In maritime cargo operations, ullage measurement helps determine what?

• A. Tank temperature
• B. Tank pressure
• C. Remaining cargo volume
• D. Ship speed

Answer: (C)

Ullage measurement focuses on the empty space above the liquid inside a tank. In maritime cargo operations, this empty space, when combined with the tank’s known geometry and calibration tables, is converted into the amount of cargo left in the tank. You measure how far the liquid surface is from the tank top (or from a fixed reference), then use that ullage reading to look up or calculate the remaining volume of cargo. Temperature and density affect the actual volume and how it expands, so temperature data may be collected to apply corrections, but the ullage reading itself is what directly yields the remaining cargo volume. Tank temperature, pressure, or ship speed don’t provide the remaining quantity from this measurement.