History, equipment and procedures

Production tree climbing is a diverse, eclectic activity involving numerous skills, activities and nuances. No matter the method of entry, line installation, size of tree, type of work or vagaries of weather, clientele or client, the basic act of stepping up to a tree and attaching yourself to the climbing system happens every time.


The earliest method of rope-assisted tree climbing did not even involve the use of a saddle, per se. The end of the climbing line was fashioned into a harness of sorts, often a bowline on the bight or triple-loop bowline with an exaggerated tail. The climber inserted their legs and/or waist, used the elongated tail to fashion a climbing hitch onto the standing part of the line and proceeded to climb.

While certainly streamlined with no excess equipment involved, this system offered dubious comfort and questionable safety due to fit and tying inconsistencies. Over time, rope saddles were evolved as a separate entity. A good discussion of saddle types and their evolution can be found in Gerald Beranek’s “Fundamentals of Tree Work.”

However, even with the arrival of saddles, the earliest connection method was still to simply tie the saddle to the climbing line. Often, two half-hitches were used. A long tail was left as before and the climbing hitch was fashioned from this.

A selection of connecting links. a) Non-locking steel snap, b) locking steel snap, c) D-shaped carabiner, d) ultra “O” carabiner, e) captive eye carabiner.

Tying directly to the saddle has the advantages of simplicity and security. A minimum of equipment is necessary. Provided the attachment knot is properly formed, set and backed up, nothing short of rope failure will separate the climber from their line. The disadvantage is the amount of time and process it takes to undo this security and reestablish it. To retie in a tree, the climber must untie and retie both the climbing hitch and the anchor knot, then retie them. To overcome this limitation, climbers introduced the steel tree snap, as it was commonly called.

Eventually, the use of carabiners borrowed from other high-angle disciplines and the use of split-tail climbing systems further advanced the evolution of connecting links as they pertain to climber and saddle.

Hardware and evolving systems

The steel tree snap allowed the climber to attach a connection directly to the climbing line once and leave it there for the entire climb. Now, if a climber wished to retie while climbing, only the climbing knot needed to be undone and retied. It was also a necessary development to open up the realm of saddle bridges. The bridge of the saddle is the section used to connect to the line. When tying the line to the bridge, all that was required was a “D” ring or two. These could either be fixed or sliding. The introduction of the snap did little to change this. The first snaps used typically had narrow gates and were too small to admit more than one or two rings. In time, larger snaps were used to allow different bridge configurations and multiple bridge connections.

Directly from the use of the original steel tree snap came the advent of carabiners and carabiner-style snaps. Today, the modern arborist has an array of snaps, carabiners and hybrids available in numerous materials. While traditionally steel, connecting links have turned more toward aluminum. Many climbers prefer the lighter weight of aluminum, especially if they are using multiple connecting links in a single system, such as some split-tail systems. Aluminum tends to be more brittle and softer than steel. Therefore, it does not react the same way to the physical abuse offered up by production climbing as steel. This does not rule aluminum out for climbing, but must be taken into consideration. Whether steel or any other material, carabiners will often get tossed and bumped while climbing. It is up to the climber to use whatever material is chosen responsibly with due respect for its life-supporting activities. A regular system of inspection and retirement should be incorporated with connecting links, as with all equipment.

An excellent resource on types, origins and proper uses of connecting links in tree work can be found on the Treemagineer’s download page (www.treemagineers.com/downloads.php ). This exhaustive description is a must-read and does the topic more justice than I could hope to muster in this article.

Early tree snaps had no protection against rollout. This is the condition in which the gate of the snap can be inadvertently opened during use. This commonly happens when a climber twists and turns, causing the gate to press against the rope, another piece of hardware or possibly a branch or a twig. This situation is not uncommon and continues to be a cause of injuries and fatalities today. Modern snaps deal better with this concern, but some systems are not as foolproof as they may seem. Recently, some newer aluminum snaps have had some roll out issues.

A modern climbing system with good interfaces. Notice how clean the splice at the red arrow makes this set up. Also notice the rubber keeper (yellow arrow) does not allow the hitch cordage to misalign the carabiner

As always, any connecting link must meet applicable industry standards. For instance, ANSI standards state that any life support connecting link should meet or exceed a strength rating of 5,000 pounds or 23 KN, be auto-locking and have two distinct motions before the gate will open.

As with any system, ease of use, while not overriding safety, is a concern. Complicated systems introduce more variables into a system. Increased variables increase the chances of mishap or malfunction. A climber must have a detailed and intimate knowledge of his climbing system before use at height. Efficiency is also important. Use a system you are comfortable, familiar and efficient with that offers the greatest amount of return with a minimum of complication.

Procedures and interfaces

A useful acronym to help a climber combine safety and efficiency is C.L.I.P. The “C” stands for clip, the physical act of attaching a connecting line to its anchor. “L” stands for lock. Every connecting link used for life support should be auto-locking and completely locked before using. There can be no safe exceptions to this rule. “I” reminds the climber to inspect the connection. Relying on an audible click or tactile (feel) inspection is unreliable. A visual inspection combined with audible and tactile approach is best. The “P” tells the climber to proceed only after the first three stages have been completed. The climber should go through the C.L.I.P. procedure every time a connecting link is disengaged and reemployed.

Interfaces refers to the mating of any two pieces of equipment. This is intrinsic to connecting links and vital. No aspect of an interface should compromise the safety features of the connecting link or the anchor. Furthermore, interfaces cannot interfere with the proper functioning of any piece of equipment. An example of a bad interface is a nonlocking snap on a D-ring of a saddle. This condition is prone to roll out as discussed earlier. Climbers must be acutely aware of interfaces and assure they are proper and secure.

As with all things tree climbing and safety, be sure to practice low and slow and become familiar with all the tools and techniques you intend to use before you use them. Remember to work safe. Safety is not a tool or technique, but a thought process.

Tony Tresselt, a writer, ISA certified arborist, TCIA certified tree care safety professional and instructor for North American Training Solutions, works for Arborist Enterprises in Lancaster, Pa.