A new generation of high-speed passenger ships is emerging from the
design offices of Japanese shipyards. One idea, from the steel and shipbuilding
company NKK, relies on an innovative hull shape to create a catamaran capable
of travelling almost as quickly as a jetfoil, but much more cheaply and
NKK has published an artist’s impressions of sleek ships capable of
carrying 200 and 400 passengers. But the secret of the technology is below
the water line of the catamaran’s hulls, which consist of a submerged V-shaped
section under a narrow strut. The company calls its design the V-Cat.
Engineers say the V-Cat is economical and, as a displacement craft rather
than a hovercraft or jetfoil, easy to scale up into large ships. It also
handles rough weather better than today’s fast ships. To pass Japanese standards,
ferries must be able to keep to 90 per cent of their schedules in waves
3 metres high.
‘The V-shaped hull softens the impact of waves,’ says Kazuo Hayashi
of NKK’s Tsurumi shipyard near Yokohama. The ship’s vertical acceleration
caused by waves is only half that of a conventional catamaran, he says.
The company has tested the design in a vessel 10 metres long, powered
by twin outboard motors. A full-size ship, powered by diesel engines, will
be capable of 40 knots (75 kilometres per hour).
Meanwhile, the rival company Mitsubishi Heavy Industries has unveiled
plans for a hybrid between a boat and an aircraft capable of 180 kilometres
per hour. The craft, called a Marine Slider, will fly 3 metres above the
sea, relying on an air cushion formed between three sets of wide wings and
The idea is to build a craft capable of carrying passengers quickly
over ranges of up to 300 kilometres, to bridge the gap between ships and
airliners. However, engineers say they still have to improve the craft’s
handling in rough weather and to reduce the estimated cost of 3 billion
yen ( Pounds sterling 13 million) for a craft 55 metres long.
Shipbuilders are interested in high-speed ferries because of the growing
demand for leisure travel in Japan. The country today has about 200 high-speed
ships (defined as travelling faster than 22 knots). About four-fifths of
them are due to be replaced by larger and faster craft.