Double girder overhead travelling cranes are composed of lifting trolleys and end-carriages on two box girders which are obtained from sheet metal with welding processes. With standard production from 2 ton to 63 tons, and process cranes from 50 to 250 tons we count with effective solutions for wide spans and high lift capacities. Thanks to the maintenance platform available in one of the beams, maintenance and fault conditions solving are facilitated. Generally, the main energy supply is provided by the bus-bar system, and the lifting group power line is provided by the c-profile or IPN profile system.