Without a rail connection, the North Frisian island of Sylt would be difficult to imagine today. The trains from the mainland over the Hindenburgdamm to Morsum, Keitum and Westerland bring tourists and commuters, cars and goods across the Wadden Sea. Now a small anniversary is imminent: In 1972 the double-track expansion of the 11.3 kilometer long railway embankment was opened, a good eight kilometers of which run directly in the mudflats. Previously, the dam was only passable on a single track. This meant a bottleneck for rail operations to Sylt, despite the depot, which opened in 1955 and was located in the middle of the mudflats, where train crossings and overtaking were possible.

The Hamburger Abendblatt reported on the expansion work on June 9, 1972: "The old track was pushed to one side, the dam was heaped up on one side, creating space for the second track." The history of the dam was more than enough half a century back. The first proposals were made in the 19th century. This newspaper wrote in 1977: “Such initiatives go back to the time when Westerland officially became a seaside resort (1855): The traveler had the choice between a long sea route from Hamburg to the southern tip (including a no less arduous land route from Hörnum to Westerland ) and a slightly longer train journey to North Schleswig with a shorter, uncertain sea journey to about the middle of the east coast of Sylt,where a moderately deep tidal creek allowed paddle steamers to move about. "

In 1876 the geologist Ludwig Meyn confirmed the feasibility of a dam structure in the mudflats. It would follow a so-called mudflat watershed, where the forces of the tide are comparatively low. The project took shape before the First World War, but was not pursued any further. Finally, in 1921, the preparatory work for the railway connection that exists today began under the leadership of the “Prussian New Water Construction Authority for Dammbau Sylt”. The actual construction work started in May 1923.

In the beginning, they relied on conventional hydraulic engineering techniques with sand flushing. The FAZ of June 3, 1977: "Between bush dams made of piles and wattle, marking the floor width of fifty meters, silt was flushed in using the 'dredging method', the water content of which could flow back laterally." the same August a decision was made. Now the dam was built on a foundation secured with wooden sheet pile walls. This elaborate technology has since proven itself. The island knows only too well how difficult it is to defend the sandy beaches of the Sylt coast against the tides by washing them up. The result was a structure around 50 meters wide at the bottom and eleven meters wide at the top, which supports the superstructure of the railway systems.

The planners had set the height of the crown to be two meters above the highest documented storm surge.

The narrowest area between the mainland and the island was chosen for the course of the dam.

At the same time, the route of the structure was moved as far north as possible in order to gain some distance from the Föhrer Tief.

According to the "Sylt Lexikon", 3.6 million cubic meters of earth and sand as well as 400,000 tons of other material (stones, gravel, bushes, piles) were used for the construction.

Around 1500 workers were involved in the construction.

Other North Sea islands like Borkum were more far-sighted

With the opening of the railway embankment on June 1, 1927, Sylt could now be reached by land for the first time instead of having to take the arduous journey by ferry. This had become even more cumbersome for islanders and tourists since 1920 because the north Schleswig port of Hoyerschleuse was now in Denmark. To get to Sylt, you first had to cross a country border, including customs clearance.

The increase in capacity on Hindenburgdamm by opening the second track in 1972 was urgently needed. Another means of transport also contributed to this, the car: In 1932 there were car trains to Westerland for the first time, today both Deutsche Bahn ("DB Sylt Shuttle") and RDC ("Der Blaue Autozug") offer such connections. For the railroad traffic on the island with the narrow-gauge railway founded in 1888, the boom in road traffic meant the end as early as 1970. Other North Sea islands such as Borkum were more far-sighted here and have preserved the rail infrastructure.

Fifty years after the double-track expansion of Hindenburgdamm, people are far from satisfied with the island's rail link. The connection is sometimes ridiculed as the “most unreliable railway line in Germany”. It was only this summer that this northernmost part of the march from Hamburg to Westerland hit the headlines again with insufficient space. Will the complete double-track expansion of the line help? In front of the dam, in particular, there is still a single-track bottleneck between Niebüll and Klanxbüll. In April 2021, the railway announced that this 13-kilometer line would be expanded to double-track during ongoing operations for more than 220 million euros. There is not yet a binding schedule for the opening.

A construction site is also the name of the dam, based on the opening by President Paul von Hindenburg.

There are always efforts to designate the route with a historically more neutral term.

At the opening ceremony in 1927 there was talk of “The Wadden Sea Dam”, “The New Way” and “Sylter Dammbau”.