Climbing arborists use a variety of knots and hitches to accomplish their work aloft, and one of the most important and most influenced by personal preference/climbing style, is their choice of which climbing hitch to use. The broad description of “climbing hitches” can be further divided into two basic types: open and closed hitches. Open climbing hitches are those hitches in which only one end of the rope or cordage used to form the hitch is secured to the climber’s harness, either tied directly to the harness or through the use of a connecting link, such as a snap hook or carabiner. The other end of the cordage is used to tie the climbing hitch around the line and is finished with a stopper or safety knot. These hitches can be used in either fixed or split tail/bridge climbing systems; and though split bridge users commonly use a spliced short length of rope for this purpose, the same effect can be safely and easily achieved by using a short length of rope with an appropriate attachment knot tied to the chosen connecting link.
The Tautline hitch is most likely the first climbing hitch used by climbing arborists in North America. Though satisfactory in both security and performance on three-strand construction ropes made of natural fibers, the Tautline hitch has several limitations on synthetic ropes of braided construction, which can be more slippery, offering less friction to keep this rolling hitch secure. This hitch may be tied with one hand, but requires the use of a stopper knot in the tail due to its tendency to roll or slide, effectively untying itself. The Tautline’s rolling nature may cause it to move away from the user until the stopper knot contacts the bar of the hitch, ceasing this movement. This effect may also cause it to tighten on the standing part of the climbing line until movement of it is difficult, if not impossible. The Tautline hitch is formed by making two turns around the standing part of the climbing line in a downward direction, and then taking the tail up above the original two turns and making two more turns around the standing part of the line downward in the same direction as the first two turns. Individual users’ preferences and rope choices may dictate more or less turns around the standing part of the line for greater or reduced friction. The lines should exit the Tautline from opposite sides in the middle of the hitch. The tail should then be formed into a stopper knot to prevent the hitch from untying itself when under load.
The Prusik hitch is quite similar in construction to the Tautline. It can be used with either a fixed or split-bridge climbing system, and can also be tied with one hand. Unlike the Tautline hitch, the Prusik does not roll and can be loosened by applying pressure on the bar of the knot, typically with the climber’s thumb. It does tend to tighten more under load, which can make it difficult to move. The Prusik is formed by making two turns around the standing part of the climbing line in a downward direction, and then taking the tail up above the original two turns and making two more turns around the standing part of the line downward in the opposite direction from the first two turns. Once again, individual users’ preferences and rope choices may dictate more or less turns around the standing part of the line. The lines should exit the Prusik from the same side in the middle of the hitch. The tail should then be formed into a stopper knot for additional security.
The Blake’s hitch can be used with both fixed and split-bridge climbing systems and, though it does not roll, should be used with a stopper knot for additional security. This hitch’s lack of a rolling effect means that it does not move away from the climbing arborist during use, and does not bind as tightly on the standing part of the climbing line. This reduced binding makes the Blake’s hitch easier to move after loading. The construction of this hitch focuses a large amount of friction on one specific point, which in long, fast descents will result in glazing of the cordage. Long and fast descents should be avoided as much as possible when using the Blake’s hitch, or any other climbing hitch. The Blake’s hitch is formed by making four turns around the standing part of the climbing line in an upward direction. The tail is then brought down between the user and the bridge, crossing beneath and capturing the bridge, and then brought up beneath the bottom two turns on the other side. The tail should then be formed into a stopper knot for additional security.
Climbing hitches are key components of a tree climbing system. Their ability to move while ascending or descending within the canopy, yet hold a load when stationary, make them a vital tool of climbing arborists. The information shared here on various open climbing hitches will hopefully assist climbers in making informed decisions about which one best suits their needs and style of climbing.
Michael (House) Tain is a contract climber, splicer, educator and writer associated with North American Training Solutions/Arbor Canada Training and Education, currently located in Lancaster, Ky.