A Rubber Tired Gantry crane (RTG) is a mobile container gantry for loading containers in ports. Pinpoint container stacking is ensured by portal cranes with rubber-tired running gear in standardized troughs. Whilst earlier RTGs ran on diesel, due to environmental and cost reasons, electric drives are more common now. This new generation of electric RTGs require modern energy chains with average travels of 200-300 m. For quick and safe coupling and uncoupling of the chains to the vehicle, necessary for every change of trough, igus® has developed a special coupling with the erover. At the central docking stations at the start and end of every trough, the igus® system comprising lifting unit, floating moving end and moving end carriage automatically completes the coupling at the crane operator‘s signal. At the moving end, a variable telescopic arm and sensors ensure that any deviations are compensated.