🔍 Key Concepts

• Fixed CO2 fire-extinguishing systems and why people must evacuate before discharge • SOLAS / 46 CFR requirements for pre-discharge alarms in machinery spaces • The minimum time needed to safely warn and evacuate personnel before CO2 fills the space

💭 Think About

• Think about how quickly CO2 can displace breathable air in a machinery space and why crew need a short but sufficient warning time. • Ask yourself: is the required alarm time closer to the time you’d need to notice the alarm and reach an exit, or to a very long evacuation period? • Consider what international regulations usually set as a minimum delay before agent release, not a generous maximum.

✅ Before You Answer

• Verify in SOLAS and/or 46 CFR (Title 46) what minimum alarm time is specified for CO2 systems protecting machinery spaces. • Make sure you are thinking of the audible alarm time before discharge, not the total time for CO2 to fully flood the space. • Check that the time you choose is reasonable for a quick escape from an engine room—long enough to react, but not so long that the fire grows unchecked.