MACSEA’s new Hull Medic system detected the onset of hull fouling that was estimated to cost around $136,000 per month of unnecessary fuel consumption by one Navy ship. Fuel was being wasted due to the 35% extra power required to maintain the ship’s operating speed with a fouled hull. As part of its mission requirements, the ship is required to maintain fixed speeds in coordination with other vessels. In order to compensate for over a one knot speed loss due to hull fouling, the crew had to apply more throttle to achieve its normal mission speed, resulting in additional power and fuel consumption.
Hull Medic calibrates each ship’s propeller as a kind of power absorption dynamometer, resulting in a highly accurate, customized model of ship performance. Coupled with advanced database filtering, high accuracy models allow Hull Medic to detect ship performance losses earlier than other methods of ship performance monitoring, allowing hull maintenance and fuel savings to occur earlier.
Even small amounts of hull fouling 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. Hull Medic detected the performance loss as soon as the ship returned to normal operations. The Navy then verified the extensive fouling through an underwater hull inspection and immediately ordered the hull to be cleaned.
The ship was one of two vessels involved in a Navy study to evaluate the relative effectiveness of alternate hull paint systems on fuel economy. Both ships were painted with different coatings during drydocking and outfitted with Hull Medic. Propeller models were then calibrated and the ships were monitored over the year-long study. Contact MACSEA for further information.