By Michael Tain
Friction plays a role in every aspect of climbing arborists’ work. The very attachment knots that secure climbers to the ends of their lines rely on friction to stay in place, and all knots and hitches are dependent on some measure of friction, regardless of their function. However, this ever-present physical property can also play an extremely important role at the tie-in point (TIP). Traditionally, climbers have simply run their lines over crotches or branch attachment points within the tree; accepting the species-dependent additional friction, wear on their ropes, and damage to the tree’s cambium as just the “cost of doing business.” This technique has distinct disadvantages, including those already mentioned, when used in a dynamic climbing system where both parts of the line move. There are several options available for climbing arborists who wish to lessen the amount of energy they expend to overcome friction at their TIP; and reduce damage to their rope and the tree they are climbing.
* Cambium Saver: This device is a simple leather tube that the climbing lines passes through, reducing friction, and wear on the tree’s cambium and the rope. Although it does not reduce friction as greatly as some of the other options, the Cambium Saver does have the distinct advantage of being fairly simple and straightforward to install. Once the climber has isolated the desired TIP with the throwline, the climbing line is pulled up and over the TIP with the Cambium Saver already on the rope. A simple slip knot keeps the leather tube from slipping down the line, and once it has reached its desired location over the top of the branch, the climber pulls the slip knot free from the ground, setting the Cambium Saver in place. Due to the Cambium Saver’s simple and rugged construction, it can simply be pulled out with a stopper knot at the end of the climb; however, this does allow for the possibility of it tying itself around a branch on the way down to the ground. Attaching a throwline to the end of the line with the stopper knot eliminates this possibility.
* Friction Saver: This device, a heavy-duty webbing strap with either steel or aluminum rings sewn in at both ends, may be both installed and retrieved from the ground, though that certainly is not required for its use. In fact, in brushy, densely canopied trees, it may be faster and more efficient to carry the Friction Saver aloft, and install it in the desired TIP upon arrival, then taking advantage of the reduced friction to work the tree. Although more complex to install, this device reduces friction a great deal more than the Cambium Saver. The Friction Saver has both a large and a small ring, and the small ring will not pass through the large. This unique design feature is what allows it to be installed and removed fairly easily from the ground with a modest amount of practice. There are various ways to install a Friction Saver, but a fairly common method, once the climber has isolated the desired TIP, is to pass one end of the throwline through the large ring, and the other through the small. A throw bag is attached to the throwline that passes through the small ring, and the excess throwline is pulled through the large ring until the throw bag begins to lift the small ring of the Friction Saver. Care must be taken to use a throw bag with a large enough ring that will not pass through the small ring, and also to ensure that there are no bends or twists in the Friction Saver itself. A large loop has now been formed with the throwline going over the branch and down through both rings of the Friction Saver. The small ring is pulled up to just beneath the TIP, and then snapped quickly over it, with the climber immediately releasing tension on the throwline. This immediate release of tension will help reduce the likelihood of violent swings or twists entangling the Friction Saver, and will encourage the throw bag to descend rapidly. With both ends of the throwline now on the ground, the climber simply unties the throw bag, attaches the climbing line, and pulls it up and through both rings. Removal of this device should only be done with a throwline in a controlled manner to prevent any damage to the Friction Saver, and to allow room for operator error.
* Rope Guide: This device must be carried aloft to install, but can be removed from the ground safely and securely in a number of ways. The Rope Guide is a camming device with a pulley that provides the TIP for the climbing line. Its camming action allows it to be adjusted to a wide variety of lengths, and even cinched up against a bare trunk where no branch attachment point exists. In addition, the Rope Guide’s pulley provides extremely smooth rope movement with the largest reduction of friction of any of the devices discussed here. The Rope Guide is adjusted to the desired length, the pulley passed through a large ring, and the climbing line then passed through the pulley. The chosen removal method will dictate additional steps that may need to be taken with this device.
There are obviously more friction reduction and management options than those discussed here; and each of these devices could be examined in much greater detail. In addition, climbers should always remember that a reduction of friction at the TIP will result in greater friction and heat in their climbing hitch, and they should climb accordingly. However, any reduction and management of friction in a dynamic climbing system will result in less rope and tree wear, as well as less energy expenditure for climbers — all positive outcomes.
Michael “House” Tain is a contract climber, splicer, educator and writer currently located in Lancaster, Ky. He can be reached via e-mail at firstname.lastname@example.org