The figure gives an idea of just how bad things are for the most famous sea mark on Germany's North Sea coast: 12.5 million euros. Experts estimate the potential renovation costs for the "Roter Sand" lighthouse at this amount. Its fire was extinguished 35 years ago - since then it has only served as a daytime beacon for seafarers. Nevertheless, the structure is of inestimable historical value - after all, it is nothing less than the world's first offshore construction.
Over 130 years ago, the engineers and workers of the time achieved an architectural masterpiece out in the Outer Weser to the north-east of Wangerooge. On a massive foundation, they erected a structure that, with its three striking bays, became the symbol of the lighthouse par excellence. As a maritime landmark, it stands halfway between Helgoland and Bremerhaven in the open sea, 30 nautical miles from Bremerhaven. Many North Sea sailors pass the lighthouse regularly.
Back in 1987, "Roter Sand" had to be saved from decay in a spectacular operation. The submerged tower base was fitted with a sleeve that was placed over the entire tower from above. Further refurbishment was necessary in 2011/12. Now, however, the tower is once again being affected by the sea and its increasing unpredictability. Storm surges and, not least, the consequences of rising sea levels are taking their toll on the structure.
So much so that it is in danger of being lost in the medium term if no measures are taken to save it. Although the oldest offshore monument is an ingenious engineering achievement of the 19th century, "the tower is not prepared for today's unforeseeable loads," explained graduate engineer Matthias Wagner recently. The project architect from the German Foundation for Monument Protection, which is in charge of the building, worked with experts from the federal government - the owner of the tower - as well as the Dresden engineering consortium GMG and participating laboratories to carry out extensive investigations to protect the lighthouse. The results have now been presented.
In particular, the puddle steels once used no longer fulfil the requirements of today's offshore structures. According to the experts, higher loads require a sustainable strengthening of the statics. This could be achieved, for example, by using spatial framework or by doubling the web plates in the individual storeys. A complex elevation of the tower base could also be necessary.
However, carrying out all the work outside at sea is hardly possible and sometimes too dangerous. One alternative that is being considered is to dismantle the upper part of the fire, refurbish it on land and then place it back on the base. But that would also be a huge undertaking. However, there is agreement that the tower should be preserved and made accessible to visitors again. Now it has to be decided how this can be done.
