By Michael Tain
The term knotless rigging is used to describe rigging systems, techniques, and methods that minimize or eliminate the use of knots or hitches as much as possible. The primary advantage of this minimization is fairly clear — greater efficiency due to time savings in not having to tie and untie knots to attach/detach branches or pieces during operations. Additionally, users may gain an increased level of rope strength by eliminating knots or hitches whose bends inherently create some level of strength loss in the line(s) in which they are tied. As with many techniques and methods, knotless rigging can also be used in conjunction with other rigging operations such as drift or slide lines. However, as with any system, technique, or method in professional tree care operations, knotless rigging is not appropriate for every tree or situation, and care should be taken to only use it when the safe efficient use of this technique is assured.
A wide variety of knots, hitches and bends may be used in a typical rigging operation, from a Timber Hitch or Cow Hitch with a Better Half (to attach a lowering block or Port-a-Wrap) to the Running Bowline or Clove Hitch with two Half Hitches that attaches the branch or piece. The goal of knotless rigging is to minimize or eliminate the use of these knots as much as possible. Several rope tools, connecting links, and techniques make this feasible at the various points in rigging systems, including the working end of the rigging line, the rigging point and the lower anchor point.
Working end of rigging line: One of the simplest methods to eliminate the need for a knot at the working end of the rigging line is to have a large eye spliced in it by a knowledgeable and professional splicer. This large eye can then be easily girth hitched, with additional marls as needed, around pieces being removed in spar pole rigging (and also in other applications if lateral branches have been removed to ease its installation). Another common knotless rigging technique for the working end of rigging lines is to have a smaller eye spliced into the end of the line with either a fixed connecting link installed — such as a captured eye ladder hook — or by using a detachable connecting link passed through the small spliced eye. The chosen connecting link is then attached to slings girth hitched around the branches or pieces to be lowered. Care should be taken not to overload the capabilities of the connecting link in this application, as it is typically the weakest point in the system. Additionally, operators should avoid attaching the connecting link back to the rigging line itself in an attempt to secure the branch or piece — this may cross or side load the connecting link with catastrophic results.
Rigging point: Typical rigging systems and techniques often attach the lowering block to the tree through the use of an eye sling tied with an appropriate hitch. Knotless rigging eliminates the need for these hitches by using rope tools such as Loopie or Whoopie slings in this application. Both of these rope tools are adjustable slings suited for a variety of tree diameters, and remain secure when attached appropriately — even on branchless spars. Of these two rope tools, Loopie slings are probably the most commonly used at the rigging point, and, due to issues of size and adjustability, are more easily used when aloft. The unspliced portion of the Loopie should pass through the block beneath the bushing, and then the sling and block are girth hitched around the tree at the desired point. The weight of the block and the unspliced portion of the sling should load on the spliced bury of the sling thus creating even greater security.
Lower anchor point: The use of Whoopie slings to attach a Port-a-Wrap at the lower anchor point is somewhat common in typical rigging systems, although eye slings with a Timber Hitch or a Cow Hitch with a Better Half are also often used; and this is also an excellent application for a Whoopie sling in a knotless rigging system. Loopie slings may also be used in this application, though users may find their use frustrating and time consuming due to the typically longer Loopie slings needed and difficulty with adjustment. The Port-a-Wrap should be girth hitched to the large non-adjustable eye of the Whoopie, and then passed through the adjustable eye around the base of the tree. The use of connecting links attaching the Port-a-Wrap to the Whoopie sling should be avoided in any dynamic rigging situation due to the possibility of side or cross loading of the connecting link.
Knotless rigging has value in many rigging applications, and users may choose to employ only parts of the technique in their rigging systems. It is of particular value when removing a tree with many branches, such as a conifer, all of which need to be lowered. The capability to lower multiple branches at a time through the use of an appropriate connecting link and multiple webbing slings significantly speeds and streamlines this process. In addition, the climbing arborist may be attaching more slings to branches while the ground crew is detaching the earlier load, thus when the connecting link comes back up, the next load is ready to go. As with all tools, methods or techniques, each component of a knotless rigging system must be examined for safety, and an informed decision made about whether or not it is appropriate for the given tree or situation. But once that examination and decision has been made, knotless rigging can safely speed up the rigging operation.
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