What is a loop with slip knot the tightens as rope pulled?

A loop with a slip knot that tightens as the rope is pulled is called a "running loop." It is widely used in various situations where a temporarily adjustable and tightening loop is required. Here's how it works:

1. Initial Setup:

- Start with a suitably sized rope.

- Hold the rope in one hand and create a small loop with the other.

2. Forming the Slip Knot:

- Pass the free end of the rope through the loop you just made.

- Pull the free end to form a slip knot.

- Slide the knot down until it sits at the base of the loop.

3. Tightening Mechanism:

- Now, when you pull the standing end (long end) of the rope, the slip knot will begin to tighten around whatever object it is looped around.

- The more tension you apply to the standing end, the tighter the loop becomes.

The running loop is a versatile and effective knot due to its self-adjusting nature. As you pull the standing end, it cinches down on the object, creating a secure hold without the need for complex knot tying.

Running loops are commonly used in tasks such as securing objects, rigging, camping, sailing, and rock climbing. They offer a dynamic way to quickly form a tight and adjustable loop without having to completely tie and untie knots each time.