JUNE 6, 2012 —The underwater hull of the Staten Island ferry Sen. John J. Marchi, was recently coated with Ecospeed in Norfolk, Va. This follows last year’s application of Ecospeed to the Staen Island ferry John Noble in Bridgeport, Conn. Ecospeed was also applied to one the company’s fuel barges in Staten Island, N.Y, earlier this year and a third ferry is planned to be coated later this year.
Under normal operation, ferries have to drydock once a year to comply with classification regulations. During the busy tourist, season the ferries need to be sailing so the best time for drydocking is the off season when there are fewer passengers. For this reason the majority of the ferries come into dry dock 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 a quality paint job cannot be assured. It is therefore essential to reduce the maintenance and paint work that has to be done in dry dock.
The use of Ecospeed on the hulls, however, opens the door to optimizing their fuel efficiency. 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 cleaning 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.
The TBT-free, copper-free and biocide-free Ecospeed coating is a vinyl ester with a high concentration of embedded glass platelets. It has a very low amount of volatile organic compounds (VOC) and is typically applied in two coats of 500 µm dft. The high film thickness and the presence of glass platelets which act as an impermeable barrier give Ecospeed excellent anti-corrosive properties. It is extremely durable, making it well suited to to regular in-water surface treatment.
Ecospeed comes with a 10 year guarantee and is expected to last the lifetime of the vessel. This is in contrast to traditional antifoulings where a new application is necessary during each drydocking.
Restoring the performance of the hull by repainting it in dry dock can be time-consuming and expensive. Once Ecospeed has been applied, this is no longer an issue. Instead, ferry operators can optimize the hull performance, and thereby fuel consumption. This is achieved by in-water maintenance outside of dry dock.