Question 949 Deck General

The correct answer is D) spraying LNG heel through spray nozzles in the tanks. During a ballast voyage, the LNG tanks on a tanker need to be kept cold to maintain the liquefaction of the natural gas. This is achieved by spraying a small amount of the remaining LNG (called the "heel") through nozzles installed in the tanks. The LNG heel acts as a coolant, helping to maintain the cryogenic temperatures required to keep the LNG in a liquid state. The other options, such as aggressive gas compression or venting gas, would not effectively maintain the tank temperatures during the ballast voyage.