Journeyman Plumber ExamTools, Equipment, and SafetyMedium
A plumbing crew is excavating a trench for a new sewer line. The trench is planned to be 6 feet deep and 3 feet wide. According to OSHA regulations, what is the minimum requirement for trench protection in stable rock?
- AShoring with hydraulic jacks
- BNo sloping or shoring required
- CSloping at 1:1 (45 degrees)
- DShielding with trench boxes
Show answer & explanationAnswer & explanation
Correct answer: B. No sloping or shoring required
OSHA regulations (1926.652(b)(7)) state that for trenches excavated in stable rock, no protective system (sloping, shoring, or shielding) is required, provided the competent person determines it to be stable and free from hazards.
Why the other options are wrong
- A. Shoring is a protective system for less stable soil types to prevent cave-ins.
- C. Sloping of 1:1 is generally for Type B soils, which are cohesive but not as stable as rock.
- D. Shielding, such as trench boxes, is a protective system used to create a safe working space within a trench in unstable soil conditions.
Stable Rock Trenching
A trenching condition where the excavation is made entirely in a solid mineral material that can be excavated with vertical sides and remain intact.
- No protective system required by OSHA
- Must be free from hazards (e.g., loose rock, water)
- Competent person must classify and approve
- Differs from other soil types (Type A, B, C)
Memory trick: Rock solid, no need for the shoring squad.