What is the efficiency rating of a running bowline?

The efficiency rating of a running bowline is considered to be approximately 50%. This knot is used for creating a fixed loop at the end of a rope, and it is particularly advantageous because it maintains its shape and is easy to untie, even under load. However, like all knots, the running bowline has some loss of strength due to its structure; it cannot hold as much weight as the rope itself would be able to without any knot.

In practical applications, understanding the efficiency of a knot is crucial, especially in contexts like rigging or rescue operations, where the reliability and strength of the knot can significantly impact safety. The 50% efficiency rating indicates that if the rope has a strength of, say, 1000 pounds, the effective strength of the rope when tied with a running bowline would be around 500 pounds, reflecting the compromise required for the knot's functionality and the material properties involved. Other knots may have different efficiency ratings based on how they are constructed and used, but the running bowline's critical features have led to its adoption in various fields despite this efficiency compromise.