The project is a combination of effort from Tuco Marine, Effect Ships International (ESI) and Diab. The team is combining ESI’s air supported vessel (ASV) technology with a light-weight carbon sandwich construction.
Diab is responsible for the carbon sandwich engineering and Devinycell core materials, while Volvo Penta will be supplying engines and high efficiency IPS propulsion systems for the first of a range of vessels.
With support from The Market Development Fund (Denmark) and Norwegian Research Council, the first vessel, a 17.7m ASV monohull with a beam of 5.2m, is now under construction. It is expected to launch in autumn.
The ASV hull is a result of more than a decade of dedicated research and technological development. Through tank testing SSPA Sweden has documented a reduction in hull resistance of almost 40 percent.
“ASV and carbon construction is a perfect match,” says Tudem. “New standards in efficiency and operational economy can be achieved. Reduced hull resistance and reduced outfitting weight gives improved speed and performance with less power. In many cases engine power (and weight) can be reduced by as much as 50 percent.”
The ASV has a very low wake wash which is of great importance for many coastal operations with high traffic density, says Tudem.
While a planing fast monohull will face tough slamming impacts in waves at high speed, the air cushion chamber of an ASV will significantly dampen and reduce hull slamming and pitch motions, contributing to improved on-board comfort, safety and effective use of the vessel.
An air cushion chamber is covering the center part of the underwater hull, with planing buoyancy bodies (often referred to as propulsion gondolas) on either side. This configuration is very positive for reducing roll motion during low speed operation or at rest in waves.
A lift fan system is located in the far forward part of the hull, ducting air down and into the air cushion chamber, while a special air cushion enclosure arrangement is maintaining and controlling the ASV functions in the aft. With this patented set up, only 3-7 percent of the installed power is used to power the fan system to keep the vessel on the cushion.
In case of an unlikely situation that the fan system fails the vessel may be safely operated, as a semi-displacement vessel, naturally with higher resistance and reduced speed.