Aluminium boatbuilder Aluminium Marine Consultants (AMC) has added a new surface effect ship (SES) design to its portfolio, which is geared towards the crew transfer vessel market.
The SES has been designed by Norway’s Espeland and Skomedal Naval Architects (ESNA). The vessel is a next generation high performance crew transfer vessel, offering turbine access in up to 2.5 m significant wave height, with a maximum speed above 40 knots and reduced speed loss in high seas.
Air Cushion
The vessel’s tern hull consists of two slender catamaran hulls with the area between the hulls closed with flexible reinforced rubber fingers in the bow and an inflated rubber bag in the stern. This allows centrifugal fans to blow air into the enclosed space, providing an air cushion that lifts up to eighty per cent of the vessel weight.
AMC's vessel can be lifted up and down approximately two metres, which means it is able to cancel up to the same height of vessel motion in waves. This is especially effective in long waves/swell, where all other vessel types will float and follow the wave surface.
As the lift fans supply air to the air cushion, the control system actively controls vent valves that either ventilate the air cushion to a low pressure or closes the valves so that the air cushion pressure is increased.
The remaining twenty per cent of the vessel’s weight is supported by side hull buoyancy, which allows for high vessel speed because frictional resistance is decreased.
The tern is equipped with a computer controlled active motion damping system that reduces vertical motions both at high and low vessel speeds thereby reducing seasickness.
