By Michael “House” Tain
Rigging in tree care — or the process of getting large heavy woody objects safely to the ground — can be a quite simple process requiring little beyond a good 12-strand rigging line, an experienced branch manager and a suitable crotch. Or it can be a very complex process necessitating a truck full of gear, thousands of feet of rope, and a squad of trained fit tree personnel.
Although even basic rigging is not always necessary — after all, what crew does not love to hear a “we fall you haul” work order — and complex rigging may be even less likely, when confronted with a tree or trees that are going to require a variety of systems to get them down safely, the crew needs to know and understand how to employ advanced rigging on the situation with which they are confronted. One of the first and most important considerations — one that affects both safety and productivity — is whether or not rigging is even necessary. Although it is very important to understand how to correctly set up and use rigging systems of various complexities, it is just as important to recognize a situation where the job could be completed without any rigging required by simply removing the target or felling the tree in a completely different direction. Rigging takes time, and time equals money. In addition, the more complex the system, the more links or areas in which something can go wrong. Both of these factors require that professional tree workers not succumb to the lure of a “boatload” of gear and some really great video for YouTube when a simpler, safer, and more efficient approach may have sufficed. However, rigging is often required; and knowledge of some of the more advanced techniques and how to use them with one another will help increase both the efficiency and safety of the crew.
As always, good communication is key on any tree job, and the demands of rigging make it even more vital. All crew members should be familiar with whatever system the crew employs; and be extremely watchful of what is going on within the rigging plan. The rigging plan should be discussed beforehand with all crew members, with everyone knowing what is supposed to happen when, and what their role is in it. In addition, the noisy environment may require alternative communication methods such as hand/arm signals, whistles, radios, etc.; and everyone should be familiar with how they will be used and employed.
This term is for rigging systems that try to minimize or eliminate the use of knots or hitches to attach pieces to the rigging line as much as possible. As a system, its greatest advantage is the speed with which pieces can be attached and detached from the system; and there may be a slight increase in overall rope strength by eliminating knots within the system. A knotless system can, as can all the techniques discussed here, also be used in conjunction with others such as drift or slide lines. A large eye spliced in the working end of the rigging line is one of the simplest methods to eliminate the need for a knot, as the large eye can then be girth hitched around the pieces to be rigged. An additional knotless rigging method is to splice a smaller eye in the end of the rigging line with some form of connecting link in it — typically a captured eye ladder hook or steel rigging carabiner. This connecting link can then be attached to slings girth hitched around the piece; and even multiple pieces if lighter loads are being rigged. Although this method is certainly acceptable and handy if used correctly, care should be taken not to side or cross load the connecting link or hook it back to the rigging line itself. This can result in poor loading and bending radii that are quite unfavorable to rope strength.
Balancing limbs in their original orientation is a technique that can be very useful over obstacles, but extremely difficult, if not impossible, to achieve by trying to guess the exact middle of the limb or piece, and attaching the working end of the rigging line there. A much better, and more successful option, is the use of spider legs or balancers — anywhere from one to as many as are required — to create a “cradle” of lines that support the piece. The unspliced ends of the spider legs or balancers are attached to the piece, and a Prusik or other suitable hitch formed around the rigging line with the large eye spliced in the other end of the spider. This provides an adjustable “rope grab,” which the climber can move up and down the rigging line to achieve near-perfect balance prior to the limb even being cut. This technique, within reason of course, can also be used in combination with the others discussed here.
Almost as valuable as balancing a limb or piece is the ability to lift it into a vertical position under control, to then be lowered to the ground or attached to one of the other advanced systems discussed here for further movement. In order to minimize violent swings, the anchor point for a lift should be as near as possible to directly above the proposed “cutting point” as possible; and the cut itself is fairly technical in nature. In short, the climber must view the limb as a tree to be “felled” upward, with a face notch on the upper surface of the branch, and a back cut below. In addition, the notch should be wide enough that the hinge will not break prior to the branch becoming vertical, once again to prevent violent movements. A general orientation would be one cut of the face notch should be perpendicular to the branch, with the other parallel to the ground, but the cut will typically be quite specific to each branch to be lifted. Lifting the branch will require the use of a GRCS or mechanical advantage system, thus adding complexity, but the technique can be quite useful in very specific situations.
Load and drift
The use of secondary lines to “drift” a piece one way or the other to a desired landing zone can be quite advantageous. Not only does a drift line produce the desired controlled movement and used correctly prevent nasty swings, it also acts to provide additional support and strength to the load. As the piece moves more toward the drift line rigging point, the drift line becomes the load line, with the previous load line becoming a means of control. The addition of friction control devices in the system, such as Port-a-wraps or a GRCS (Good Rigging Control System) will make the system even smoother and more efficient. In particular, a GRCS on the drift line can allow one person to easily move a very large load quite easily and quickly in the desired direction.
This system, often called zip or speed lines, also has a variety of advantages in certain rigging situations. It enables crews to “slide” a load or piece, under control, over obstacles or hazards right to the feed tray of the chipper if so desired. Although quite useful, slide lines are also very gear intensive, and, if used improperly, almost guaranteed to cause some serious damage. Their use will require very good anchor points at both ends, some form of system (typically mechanical advantage) to remove slack from the slide line for each load, and some means to control the speed of the slide. If any of these components are not possible or missing, a different system or method is probably a better option. As with the other systems, a slide line could be used in conjunction, such as a balanced limb being attached to the slide line for its descent, with what was previously the load line supporting it becoming a control line. An additional consideration when using a slide line is what the traveler or carriage is going to consist of. This is the hardware that “travels” down and up the slide line conveying the load. Although a simple carabiner may seem quite sufficient and expedient, it is typically a poor choice except in the lightest of loads and situations. Better options — both to minimize friction and ensure strength — would include some sort of pulley (several of which are designed and intended for slide line use). The landing zone or end point of the slide line should also have some form of system, such as a Port-a-wrap, that allows the slide line to be “slacked” to allow the load to be detached, unless the climber enjoys watching branch managers struggle with large woody debris several feet off the ground.
Advanced rigging techniques can’t be mastered by reading this brief description; but the basic information, advantages, and disadvantages discussed here can assist in further discovering the joys and wonders of rigging. Additional education and training in these techniques, along with the many others constantly being developed and refined cannot help but lead to safer, more efficient tree care professionals.
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 firstname.lastname@example.org.