Bottom mounted crude oil washing machines are primarily used for _________.

Correct Answer: Option D — areas where direct impingement from deck mounted machines cannot be satisfactorily reached

Bottom-mounted COW machines are specifically designed to target 'shadow areas'—regions within the tank structure, such as under stringers or stiffeners, where the jet from deck-mounted machines cannot reach. This ensures comprehensive cleaning coverage, preventing the accumulation of sludge in difficult-to-reach areas of the cargo tank.