A portable ladder must extend how many feet above the upper surface of an excavated trench?

A portable ladder must extend at least 3 feet above the upper surface of an excavated trench to ensure safe access and egress for workers. This 3-foot extension provides sufficient height for a worker to grab the ladder firmly and safely transition from the ladder to the edge of the trench, reducing the risk of slipping or losing balance.

The requirement for a 3-foot extension is grounded in safety standards that prioritize ensuring a secure grip and minimizing the distance a worker must reach, which enhances stability. This is particularly important in environments where workers may be carrying tools or equipment, as they need both hands to maintain control while climbing. Proper ladder positioning is critical to maintaining safety protocols during operations near excavated areas.