. Although it can be used aloft, easy adjustment will be much simpler at ground level. The loopie is an endless loop with the advantage of being adjustable, and is typically put in place by girth hitching it around the branch or trunk to attach a rigging block. Its adjustability and ease of use makes it an excellent choice for rigging set-up aloft.
Eye and eyes
Often called eye and eye Prusiks, these rope tools have an eye at both ends; and though they are most often used in dynamic climbing situations to create the climber’s hitch, they also can be used in rigging operations to “grab” a rope, control a load, or attach another pulley to the line for mechanical advantage. The key thing to remember when using an eye and eye in rigging operations is that more friction is likely the desired outcome, so more wraps with the chosen friction hitch are probably going to be needed to achieve that.
The better informed and more knowledgeable tree crews are about rope and rope tools, the better the choices and decisions they are able to make about rope, and in the end, the safer and more efficient they will be.
Michael “House” Tain is a contract climber, splicer, educator and writer associated with North American Training Solutions www.northamericantrainingsolutions.com and Arbor Canada Training and Education www.arborcanada.com. He is currently located in Lancaster, Ky., and can be reached via e-mail at email@example.com.