Swedish ferry is fast and green

Constructed by French shipyard Alstom Leroux Naval at a cost of some FF230 million ($39.82 million), the 112m Corsaire 11500 ferry Gotland was handed over to its owner, Rederi AB Gotland, in mid-February.

The vessel will carry up to 700 passengers and 140 cars between Visby on the south east coast of Sweden and the island of Gotland. Making three round-trips daily at a service speed of 35kt, the ferry will provide this service 18 hrs a day, 365 days a year, each journey lasting two hours thirty minutes, with a turn round time of just 30-40 minutes.

As Rederi AB GotlandÕs project manager for the new fast ferry, Bo Petersen, explains, the requirement to provide a year-round service through the harsh winter climate in the Baltic was a major influence on the design. So too were Swedish environmental regulations, which place strict limits on emissions from vessels operating in the area. The company needed a vessel with a length of around 112m, with two car decks, two passenger decks, and waterjet propulsors that could provide a service speed of about 35kt at full load at 90 per cent engine MCR. Using the Corsaire 11500 as its basis, the detailed design of the fast ferry – which will be capable of navigating in water at a temperature of 0 degC, and an air temperature of Š30 degC – was produced jointly by the owner and the yard.

Constructed with an EH 36 high tensile steel hull and aluminium alloy superstructure, Gotland has a deep-vee hullform with ten transverse bulkheads. A partial double bottom has been built in to provide protection in the event that the hull is damaged through grounding, an arrangement that provides sufficient residual integrity to maintain damaged stability even in a ?worst caseÕ scenario. The shipÕs engine rooms are separated by a watertight compartment, thus ensuring that one engine room remains operational, even in the event of damage to two compartments in the engine room area.