RISK – Crushing
The “line of fire” is the potential direction of a load, rigging, plant and fixed object impact or crush hazard should a failure occur.
All lifting operations personnel must maintain effective plant/people separation, adequate escape routes and under no circumstances put themselves or others in a situation where the risk of crushing is present.
WorkSafe New Zealand. Safe Work with Precast Concrete
On large sites where multiple tower cranes are in operation and radii overlap, systems should be in place to ensure workers are warned and removed from the path of loads, or protected by suitable overhead structures.
Work through the hierarchy of control and implement the most effective control possible.
Elimination
- Does the load need to be lifted?
- Do people need to be there (can it be done after hours)?
- Clear the area of all people before a lift
Substitution
- Is there another way to lift the load (i.e. trolley, hoist, air jack)?
- Is there another product that can be used to reduce lifts (i.e. pre-cast instead of stick build)?
Isolation
- Keep people away from the lift area
- Schedule work/shifts around the crane activity
Engineering
- Redesign the task or use gantries for overhead protection or positioning of cranes (where possible)
- Consider building design that requires fewer lifts (e.g. flat slabs, uniform depth)
- Consider use of warning alarms / crane cameras / proximity detectors and alerts
- Crane anti-collision system
- Set up designated "load flight paths" and exclusion zones where possible - review and reroute access ways to suit
Administrative
- Doggers to alert others of approaching loads "load coming in / load going out"
- Use pre-starts to make people aware of planned lifting activities
- Trade who "owns the load" to assist the dogger in directing workers / clearing a path
- Erect signage
PPE
- Doggers to be highly visible
- Full PPE to be worn at all times
Riggers and Doggers may have to work near a suspended load in order to guide it into position. The use of tag lines can help keep these workers out of harms way. The tag line will put distance between the Dogger/Rigger and the load in the event the load shifts or moves unexpectedly. For pick & carry operations such as a telehandler or an articulated pick & carry cranes, taglines should be lashed to the machine whilst mobiling a load to ensure the Dogger is not in the line-of-fire.
When tending tag lines, never loop the line around your hand, arm, or body. This could result in you being dragged with the load. Wear gloves to avoid rope burn. Be sure your travel path is clear and safe before the load is suspended.
