In what’s being hailed as an engineering masterpiece, two important German shipping canals have been joined by a giant kilometer-long concrete bathtub. The new waterway near the eastern town of Magdeburg opens Friday.

Public infrastructure projects are notorious for taking longer than expected, but Germany’s new water bridge tying the Elbe-Havel canal to the important Mittelland canal, which leads to the country’s industrial Ruhr Valley heartland, was over 80 years in the planning.

Engineers first dreamt of joining the two waterways as far back as 1919. Construction to bridge the Elbe river near Magdeburg actually started in the 1930s, but progress was halted during the Second World War in 1942. After the Cold War split Germany the project was shelved indefinitely, but things were put back on track following reunification in 1990. 
 

Taking six years to build and costing around half a billion euros, the massive undertaking will connect Berlin’s inland harbor with the ports along the Rhine river. At the center of the project is Europe’s longest water bridge measuring in just shy of a kilometer at 918 meters. The huge tub to transport ships over the Elbe took 24,000 metric tons of steel and 68,000 cubic meters of concrete to build.

The water bridge will enable river barges to avoid a lengthy and sometimes unreliable passage along the Elbe. Shipping can often come to a halt on the stretch if the river’s water mark falls to unacceptably low levels.

“It’s important to us to make the waterways attractive to industry as a safe and environmentally friendly transportation way,” German Transportation Minister Manfred Stolpe said at the opening ceremony on Friday, according to the Associated Press.