The electric bus charging mast „Flow“: An ecological rapid-charging system for the new plug in hybrid buses of the Hamburger Hochbahn AG. With a charging time of only 7 minutes, „Flow“ is the visible key element of this innovative technology. The shape derives partly from the given power connector, proven from railway technology, and a natural form of design language. The shape consciously combines both aspects, nature and technique, into one characteristic statement. The GFK-parts withstand both: extreme vandalism and weather. The barrier-free emergency button and the info panel are integrated flush with the adjacent areas. Discreet LED stripes visualise the impressive charging procedure. Being mounted in a large number, the quite shape given to „Flow“ is both: an unobstructive part of future city architecture and an eco-landmark.