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MNM Close Call Accident Alert Surface - Dimension Stone

Surface – Dimension Stone – On Monday, October 23, 2017, the boom of a Pellegrini stiff leg derrick failed while lifting a muck bucket. The crane operator and the foreman were in the operator’s station, or “crow’s nest,” on the edge of the high-wall. As the boom started to fail, they were able to run to safety before the operator’s station was crushed. The derrick collapsed into the quarry, but no injuries occurred.

MNM Serious Accident Alert Dimension Stone
Best Practices: 
  • Do not overload the crane.  Know the load chart and weight of the object to be lifted in order to avoid tipping or causing structural damage to the crane.
  • Periodically inspect the crane in accordance with the procedures in the operator’s manual. 
  • Follow the manufacturer’s guidelines when making repairs or conducting other maintenance on the derrick.
  • Examine and test all safety devices on a regular basis and ensure that they are operating properly.
  • When using cable clips to secure a wire rope, always apply the proper torque, use the amount required based on the rope diameter, and follow the rigger’s rule of “never saddle a dead horse” when positioning the clip.
  • Never side load the boom by rapidly swinging the load or picking up a load when it is not directly under the boom tip. Side loading the boom could cause a collapse.