A member has reported that in spite of clear work instructions and procedures to the contrary, shackles and hooks at the worksite were being regularly modified by welding. Rigging suppliers or individual worksites were carrying out welding modifications (mainly to shackles) after delivery from the manufacturer. This practice invalidates the manufacturer’s certificate and is potentially hazardous.
The welding of shackles (after delivery from manufacturer) has the effect of adversely altering the material properties and increases the risk of failure by various brittle modes. In addition to this increased risk, the nature of the failure is unpredictable, is not time dependant and cannot be prevented by inspection.
Our member recommends that all shackles and hooks that have been modified by welding should be removed from service. Equipment suppliers should be instructed not to modify or issue modified shackles or hooks for use on any worksite.