Inspection Detail

Inspection: 119721769 - Sierra Gypsum West, Inc.

Inspection Information - Office: American Canyon District Office

Investigation Summary

A CREW OF EMPLOYEES WAS ASSIGNED TO UNLOAD BULK DRYWALL INTO A HOUSE FOR FUTURE USE BY DRYWALL INSTALLERS. THE SLOPE AND ANGLE OF THE DRIVEWAY PREVENTED THE USE OF A FORKLIFT, SO A BOOM TRUCK WAS USED INSTEAD. THE CRANE ON THE TRUCK WAS A HYDRAULIC KNUCKLE-BOOM UNIT WITH A PERMANENTLY ATTACHED DRYWALL CRADLE. SPACE AT THE BUILDING SITE WAS VERY RESTRICTED, AND A 12-KILOVOLT OVERHEAD POWER LINE RAN ALONG ONE SIDE OF THE SITE. THE TRUCK WAS POSITIONED WITH THE BOOM APPROXIMATELY PARALLEL TO THE POWER LINE. THE PROPERTY OWNER WARNED THE CRANE OPERATOR NOT TO SWING THE BOOM OUT BECAUSE OF THE PRESENCE OF THE POWER LINE. HOWEVER, THE OPERATOR'S NORMAL PRACTICE UPON STARTING THE CRANE WAS TO SWING THE BOOM TO THE RIGHT AND TO THE LEFT TO ENSURE PROPER OPERATION OF THE BOOM. THE OPERATOR LIFTED THE BOOM LOWERED THE KNUCKLE SECTION THROUGH ABOUT ONE QUARTER OF ITS ARC AND THEN SWUNG IT LEFT TOWARD THE POWER LINE. HIS OPERATING POSITION WAS ON THE SIDE OF THE TRUCK OPPOSITE TO THE POWER LINE, AND HIS VIEW WAS PARTIALLY OBSTRUCTED. NO SPOTTER WAS USED TO ASSIST HIM IN MAINTAINING CLEARANCE FROM THE POWER LINE. HE SWUNG THE BOOM TOWARD THE LINE; AND, WHEN HE FELT HE WAS GETTING CLOSE, HE STOPPED THE BOOM. THE CRADLE THEN SWUNG INTO THE POWER LINE. AN EMPLOYEE WHO WAS LOCKING A VALVE ON THE OPPOSITE-SIDE OUTRIGGER RECEIVED A SEVERE ELECTRIC SHOCK AND SUSTAINED BURNS TO HIS RIGHT HAND, LEFT SHOULDER, AND LEFT LEG. (HIS LEFT SHOULDER WAS NEXT TO A METAL PICKET FENCE.) HE WAS HOSPITALIZED FOR HIS INJURIES.

Keywords: BURN, BOOM TRUCK, OVERHEAD POWER LINE, ELECTRICAL, BOOM, E GI IA, ELECTRIC SHOCK, TRUCK BOOM