 The service used old rolling stock, consisting of class 111 locomotives hauling five double-deck carriages.At the introduction of the next stage of the integrated timetable (ITF2) in December 2002, the line was the most vulnerable to delay in North Rhine-Westphalia.The causes of these delays were the single track sections of the Sieg Railway, work in connection with the completion of the Cologne–Frankfurt high-speed line and the upgrading of the Sieg Railway for S-Bahn operations, speed restrictions between Cologne and Krefeld and a very short turnaround time in Krefeld of 12 minutes.