The C Line is the third line of the Frankfurt U-Bahn. It opened on 11 October 1986[3]: 13 and runs east-west through the city centre via Hauptwache and Konstablerwache. In the East it has branches to Frankfurt Ost railway station and Enkheim. To the North-west of the city centre it runs under Bockenheimer Landstraße before splitting into two branches to Hausen and Praunheim. The main services on the line are the U6 (Hausen-Frankfurt Ost) and U7 (Praunheim-Enkheim). Part of the branch to Enkheim also carries U4 services.
^C trunk line mileage is referenced from km 10.00, at the intersection of the C and A tunnels at Hauptwache station.
^In the C1 tunnel towards Enkheim, the distances are calculated differently due to the cross-platform interchange system, each starting at the corresponding branch off the main line: Track 1 towards Enkheim begins at the junction between Zoo and Frankfurt Ost stations. Track 2 from Enkheim is measured from the junction between Zoo and Konstablerwache stations.
^ abc"Die Frankfurter U-Bahn 1968-2008" (Document) (in German). Verkehrsgesellschaft Frankfurt. September 2008.