Claim: The bank effect is important in determining the limiting conditions in which a ship can safely navigate a waterway and is dependent on various parameters, such as propeller action (similar to Archimedes' screw).
Evidence: A reliable estimation of bank effects is important for determining the limiting conditions in which a ship can safely navigate a waterway. This phenomenon depends on many parameters, such as bank shape, water depth, ship-bank distance, ship properties, ship speed and propeller action. A propeller is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral, that, when rotated, performs an action which is similar to Archimedes' screw.