Fire Suppression Systems

Fire Suppression Systems – General Points

• Sprinkler, Spray, and Fog systems, once engaged, will also sound an audible alarm.
• Automatic suppression systems that trigger (usually upon reaching a certain temperature or detecting a certain level of smoke) will only ever be water based systems.  CO2 systems are never automatically activated due to the danger they pose to human life.

Water Sprinkler Systems

• Upon the temperature reaching a certain threshold, water will begin spraying water through the sprinkler heads
• Because they’re heat activated, this means these systems are both a detection system and fire suppression system
• These typically do not shut of automatically and will need to be shut off manually once the situation is deemed safe

Water Spray Systems

• Water spray systems on ships are designed to protect large areas
• These systems typically consist of a network of nozzles or monitors strategically placed to cover a wide area.
• In the event of a fire, water spray systems can be activated to create a curtain of water that shields surrounding surfaces from radiant heat and flames.
• By forming a water barrier, these systems help prevent the fire from spreading to other parts of the ship and can also protect personnel and equipment during firefighting operation

Water Fog Systems

• Fog systems emit a fine mist of water in order to lower the temperature and suppress the fire
• The mist has an increased water surface area compared to sprinkler systems.  Because of this, they are able to cool an area more efficiently (per volume of water)
• Fog systems are typically less damaging to sensitive equipment than sprinkler or spray systems
• The fine droplets can also help scrub smoke particles out of the air thereby increasing visibility and reducing smoke damage

CO2 Systems

• CO2 systems are a way to combat fires by way of displacing the oxygen in the area that the fire needs as fuel
• Once deployed, CO2 systems are typically very fast acting and can often put out a fire in a matter of seconds
• Things to consider when engaging CO2 systems:
  • A room flooded with CO2 will be extremely hazardous to people as they’ll be unable to breath.  Prior to activation, a headcount of the people onboard the ship is often required.
  • Vents to the area should first be closed in order to properly saturate the area with CO2
  • CO2 systems don’t reduce the temperature of the affected area.  This means boundary cooling (spraying cold water on the boundary areas) and letting the area cool over time are effective strategies in controlling the temperature.
  • CO2 systems will need to be ventilated properly prior to anyone entering the area
• The CO2 alarm control is typically located outside of the protected space, usually in either ship’s control room or bridge.