capstan effect
noun1
The friction between a rope (or other flexible material) around a curved surface (the capstan) exponentially amplifies the holding force, allowing a small tension on one side to resist a much larger tension on the other.
- When a cable is being installed, the tension in the cable increases in the straight sections of pipe and is reduced at the bends by the ‘capstan effect’, the input and output tensions expressed by the equation:[…].1999, Alan Harmer, editor, Communication Cables and Related Technologies, IOS Press, →ISBN, page 194: