Hydro Excavation Safety Article: Safe Trenching
Trenching is a big part of what we as Hydro Excavators provide to clients. As a safe and non-destructive approach to excavation, Hydro Excavation works when it comes to locating utility lines we know exist… but aren’t exactly sure where they live. And though a straight line cut into the ground for the purposes of locating a line may seem pretty straight forward, an estimated 400 workers lose their lives each year in trench related accidents while another 6,400 are seriously injured. So, in this Hydro Excavation Safety Article we are taking a look a Trenching Safety.
What Is a Trench
- A narrow excavation that is deeper than it is wide
- A Trench is no more than 15 feet wide at bottom
- Without support the walls of an excavated trench will eventually fail
Trench cave-ins can cause serious injury and even death. With a 125 lb. /cubic foot weight, soil from a cave-in alone can crush a worker. Add into that possible rocks, debris, and other objects it’s not hard to begin to imagine how trench cave-ins can be dangerous. Another lesser known fact is that even if the worker's head remains exposed, they may still suffocate because the weight on the soil does not allow the chest to expand for breathing. A final concern when it comes to trench cave-ins is the suction effect of the soil causing complete immobilization of the victim.
Signs of Soil Distress
When working around Hydro Excavated Trenches knowing the signs of soil distress leading to cave-ins could save lives:
- Fissures or cracks on the inside “face” of the excavated trench
- Slumping of material from the excavation face
- Bulging or heaving of material at the bottom of the trench wall
- Sinking of excavation’s edge
- Ravelling or small amounts of material trickling into trench
When working around trenches there are a few ways to increase the safety of the job site. Avoid placing large, vibrating machinery next to the trench. Avoid driving large vehicles and loads next to the trench. Be more aware of the possibility of cave-ins during or after heavy rains. At the same time, very hot, dry weather can also lead to cave-ins.
When it comes to working around trenches, it’s important to remember:
- Cave-ins can happen suddenly – entrapping, burying and injuring workers
- Be aware of the soil conditions and look for signs of soil distress
- Be aware of all the hazards located near the excavated trench
- Always use protection systems