Rolls-Royce has unveiled ELegance – a new podded propulsion system for units in the 1.5MW to 7MW power range. The ELegance pods – one with an open propeller, the other ducted – have been designed to complement and complete the company’s existing portfolio of mechanical and electric propulsion systems.
Rolls-Royce, which is currently building a 4.6MW ELegance pod at its Rauma facility in Finland, is in discussions with shipowners to install the pod in a pilot project.
Per Nahnfeldt, general manager, product – electric propulsion, Rolls-Royce, said, “For many years we have recognized the gap in the propulsion market for smaller pods, including ice-class, in the 1.5MW to 7MW power range. These new pods – based on our permanent magnet technology – sit well with our range of frequency drives and electrical systems. We can now provide a complete fully electric propulsion package.”
The 1A Super and Polar Code 6 ice class pods feature a ‘twin tail’ concept to improve efficiency and reduce cavitation-induced noise and vibration. A new integrated hull fitting interface allows a compact head-box to be used, minimizing drag and further improving hull efficiency. This also allows the height and tilt of the pod to be adjusted, enabling operators to select the optimum propeller size for the vessel.
Andreas Seth, SVP, electrical, automation and control – marine, Rolls-Royce, said, “The PM technology and the motor fitting in the casing have allowed us to create a sleek, slimline pod, which adds significantly to hydrodynamic efficiency.”
Should the pods need to be replaced, they can be lifted and mounted in water. According to Nahnfeldt, this provides a means for replacement of the complete units, including the steering gear, for ease of maintenance and service in, as well as out of, dry dock. “Both pushing and pulling pods have been designed with several layers of redundancy on critical and hard-to-reach components, with service points positioned for easy access.”
Maintenance is optimized by way of fewer moving parts within the below-the-waterline housing, and the only components that require dry-docking are the pod’s bearings and seals, which have a life expectancy of a minimum of 10 years. “This reduced maintenance requirement correlates directly to low lifecycle costs,” said Nahnfeldt, adding that the sealing solution that has been selected has no oil-to-sea interfaces. “Should system oil leak at all, it is fed into a dedicated sump connected to the ship’s bilge system.”