JEI Metallurgical expert witness


Recent Investigations - Industrial Equipment Accidents


Excavator Accident

Electrical arcing occurred when a high voltage/high current cross-country power line contacted the boom of a CAT excavator.  Current flowed throughout the entire excavator in passing to the ground. In fact, the current that passed through the CAT excavator "crystallized" the ground around the excavator. A view of the subject excavator at the accident scene is shown in Photograph A.

Cat Excavator
Photograph A High voltage power line contacted the excavator boom.

Metallurgical evaluation of various CAT excavator parts revealed that considerable arcing damage occurred at component part joints and junctions. Photograph B shows engine main bearing arcing damage.

Main Bearing Arcing Damage
Photograph B Main bearing arcing damage.

Photograph C shows external electrical arcing damage to electrical conduit on the subject excavator.

Arcing Damage on Electrical Conduit
Photograph C Arcing damage on electrical conduit.

After metallurgical analysis, it was concluded that replacement of individual arc damage parts would be more costly than merely replacing the entire CAT excavator.


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Updated 12/18/12