VESSEL REFIT | Cöllni 1929 – Compact electric mooring boat in operation at Port of Hamburg

A compact mooring workboat is once again in operation in the Port of Hamburg in Germany following a conversion project that saw its diesel propulsion system replaced with an electric arrangement consisting of an inboard motor and batteries.

Cöllni 1929 underwent the conversion at the family-owned Von Cölln Shipyard in the Finkenwerder district of Hamburg. The three-month-long upgrade on the 9.15- by 3.22-metre boat entailed the replacement of its diesel engine with a Torqeedo 111kW battery-powered inboard motor that generates only minimal noise and no pollution.

The electric propulsion also significantly reduces the vessel's displacement, making it more manoeuvrable and highly responsive to operator input, which is especially important when navigating busy waterways like those of Germany's second-largest city. Acceleration is also quicker compared to a conventionally-powered mooring boat.

The three-month propulsion retrofit on Cöllni 1929 was done following the Hamburg city government's decision to commit to significantly reducing air pollution generated by marine transport on the nearby Lake Alster. The long-term goal is to make shipping on the lake completely emission-free by 2030.

Torqeedo also fitted the boat with a computer that allows the crew to know the current state of available battery power at any given time, thereby enabling sailings to be planned accordingly. Fully charged batteries ensure maximum sailing times of seven hours in still water and two hours when the boat is cruising against the current. However, its normal operating profile will require a service speed of only a little over four knots, and being limited to this speed will extend the endurance to allow whole day operations whether in assisting ferries or repairing jetties.

Cöllni 1929's area of operations will be in Lake Alster, where it will be used primarily for ship handling of passenger and cargo vessels. Its secondary duties will include limited cargo transport and repair of structures such as bridges and jetties.

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