Recently the underwater hull of m/v John Noble, one of the ferries owned by Staten Island Ferries was coated with Ecospeed in Bridgeport, Connecticut, U.S.A.
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.
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 fuel penalty resulting from biofouling is 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 an issue. Instead, the owners of m/v John Noble and any other ferry operator can optimize the hull performance, and thereby fuel consumption, by in-water maintenance which can be done economically outside of drydock.