With the construction of the Kiel Canal, its bridges and locks, engineers entered new technological territory at the end of the 19th century, and the most modern machines were used to carry it out. A marvel of engineering is created in just eight years.

by Stefanie Grossmann

The ambitious engineers led by Chief Architect Otto Baensch were faced with major challenges when, in 1886, they were commissioned by the Reich Office of the Interior to design the construction plan for the Kiel Canal. If their calculations for the construction are not correct, half of Schleswig-Holstein could sink in the mud. Because the land between the seas is characterized by difficult terrain.

The most important construction project in the German Reich

When the construction work finally begins in March 1888, the largest earth and hydraulic construction site in Europe is growing in Schleswig-Holstein. The new waterway between Kiel and Brunsbüttel is to be almost 100 kilometers long, 67 meters wide and nine meters deep. The project is considered the most important building in the German Empire.

Swampy marshland is typical of the western part of the development area, some of which is below sea level. In the east lie chains of hills formed by the ice age, which drop steeply to the Baltic Sea. Two thirds of the construction work is planned in dry ground, which is interrupted by smaller lake areas and moors. A third of the construction site follows the course of the old Eider Canal over a length of 38 kilometers from Holtenau to Rendsburg. The soil to be excavated often consists of sand and clay. On the other hand, there is a lack of solid rocky ground, which is necessary for a stable construction of the canal. Instead, the soil is interspersed with many large boulders that have to be laboriously excavated.

Nord-Ostsee-Kanal:New construction separates villages and people

Some of the land required for the construction belongs to private owners who have to be expropriated and compensated. That alone devours ten of the estimated 156 million gold marks. In addition, straightening is pending, for example between Auberg and Gut Knoop near Holtenau land is being removed. Old park landscapes give way to the mammoth project. The construction of the new canal changes cities like Rendsburg, cuts up roads and railway lines and separates villages like Sehestedt and their residents - sometimes even families - from one day to the next. From now on, they can only get to the other side of the river by hand-operated ferries. A total of 16 ferry docks are being built on the Kiel Canal.

The entire canal is designed to be at sea level

According to the plans, the new canal should run at sea level, which means that the water level of the Kiel Fjord must be as far as Brunsbüttel. To do this, the engineers are not only lowering the water level of Lake Flemhude by seven meters at the Achterwehr, but also that of the Eider. In return, the canal must run higher than the land in the wide, great Dithmarschen. Dike and secure is therefore the motto of the planners. And since the water can no longer run off at these points, the land has to be permanently drained by pumps.

Sand and stones reinforce embankments

The moor is difficult to tame, the dikes keep slipping down. 1.8 million cubic meters of sand are needed to drain the muddy ground. To do this, workers cut open the ground cover, pour sand into the scar and press it firmly. In addition, 800 million paving stones and bricks are needed to fortify and protect the bank. These are manufactured in two brickworks specially built for this purpose. Until shortly before the end of construction of the canal in 1894, the bank reinforcements kept slipping down in some places - on the north side up to a length of 430 meters. Because the meager föhn sand simply doesn't offer enough stability.

Bridges reconnect people along the canal

The fact that the canal separates almost the entire country poses problems for the engineers carrying out the work. These should solve several bridge constructions in order to cross it. The plans include two high bridges near Grünental and Levensau for road and rail. Their height should be a uniform 42 meters above the highest water level. Because of the rough terrain and the risk of landslides on bank slopes, the arches are kept relatively flat, supported on abutments in the form of gate towers.

Elevated railway bridge near Rendsburg becomes a masterpiece

The five planned swing bridges are different. The structural advantage of this construction:It runs at dike height and can be built on less stable ground. The disadvantage of this is that you can only use them when there is no ship navigating the canal. One of the strategically most important swing bridges runs near Rendsburg to serve the important traffic connection from Hamburg to Flensburg. There, two single, single-track swing bridges will be built at a distance of 150 meters. Their operation works hydraulically in the form of a block and tackle. Today a high railway bridge crosses the canal here - the impressive steel construction is one of the most famous technical monuments in Germany and almost as famous as the Eiffel Tower in Paris.

Double locks are milestones in canal construction

The Kiel Canal is a mirror-image canal with locks at the ends. They do not overcome any differences in height, but only compensate for the different water levels of the North Sea and Baltic Sea. It must not be more than 30 centimeters above the normal level, otherwise ferries will no longer be able to reach the piers. The construction of the locks is like a work of art - two massive lock chambers are created at the canal ends:150 meters long and 25 meters wide. Double ebb and flow gates are designed to withstand the enormous water pressure, especially the high water in the North Sea. The Holtenau sluice is built exclusively as a drywall construction - unlike the structure in Brunsbüttel, the base and first structure of which the workers pull up in the water. A thick layer of concrete and pumps keep the water out during the masonry work. In the end, 90 million bricks have been installed. In 1894 the imposing locks were finished.

The Kiel Canal was built in the century

Nord-Ostsee-Kanal gives the country a different face

When completed, the Kiel Canal was considered a marvel of engineering, but when it opened, it proved too small for warships to pass through. As early as 1907, the building had to be massively expanded. The work on this was completed in 1914, the effort and costs are higher than the actual construction itself.

Contrary to what was assumed, the canal does not get its water from the sea. On the contrary:the Kiel Canal directs the water into the North Sea through the Eider and other smaller canals as well as artificial pumping stations. Overall, it drains an area of ​​1,580 square kilometers. That is still the case today. The waterway is, so to speak, a receiving water that prevents flooding. Without him, a large part of Schleswig-Holstein would be under water. So the canal creates a whole new cultural landscape that connects the seas but divides the land.