While some makers of pod drives and rim thrusters have used the last year to optimise their portfolios, one company developed a completly new series of pods. HANSA gives an overview of the market
More efficiency, more power, more electrification – the booming cruise ship market with its special efficiency, comfort, ice class and maneuverability[ds_preview] needs as well as the ferry sector, working on cleaning up its act, are driving the recent development of pod drive technology.
Rolls-Royce’s new ELegance ice-class pods illustrate this trend. The R & D process took four years resulting in a completely new podded propulsion system, designed to meet customer demand for more choices in the electric propulsion segment. The new pods are available in a range of 1.5 to 7 MW and are best suited for the cruise, passenger and ferry segments, but also for other applications like rigs, tugs and workboats.
Both pod types, open propeller or ducted, build on the experience gained from the Mermaid range’s more than 4,000,000 operational hours and data from Rolls-Royce’s range of mechanical thruster products.
ELegance thrusters incorporate the latest in permanent magnet (PM) motor technology. Per Nahnfeldt, General Manager Product – Electric Propulsion, says: »Based on an extensive system optimisation approach, this has resulted in a pod that optimises the trade-off between electrical, mechanical and hydrodynamic efficiency, utilizing our expertise within all these fields. The PM technology and the motor fitting in the casing, inherited from the Mermaid range, allowed us to create a sleek, slimline pod, which adds significantly to hydrodynamic efficiency.«
The pods are delivered together with Rolls-Royce’s Active Front End Converters, either fed from a conventional 690 V system or through transformers on a medium voltage distribution system, such as the Rolls-Royce SAVe Step solution. Batteries can be integrated to perform load smoothing on the engines and increase redundancy. SAVe allows a power-generating capacity reduction by up to 30 %.
The pods meet 1A Super and Polar Code 6 ice-class requirements. Rolls-Royce is now building a 4.6 MW unit.
An order for pod maker ABB from Viking Line also serves to illustrate the recent market dynamics: ABB’s Twin XO 2100-type Azipod units will be installed on the new Viking Line cruise ferry. The 63,000GT vessel with a capacity for 2,800 passengers being built in China is the first cruise ferry to be fitted with this technology. The XO features intelligent control systems and advanced condition monitoring. A remote diagnostics system enables connectivity to ABB Ability Collaborative Operation Centers. The Azipod XO units are also designed to match the ship’s ice class 1A Super notation.
The table provides an overview of available products in the pod/rim thruster segment.
