Trench safety is on our minds given the recent story about the man being trapped in a trench after it partially collapsed. We’re happy that the outcome was good, but it makes us think of safety and if the trench was set up properly or not. We do know that OSHA is going to investigate.
Trench Accident Stats
- About 400 U.S. workers die in trench related accidents each year
- About 6,400 are seriously injured
- 79% of fatalities occur in trenches less than 14 feet deep
Cave-in Accidents and Injuries
- Soil is heavy, it weighs 90-140 lbs per cubic foot
- A worker can be crushed by soil, rock, or an object
- Suffocation can occur even if a worker’s head is not buried – soil prevents chest expansion
- Soil pressure on unsupported walls create subsidence
- Bulging side walls can quickly lead to a cave-in
- A trench collapse typically dumps 3-5 tons of soil on an unsuspecting victim.
OSHA requires Protection of Employees in Excavations
Each employee in an excavation must be protected from cave-ins by an adequate protective system designed in accordance with OSHA Section 1926.652 (b) & (c) except when:
- Excavations are made entirely in stable rock; or
- Excavations are less than 5 feet in depth and examination of the ground by a competent person provides no indication of a potential cave-in
- Options Include
- Sloping and benching
- Shoring/sheet piling/shielding (e.g. trench boxes)
- Designed by P.E if deeper than 20 feet
Basic Trench Safety
- Determine the classification of soil prior to an excavation, conduct test borings
- OSHA requires excavation protection in trench unless you meet the exemption
- Keep spoils at least 2 feet away from the side of any trench
Make sure you know the latest code regulations to keep you and your coworkers safe. Is it time to renew your CSL or hosting license?