19. December 2022

VEM contributes to environmentally friendly ferries

water-cooled permanent magnet motors of VEM

Making ships more environmentally friendly isn't easy, especially when converting a ferry built in 1965. This was the challenge faced by a long-standing partner of VEM when asked to equip a ferry with electric drive systems. A project for which the system integrator brought a competent electromechanical engineer on board.

Combining tradition and modernity - emission-free retrofit projects in marine transport

The passenger and car ferry, which weighs almost 400 tonnes, can carry up to 450 passengers and 27 cars on one trip across Lake Maggiore. Previously, it was powered by two diesel engines with an output of 310 kW each. But it wasn't only the old and less environmentally friendly drive systems that were replaced. The entire propeller system was redesigned. The high-maintenance variable-pitch propellers have been replaced by highly efficient fixed-pitch propellers. The drive characteristics are now determined by variable-speed drives. And all this with significantly increased efficiency, especially in the partial-load range. This also reduced the complexity of the entire system. A decisive advantage for the operator of the fleet. A significant reduction in fuel consumption was achieved through the use of battery and hybrid technology.

The batteries are charged via an on-shore connection. This meant that not only did the ship conversion have to be coordinated, but the ferry's connections and interfaces also had to be completely retrofitted.

VEM cooperates successfully in shipbuilding

For all those involved, it was a challenging job to equip a ferry that was over 50 years old with an electric drive. A completely newly integrated DC system now regulates the power flow between the battery, the navigation system and other consumption on board.

The VEM plant in Wernigerode took over the production of two identical water-jacket-cooled permanent magnet motors for the ferry. The motors directly drive the propeller shaft. This meant that the gearboxes could be dispensed with - an important step in terms of optimising efficiency. The very compact design of the new drives is ideally suited to retrofit applications, as deck heights and installation spaces are often limited.

VEM - a German brand at the highest level

The traditional German company was perfectly suited to the requirements of the cooperation partner. The VEM group of companies develops and manufactures generators and motors for small and large ships worldwide. Its plants produce propeller motors with an output of up to 40 megawatts.

The water-cooled permanent magnet motor series was completely revised by VEM only recently. Standardisation and suitability for a wide range of marine applications were the development goals. Thanks to the permanent magnet technology and the necessary converters, a broad speed-adjustment range is possible. This is where the full benefits of permanent magnet technology come into play - exceptionally high efficiency in the partial-load range with minimal installation space. Thus, VEM was able to provide an optimal solution for the project. In addition, the water-jacket-cooled design helped to reduce noise emissions. This was another of the client's goals. VEM PM motors are available in both horizontal and vertical orientation across a broad power range.

The VEM Group's decades of experience in the development of customised drives guaranteed the success of this retrofit project. The rotor geometries had to be completely redeveloped and their installation optimised. The use of embedded magnets ensures an extremely long service life for the components and once again demonstrates the high quality standards of VEM motors.

A strong partner at your side: punctual, reliable, innovative

As in countless other major projects, the VEM Group was a strong partner, thanks to its extensive experience and exceptionally high production quality. Interdisciplinary competencies and technical expertise enabled the company to overcome a number of hurdles in the process and ultimately deliver a VEM product of the highest quality and to the latest technical standards, on schedule.

Following this success, other ferry operators have already shown interest in this kind of retrofitting. VEM will be happy to help them make their crossings safer, quieter, more energy-efficient and emission-free.

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