First ever ASV monohull with pod propulsion

The company now has a proper full scale 20m x 5,4m test-vessel in the water for demonstration and proof of concept. The ASV technology is patented ‘world-wide’ and has been developed in collaboration with SSPA Sweden (tank testing and concept optimization), Volvo Penta (propulsion and engine systems), Humphree AB (interceptor and ride control), Bosch Rexroth (hydraulic system for lift fan) and Universal Fans Ltd (supplying the lift fan system).

As much as 80% of the vessel’s operational weight is supported on a cushion of pressurized air, entrapped underneath the hull. The only feature that differentiates the ASV from most vessels is the air intakes in the forward top of the hull sides.

This new technology significantly reduces wetted surface area and friction between hull and water. The size of the engines to propel the ASV’s can be reduced compared with the market leading conventional vessels of same size and performance. Whereas two 1,200 – 1,360hp is the norm for 20m pleasure boats with cruising speeds of around 30 knots, the ASV Mono test vessel uses only two 435hp for propulsion. In addition approx 80 – 120hp, depending on sea conditions, is required to power the lift fan.

Fuel consumption is equally impressive. At approx 30 knots speed the market leading international brands are using 11 – 13 litres per nautical mile compared to the ASV Mono which consumes only 5.7 litres in total (propulsion and lift fan power). Not only is this good news for the owner/operator of the vessel, it is certainly also beneficial for the environment by reducing emissions by 50%.

The ASV mono test vessel is using two small Volvo Penta IPS 600s podded propulsors which, combined with the new patented air supported vessel configuration, is an ideal match. The installation of the driveline and lift fan system is extremely compact and requires modest space, leaving more than normal volume and space free for interior accommodation.

The ASV Mono concept can easily be up-scaled and will be suited for vessels from 13-15m length up to 50m and more. The air support is active from standstill and contributes to almost no ‘hump’. The acceleration from standstill through to 20 – 25 – 30 knots is very fast due to the markedly reduced hull water resistance. Because the vessel rides high in the water with almost no trim, the resulting wake wash is considerably less than most displacement vessels. Depending on vessel configuration and size the ASV and pod propulsion combination will be ideal for vessels with cruising speeds between 20 and 40 knots.

In terms of markets and applications, different variants of the ASV mono concept will be very competitive including pleasure boats and yachts, navy, patrol and paramilitary vessels, various types of commercial vessels including ferries and water busses. ESI intends to license out the ASV technology to yards and builders and will provide solutions for hull form and main ASV systems while the yards will design superstructures and arrangements.