Can a single overhand knot be used as a safety knot in rope?

A single overhand knot is not recommended as a safety knot in rope rescue applications. The primary purpose of a safety knot is to provide an extra layer of security to ensure that the working knot does not come undone under load. While a single overhand knot is simple to tie, it lacks the stability and secure nature required for safety in dynamic scenarios, such as those encountered in rope rescue operations.

A more effective safety knot is typically a double overhand knot or a figure-eight backup knot. These knots provide greater security and are much less likely to slip or come undone when under stress. The single overhand knot can jam and be difficult to untie after being loaded, making it a poor choice for safety applications.

Considering these factors, the correct answer highlights that a single overhand knot cannot serve effectively as a safety knot in rope rescue situations, emphasizing the importance of using adequate knots that provide reliability and security.