Unsupported boom drops while instructor and student working underneath
A secondary school forestry program instructor and student were attempting to repair a leaking hydraulic hose in a grapple log loader. A cedar post was placed under the elevated boom for support but the boom was not lowered onto the post. When the hydraulic hose was disconnected, the boom dropped. The boom struck the student a glancing blow and then pinned the instructor to the loader frame. The cedar post split but prevented more serious injuries.
Findings as to causes
- The instructor and student were doing repairs under the elevated boom of a log loader. The boom had not been adequately secured against falling. The boom dropped when the hydraulic hose was disconnected.
- There were no written safe work procedures for workers to reference for maintenance of heavy equipment in the forest service program. Maintenance activities must be defined to determine whether an instructor or an outside contractor will perform these duties.