In my experience, I have found most older built cooling towers to be Permit-Required Confined Spaces (PRCS); however, some of the newer designs have addressed the hazards which make these units PRCS (e.g., guarding the fan and shaft within the unit) or these spaces may be eligible for reclassification using 1910.146(c)(7). But this OSHA fatality inspection shows us that serious hazards within these units MUST BE managed before entry…
On February 8, 2008, Employee #1 worked as an HVAC technician. He was working alone. The computer overseeing a cooling tower on the penthouse level roof of the city hall building had picked up a vibration alarm. It displayed the alarm on a device being monitored by Employee #1.
Employee #1 sent himself to determine the reason for the alarm.
Employee #1 entered the cooling tower WITHOUT shutting off or locking out power to the unit.
The vibration switch consisted of a steel ball resting on a pedestal, just below which was a spring-loaded platform. A circuit was opened if the ball landed on the platform due to excessive fan vibration.
It is believed that Employee #1 stood on an A-frame ladder to reset the vibration switch. When he removed the steel ball from the platform, the circuit closed, and the unit began running. Employee #1’s jacket was caught up in the shaft of the unit’s fan, located immediately above the vibration switch. As Employee #1 was suspended by one arm, his head was struck repeatedly by the blades of the rotating fan. Employee #1 subsequently died from his injuries.
There were no witnesses to the incident.
