The Ringbahn (German for Circular Railway) is a 37.5 km (23.3 mi) long railway line of the Berlin S-Bahn network in Germany that circles Berlin's inner city area. Its course is made up of the double tracked S-Bahn ring and the parallel freight ring. The S-Bahn lines S 41 (clockwise) and S 42 (counterclockwise) have the rare continual service pattern of a full ring, without a terminus. In addition, the Lines S45, S46 and S47 use a section of the southern and western Ring, while the Lines S8 and S85 use section of the eastern Ring. The combined number of passengers is about 400,000 passengers a day. Due to its distinctive shape, the line is often referred to as the Hundekopf (Dog's Head).