Which fire suppression system is used to fight alpha fires?

• A. Halons system
• B. AFFF system
• C. CO2 system
• D. Firemain

Answer: (D)

Alpha fires involve ordinary combustibles like wood, paper, or textiles. The most effective way to suppress these on a ship is to apply cooling water from the Firemain system. Water absorbs heat, lowers the temperature of the fuel and surroundings, and slows or stops the combustion process, making it the standard method for these fires. The Firemain is the ship’s dedicated network that delivers water to hoses and monitors across compartments, allowing crews to reach and control the fire quickly.

The other systems are geared toward different fire types or situations: Halons (or their modern substitutes) are used for electrical/electronic fires in spaces where water would damage equipment; CO2 is used in enclosed spaces to displace oxygen, which can pose a danger to personnel; AFFF foam is specialized for hydrocarbon liquid fires, creating a foam blanket to smother and cool oils and fuels. For alpha fires, water from Firemain is the appropriate, general-purpose solution.