Prior to the closure of the Westphalian line between Welver and Unna-Königsborn in 1968, passenger services were established on the line between Unna and Unna-Königsborn on 26 May 1963, continuing to Dortmund Stadthaus station. In 1972 a regular interval regional service was established from Unna via Unna-Königsborn, Dortmund Stadthaus and Dortmund-Dorstfeld to Dortmund-Marten Süd, which was extended in 1983 to Dortmund-Lütgendortmund. This was a direct precursor of line S 4 of the Rhine-Ruhr S-Bahn. In preparation for the S-Bahn, electrification of the line from Unna to Unna-Königsborn was completed on 25 May 1984 and on 28 June 1984 it was upgraded with a top speed of 80 km/h. S-Bahn services commenced on 3 June 1984 and operates at 20-minute intervals. Notes Railway lines in North Rhine-Westphalia Railway lines opened in 1899 1899 establishments in Germany Buildings and structures in Unna (district) Unna