By Michael “House” Tain
The footlock, a method of ascending smoothly and efficiently into the canopy, has been a mainstay of the tree care industry for years; though the element of “security” in the term secured footlock is a relatively recent development. Not all that many years ago, the only security provided when footlocking was by the climber’s hands and feet; and a failure of either set of extremities could lead to an abrupt and painful descent. The ability of the climber to perform an “on-rope rest” while ascending with the footlock was intended to give them the opportunity to regain their energy and vigor to continue the ascent, but once again relied solely on the grip of their hands and friction of their feet for any security. The days of footlock ascents in this manner are long gone now; and any climber using the footlock technique must be secured in some manner — not only to satisfy the applicable standards/regulations, but also to prevent their untimely and speedy descent to ground level. The original method that brought “security” to the secured footlock was a length of cordage attached to the climber forming some type of hitch around the line being ascended, but modern times have brought a variety of tools and methods that provide security. Regardless of which method or tool of security that is employed, users of the secured footlock are well advised to understand not only the capabilities of this technique, but also its limitations. However, once understood and practiced, few techniques for ascent are more efficient and simple than the secured footlock.
The “security” in secured footlock
Although there are a variety of options for securing the climber in a secured footlock, in general they can be broken down into two basic types — climbing hitches and mechanical devices. Any climbing hitch that will grip a doubled or single line adequately when loaded is acceptable for secured footlock; but probably the one most commonly used is the Prusik. This hitch can be created from any number of types of cordage or spliced/stitched rope tools, though users must abide by the ANSI standards requirement of rope strength for personal support (5,400 pounds). The cordage loop or rope tool is simply passed through itself around the ascent line(s) three times, creating what is referred to as a six coil/three wrap Prusik. Climbers may certainly choose to use more wraps around the ascent line in creating their Prusik, which will result in more cordage to cordage surface for grip, but must also realize that this additional friction may work against them in pushing the hitch up during the ascent. Although there are certainly quite small diameter cordages available that meet the necessary strength requirements, prospective users should recognize that the difference in diameter may cause the Prusik to grip so well when weighted that it will be difficult to loosen. Testing in a research setting has shown that a wide difference in diameter of cordage can actually cause damage to the surface fibers of the ascent line when heavily loaded. In general, once the technique is mastered, the climber’s weight is rarely on the Prusik unless they lose their grip and need the hitch to “catch” them, or need to rest at a particular point in the ascent. As mentioned previously, there are a number of mechanical devices intended to take the place of the climbing hitch in the secured footlock technique, and many of them are quite effective and easy to employ (though often less economical than the simple length of cordage forming a climbing hitch). In addition, the guidance provided by industry organizations and standards requires that mechanical devices used in this manner be “backed-up” with a cordage hitch of some form to prevent a fall in the event of mechanical failure. This requirement can increase complexity when using mechanical devices for the secured footlock technique.
Tied, dressed, and set
While working arborists should already be familiar with the concept of tied, dressed and set (TDS) as it applies to the knots/hitches they use in tree operations, it is of particular importance when using a hitch in the secured footlock technique. Prior to beginning the ascent, the user should make sure the chosen hitch is tied correctly, dressed (ensure that all the parts of the knot/hitch are in proper alignment), and set by putting their full body weight on the hitch to make sure it grips the ascent line in the correct manner. If the Prusik is being used, the two parts of the cordage should exit from the center of the three wraps, with each of the wraps in alignment and little or no overlap. Once set with the climber’s weight, the wraps may end up overlapping one another, but the climber should re-dress the hitch prior to re-starting their ascent. Different knots or hitches will require different dressage, but the climber should always go through this process prior to the ascent and again after any loading of the hitch during the ascent.
When using the secured footlock technique on a static line(s), climbers must understand the forces involved, and created, in static systems. Of particular importance is the knowledge that the hitch, regardless of which one is being used, is bearing their full body weight (instead of the roughly half that would be present in a dynamic system). This nugget of knowledge is very important to the climber in that it precludes the use of the hitch for descent, as attempting to descend on the hitch in this static system can quickly result in uncontrollable speed and falling at whatever rate gravity desires. In addition, this inability to use the hitch for descent means that the climber must also have some means of descent available on their harness, along with the knowledge and training of how to install/use it if necessary during the ascent. Some examples of possible descent devices in this application are Figure Eights, ATCs, or Petzl Piranhas — all of which can hang unobtrusively from the climber’s harness until needed.
The climber’s hands must always remain below the hitch during the ascent. Once again, a climbing hitch in a static system performs and functions differently than one in a dynamic system, and inadvertently grabbing the hitch can cause it to release and lead to a painful introduction to ground level. The best way to ensure the hands remain below the hitch is to adjust the length of the cordage creating it, resulting in a length that allows the climber to push the hitch up smoothly while footlocking, but makes it difficult to get the paws above it.
The topic of spread is an important one in the secured footlock technique, particularly when using a doubled line over a particular branch or through a branch union. As the two parts of ascent line go over a branch, the diameter of the branch naturally “spreads” the two parts away from one another. Advancing the hitch providing security into this “spread” can cause the hitch to fail if loaded. A good guideline to follow is that the hitch should remain 5 inches below the branch for every 1 inch of branch diameter. Spread can be eliminated entirely from the secured footlock equation through the use of a single line, or by using a midline knot advanced to beneath the branch to bring the two parts of line close together in a doubled line. In addition, the use of friction management devices such as Friction Savers or Rope Guides will eliminate spread.
Dirty, dirty debris
As every tree crew knows the world of the canopy and tree care is not necessarily a clean one, with large amounts of dust, twigs, chips and debris abounding. Although relatively small pieces of dust or chain saw chips are typically not an issue, leaves, twigs and bits of debris between the two parts of line, in the coils of the hitch, or in the pieces/parts of a mechanical ascent device can play havoc with its effectiveness in providing security in the event of a fall. While ascending, climbers should keep their hitch or device as clean and clear of debris as possible.
Putting it all together
A written description of the actual footlock movements cannot full convey all the moving parts of this technique, but a few basic suggestions may be helpful to newcomers to the secured footlock. The legs are a much more powerful muscular force than the arms, regardless of how many curls may be getting done at the gym, so climbers would be well advised to use them as much as possible when footlocking. Climbers should attempt, as much as possible, to keep their body and legs in line with vertical orientation of the ascent line, pushing or “standing” up with the muscles of the thighs, extending the legs out horizontally is a waste of time and precious energy. The muscles of the arms fully extended will last longer than they will if constantly in a flexed position; and the higher the climber can bring their feet up, working those core muscles, the greater the distance they will travel upward with each lock. Once the lock has been achieved with the feet, the climber should “stand” up, as vertically as possible, and let the tops of the hands advance the hitch up the ascent line. Then re-grip the rope with hands and extended arms, lift the feet high, and begin anew.
The secured footlock technique is an extremely efficient and quick way to ascend into the canopy to begin work. Once practiced, it can make the commute to work smooth and elegant rather than an ungainly chore. Yet, like any technique, it has requirements and limitations; and the basic descriptions and information included here should assist users in understanding how to, and perhaps more importantly, how [ital>not to<ITAL] use this valuable technique.
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.