to branch lines to Tinglev and Højer Sluse, which was the port for a ferry connection to Sylt. The line was extended to Bredebro, Scherrebek, Ribe and Bramming, where it connected with the Danish rail network. 1920-1926 In 1920 northern Schleswig became part of Denmark, and the border was established between Niebüll and Tønder. This meant that traffic to Sylt had to cross the German-Danish border twice, although the Danish authorities allowed sealed transit trains to operate, avoiding customs inspections of passengers. The operation of transit trains and the Hoyer–Sylt ferry ended with the inauguration of the Hindenburg causeway in 1927. Originally, the Marsh Railway ran from Wilster directly to St. Michaelisdonn. During the construction of the Kiel Canal a swing bridge was built on the line at Taterpfahl near St. Margarethen. During the widening of the canal in 1920, a new non-opening high bridge was built on the geest at Hochdonn on a 5.8 km long bypass route. The new train route with the new bridge was originally planned directly from Itzehoe to Meldorf, but because of protests from Wilster and Sankt Michaelisdonn, the line was elongated and rerouted to include these towns. The old track was rebuilt to run from Wilster to Brunsbüttelkoog and on the north side to Brunsbüttel Nord. 1927-1948 Significant changes took place on 1 June 1927 with the opening of Hindenburg causeway, which was prepared in 1922 by prolonging the line from Niebüll to Klanxbüll to enable material transports. Deutsche Reichsbahn (German State Railways) opened a new station at Westerland together with the connecting part of the line. The Sylt Island Railway lost its traffic between Munkmarsch and Westerland, because the ferry service between Hoyer and Sylt had been closed. The Island Railway built a station next to the Reichsbahn station, with a simple reception building. 1948–1993 After World War II many (often long) express trains ran to Westerland, especially in the summer season. Most trains ran beyond Hamburg towards Cologne and the Ruhr, some went to southern Germany. Daily service also operated as interzonal trains from Berlin (running without stopping in the former East Germany), which were augmented in the summer at weekends by a second pair of trains. Until the 1970s, these services were hauled by class 01.10 locomotives. These were replaced by class 218 diesels. A significant improvement of services on the Marsh line occurred with the timetable of summer 1978.