Propeller Retrofit Gives Significant Fuel Savings

An optimized propeller from MAN Diesel has helped the Scandlines passenger ferry, the M/V Sassnitz, achieve increased efficiency of 12% on its daily sail between Trelleborg, Sweden and Sassnitz, Germany.
 
Scandlines is one of Europe’s largest ferry companies, a result of the fusion between the largest, national ferry lines in Denmark and Germany. Business is based on the swift and reliable transport of both passengers and cargo on international routes within Danish, German and Swedish waters, as well as further afield to the Baltic states and Finland.

Scandlines operates 17 ferries on eight routes between 11 harbours in the Baltic Sea. Last year, the shipping company transported more than 17.3 million passengers, four million cars, one million lorries, 84,000 goods wagons, and 68,000 busses.

Rasmus Nielsen, Scandlines’ project engineer said: “We started to look at propeller retrofit solutions as a direct consequence of high fuel prices. Aboard the M/V 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 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.

M/V Sassnitz Principal Data:
Route     Sassnitz – Trelleborg
Type     Ro-Pax
Construction year     1989 / 1994
Gross tonnage     21,154
Shipbuilder     Danyard A/S, Frederikshavn, Denmark
Port of registry     Sassnitz
Flag     German
Engines     2 × MAN 8L40/54 2 × MAN 6L40/54
Output (kW)     18,200
Length, oa     171.5 m
Breadth incl. fender     24.1 m
Service speed     19 kn
Train capacity     5 tracks, 711.5 m
Lane metres, lorries     1,235 m
Car capacity     314
Passenger capacity    875