Rope ends
A rope end is the piece of rope coming out of a knot. Usually, a rope end would be short, so that an end knot would have one rope end, and a bend would have two. One can claim that an end knot has two ends: a short one and a long one (the rope itself), and so a bend has two short ends and two long ones. The length of the rope end strongly affects the safety of a knot.
rope end length
minimum length
The minimum length of a rope end is deternined by the rope diameter, its knotability and by how tight the knot is.
We can understand the reason for a aminimum rope end length from the definition of the essence of the rope:
A rope is a tool for transfering force over long distances. A rope can transfer only pull forces, but these can be in eery possible route (not stright lines only). In this, a rope differs from a rod, that can transfer pullung and pushing forces, but only in a straight line, and from cables, that can also push, but only for short distances.
In fact, a rope can also push, but only for very short distances, distances that are similar to the rope's diameter (the distance is a certain small coefficient times the rope's diameter). The exact figure of the coefficient depends on the construction of the rope, the material it's made of and actually - on the rope's knotability. For all ropes, a good estimate will be a few times the rope's diameter. That means that the rope end's length must be greater than the distance through which the rope can push. This will make sure the knot will not get untied just because something had accidentaly pusshed the end into the knot.
maximum length
There is no real maximum length for rope ends, but one does not exted it unnecessarily. There are a few reasons:
- Long rope ends can be confusing. If the rope end is long, it is harder to tell which is the end and which is the rope. Someone might end up using the end instead of the rope and find himself with a short rope.
- It shortens the rope itself. Not by much, but...
- It is considered bad style to have unnecessarily long ends. There is a feeling that a climber who does not keep his knots well dressed, with short ends etc, might also not pay attention to belay, anchors etc. It might not always be true, but is a common belief.
rules of thumb
- MInimum length for rope ends should be 5-10 times the rope diameter.
- in kernmantle ropes used for climbing and rappeling, it is usefull to remember that rope ends should be between the width and the length of your palm. This applies for 9mm to 11mm ropes.
Contributions to this page by: Micha Yaniv and others
