The cranes have to move containers, whether empty or fully loaded, quickly and safely. Therefore the drives need an overload capacity of up to 400%. This generates a high dynamic response with a low moment of inertia in order to lift the containers up and down quickly.

The drives must be efficient and durable, because failures in ports are associated with very high costs. High intermediate circuit voltages and fast switching semiconductor components require special insulation and special winding wires. These ensure that the motor winding is virtually resistant to partial discharges to ensure the longevity and reliability of the drive. In addition, the drives must also withstand harsh weather conditions such as seawater or increased humidity.