Under what circumstance should blocking and cribbing be placed under a crane's outrigger beam?

• A. Never
• B. Only when the ground is firm
• C. Only when the crane is on rubber
• D. Only during rail track operations

Answer: (A)

Outriggers are designed to transfer the crane’s load directly to solid ground through the pads. Blocking or cribbing under the outrigger beam would introduce an unstable interface between the beam and the cribbing, changing the load path and potentially allowing the beam to move, tilt, or slip as lifting begins. That can create unpredictable stability and increase the risk of tipping or losing control of the load. If the ground isn’t suitable, the correct approach is to reposition to firm, level ground or use manufacturer-approved methods under the outrigger pads (not under the beam itself). The other situations described don’t justify placing cribbing under the beam because they do not address the need for a reliable, direct load path from the outriggers to solid support.