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All photos by Michael "House" Tain lock 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 This knot, called the Grapevine or Double Fisherman's, is very useful for connecting the ends of two parts of line together, though it is not one that is all that easily untied after loading. It is a common knot for creating will result in more cordage to cordage surface for grip, an endless loop for a footlock Prusik (tied in this case in larger diameter line for illustrative purposes). 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 Petzl Piranha DMM Offset Eight, are ones of the type a form to prevent a fall in the event of mechanical fail- These two descent devices, (left to right) the for descent in and thesystem. secured footlock user should have available a static ure.This requirement can increase complexity when using mechanical devices for the secured footlock technique. in tree operations, it is of particular importance when using a hitch in the secured footlock technique. Prior to beginning the ascent, the user Tied, dressed, and set should make sure the chosen hitch is tied correctly, dressed (ensure that While working arborists should already be familiar with the concept all the parts of the knot/hitch are in proper alignment), and set by putting of tied, dressed and set (TDS) as it applies to the knots/hitches they use their full body weight on the hitch to make sure it grips the ascent line www.arborage.com Arbor Age / November/December 2013 15