Trenching and excavation companies should make every effort to prevent cave-ins. Trench collapses kill construction workers on a frequent basis. All workers on the trenching / excavation jobsite should be familiar with trenching safety practices. Even though trench safety has been taught for thirty years, they still kill construction workers today.
Excavation Trigger Numbers
- 4 feet — need to be given adequate access or egress. (ladder or steps into the trench)
- 4 feet — atmospheric testing where there is likely to be a hazard.
- 5 feet — sloping or shoring required.
- 25 feet of lateral travel requires additional access or egress installed. (ladder every 50 feet)
- 18 inches — minimum clearance above the ground for trench box.
- 6 feet — fall protection is required. (guardrails to prevent falls into the trench)
- Less than 5 feet shoring is not required after daily inspection from competent person and no indication of potential cave‐in. (rare instance)
More Trench Safety Info:
- Make sure materials or equipment that may fall or roll into the trench are moved at least 2 feet back.
- Provide warning systems when trenches are near traffic areas.
- Never allow workers to stand or work beneath loads or digging equipment.
- Never lift or lower workers with digging equipment
- Provide safe access to all trenches 4 feet or deeper.
- Ladders must be within 25 feet of all workers.
Trench Rescues
- Extensive
- Multiple personnel
- Involvement by many government agencies
- Trench rescues require many hours of labor
- Survival is not likely
UNSAFE TRENCH! NO SHORING & WATER INFILTRATION

ANY TRENCH 5 FEET IN DEPTH REQUIRES PROTECTIVE SHORING, SHIELDING, BENCHING OR SLOPING.
