Situations and scenarios arise every day in field tree care operations where a crew needs some means of attaching “something” midway along an existing line. Scenarios range from the simple, such as the need to get a water bottle aloft so the prima donna climber doesn’t dehydrate, to the complex, such as the need to establish a mechanical advantage “grab” point in the middle of the line before the poorly judged tree goes the wrong way toward the homeowner’s prized Jaguar. Regardless of complexity, the ability of crew members to establish an attachment point at any place along an existing line is extremely advantageous, and is an excellent additional tool for the mental toolbox. Unfortunately, as with so many tools and techniques, there is no “one-size-fits-all” midline attachment method, so just as important as knowing how to establish a midline attachment point is choosing the correct one for the best results.
Strength & ease of use
Strength, or, more succinctly, the amount of strength loss created by the midline attachment method, often can be visibly detected by the presence of “bends” in the line. At the most basic level, when it comes to cordage, sharper bends create greater strength loss, thus the fewer bends a chosen method puts the line through, the more strength should be retained.
Ease of use is almost self-explanatory: A midline attachment method that is difficult to put in place, or takes a great deal of time, may just not be that helpful except in extremely specific situations where its particular advantages are needed. Any midline attachment method can be viewed through these two factors, and a decision made on whether it is a good choice in the given situation. For example, mechanical ascenders are very easy to use as a midline attachment, however their tendency to tear the fibers of the rope under extreme loads make them an unwise choice in many applications. Some knots, such as the Bowline on a Bight, are fairly secure as midline attachment methods, yet the strength loss they create in the rope through their sharp bends and the difficulty of untying them after heavy loading makes them a poor choice in certain situations.
The Alpine Butterfly, an easily tied midline attachment knot with mountaineering roots, does create some strength loss in the rope through its sharp bends, but in testing has shown to create less strength loss than the traditional Bowline or Bowline on a Bight variations. While verbal descriptions of knot tying are difficult, the following in conjunction with the accompanying photographs should lead the crew through the simple steps of this useful knot.
A simple method of tying the alpine butterfly is to make three turns around the palm of the hand, from thumb to fingertips. The turn closest to the thumb is passed over the other two turns to the fingertip end, followed by the next turn, adjacent to the thumb, in the same manner. The turn now closest to the fingertips is then brought back through the other two, forming the loop for attachment. Both ends of the standing part of the line are then pulled in opposite directions to dress and set the knot. The Alpine Butterfly may be loaded on both ends of the line traveling “in” and “out” of the knot and in the midline attachment loop created, all simultaneously if required by the situation.
Triple Bowline/Blackwater/Lineman’s Loop
This knot, whose name seems to vary widely with geographic location, also is an easily tied midline attachment knot that creates less strength loss than the traditional Bowline variations. An additional advantage to this knot, gained from field use and experience, is that it is easier to untie than many of the other knots after extreme loading. Once again, verbal descriptions of knot tying can be challenging, but the following along with the accompanying photographs should make the tying of this knot fairly easy.
A basic method of tying the Triple Bowline is very similar to the Alpine Butterfly, and in fact starts in the same manner. Three turns are made around the palm of the hand, from thumbs to fingertips. The turn closest to the thumb is then passed over to the middle, between the other two turns. The turn closest to the fingertips is now taken to the “new” middle, between the other two turns. In the final step, the turn now closest to the thumb is also taken to the “new” middle and pulled through, forming the loop for attachment. Both ends of the standing part of the line are then pulled in opposite directions to dress and set the knot. As with the Alpine Butterfly, both ends of the line and the midline attachment loop may be loaded if required by the situation, meaning both ends of the line traveling “in” and “out” of the knot, along with the loop created.
Hitches, tails, eye & eye, etc.
The use of an eye and eye or two-eyed bridge/tail to create a midline attachment point can be quite advantageous when minimal strength loss and adjustability are desired. Any of a variety of climbing-style hitches may be used, though additional wraps are taken to increase the amount of friction or grip provided by the chosen hitch.
Hitches such as the Michoacan, Schwaebisch and others all function fairly well in this application, though care must be taken to use those extra wraps to provide the desired “grippage.” A fairly simple and secure one is a variation on the Valdotain Tresse or Vt. As many turns as possible with the given eye and eye are taken in an upward direction on the line. The two ends are then brought together and held securely at the bottom of the turns, as the top turn is rolled down over the other ones, creating the braid or tresse in the Valdotain tresse. This Vt variation also has the advantage of being much easier to adjust or move after loading than a traditional Prusik hitch.
Directional Quick Hitch
The Quick Hitch is an easily tied and untied simple slip knot in the standing part of the line. Though not suitable for heavy loads and all applications, its use is quite valuable in sending a variety of equipment aloft, preventing rigging lines from inadvertently passing through a block or pulley, or even snaring a forgotten Friction Saver out of a tree.
It’s formed by creating a loop in the line, and then passing a bight through it, from above or below the loop. Particular attention should be paid to how the Quick Hitch will be loaded when deciding from which direction to pass the bight through the loop. A bight from beneath the loop will allow for easy release from below, while a bight from above allows for upper release. In either case, the hitch is easily untied with a simple tug in the appropriate direction.
Slipped Sheet Bend
This knot, a slipped variation of the Sheet Bend, is very useful when sending additional ropes aloft. Its security and simplicity make it a very efficient knot to master. It is tied by forming a bight in the upper line, then passing the end of the rope to go aloft through and around the back of the bight. A Sheet Bend would be finished with the end of the line to go aloft passing beneath itself, but, in this slipped variation, a bight is formed and passed underneath. This allows for quick, easy, one-handed release by the climber in the canopy.
ALL PHOTOS: MICHAEL (HOUSE) TAIN