The purpose of the “ECO-Island Ferry” project is to demonstrate the opportunities for fuel cost savings and reduction of environmental impact, if the vessel is built in modern light weight materials instead of traditional steel.
An ECO-Island Ferry is defined as a ferry built of light weight carbon fibre materials, where the weight saving on the hull is used solely for reducing fuel consumption and thereby lowering the environmental impact (CO2 footprint).
It is a well-known fact that there is a fixed physical relationship between the weight of at transported load (ship+cargo) and the required power (horsepower). It is therefore obvious that the lighter the vessel itself is, the more pay load can be transported with the same power.
Other sectors of the transportation industry has been very well aware of this fact for years, and are constantly striving for designing lighter transportation vehicles.
Increasing fuel costs and environmental issues have become a key factor in modern shipbuilding, and it is therefore relevant to search for new methods to improve the efficiency - also for vessels.
Upcoming requirements from IMO will classify vessels above 400 GT according to their energy efficiency design index – EEDI. The new IMO regulations will be implemented from 2013 to 2025. These requirements will most likely – in a modified form – include smaller vessels too. A lighter vessel will have a relatively higher energy efficiency than a heavier one.
Traditionally, vessels have been built in steel - or to a certain degree – aluminium. The choice of composite materials as the main structural material for a vessel hull is desired to reach higher speed with the same power, or to carry a larger payload with the same displacement.
A ship hull built of carbon-reinforced sandwich weighs only approximately 1/3 of a steel hull with the same displacement. Even if the equipment and installations in the ship are the same as in a similar steel vessel, the lighter vessel will require substantially less engine power to transport the same payload with the same speed.
But a carbon fibre ferry has a higher initial cost than a similar steel ferry, and the legislation in general requires or expects vessels to be built from steel or other non- combustible material.