ZAP: Zero Emission Auxiliary Propulsor

The International Maritime Organisation (IMO) has introduced several measures to lower the CO2 emissions from the fleet in active service and the permissible limits will be further reduced in the coming years. This is due to the IMO's goal to cut carbon emissions by 40% relative to the 2008 level until 2030 and to reduce the total green house gas emissions of the shipping industry by 50% up to the year 2050. Fleet operators must therefore adapt their existing ships to the new requirements and retrofit appropriate systems. In view of the complexity of today's ship systems, the challenge is to identify solutions that are as efficient as possible, require only minor interventions in the existing ship structure and reduce emissions to a large extent.

As part of the ZAP (Zero Emission Auxiliary Propulsor) project, a new type of active rudder will be developed that can be retrofitted in place of the conventional rudder and, together with an electrification package, will enable zero-emission cruising. The active rudder is equipped with a ducted propeller and an electric motor integrated into the rudder, which offers additional operating capabilities. Among them, the propulsion of the vessel only by the active rudder, for slow transits or port approaches, where the main engine may be shut down. This will lead to considerable reductions in air pollution or noise emissions. In addition to that, the manoeuvrability at slow speeds is enhanced which increases the safety and operability in crosswind conditions. Such a retrofit is interesting for both cargo and passenger vessels. It can relieve port areas as the Elbe/Hamburg region and reduce the impact of shipping on ecologically sensitive areas such as the Geirangerfjord. The project includes extensive research activities based on numerous simulations for the development of the ZAP concept, with the aim of developing a fully functional product.