One of the original fundamental access techniques, is foot locking. It's an old school technique, before we had Rope Wrenches and the like, but it's such a valuable technique to have in your mental toolbox. This blog explains how to foot lock up the tree by
1. Choking your access line with an alpine butterfly at the top
2. Installing your Foot Locking Prusik
3. Foot locking up into the tree and installing your double rope system using your foot locking prusik.
4. Climbing, then descending and de-rigging the system from the ground
We're going to take a look at foot locking. What we're going to do is foot lock up into the canopy and then climb directly off of this foot locking prusik with a double rope climbing system. So we've just shot a line up the tree to install this foot locking line and sent an alpine butterfly to choke up around the branch at the top - a standard way of setting up a foot locking line.
We are going to use Sterling RIT foot locking prusik, which is a heat resistant cord and this is going to be clipped to me. We are also using another life support prusik sling wrapped around the foot locking prusik. So when I get up above this first branch, what I can do is pull up my hitch climber system clip it into the small prusik, and that will allow me to climb doubled rope off of the foot locking line. So let's get into it...
What I'm going to do is set the foot locking line, clip in, and also remember to tie a marlinspike knot (a.k.a. a slip knot) at the bottom of the foot locking line. This does two things:
1. It helps to keep these two legs of rope together.
2. It gives me somewhere to clip on my climbing system so that when I get up to the top of the tree, I can simply pull this up and not have to carry this up with me.
Since we are footlocking, you can strip everything off the back of your harness except for a figure of eight device, because if anything happens, you generally need a figure of eight to descend the line.
So the mechanics of foot locking is to secure yourself onto the climbing line with a foot locking prusik and then to wrap the rope around your feet in a way that it locks so that you can stand up.
To foot lock, what you're going to do is you're going to put the climbing line on the outside of one of your feet. And then you're going to take the lower section of rope underneath your foot and capture it with the other foot and then wrap around and stand on top. You should be able to stand on the rope and be able to comfortably hold your position.
To tie your foot locking prusik, obviously, you need a long prusik. This is just one continuous loop, but you will get some which are eye to eye, so a small eye on one end and an oversize eye on the other. So what I'm going to do is tie a Klemheist knot. Just form a loop at the top and then wrap downwards several times - the number of wraps determines the friction for your body weight. Dan is around 80kg and will wrap three times. And then what you do is choke it through the big eye and then you obviously need to dress and set it. And what you'll end up with is one big loop at the top with your foot locking prusik threaded through it like this.
And then I can move up the other (smaller) prusik which we're going to anchor off of, move that closer up to the top. And this is actually going to double as a point which I can clip my neck elastic into just to keep the foot locking prusik taut between my bridge ring and neck elastic - just to keep it closer to me.
So once you've foot locked up into the canopy where you've anchored the foot locking prusik. All you need to do is pull up the double rope system, which is attached to the Marlinspike and pre-installed with the hitch climbing system. Add the double rope system onto the life support, foot locking prusik and transfer over on to the DdRT system.
What you can do is move this climbing system as close to the top of the foot locking prusik as possible and start loading it up. So now it's got my weight and the foot locking prusik is unweighted. Now what we want to do is put a marlin spike in the access line, underneath the foot locking prusik, to just stop the foot locking prusik creeping down. And if the small prusik were to creep down, it's stopped by this carabiner in this eye. This will need to be unclipped before descending down and out of the tree to retrieve the system from the ground. So now we can climb off of this point and access any branch below us.
So if the work we needed to do was purely on a lower limb, say it's over the top of a house with dead wood which needs to be taken off of, or maybe some of it needs to be brought in, then it means that we can foot lock up and climb off of this high point directly with a double rope system.
And the other thing is it also gives me the value of having a high, high point instead of just coming up to this branch. If I needed to get out over to the other side of the tree, I can redirect up over another branch and then go straight out over. This is purely a technique for essentially accessing one lower section of the tree. If that's the only work you actually need to do.
So what I'll do is I'll show you how to de-rig this system. After unclipping the carabiner from the marlinspike that prevented the creeping, you can descend straight down and retrieve the whole system from the ground.
To retrieve this system from the ground, remember, there is an alpine butterfly knot choked up the top of this tree. And it is hard to break the friction of the foot locking prusik (bearing in mind we've climbed off of it). So we're going to pull on one side of the line and hopefully get the side of the line that isn't choked. It can be quite hard to initially break the friction at first.
Continue pulling down one side of the rope and effectively walking the foot locking prusik down. A great tip is to use a poor man's pantin by wrapping a half hitch around your boot and using that to pull down the foot locking prusik. The whole system should be coming back down to the ground now.
As soon as you can reach the foot locking prusik, break the remaining friction and remove the double rope climbing system and foot locking prusik completely. All that remains is the access line with the alpine butterfly, which was choked at the top of the tree.
So we've just gone through all the details of how to foot lock up the tree by choking your access line with an alpine butterfly at the top and then installing your double rope system onto the access line using your foot locking prusik.
Hopefully that was useful for you. If there's anyone which doesn't know this technique, give it a share and hopefully they get some value out of it. Cheers.