🔍 Key Concepts

• Behavior of heavy fuel oil (HFO) fires in an enclosed machinery space • Importance of ventilation control and remote shutdowns before attacking a machinery-space fire • Proper use of a fixed fire-extinguishing system versus sending in a hose/portable team

💭 Think About

• Look at the arrows in the illustration: what do they show about air and smoke movement if door "E" is opened or people advance a hose team? • In a large, well-developed oil fire in a purifier room, which is safer and more effective first: sending people into the space or controlling the space from outside? • For a machinery-space oil fire, what sequence of actions is normally required before releasing a fixed gas system (CO₂, etc.)?

✅ Before You Answer

• Verify which option controls both ventilation and electrical power to the space before fire attack. • Check which choice keeps personnel out of the fire compartment while a large HFO fire is being fought. • Eliminate any options that increase air supply to the fire by opening doors or by continuing mechanical ventilation.