Swiss operator's ferry returns to service following battery retrofit

German shipbuilder Ampereship has completed its conversion of a diesel-powered passenger vessel to fully electric propulsion.

The converted ferry Uetliberg recently completed its first electric-only voyage on Lake Zurich in Switzerland. Originally built in 1999, the 42.4-metre-long vessel belongs to the fleet of Swiss shipping company Zürichsee-Schifffahrtsgesellschaft (ZSG).

Ampereship was commissioned by ZSG to plan and design Uetliberg's conversion to electric propulsion.

"With the ZSG contract, we are expanding our maritime e-mobility business to existing ships," said Ingo Schillinger, Business Unit Manager at Ampereship.

"The maiden voyage of the fully electric passenger ship Uetliberg shows that it is now possible to retrofit a passenger ship that has been in service for years with a transport capacity of up to 300 people with a promising alternative electric drive system."

The project was carried out in close cooperation with ZSG. Ampereship manufactured several steel sections for the ship, which was given a newly shaped bulbous bow, an extended stern, and additional bulkheads.

The steel sections were delivered to ZSG's own shipyard on Lake Zurich, where the ship conversion was carried out under the construction management of Ampereship.

The electrical engineering equipment was completely planned and designed by Ampereship engineers, and this encompassed automation and control technology as well as electric motors and battery packs.

A total of 7,200 battery cells with an energy output of 3.6 MWh were installed. Ampereship said 113,000 liters of diesel fuel can be saved annually through the use of the batteries.

There are also plans to convert Uetliberg's identical sisters Albis and Pfannenstiel to fully electric propulsion by 2027. Ampereship has again been commissioned for this project.