I recently wrote about the Rødby to Puttgarden train ferry, linking southern Denmark to northern Germany. This route opened in May 1963 and slashed journey times for both rail and road transport between København and Hamburg. Yet it was also a lesser-known part of the Cold War story.
The two ferry terminals were built at the points of each country nearest each other, which both happened to be on islands in the Baltic. One of the consequences of this is that any journey from Denmark to Germany via this route not only necessitates a ride on a ferry – well, for the foreseeable future at least (construction of a fixed link will begin in 2018) – but leapfrogging a number of islands along the way.
Accordingly, the infrastructure that required constructing in 1963 was not confined to the ferry terminals and their associated roads and railways, but also two substantial bridges. On the Danish side, there was the Frederik IX Bridge linking the islands of Falster and Lolland; on the German side, there was the Fehmarnsundbrücke linking the island of Fehmarn, on which Puttgarden port stands, and the German mainland.
The Fehmarnsundbrücke carries a two-lane road, a single-track railway, and a pedestrian walkway. It is 963.4m long and is high enough for ships to pass under, and was built as a replacement for the little ferry that used to shuttle from the mainland to Fehmarn. It was formally opened on 30 April 1963, although when severe weather had caused the suspension of the Fehmarn ferry three months previously, people had been permitted to use it at their own risk. Its engineers were G. Fischer, T. Jahnke and P. Stein from the firm Gutehoffnungshutte Sterkrade AG based in Oberhausen, with architectural design overseen by Gerd Lohmer.
Lohmer (1909-1981) was a renowned West German architect who specialised in bridges. In the wake of World War 2, he found gainful employment in bridge design – either on the reconstruction and redesign of bridges damaged in the conflict (e.g. the Nibelungenbrücke in Worms), or on brand new ones (e.g. the Konrad-Adenuer-Brücke in then-capital city Bonn). In recent years, it has been granted the status of a protected national monument, and is well-loved by locals, who have nicknamed it the “Kleiderbügel” (clothes hanger) due to its distinctive shape, and adopted it as a local symbol.
The story would probably end here, were it not for the complicated and heated political environment which existed at the time of the bridge’s construction.

In 1963, the Cuban Missile Crisis had only just passed and the Cold War was still at very real risk of turning “hot”. The threat of a Soviet invasion of West Germany was one which was taken very seriously. The area to the east of Fulda – termed the “Fulda Gap” – was generally considered to be the route the Soviets would most likely take if they invaded – as there was little by way of natural barriers to a massive tank attack. However it was not the only possibility.
Denmark’s stance in the Cold War is a complex but interesting topic. Breaking a tradition of neutrality, it was a founding member of NATO in 1949, which meant it courted hostility from the Soviet Union who now treated it as an enemy. Denmark could well have held strategic importance for the Soviets – not least could it have constituted something of a stepping stone to Greenland, from where its nuclear warheads could have reached the USA – but also a way into neutral Sweden – from where Norway, and thence the North Atlantic, would have been feasible targets. Sweden boasted strong coastal fortifications, intended to defend it from a Soviet attack, therefore an “entrance” via Denmark would have been a clever way for Warsaw Pact forces to circumnavigate them.
Occupation of Denmark would have put West Germany – and from it the rest of Western Europe – within easy reach. The existence of the newly-constructed train ferry would have made the movement of rail based forces, armaments, supplies, and so on much easier. Equally, it could have formed a route for Soviet forces that had already conquered West Germany, into Denmark. In either event, the Fehmarnsundbrücke may have taken on an immense strategic importance.
As a result, the design of the bridge featured six “Sprengschächte” – or “explosive vaults” – beneath the tarmac of the road’s surface. In the event of an invasion, explosives could be placed into the vaults by soldiers and then detonated remotely (from a military location approximately a mile away), thereby causing significant disruption and delay to the advance. Fortunately, this was never required. However, the remnants of the Sprengschächte can still be seen today – in the form of six patches of darker tarmac on the surface of the road, at the mainland end of the bridge. You can actually see them in very brief passing on my video above – although here is a far more useful photo!
These were by no means the only Sprengschächte that were placed on German roads for this purpose. Indeed, whole hosts of them existed in the Fulda Gap and were officially maintained up until the early 1990s and the reunification of the two Germanies. However the fact that these existed within the design of such a famous structure makes them noteworthy indeed.
Today, trains from Hamburg and Lübeck to Puttgarden (most of which continue across to Denmark via the train ferry) as well as high volumes of road traffic, continue to thunder across the bridge, their passengers most likely unaware of what used to lie beneath.