Inland shipping holds the ACES

10 May 2011
The ACES system should save around 15% of fuel costs for the Damen River Liner 11.45e

The ACES system should save around 15% of fuel costs for the Damen River Liner 11.45e

Damen Shipyards has announced the completion of development of its air chamber energy saving (ACES) technology, following trials based on an inland waterways tanker vessel.

Damen company Bodewes Binnenvaart, seeking to meet the challenge of lower fuel consumption from reduced hull resistance, has worked with partners including the Dutch Institute Marin in Wageningen and DST in Duisburg, Germany to investigate methods of reducing the frictional drag on ships by inserting air between the ship’s hull and the water. The research centred on the physical mechanisms, and how these could best be incorporated into the design of a vessel, and the energy savings which would result.

According to the Damen Shipyards group, the resistance of a vessel in water can be subdivided into the following components: friction resistance, form resistance and wave-making resistance, of which the friction resistance at the key speeds for transport vessels makes up some 60%-70% of total resistance. The energy-saving air-lubricated ships project (commonly referred to by its Dutch acronym PELS) instigated by Damen Shipyards showed that the air chamber concept, whereby air is blown into recesses in the bottom of the ship, resulted in the greatest efficiency.

Bodewes Binnenvaart subsequently submitted an existing, conventional inland shipping barge for the validation of the model-scale tests. The actual form of the air chambers was decided based on the data collected during the model tests. Test sailings were conducted in 2009 and 2010 in different conditions on Dutch inland shipping routes to build up a representative picture of the average sailing profile for this type of vessel. These data were compared with the data collected during the model tests at Marin and DST, which provided a mathematical model.

The outcome was a reduction in resistance of some 10% to 20% at typical operational speeds for this ship. Application of the ACES concept to a standard Damen River Liner DRL 11.45e is therefore expected to yield average fuel savings of around 15%. For a conventional vessel with a usage of 400m3/year, application of ACES is predicted to save the owner some 60m3/year, with corresponding savings in CO2 emissions.

Damen points out that because the system is not linked to a particular type of engine or specific number of revolutions and its workings are not influenced by the use of follow-up techniques for exhaust fumes, its application represents a welcome addition to the options currently available to ship owners. The company says it is equally suited to dry bulk cargo vessels, and ships fitted with the system can be classed by Bureau Veritas according to the notation: ‘Air Lubricated Vessel’.

In addition to the members of the project team (namely Damen, Bodewes Binnenvaart, Marinvention, DST, Marin, Imtech and the Netherlands Shipbuilding Industry Association VNSI) the Dutch Ministry of Economic Affairs and Gelderland Province contributed to the technological development. After completion of the PELS 2 project, additional research was carried out with the support of the European Commission. Damen says that the system will be brought to the market for various vessel types, being applicable to all inland shipping.

Links to related companies and recent articles ...

Damen

view more