🔍 Key Concepts

• How mechanical foam is formed in standard marine firefighting systems • Difference between mechanical foam and chemical foam • Basic components needed to make firefighting foam (concentrate, water, air)

💭 Think About

• Think about what equipment on a vessel (foam proportioners, branch pipes, nozzles) actually does to the foam solution as it passes through. • Ask yourself: does mechanical foam depend more on mixing and agitation, or on a chemical reaction to create gas? • Consider what three things must come together to create an expanding blanket of foam from a liquid concentrate on board.

✅ Before You Answer

• Identify whether mechanical foam relies primarily on physical mixing or on a chemical reaction. • Confirm what three components are normally run through marine foam-making equipment: foam concentrate, water, and what third element? • Eliminate any options that describe the foam forming only when it touches the fire, instead of being formed before it reaches the flames.