CASE STUDY Day 2:
A crew is scheduled to install a large duct riser in a high-rise building. The work includes crane activity and exposure to gravitational and suspended-load energy, including work near shaft edges. Before work begins, the crew meets to identify hazardous energy and apply the Hierarchy of Energy Control:
Energy Elimination:
The duct riser is prefabricated into four sections to eliminate significant field assembly and reduce time spent exposed at height.
Energy Reduction:
The crew selects equipment and methods that reduce instability and manual handling demands (e.g., a stable powered platform rather than climbing/positioning methods that increase exposure).
Energy Isolation:
Rigging connections are engineered and stamped by a PE (no field improvisation). Shaft edges are protected with guardrails/hard barricades. Exclusion zones are established to separate workers from suspended-load paths.
Alternative Controls:
During the pre-task meeting, the crew aligns with the crane operator, assigns roles, confirms travel paths, identifies required lift inspections, and agrees to stop work if controls are disturbed or conditions change.
PPE (Last Line):
Workers use required minimum PPE for most of the task, and where a leading-edge exposure remains, fall protection is used as the final layer—not the primary control.
WRAP UP:
Most of the protection in a task should come from how the work is designed, planned, and physically controlled—not from PPE at the end. PPE is important, but it is a last line of defense. The strongest protection happens when hazardous energy is eliminated, reduced, or isolated through planning, engineered safeguards, and verified field conditions before work begins.
