CONSTRUCTION MACHINE

The invention relates to a construction machine having an upper carriage, an undercarriage which has a running gear and on which the upper carriage is rotatably supported about an upright axis, and a feed arm for at least one energy line, with which energy can be supplied from the outside to the construction machine, wherein the feed arm is adjustably supported on the upper carriage. In accordance with the invention at least one drive means for actively adjusting the feed arm relative to the upper carriage is provided.