Hydrex Underwater technology

Recently the underwater hull of the second of the three 98-meter ferries crossing Delaware Bay from Cape May to Lewes was coated with Ecospeed in Staten Island, New York.

MV Twin Capes is owned by the Delaware River and Bay Authority (DRBA) and was one of the original three vessels of the company’s 1970s fleet. Her sister ships are the MV Cape May and MV Delaware; the latter was coated with Ecospeed at the beginning of 2011.

Under normal operation, ferries have to drydock once a year to comply with classification regulations. During the busy tourist season these ferries need to be sailing to make money so the best time for drydocking is the off season when there are fewer passengers. For this reason the majority of these ferries come into drydock for a short time during the winter months. The owner is then presented with bad weather conditions in which to perform repair work to the paint system, and often therefore a quality paint job cannot be assured. It is therefore essential to reduce the maintenance and paint work that has to be done in drydock. The use of Ecospeed on the hulls, however, opens the door to looking deeper into how to optimize their fuel efficiency in between dockings. Ferries sail on a fixed route, so the ports they visit and the turnaround time is known in advance. Knowing the exact schedule makes it possible to implement a stricter underwater maintenance program.

Hydrex can help ferry operators by monitoring the condition of the ship hull through detailed in-water inspections. A tailor-made maintenance program can then be set up. This, combined with Ecospeed’s performance-enhancing benefits, enables ferry owners to optimize the hulls and thus the fuel efficiency of their vessels. The smoothness attained by the coating provides best hydrodynamic conditions for the vessel to operate at maximum efficiency.

Regular underwater treatment of Ecospeed is used as a performance enhancement measure. Added drag caused by marine fouling is kept under control. Moreover, the coating’s surface texture and hence its hydrodynamic efficiency improves with each treatment. As a result, by adjusting the treatment interval, the increased fuel costs are minimized to significantly lower levels than would be the case for an SPC or foul release paint.

Restoring the performance of the hull by repainting it can be time-consuming and therefore expensive in drydock. However, once Ecospeed has been applied, this is no longer the case. Instead, the owners of MV Twin Cape and any other ferry operator can optimize the hull performance, and thereby fuel consumption, by inwater maintenance which can be done economically outside of drydock.