Trench Collapse
Program: Heavy Equipment Operation
Trench Collapse
A cubic yard of soil can weigh as much as a small car. A trench wall gives no warning.
The rule. OSHA 29 CFR 1926 Subpart P: any trench 5 feet deep or more needs a protective system, sloping, benching, shoring or a trench box, unless it is dug entirely in stable rock. Trenches 20 feet or deeper need a system designed by a professional engineer.
The competent person. Someone trained to classify the soil and inspect the trench every day, and after every rain.
The basics. Spoil piles at least 2 feet back from the edge. A ladder within 25 feet of every worker in a trench 4 feet or deeper. Call 811 before you dig. Test the air.
The trades. Heavy-equipment operators, pipe layers, plumbers, utility workers, electricians running conduit.
Try it. Pour the sand. Watch the wall fail. Then set the box and pour again.
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