Previous columns have provided a basic introduction to the art and science of splicing, the process whereby a rope may be repaired, fastened back to itself to create an attachment point, or even made into an eminently useful rope tool. Rather than review much of that previously discussed material and information, this column will provide more in-depth information on splicing methods for the different constructions and fibers that make up the majority of rope used in the tree care industry.
Readers familiar with previous discussions will remember that one of the great advantages of splices is that they retain much more rope strength than a knot and are much more efficient to attach/detach objects from in comparison to knots and hitches, thereby saving time and energy throughout their working life. In addition, you should have a grasp of the manner in which splices work: by using the friction of the rope fibers against one another to provide even more “grip” or strength as the attachment is pulled on harder while keeping the overall rope fibers in better alignment than the inherently weaker knot or hitch. These basic bits of information will assist in understanding the current discussion of splicing of different ropes.
As can be seen in the table, which only contains the most common and basic varieties of rope construction, there are a wide variety of ropes in use daily in the tree industry. Some of the types of construction listed below could be divided even further, but for simplicity’s sake this selection will serve to give general information about rope construction and help you gain an understanding of the splicing challenges of each type. Each of the construction types listed can be spliced, though there are certainly brands or makes within most constructions that either cannot or are so difficult and ungainly to splice as to make it counterproductive, not to mention stressful, to do so.
Three strand is not only the rope of our forbearers in the tree industry, but also the rope of our general ancestors back many hundreds, if not thousands, of years. Some chronologically gifted climbers can still remember the joys and beauty of working and even climbing with it. This rope was made of natural fibers for many years, which in itself presented its own use and wear challenges. Now it is almost always found on a tree work site in its synthetic form. While once the climbing line of choice, it is now used almost exclusively for rigging, lightweight and otherwise. As can be seen in the table it is particularly suited to natural crotch rigging, where it tolerates wear and friction better than many other more “advanced” ropes.
While three strand can be spliced into a number of useful rope tools, two of the most common are an adjustable lanyard or an eye at the end of the line. Splicing three strand requires the use of a tuck splice in which the strength of the splice is generated by the friction provided by all three strands being “tucked” individually back through themselves. As in all splicing, care must be taken to pass enough material back through the rope, in this case in tucks, to provide enough strength for the splice to be successful. General three strand splices will require 16 crowns of rope for the section that is to be tucked, and then each of those three strands tucked a minimum of five times through the other strands of the rope.
Twelve strand, solid braid
This was the next rope “evolution” in the industry and continues to be a popular climbing and rigging line. This is partially due to its economical price, but also because rope choices are quite personal to tree folk, and when one is found that is to their liking they typically settle in with it.
While not commonly done, solid braid twelve strand can be spliced, though even a talented and experienced splicer will require a great deal of time to complete it, and the end result often looks like something a five-year-old did. This is due to the nature of its construction. Since it is a solid braid, each strand needs to be tuck spliced, much like the three strand; and one can imagine the effort and appearance of tucking each of twelve strands individually five times. A better option for an attachment loop or rope tool out of this construction of rope is industrial stitching, which several arborist retailers/manufacturers offer.
Sixteen-strand rope is a very common choice for climbing lines and may also be used as a rigging line, as long as climbing ropes are never used for rigging and vice versa. Most of these ropes have the vast majority of their strength in the sixteen-strand braided cover, with the materials of the core simply helping to keep the rope “round” during use. This makes any strength loss through severed or burned fibers fairly obvious to the user when they inspect their climbing line daily, but also changes the type of splice that is used to create an eye.
This rope is spliced through a bury splice, and though fairly simple once understood and practiced, step-by step instructions are beyond the space and intention of this column. A description would include, once again, the importance of accurate measurements in the set up of the splice and the general manner in which the splice is done. In short, the core is pulled from almost all the section of the rope to be spliced, with the strands of the cover forming the eye and providing, due to the construction type, almost all of the strength. The cover is buried back inside itself and in the final section crosses over and lays along the core inside the rope. This last overlap between core and cover not only completes the splice, but also keeps the core from milking down the line, leaving the user with a less-than-helpful “flat” spot or section.
Double-braid ropes are literally ropes within ropes. Though the strength breakdown will vary with make and manufacturer, both core and cover, in general, bear about half the load, thus each providing to the overall strength of the line.
Previously used almost exclusively for rigging, many of the available smaller-diameter climbing lines are now of a double-braid construction. As noted in the table, double-braid lines are best suited for blocks when being used for rigging or some sort of friction management device when being used in dynamic climbing, as the inherent friction of a natural crotch can not only be hard on their cover, but also place more of the load on the cope, thus decreasing overall strength.
Most double braids are spliced using a type of bury splice, but would-be splicers must be aware if they are dealing with a core-dependent double braid, as that will not only change the equation, but also the splice method. A core-dependent double braid is one in which the majority of the strength is in the core, with the cover simply providing general protection, therefore the core will have to be spliced in a manner suitable to its construction, and the core integrated to protect, but not detract from, the core’s splice. While appearing to be a complicated splice when first confronted, the double braid, as with most splices, grows easier and faster with time, particularly with an understanding of the rope’s construction and strength. Measurements are, of course, key to producing a safe and usable splice. Once again, while step-by-step directions are not possible, a general description is as follows: The core is pulled out of the cover for the specified distance, leaving the splicer with, in a sense, two ropes at the end of the line. The cover is tapered, though this can be done either before or after the bury it is the process of specific strands being removed to decrease the diameter of the cover, and then the cover buried within a certain distance of the core. The core is then buried back within the cover, once again for a specific distance, and both ends pulled on alternately to tighten the “crossover,” the area where core and cover overlap in the proposed eye. After some additional tapering and smoothing, the integrated core and cover are pulled back inside the original cover, creating the desired eye in the end of the line.
Want to learn?
First and foremost, splicing, while quite satisfying, is not an activity to be undertaken lightly. Improper understanding, poor attention to detail and shortcuts can lead to property damage, bodily damage and even death. The splicer won’t get more than their pride hurt creating the splice, but the end user is literally hanging their life on it. Rope manufacturers such as Yale, Samson and New England are a wealth of information about the construction and splicing techniques for their particular ropes, and in many cases have directions/kits that can help a would-be splicer get started. In addition, a number of companies, including Brion Toss Yacht Riggers, Arboriculture Canada Training and Education, and North American Training Solutions, provide hands-on instruction through classes and seminars.
While this discussion has simply touched the surface of the interaction between splicing techniques and rope construction/fibers, it provides an introduction to how the two may interact either successfully or unsuccessfully. Additional factors such as the type of material making the rope, the intended end use of the rope tool and many others will all affect the splicing method, but this basic introduction can help interested tree care professionals continue down the road so recently traveled by their lost companions Stanley Longstaff and Pete Donzelli, and the thousands who have traveled the splicing trail before them.
By: MICHAEL TAIN SEPTEMBER 1, 2012
(Courtesy of Tree Services Magazine: http://www.treeservicesmagazine.com)