QEHSOperations
Trench boxTrench shield
A steel or aluminium protective system placed in a trench to protect workers from cave-ins during excavation work.
A trench box (also called a trench shield) is not designed to prevent cave-ins but to protect workers if one occurs. It is one of several protective systems allowed under OSHA 1926 Subpart P, along with sloping, benching, and shoring. Trench boxes must be designed by a registered professional engineer or manufactured to a recognised standard, extend at least 18 inches above the excavation face, and be properly installed with no lateral movement. They are commonly used for utility work, pipe laying, and foundation excavation.