Trench boxes are designed to protect workers from cave-ins rather than to support trench face.

• A. They are designed to support trench walls
• B. They remove soil from trenches
• C. They protect workers from cave-ins and similar incidents rather than supporting the trench face
• D. They are used to anchor utilities

Answer: (C)

Trench boxes (trench shields) are protective systems placed in trenches to shield workers from a potential cave-in. Their main function is to resist earth pressure and provide a safe refuge if the trench walls fail, rather than permanently supporting the trench face. Active wall support is provided by shoring or bracing systems, which are designed to hold the trench walls in place during excavation. The other activities—removing soil or anchoring utilities—are different tasks and not the primary purpose of trench boxes.