What system is used for inerting in a ship's tank?

The flue gas system is the correct choice for inerting a ship's tank because it involves using the exhaust gases from the vessel's combustion engines to create an inert atmosphere within the tank. This inert atmosphere is essential for ensuring that flammable vapors do not ignite, thus preventing explosions and fire hazards when handling volatile cargoes.

Inerting is particularly important when loading and unloading cargoes that produce flammable vapors, as it displaces oxygen and reduces the likelihood of combustion. The flue gas, being a mixture of gases that contains a low concentration of oxygen, can safely fill the tank, maintaining a safe environment for staff and the cargo.

While other systems like steam or pressure systems might be involved in different operational aspects aboard a ship, they do not serve the primary function of creating a safe inert atmosphere within tanks. Ventilation systems typically aim to remove vapors and ensure air circulation, rather than provide inerting capabilities. Thus, the flue gas system stands out as the method specifically designed for the purpose of inerting tanks to enhance safety during cargo operations.