🔍 Key Concepts

• Thermal expansion of liquid cargoes in closed or partially closed tanks • Function and design of an expansion trunk/ullage space on tank vessels • Industry practice and regulatory intent to maintain safe ullage (empty space) above cargo

💭 Think About

• Which option clearly leaves a dedicated space for cargo expansion without risking overflow through vents? • How is an expansion trunk intended to be used: filled completely, or left with space for liquid to rise? • Look at each choice and ask: if the cargo warms up and expands significantly, where will that extra volume safely go?

✅ Before You Answer

• Verify which option provides a defined space above the liquid that is specifically meant for expansion, not just “close to full.” • Check whether any option would cause cargo to overflow vents or expansion trunks if there is normal temperature rise. • Confirm that the correct practice is to leave sufficient ullage rather than filling right up to vents or almost 100% capacity.