Ferry Decks go Stainless
 SHAVING many tonnes off the weight of car ferries could improve the fuel efficiencies of fleets around the world  |
A new type of ferry deck, consisting entirely of stainless steel, is expected to boost
profits
Nickel magazine, Mar. 01 -- The MacGregor Group, a shipbuilding enterprise headquartered in
Stockholm, Sweden, has just introduced "Corex," a sandwich panel for ferry decks made of S30400 stainless steel. The modular panels are the result of several years of research aimed
at increasing the profitability of roll-on/roll-off (RoRo) ships by improving the payload, flexibility and
earning power of the vessels.
MacGregor chose stainless steel for construction mainly to prevent corrosion and lower maintenance costs.
"The sandwich panel consists of large areas with no access for painting or corrosion inspection," explains
Michael Koch, a Goteborg-based sales manager for MacGregor. "To seal the panel air-tight would be expensive,
and minor damage could expose the panel to air anyway." An additional environmental consideration is the
reduced, or zero use of paints and anti-corrosion coatings over the life of the ferry.
But the new panels promise more than environmental advantages and longevity. Decks built from the stainless steel panels are much thinner than conventional car decks, allowing more head space for trailers and lowering the ship's centre of gravity, which, in turn, provides better stability. Corex decks are 100 millimetres thick, compared with a thickness of 350 millimetres for conventional steel and aluminium decks.
The thinner the deck, the greater the payload. The improved stability allows for additional passenger accommodation or entertainment facilities on the top deck, or additional deck space for cars and trailers. For example, using the sandwich panel in a new medium-sized ferry would increase the ferry's car-carrying capacity by up to 10%, according to a MacGregor case study.
Ferries built with Corex panels may also be faster and more fuel efficient than traditional ferries because they are lighter. The stainless steel deck weighs 45 kilograms per square metre compared with 85 kilograms for conventional steel.
The panels consist of upper and lower plates joined by a system of stainless steel, internal reinforcing rods. The modular components can be welded together to form larger continuous sections. They also come equipped with a jigger winch for easy installation and allow an even load distribution in all directions.
The average car/passenger ferry needs about 1,500 square metres of car deck, according to Koch, so the total amount of S30400 stainless steel used in a ferry this size would be about 60 tonnes. A realistic market is about half a dozen of these vessels a year, or 360 tonnes of stainless steel, he says.
The car decks are initially being used for fixed and hoistable car decks and ramps and are designed for either new vessels or conversions on older ships. The deck height freed up by replacing conventional decks allows older ferries to carry higher trailers and make second-hand ships more valuable, MacGregor says.
Photo: The MacGregor Group
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Michael Koch, Area Sales Manager |
