The Umlauftank 2 is a research complex which was built by the Research Institute for Water and Naval Architecture (Versuchsanstalt fur Wasser- und Schiffsbau - VWS) at the Technical University of Berlin. Research facilities for the institute have existed since the early 1900s. They were continuously expanded and renewed. The Umlauftank 2 is the result of the last major construction phase which lasted from 1969 to 1974. The building was designed by the architect Ludwig Leo and the engineering firm Chr. Boes.
In the 1960s the existing "Umlauftank" - a cavitation tunnel to research ship hydrodynamics, applied hydromechanics and make environmental and navigational engineering tests via scaled replica of ships - was too old meet the research standards of the time and had to be replaced. A new tunnel had to be built. This tunnel turned out to be a colossal circuit pipe system with a maximum diameter of 8 meters. Water is pumped through the circuit by means of two Diesel engines. Instead of hiding the pipe behind a facade, Leo decided to feature it - as it is building's main function - prominently in the exterior design. The huge pipe is painted in pink and encloses the main building giving it its unique silhouette.
The main building houses a number of water basins which can simulate different oceanic wave conditions. It contains the measuring section, measuring instruments, controls and dashboards. the experiments can be prepared and observed from a series of decks.
As with the DLRG building, the architect Ludwig Leo drilled down on the building functions by stressing them and integrating them in the external design and in this way creating the building's strong character. In both buildings he draws on the ship analogy. This is even more apparent at the Umlauftank which can be mistaken with an ocean liner stranded in the middle of Berlin.
The Umlauftank 2 is a historic monument since 1996. In 2004 the research activities were discontinued at the site as computer simulations are nowadays a more efficient means to conduct this type of research.