Why Knot?

It can be any variation of the Prussik or the Taut Line hitch or the Blakes hitch or any other knot that grips the climbing rope when loaded. They are brilliant knots and hitches but does the tree industry abuse them to the point of destruction.
The prussik was originally designed for ascending not descending. The use of the prussik and other similar friction knots for the tree industry has varied from the original intended use of the knot. It purpose as a rope grab or rope adjuster has changed from a static use to a dynamic use, that is from a stationary knot that was only moved with no body weight applied to a sliding knot with body weight applied.

I personally have some problems with the Prussik and other friction knots methods of climbing as used by climbing arborists is as follows:

1. The knots offer friction both up and down, so this means that you have to drag it up the rope as you go. This is not energy efficient and greatly limits the climbing techniques available to the climber. Friction can work for you or against you, when descending it works for you and when ascending it works against you. It will not follow you up a rope or easily slide as you limb walk, The friction is great when you need it and a pain when you don’t.

2. The prussik knot was designed to be unloaded before adjusting the location of the knot on the climbing rope. The climbing arborist was intended to slide the prussik knot down unloaded and then lower their body weight down until the prussik knot was reloaded and then repeat the process. Of course this was bound to be modified to the current industry excepted method of dragging the prussik down the climbing rope fully loaded and also some times at high speed. Part of the industry even encourages climbing arborists to descend climbing ropes as fast as possible all in the name of a competition.

3. Sliding a friction knot down a climbing rope while under load creates friction and this friction generates heat and this heat can and does melt rope. This melting can lead to prussik loop failure especially with 8mm diameter cord. One of the golden rules of fibre rope management is “never run a synthetic fibre through or over a synthetic fibre”, especially when it is carrying your body weight. Imagine a lowering rope running over the top of your climbing rope as a load is lowered. The friction heat that is generated by these two ropes passing each other is incredible, it takes only seconds to melt through a rope.

4. The body thrust method of ascending trees is hard work, it requires hauling your body weight up a rope and dragging the Prussik knot with you as you ascend. It requires a large amount of energy and upper body strength to ascend using this method. For some one who does spikeless work on a daily basis it’s a killer and it has long term health risks such as back problems as well. There must be an easier way.

5. The knot's ability to hold is quite often dependent on the climbing rope type and diameter or the type or diameter of the prussik loop itself. The variables are great and some climbers find the knot slips under load or it tightens up to much to easily adjust. It requires the user to have a good understanding of the many variables that exist and make the appropriate choose. It is recommended to use the largest diameter rope for the friction knot and if possible the same diameter and type of rope as your climbing rope but this depends on many factors. The reason for this is that it provides a larger surface area of friction knot in contact with the climbing rope and less risk on total melt down.of the friction knot.

Spikeless tree climbing is hard work and it is not made any easier by out of date techniques. The traditional body thrust climbing method has been around forever and is still widely taught and used today. It offers a cheap, simple and safe system of ascending and working in a tree. To date nothing has fully replaced the friction knot used in the arborists climbing system. No one piece of mechanical climbing equipment has yet taken the prussik’s place, its ability to offer control up or down a rope has never been matched to the point of phasing out the arborists friction knots.
An auto locking mechanical descender is great for descending but lacks the ability for easy ascending and an ascender is brilliant for ascending but lacks the ability to offer friction for descending. Descenders offer friction by bending the rope and it’s this bending that makes ascending so difficult. We have a need for an inline device that offers variable friction when descending and no friction when ascending.
We currently have two schools of climbing arborists working in the industry today. That is the friction knot user and then the mechanical device user. The new generation tree climber is working smarter not harder, adapting equipment used by rope access operators to make accessing and working in trees a whole lot easier. But if you are a happy friction knot user then you still don’t have to be left out of the technology loop. If you are comfortable with your tried and tested systems but aren’t keen on all the hard work then we may have an option for you.
Well by simply adding just one extra item of equipment to your kit you will experience a much easier spikeless life or at least partly eliminate the body thrust method for accessing trees. The simple addiction of a foot ascender to your standard prussik system will require little change or adaption and is relatively simple to set up and easy to learn how to use.

It’s a long way to the top if you haven’t got a foot ascender.

The foot ascender allows the climber to use the strong leg muscles for ascending not the upper body like the body thrust and the foot ascender allows the climber to remain in an upright position, thus reducing back stain and injury. The ascender provides a foothold anywhere on the rope very much like a pair of spikes does on a tree. The climber simply stands up on the elevated ascender and then slides the friction knot up the climbing rope and sits back in the harness. This process is repeated until the desired height is reached. One of the great benefits of this method is that it allows the climber to ascend a free hanging rope that is rigged away from the trunk. This is the opposite of the body thrust that is ideally rigged against the trunk.
The foot ascender can be attached directly to the inside of your boot as shown in figure one or on a foot loop as shown in figure two.

Both systems have their advantages and disadvantages over each other as listed below.

Direct attachment to the boot
1. Advantage: The foot ascender can stay on the boot during the whole job.
2. Advantage: The foot ascender requires no hand operation once fitting.
3. Disadvantage: Your hands cannot easily reach the foot ascender.
4. Disadvantage: A short suitable ascender is required for foot mounting.

Attachment via a foot loop
1. Advantage: The ascender can be almost any type of ascender.
2. Advantage: Your hand can assist with sliding the ascender up the rope.
3. Disadvantage: Needs hand and foot operation at the same time.
4. Disadvantage: Needs to be stored on your harness when not in use.

Except change as your friend, any thing that makes your job easier must be a good thing. The new generation climbing arborist will be more efficient with time and energy, they will introduce change in the industry and this change will be for the better. The foot ascender may be your own step towards this change but it will also be a step towards safer and easier work practices.