A fixed installation designed to displace the oxygen in the protected space and thus extinguish the fire, usually used to fight fires in engine rooms, boiler rooms, pump rooms and holds. The system normally consists of a series of large CO2 cylinders. The CO2 is supplied from the cylinder manifold to suitable points with diffusing nozzles. The discharge valve is located in a locked cabinet. Opening the cabinet activates an alarm to give personnel time for evacuation. Since the effectiveness of fixed CO2 fire fighting system diminishes the longer the fire burns, the speed is essential if CO2 is to be effective.
Note: Before CO2 system can be activated, engines need to be shut off, the machinery space needs to be evacuated, all openings and vent need to be shut and total evacuation has to be verified. Consequently, it can take 20 minutes or longer from the time of a fire is spotted to activate the system. Such delay not only allows fire to spread freely causing considerable danger to personnel and damage to equipment, but also makes a vessel lose its manoeuvrability.
Further reading: ABS Guidance Notes on “Fire-Fighting Systems”, can be downloaded from www.eagle.org