Which knot is used to increase the tension on a line?

The trucker hitch is a versatile knot commonly used to increase the tension on a line effectively. It combines a loop knot with a mechanical advantage, which allows for the user to easily apply significant tension to the line, making it particularly useful for securing loads, rigging tarps, or setting up tent lines. The structure of the trucker hitch creates a pulley-like effect; by wrapping the working end of the line around a stationary part and then through a loop, it allows the user to pull the line tighter than normal, securing it firmly in place.

In contrast, the other knots listed do not provide a mechanism for increasing line tension in the same way. The bowline creates a fixed loop at the end of the rope and is primarily used for safe connections rather than tension. The barrel hitch is designed for lifting cylindrical objects, where it grips the surface but does not generate additional tension. The clove hitch is often used for securing a rope to a post or similar object, but it does not have the capability to increase tension effectively like the trucker hitch does. This makes the trucker hitch the optimal choice for applications requiring significant tension on a line.