Final answer:
The greatest hazard facing a worker in a trench is cave-ins. This can occur due to lack of proper shoring, water accumulation, or vibrations.
Step-by-step explanation:
The greatest hazard facing a worker in a trench is cave-ins. A cave-in occurs when the walls of the trench collapse, burying the worker under soil or debris. This can result in serious injuries or even death. Here are some reasons why cave-ins can happen:
- Lack of proper shoring: If the trench is not properly supported with shoring materials such as braces or boxes, the walls can easily collapse.
- Water accumulation: If water accumulates in the trench, it can weaken the soil and increase the risk of a cave-in.
- Vibrations: Vibrations from nearby equipment or traffic can destabilize the trench walls, leading to a collapse.
Workers in trenches should follow safety protocols such as using protective equipment, staying away from trench edges, and having a competent person inspect the trench regularly to ensure its stability.