Line S 13 is a S-Bahn line of the Rhine-Ruhr network. It is operated by DB Regio with class 423 electric multiple units. At peak times, the S13 services begin or end at Düren and run via Cologne to Troisdorf. In the off peak, half the S13 trains begin or end at Sindorf. It runs with line S12 for most of its route, splitting from it only to run through Cologne/Bonn Airport. On working days, two services operate every hour (20 or 40 minutes apart) and together with an hourly service on line S19, services operate at 20-minute intervals. Between the peaks the S12, S13 and S19 services provide a service every 10 minutes on the central section between Köln-Ehrenfeld and Köln-Trimbornstraße.