It is a lanyard that fills two basic functions: 1) a self-belay during your time at the belay station; 2) a more comfortable hang at the belay station. The climber fastens one end to the harness using a simple prusik (cow hitch), the second end is fitted with a carabiner that is connected to a specific protection point. Its length should be set in such a way that it can be comfortable to hang in it. It must be set individually according to the person’s height. Of course, be careful not to exceed the length of the cowstail, which must be long enough that you can reach its carabiner with your hand when you are sitting in it. A cowstail is an important part of your gear, above all when climbing multiple pitches; if you are planning to rappel you will need it constantly. At first glance a cowstail looks ordinary and simple, despite the fact that errors can be made when it is used. And since the cowstail serves as de facto protection, it protects you in certain moments against falling, and therefore any mistakes concerning it are very dangerous.
The hazards of the rubber collar
Often a webbing runner closed in a loop is used to create a cowstail, with the carabiner end often equipped with a rubber collar. Either a normal rubber band, or certain special rubber protectors which are otherwise used with quickdraws. The motivation for using such equipment is usually an effort to fix the lanyard firmly to the carabiner, and also to protect the material of the lanyard from scraping against the rock. Except that the placement of this rubber collar carries great danger.
There is a risk that one of the strands of the lanyard will clip its way through the gate, thereby ending up with the entire lanyard outside of the carabiner. If the rubber collar weren’t there, then in such a case normally the lanyard would immediately fall out of the carabiner, and the climber would discover the disruption of the connection in a timely manner. And yet, in cases where you have a rubber collar, the lanyard continues to be held “falsely” to the carabiner. Once it is loaded with the weight of a person, such a weak rubber collar cannot hold on, and the lanyard will tear off.
A strand of a lanyard can usually clip through the gate for any of the following reasons: 1. A mistake from lack of concentration, the clipping of the carabiner has been carried out blindly; 2. Chaotic conditions at the belay station, above all unclear organization of runners and slings; 3. Movement at the belay station causing the lanyard to wind across the gate of a carabiner whose locking sleeve has been forgotten to be screwed in, or that has no locking sleeve at all; 4. Unfamiliarity with the danger.
The danger of a cowstail made of a lanyard on a carabiner closed with a rubber collar. If one of the strands of the lanyard clips through the gate, the rubber collar will tear when loaded and will result in a fall.
How to prevent this danger? There are several options.
One is the option of using any of certain special cowstails which are sewn together by the manufacturer; in other words, not lanyards sewn in a simple loop (in this way the possibility of one strand of the lanyard clipping through the gate is ruled out).
A frequent solution is to tie an overhand knot in the bight under the rubber collar in order to create a loop in the lanyard whose length is so small that it won’t enable the lanyard to clip through the gate of the runner when fixing the end of the lanyard to the bottom elbow of the carabiner. When the otherwise dangerous situation occurs that the longer strand of the lanyard clips through the gate, the rubber collar does not tear out at all because the knot actually provides you with a second loop through which the cowstail continues to hold in the carabiner. Of course, this solution is not entirely ideal. The overhand knot in this case is loaded anomalously and this reduces the strength of the lanyard.
Tying the end of a cowstail with an overhand knot in the bight. The loop thereby created in the lanyard must be small enough that even this loop cannot allow a strand to clip through the gate of the carabiner of the cowstail. — Of course, in this case the overhand knot will be loaded anomalously, which will cause the lanyard to lose strength in the knot.
Another possible solution is to make an additional turn in the strand of the lanyard as a backup. If a strand of the lanyard clips through the gate of the carabiner, then this turn will come undone, but the main loop of the lanyard will remain in the carabiner. This solution is relatively elegant, and the breaking strength of the lanyard will remain practically unaffected, but this solution addresses only one incident. In the case that the other strand of the lanyard clips through the gate as well, you will not be protected.
Winding an additional backup turn into the strands of the cowstail. An elegant solution where the strength of the lanyard is reduced only minimally; however, this solution protects only against this mistake occurring once. At the same time the lanyard is fixed to the carabiner less, the turn does not grip it as tightly.
From experience thus far the best solution is to use a clove hitch to connect the carabiner to the cowstail. This reduces breaking strength only slightly, and cinches well around the lanyard so the cowstail will remain fastened to the carabiner relatively well, which contributes to easier and safer manipulation of the cowstail, and reliably secures it even if a strand of the lanyard repeatedly clips through the gate of the carabiner.
The best solution is to tie a clove hitch. Minimal loss of breaking strength, relatively good cinching around the carabiner, and protection even in the case of repeated accidental clipping through the gate.
A popular configuration of cowstails is the so-called daisy chain. This is a runner which is sewn to itself in multiple places in such a manner as to create a series of small pockets in a row. It enables a person to create a cowstail of the most suitable length. A daisy chain is connected using a prusik (cow) hitch by one end to the seat harness, the other end is equipped with a locking carabiner. Setting the length takes place in such a way that you clip the pocket that is the most ideal distance from your harness into the carabiner of the runner.
More in e-book.
Mountaineering Methodology – Part 3 – Belaying and Rappelling
Available for download from Apple iTunes (in the Books section).
For example U.S. store – link
Another countries – look on the page Download
Another possibility is Google Play. This version is a simplified (as PDF).
Mountaineering Methodology – Part 3 – Belaying and Rappelling
Available for download from Google Play.