Retrofit improves ferry propeller efficiency

Rasmus Nielsen, Scandlines’ project engineer says: “We started to look at propeller retrofit solutions as a direct consequence of high fuel prices. Aboard the Sassnitz, we have replaced the propeller blades with a modern, optimised design. Our tests document that this has realised an increased efficiency of no less than 12%. Originally, MAN Diesel had 8-10% as a target, so therefore it’s very pleasing that our measurements show an even better result.”

He adds: “The ship reverses a lot in-harbour and therefore it’s vital for us to attain the optimal propeller blade design. As such, the propeller set-up has been optimised to best fit this particular operating profile without compromising overall efficiency.”

In order to optimise the process, the 1989 built Sassnitz’s operating profile was thoroughly analysed by MAN Diesel’s propeller design department. MAN Diesel PrimeServ participated in the installation of the new propeller blades on the Sassnitz, which is powered by four MAN L40/54 engines.

“MAN Diesel and Scandlines have cooperated with each other for over 20 years on controllable pitch propellers,” says Brian Grusgaard, manager of upgrading and retrofit support at MAN Diesel propulsion after-sales. “Scandlines is a front runner within retrofit propeller optimisation and the Sassnitz’s fuel consumption has now been reduced, which is also an environmentally friendly solution. We expect many such retrofits in the future, and are currently in contact with a good number of other ship owners who are very interested in propeller optimisation.”