Ship Hull Fouling
Ship Hull Fouling Indicated by Propeller Shaft Torque Measurements
MACSEA’s new Hull Medic system detected hull fouling estimated to cost one USA Navy ship over $100,000 per month in extra fuel consumption. About 35% extra power, as measured by the Binsfeld torquemeters, was required to maintain the ship’s operating speed with a fouled hull.
Hull Medic calibrates each ship’s propeller as a power absorption dynamometer, using the unique relationship between speed, propeller rpm, and shaft power. The TorqueTrak Revolution instrument from Binsfeld Engineering was selected to provide high-accuracy torque and power measurements on two ships as part of a Navy study to evaluate the effectiveness of alternate hull paint systems on fuel economy. Even small amounts of hull fouling like slime translate into large fuel penalties for active ships and the sooner the hull is cleaned, the more fuel can be saved. The fuel penalty of the Navy ship resulted from the ship sitting at birth throughout most of the warm summer months. With the help of the TorqueTrak Revolution instrument, Hull Medic detected the performance loss as soon as the ship returned to normal operations.