- Cambium Saver: This device is probably one of the simplest available, and immensely easy to install and remove. The Cambium Saver is a sewn leather tube pre-shaped in a curve. The climbing line passes through it, reducing the amount of friction that the climber has to work against while also protecting both rope and bark from excessive wear and heat due to mutual contact. Once the desired tie-in point is attained with the throwline, the end of the climbing line, with the Cambium Saver already installed on it, is pulled up into the TIP. A slip knot beneath the device keeps it in place on the rope; and allows the user to release it from the ground, installing the Cambium Saver over or around the desired tie-in point. Removal is easily accomplished by tying an overhand knot in the climbing line, pulling it up to the device, and simply pulling it out to remove it.
A Cambium Saver in place for installation on a climbing line being pulled aloft by a throwline with a slip knot to keep the device in place beneath it.The Cambium Saver in place in the desired TIP, prior to the final step of pulling the slip knot loose from the ground.
- Friction Saver: The Friction Saver, developed by ArborMaster Training and manufactured by Buckingham, consists of a large and small ring at opposite ends of a heavy duty machine stitched webbing strap. The climber’s rope passes through the rings after installation, reducing friction even more than the Cambium Saver, while still protecting the tree and rope from contact with each other. The large ring, marked by the orange end of the webbing, and the small ring, marked by the green end, allows the Friction Saver to both be installed and removed in/from the desired tie-in point from the ground. The installation of a small Prusik cord on the device also allows it to be used in a choking fashion when spur climbing or when no branch attachment point is present at the desired TIP, though the choking feature cannot be installed from the ground.
In the second step of Friction Saver installation, pull on the throwline passed through the large ring raising the Friction Saver to just beneath the desired TIP. Pulling at a slight angle will help prevent twisting and tangling.
With a quick snap, pull the small ring and throwbag over the desired TIP and release the throwline immediately to reduce the chance of entanglement. In the final step of Friction Saver installation, the throwline is used to pull the climbing line through the two rings.
- Rope Guide: This device, developed and manufactured by Advanced Ropeclimbing Technology, employs both a camming system to allow it to be choked against the tree or let out to the desired length, and an extremely smooth and fluid pulley that the climbing line passes through. The smooth friction reducing capability of this device’s pulley is greater than that of either the Friction or Cambium Saver; and the design of the overall device prevents excessive contact between rope and tree. Although the Rope Guide can be installed from the ground with some imagination, it is not as simple a process as some of the other devices discussed here; and is most commonly carried aloft while footlocking to be installed by hand once the desired tie-in point has been reached. The device can be removed from the ground either by a second line installed when aloft, or through the use of a Double Snapper, also from ART, for remote retrieval.
- Buck Blocks or MagBloc: This device, designed and developed by Scott Prophett and Scott Winningham, and introduced to the tree care industry this year by Buckingham, is available in both a climbing and rigging configuration. The Buck Blocks provide users with the capability to climb out of an actual block at the tie-in point, improving the rope’s bend radius and reducing friction immensely, while still being easily installed and removed from the ground through the use of throwline. The rope, once installed, runs through a rope channel across the two rotating sheaves, while the separate halves of the device are held securely together by rare earth magnets. The amount of friction reduction, due to the two rotating sheaves, is greater than either the Cambium or Friction Saver, while still protecting both the tree and rope from contact and associated wear.
- Creative Devices: Climbing arborists who wish to “create” their own friction management device rather than purchase one are only limited by their imagination, and the always important breaking strength standards for personal support. Any variety of straps, slings, spliced rope tools, connecting links, and pulleys can be combined to reduce friction at the TIP; and with some time or thought, allow for easy installation and retrieval from the ground.
Managing friction effectively at the tie-in point will not only help climbing arborists work more safely and efficiently, but also increase the lifespan of their ropes, while reducing heat and friction damage to the trees they are there to care for. Although this brief introduction cannot fully encompass the various advantages and disadvantages of specific friction management devices, it does provide a glimpse into the possibilities and an introduction to their use, hopefully helping tree care professionals focus on keeping friction as a force for good rather than evil. Author: Michael Tain