Modifications to the propulsion system include a newly designed Azipod fin shape and a new pod cap structure, called X-tail.
The revised fin structure receives water flow from the propeller at a new, less acute angle, and its new curved design redirects the flow more efficiently. The unit’s new X-tail, installed for the pod cap structure, straightens water flow on ejection from the Azipod propulsor, minimizing water swirling, ABB says.
Royal Caribbean International’s Radiance of the Seas was the first cruise ship to use the new fin shape and X-tail. The modifications to Azipod were completed during her drydock in May 2011. Her sailing from May to September saw more than a 2 percent improvement in hydrodynamic efficiency, compared to a sister vessel and her previous operational portfolio, ABB says.
In April last year, a consortium of shipping industry bodies led by Ricardo announced that it was pursuing an end-goal of reducing operational fuel consumption by 15-25 percent through measures including the energy management of propulsion and auxiliary power systems.