Tying Off For SRT
As with every activity there are numerous ways of doing things. There are many ways to create secure and safe tie-offs for single rope technique (SRT). The methods described below are the ones that I, personally, use most often. Everybody has favorites and these are mine. These are not the only ways to create tie-offs, and most of you will have some different way beyond those mentioned here. Each of those described has its place and each will be used at one time or another, dependent upon existing circumstances. Sometimes, but not very often, I may employ other methods that go beyond those described here.
Tie-offs, generally speaking, can be grouped into two categories, ground-level-tie-offs and in-tree tie-offs. Each has its place, each has its own set of pros and cons, and the decision of which to use and how is mostly determined by existing circumstances relative to the climb that is about to be attempted. The best climbers will set personal preferences aside and go with that tie-off that is best suited to the immediate challenge.
Ground Level Tie-offs
The decision to create a ground-level-tie-off can result from a number of existing factors. Ground-level-tie-offs are generally quicker to rig than in-tree tie-offs. They are more consistent with most rescue techniques and allow for victim recovery- in most cases-without the rescuer having to ascend to the victim. They allow for climbing to proceed without having to take the time and effort necessary to isolate the rope's route upward.
The downside to using a GLTO is that once in the tree, the climber then has only one end of the rope available for use in advancing the climb. This is not a problem for those using lanyards or those versed in the use of Third-Rope technique. This is not a problem if there are others on the ground who can untie the tie-off once the climber is secure on a new setting. This, however, can be scary and climbers should be absolutely sure that untying will not occur prematurely! Nor is it a problem if the climber has rigged for a ground-level tie-off /in-tree rope retrieval. Another negative aspect is that creating a GLTO will require twice as much rope as that necessary for the climb itself; a climb to a limb seventy-five feet above will require at least one hundred and fifty feet of rope.
There is an upside to having twice as much rope as is necessary to reach the entry setting. When it's time to come down the climber has enough rope to descend without having to rig some sort of pull down.
Care should be exercised in the selection of ground-level tie-off points. Sometimes climbers will be tying off to the same tree in which they are climbing, and sometimes they will create tie-off-points(TOPs) on neighboring trees or other suitable anchor points. While tying off to smaller neighboring trees be sure that the tree is alive, that the diameter of the tree is of a size consistent with safety concerns, and that the tree is well-anchored to the ground (ie: Not likely to be pulled out of the ground!).
Descending series of half-hitches finished off with a timber hitch
This is my favorite for a ground level tie-off. My personal rule of thumb is to have at least one half-hitch above the timber hitch. Two is better and three makes me feel real good. If there is enough rope to spare I might add even more, although I don't feel that more is really necessary. The idea is that the topmost half-hitch will absorb most of the force created by the climber's weight. Each subsequent half-hitch, as they descend in order down the tree, will have less and less force exerted upon it. By the time the timber hitch is reached, there is very little force on that knot. There is so little force on the timber hitch, in fact, that if it were untied a person could hold another climber suspended in the air with little more than two fingers. Using three half hitches in descending order, I have been able to hold a two-hundred and fifty pound climber up in the air with nothing more than a thumb and index finger holding the rope. There is very little force on the timber hitch.
For tying the timber hitch, my rule of thumb is to have at least three wraps with each touching the wood. A wrap that does not touch wood does not count. Although three is the minimum, I will usually use as many wraps as I have rope, finishing off with an overhand knot around the rope and a stopper in the tip of the rope.
There are those who insist that a timber hitch can untie itself or slide up the tree if there is slack in the rope. I have never had this even begin to happen and I challenge anyone to show me, when the series of half-hitches and timber hitch have been tied as just described.
The amount of force exerted on each component of the system will vary depending on the diameter of the tree being tied off to, and the amount of friction created by the roughness or smoothness of the bark against the rope.
This is a good system that can work well in rescue scenarios when a victim needs to be lowered to the ground. It is possible for the timber hitch to be untied, even while the system is loaded, and the lowering itself can be controlled by the friction within the remaining half-hitches.
The downside to this method of tying off is that sometimes there is no suitable place to create the tie-off. Trees that are being climbed often have a circumference so large as to preclude there being enough rope to create the system, denying the possibility of tying off to the tree being climbed.
High strength tie-off (HSTO)
The high strength tie-off works almost as well as the half-hitch/timber hitch combination. There are those who say that it is as good or better than the other. This is mostly a matter of personal preference rather than any sort of serious issue.
To create the high strength tie-off, simply tie a figure-eight-on-a-bight in the end of the rope, wrap the rope around the anchor two or more times, then clip the F8OAB to the rope coming off the wrap with a carabiner. Force is distributed circumferentially around the tree being tied off to.
On the plus side, this uses slightly less rope than the half-hitch/timber hitch system. It can also be used as a lowering system in rescue scenarios.
Downside issues are about the same as for the half-hitch/timber hitch combination. Care must be taken to make sure that no angle is created in the rope where the carabiner is attached. The rope going up should come away from the tree being tied to in a straight line tangential to the wraps, leaving very little if any pressure on the connecting point. Any pressure created by such an angle here could result in an inability to unclip from the anchor while the rope is weighted.
Wrap three, pull two, tie-off (W3P2)
I will use this method when I don't have enough rope to create the half-hitch/timber hitch system or the high strength tie-off. A seventy-six or seventy-seven foot entry pitch is just a bit long for a one-hundred and fifty foot piece of rope. Both ends might touch the ground-maybe-but is there enough left over for a good tie-off? Sometimes not.
It is best to use one-inch tubular nylon webbing to create the wrap-three-pull-two. The flat webbing creates more friction between itself and the tree, thus making the setting a little more secure, placing less strain on the connecting bend. I will usually have at least one twelve-foot length in my pack. Rope will also work, but does not create as much friction with the tree as webbing. Start by placing the center point of the webbing on the back side of the tree away from where the climber will leave the ground. Bring the two ends around opposite sides of the tree, let them cross, then wrap again. With both ends right in front of you, connect the two ends with a water knot (ring bend). You will now have three bands of webbing in front of you, with your water knot in one of them. Place a carabiner around the two without the knot and pull them away from the tree. The friction of these two bands of webbing against the tree leaves little pressure on the water knot. You now have created a wrap-three-pull-two. Tie a figure-eight-on-a-bight in the end of the climbing rope and clip into the carabiner.
On the plus side, this method takes up very little of the climbing rope while offering just as much strength and security as the other tie-offs. By tying the W3P2 toward the climber, the climber is able to monitor the tie-off while ascending.
The downside issues are that this method requires just a little more equipment (Nylon webbing plus an extra 'biner), and that the system cannot be released while loaded. This is not good if a rescue becomes necessary. There are also those who worry that the W3P2 could slide up the trunk of the tree being tied to if slack is allowed and then force re-applied. I have never seen one move more than an inch, however, and it is something I do not even consider.
Tie-off for in-tree rope retrieval
Although a bit complicated this is one way to resolve the issue of having a ground level tie-off with no one to untie the setting once the climber is in the tree and has created a new and safe setting.
Start with a W3P2, but instead of clipping in the rope to the 'biner, add a micropulley to the 'biner. Run the rope downward through the micropulley then place a F8OAB in the rope, beneath the 'biner. Add a carabiner to the F8OAB. The F8OAB, along with the carabiner, will act as a stopper to prevent the rope from passing back through the pulley. Tie a throwline to the carabiner on the end of the rope beneath the pulley and commence climbing, playing out the throwline as you climb. Or you may forsake using your throwline by simply connecting the two ends of the rope together in an endless loop (you still have the carabiner there to act as a stopper against the pulley). Once the entry pitch has been climbed, switch to a lanyard, come off the main rope, then use the throwline (or rope) to pull the climbing rope through the pulley and up to your position in the tree. The W3P2 with its pulley will remain in place until you descend and recover them.
On the plus side, this allows the climber to have a ground-level tie-off without needing someone to be present to untie the tie-off, once the entry pitch has been climbed and a new safe and secure setting has been created.
On the downside, this is a bit more complex than other methods for tying off and there is more potential for things to go wrong. It requires more attention to detail. It requires a bit more gear (webbing, extra 'biners and a micropulley). It does not help with rescue. And, as with all of the above, there may not be a good place to create the tie-off.
The decision to create an in-tree tie-off can result from a number of existing factors. Solo climbers who want both ends of their rope available for advancing a climb in the tree will find a limb cinch to be more accommodating, negating the necessity for having someone on the ground untie a tie-off once the climber is secured in the tree on a new setting. In-tree tie-offs (ITTOs) can also be created with less rope than that necessary for GLTOs
The most important downside to creating ITTOs is that an isolated route is usually-but not always-necessary in order to rig an effective tie-off. A non-isolated route will result in the climber's being able to only climb to the lower of those limbs included within the arc of the rope, before needing to create a new setting. Care should be taken, especially on non-isolated routes, to make sure that there is at least one bombproof limb included within the arc of the setting. Small limbs and suckers can also be a major issue as the climbing rope and cinch are hauled upward. Even the smallest of interfering limbs and vines can bring things to a halt. A cinch that has not been hauled all the way to the top can also result in a scary and sometimes nasty drop as the climber advances upwards.
In-tree tie-offs can also present problems in rescue situations. A victim can no longer be simply lowered to the ground on the victim's own climbing rope. ITTOs should not be employed for use with inexperienced climbers who might need to be rescued from unforeseen predicaments.
Once again, be sure to select good limbs for the rope to pass over and don't make the mistake of assuming that several small limbs will do as good a job as one big limb.
Limb Cinch On A Running Bowline
This is probably the quickest and easiest way to create an in-tree tie-off. Toss or shoot your throwline over a good limb and isolate the setting if possible. Always remove the throwbag from the throwline. Attach the rope to the throwline and begin hauling the rope up. As soon as the rope passes over the anchor limb, stop and use the rope at your feet to tie a running bowline around the throwline. Continue the hauling as the tip of the rope coming down passes through the running bowline and continue hauling until the bowline and the rope are cinched to the anchor limb. You are ready to climb.
The upside is that it's quick and easy to create. The climber only needs a few more feet of rope than what is necessary to reach the limb.
The downside is that you now have a rope that must be climbed all the way to the top in order to retrieve it. There is no pull-down capability here. Another downside exists if the climber has been unable to isolate the setting. This means being able to advance up the rope only as far as the first limb encountered before needing to create a new setting.
Another important downside is that the climber must rig for a pull-down when ready to descend, unless there is enough rope for both ends to reach the ground. A pull-down can be rigged by tying throwline to the bowline so that the cinch can be de-rigged once the climber is on the ground.
Limb cinch on delta
This tie-off is almost identical to that created with the running bowline. Everything is done the same except that a F8OAB is tied in the end of the rope at your feet, a delta inserted in the loop of the 8, screwed shut around the throwline and the hauling continued as the rope coming down passes through the delta. Continue hauling until the limb has been cinched. You are, once again, ready to climb.
The upside is that, like the running bowline, this tie-off is quite fast and easy to create. Using a delta will also eliminate rope-on-rope abrasion and adds a tri-directional distribution of force to the setting.
The downside is that you now need a delta. There is no pull-down capability and the climber needs to understand that terminating the climb before reaching the top of the entry pitch is not an option unless the climber is willing to walk away and leave the rope in the tree.
Another important downside is that the climber must rig for a pull-down when ready to descend, unless there is enough rope for both ends to reach the ground. A pull-down can be rigged by tying throwline to the delta so that the cinch can be de-rigged once the climber is on the ground.
Remember that just because you went up on SRT does not necessarily mean that you must come down on SRT. With enough rope for both sides to reach the ground, a DRT descent is not a bad option at all.
Limb cinch with throwline pull-down
Either of the previous two tie-offs will be more effective if pull-down capability is added to the system before climbing. This will eliminate the mandatory necessity of climbing all the way to the top in order to be able to retrieve the rope from the setting, and will facilitate recovery of the rope at climb's end.
Simply tie a length of strong line (or even another rope) to the loop in the running bowline, or to the delta, before hauling the cinch all the way to the top of the tree. This way, in case the climber should so wish, the cinch, and the rope, can be retrieved by simply pulling down on the line and bringing the cinch back to the ground.
The upside to this is obvious. The climber can now retrieve a rope without necessarily having to ascend to the anchoring limb to do so.
The downside is that there are now things that can go wrong. If the string/line being used for the pull-down is not strong enough, it might break before bringing the cinch to the ground. There is a further issue with the potential to get tangled in the pull-down line while climbing. Serious line management is necessary here!
Mid-line limb cinch with rope pull down
If your rope is long enough, a mid-line cinch can be created. For this one, a delta (or similar item) becomes a serious necessity. Do everything as before up until the point when the rope passes over the anchor limb. Then tie a F8OAB (or anchor hitch, or any other nice mid-line knot) in the rope at your side. Insert delta into the loop created, insert rope into delta, and continue hauling until the limb is cinched. If there was enough rope the climber should now have a cinch in place in the tree and both ends of the rope on the ground. The rope itself will function as the pull-down.
The upside is that the rope itself functions as the pull-down and no extra string or line is necessary.
The downside is that you need a rope that is twice the length of the height of the setting in order to have both ends on the ground.
Limb cinch on continuous loop
First, pull your rope up, over the limb, and back to the ground. You will need a rope twice the length of the height to your setting. Once you have both ends on the ground, tie the two ends together to create an endless loop (I usually use a figure eight follow through, or re-threaded figure eight, whichever you choose to call it). Then a F8OAB in the rope on either side of the knot at least a couple of feet away from the connection knot. Insert delta in the loop of the F8OAB, insert rope from the other side of the setting and haul the cinch right on up to the limb.
This is my favorite way to do a limb cinch when I have enough rope, because now both ends of my rope are at the top and I don't have to haul an end up with me to advance the climb. Once I have climbed up to the cinch I simply separate the two ends of the rope and use the end not involved in the cinch to create a new DRT setting for advancing the climb. Once the new setting has been created and I have transferred my weight to it, I can de-rig the cinch, pull the rope off the limb and continue the climb, using both ends of the rope. If I don't ever reach the top of my entry pitch, for whatever reason, there's no problem because I have a convenient pull-down ready to go.
The only downside is that it takes more rope than a simple cinch with delta or bowline.
Take care always to make sure that you are climbing on the side that has been cinched, rather than on the pull-down side!
Always remember than when nothing else works, there is no rule that says the climber can't tie off to her/himself. Doing so places the climber on a system that employs an SRT technique on one side, while the tie off on the other side allows for a bit of mechanical advantage making the climb slower but less physically demanding. The SRT system is then acting like a DRT system!