DH Pace Company, Inc., dba Overhead Door Company of St. Louis

Incident Narrative

An employee was servicing a traffic arresting barrier gate that was equipped with a retractable bollard. The bollard is moved into the up position by use of a pump and hydraulic pressure. The bollard moves into the down position by gravity as a solenoid is triggered to open a valve to relieve hydraulic pressure. When the gate is closed, the bollard is in the up position. When the gate is triggered to be opened, the bollard retracts below the road surface and then the gate slides open. There was a removable access panel that allows access below the surface of the road to a pit where adjustments to limit switches, sensors, etc. may be made. After diagnosing the problems with the gate, the employee discovered an issue with the proximity sensor within the pit below the access panel. While adhering magnets to the surface of the bollard in line with the proximity sensor, the bollard unexpectedly descended into the frame sleeve below the road surface without the hydraulic pump activating. The employee's hands were in the pit at the time and his fingers were inside the frame sleeve. The employee's left middle and ring fingertips were amputated. The right middle fingertip was also amputated.