Inspection Detail

Inspection: 104550306 - Structural Specialties

Inspection Information - Office: Minnesota Department Of Labor And Industry

Investigation Summary

AT A BRIDGE CONSTRUCTION SITE, A BUCYRUS ERIE, 30B, 50 TON TRUCK CRANE NEEDED TO BE MOVED ACROSS THE RIVER. BEFORE MOVING THE CRANE A FIVE MAN WORK CREW WAS GOING TO REMOVE THE COUNTERWEIGHT FROM THE REAR OF THE SUPERSTRUCTURE AND DISASSEMBLE THE 100 FOOT BOOM AT TWO POINTS ALONG THE BOOM LENGTH. THE COUNTERWEIGHT AND TWO FORTY-FOOT BOOM SECTIONS WERE TO BE LOADED ONTO A HIGHBOY TRAILER. ONLY THE BOOM FOOT SECTION WAS TO REMAIN ATTACHED TO THE CRANE. THE LOAD BLOCK(S) HAD BEEN REMOVED AND HOIST LINE(S) REELED IN. FOUR EMPLOYEES WERE WORKING AT THE REAR OF THE CRANE, WHERE THE COUNTERWEIGHT HAD JUST BEEN REMOVED AND WAS BEING LOADED ONTO A HIGHBOY TRAILER. EMPLOYEE #1, THE CRANE OPERATOR, HAD LOWERED THE BOOM TO WITHIN 3 1/2 FEET OF GROUND LEVEL. AS IN NORMAL OPERATIONS, THE PENDENT CABLES WERE STILL ATTACHED TO THE BRIDLE ARMS. WORKING FROM A POSITION BENEATH THE BOOM, EMPLOYEE #1 REMOVED THE COTTER PINS AND POUNDED OUT BOTH OF THE LOWER CONNECTOR PINS AT THE POINT WHERE THE BOOM FOOT SECTION ATTACHED TO THE FIRST BOOM SECTION. AS EMPLOYEE #1 POUNDED OUT THE SECOND OF THE LOWER CONNECTOR PINS AT THE PICTURE-FRAME CONNECTION AT THE TIP OF THE BOOM SECTION, THE BOOM COLLAPSED ONTO HIM. CONTRARY TO NORMAL PROCEDURE, THE BRIDLE ARMS HAD NOT BEEN CONNECTED TO THE BOOM FOOT SECTION, TO SUPPORT THE BOOM AT ITS BASE. THE BOOM HAD NOT BEEN FULLY LOWERED OR ADEQUATELY BLOCKED OR CRIBBED. EMPLOYEE #1 WAS WORKING UNDER THE BOOM AT AN UNSUPPORTED JOINT. EMPLOYEE #1 DIED FROM MULTIPLE CRUSHING INJURIES TO THE NECK, CHEST AND PELVIC AREAS.

Keywords: CHEST, DISMANTLING, BLOCKS, CRANE BOOM, TRUCK CRANE, CONSTRUCTION, CRUSHED, PELVIS, NECK, CRANE