S1 (Rhine-Ruhr S-Bahn) Services ran via Düsseldorf Airport Terminal station from 24 May 1998 to 28 May 2000. Services were extended from Düsseldorf to Solingen on 13 December 2009, replacing part of the former line S 7 service. S1 (Rhine-Ruhr S-Bahn) Line S1 is a S-Bahn line on the Rhine-Ruhr network. It is operated by DB Regio. It runs from Dortmund west over Essen to Duisburg. From there it travels south to Düsseldorf and Hilden before continuing to Solingen. It is operated at 20 minute intervals, using coupled sets of class 422 four-car electrical multiple units. Line S 1 runs over lines built
Battle of the Ruhr the Ruhr, Bomber Command estimated about 70% of their aircraft losses were due to fighters. By July 1943, the German night fighter force totalled 550. Through the summer of 1943, the Germans increased the ground-based anti-aircraft defences in the Ruhr Area; by July 1943 there were more than 1,000 large flak guns (88 mm caliber guns or greater) and 1,500 lighter guns (chiefly 20 mm and 37 mm calibre). This was about one-third of all anti-aircraft guns in Germany. Six-hundred thousand personnel were required to man the AA defences of Germany. The British crews called the area sarcastically "Happy Valley"