🔍 Key Concepts

• Fire tetrahedron: what element can you remove most quickly in an enclosed oil cargo tank? • Behavior of CO₂ systems in large, mostly closed spaces vs. small/local fires • Importance of sealing the space before using smothering agents

💭 Think About

• In an enclosed cargo tank fire, which action best prepares the space so that any smothering agent (like CO₂) will actually stay inside and be effective? • If you start cooling outside structures before doing anything else, what is happening to the fire inside the tank in terms of oxygen supply? • Think about the correct sequence: close/contain, then apply smothering/cooling. Which answer choice matches the FIRST step in that logical order?

✅ Before You Answer

• Identify which choice directly reduces the oxygen supply to the fire inside the tank. • Check which action must be done before releasing CO₂ so it doesn’t escape immediately to atmosphere. • Eliminate any choices that deal mainly with protecting surrounding structures rather than controlling the tank’s internal fire environment first.