By Michael “House” Tain
Attaching another line, a piece of gear, or even a floating anchor point to the middle of an existing line is a scenario that arises on a fairly regular basis in the tree care industry; and is also a situation that can not only be problematic to carry out, but downright dangerous if done improperly. “Poor outcomes” can range from the fairly minor (a desired rigging line falling free from the ascending line and “monkey knot” just as it reaches the climber) to the catastrophic (a poorly chosen midline knot or attachment method failing under the stress and force of a rigging/pulling operation leaving ropes and large woody debris flying in unintended directions).
[As an aside, a “monkey knot” is where one does not know the correct knot/hitch; and “monkeys” around until some form of knot/hitch is created.]
There are a variety of knots, hitches, and midline attachment methods available — some quite simple and others more complex. But regardless of which method is used, it is imperative that, in the interest of safety and efficiency, the tree crew involved have the necessary knowledge and training to make the correct choice.
Strong and easy
Although the tree crew should be choosing their midline attachment method based on strength and ease of use, they should also keep in mind that these two factors may often affect one another. Strength, whenever a discussion of knots and hitches is involved, is primarily about how much strength will be lost in the line through creating a hitch or knot. As is well known among the tree folk and cordage connoisseurs everywhere, the bends created in a line when tying a knot cause strength loss (generally the sharper or more acute the bends the more strength is lost). Ease of use is a fairly simple concept to comprehend — if a chosen midline attachment method takes a great deal of time to put in place, and can only be removed through the use of a fid or sharp edged implement, it is pretty clearly not that easy to use. There are midline attachment methods that may take longer to “set up,” thus reducing their ease of use factor; but if the particular method creates the minimal strength loss needed for the scenario, the additional time is well spent. Knowledgeable and well-trained tree crews are constantly balancing these two factors throughout their daily work; and making choices that make the most sense for strength and ease of use. Some examples of midline attachment methods that are extremely easy to use are mechanical ascenders or other similar devices. The downside is that under extreme loads many ascenders will begin to tear the cover of the rope, thereby causing strength loss; so perhaps they are best suited for very minor loads or the climbing applications for which they are designed and intended. A Bowline on a Bight is a knot that is fairly easy to tie midline, but its sharp bends create significant strength loss, and it can involve some effort to untie after heavy loading — thereby proving itself lacking in both strength and ease of use for midline attachment of heavy loads.
The Alpine Butterfly is not only fairly easy to create once practiced, but has a moniker guaranteed to bring a grin to nature-loving tree folk. This knot, which, as the heading suggests, came from the world of mountaineering, creates some strength loss through its sharp bends. But head-to-head testing done with the same type ropes has shown that it creates less strength loss than the traditional Bowline variations. There are a number of methods to tie it, but perhaps the simplest involves making three turns around the palm of the hand, starting from thumb to finger tips. 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 from both ends of the line and in the midline attachment loop created, all simultaneously if required by the situation. Extreme loads may lead to some difficulty in untying the knot, but the presence of symmetrical “rolled” turns allows the user to “push” the knot apart.
Dark water, utilities, and three traditionals
The Blackwater/Lineman’s Loop/Triple Bowline is a knot that has various titles depending on where one is geographically located, but is tied and used the same regardless of name and location. The Blackwater, like the Alpine Butterfly, does create some strength loss through its bends, but, once again, in head-to-head testing with the traditional Bowline variations, this knot was “stronger.” The Lineman’s Loop also, at least from personal experience and conversations with other users, seems to be much easier to untie after extreme loading than some of the other options. It also has several methods in which it can be tied; but one of the simpler methods involves three turns around the palm of the hand from thumb to fingertips, but then digresses to create the Triple Bowline. 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.
If you’ve got eyes, use them
Both eye and eye or Cyclops (single eyed) bridges or tails can be used to create a midline attachment point; and can be of great value when adjustability and minimal strength loss are desired. Pretty much any climbing hitch may be used in this application, though additional turns will often be added to increase security and friction. The use of Cyclops tails will obviously limit the user to hitches such as the Blake’s or Tautline, while a two-eyed tail opens the whole pantheon of hitches to availability. One that is fairly commonly used with a two-eyed tail/bridge, and relatively simple to tie is 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 secure 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 added advantage of being much easier to adjust or move after loading than a traditional Prusik hitch.
A Quick Hitch is an easily tied and untied simple slip knot in the standing part of the line. While it should not be used for heavy loads, and is not appropriate in all applications, it can be very helpful in sending additional gear, equipment, and even lunches aloft. A properly tied Quick Hitch can help prevent rigging lines from passing through a block or pulley inadvertently, and even snaring a forgotten Friction Saver out of a tree. It is formed by creating a loop in the line, and then passing a bight through it, either 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. In the case of items that are going to rest within the loop, the loop can be cinched down upon it prior to movement.
The Slipped Sheet Bend, a gift from the seafarers of yore and present, is an excellent choice when sending additional lines aloft. The knot’s simplicity and security make it an excellent tool to have in the mental toolbox, and one that will be used on a daily basis. A bight is formed in the existing or upper line, then the working end of the line to go aloft is passed through and around the back of the bight. A true Sheet Bend would be created by passing the working end of the line to go aloft beneath itself, but in this slipped version a bight is created and placed beneath the line to go aloft. This variation allows for quick one-handed release once the knot reaches the climber.
The midline attachment methods and principles discussed here are an introduction to finding a knot for that middle spot. There are a far greater variety of knots and methods available than those discussed here, but these basic ideas can help tree crews make the safest and most efficient choice when confronted with a blank line and a need to attach something to it.
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.