Versuchsanstalt für Wasserbau und Schiffbau Berlin, Research facility for water engineering and shipbuilding in Berlin-Mitte, Germany.

The Versuchsanstalt für Wasserbau und Schiffbau, known as the Rosa Röhre, stands on the Schleuseninsel in the Landwehrkanal in Berlin-Charlottenburg. Ludwig Leo designed the 1968–1974 building: a pink circulation pipe pierces a blue-clad laboratory cube, both carried by a welded steel frame on a 4.2 m reinforced concrete base. A semicircular brick structure with a continuous window band projects into the canal.

The research institute was founded in 1903 on the Schleuseninsel in Charlottenburg; Kaiser Wilhelm II had rejected an earlier site at his riding ground with the note "Mein Reitplatz bleibt". A first conversion in 1927–1930 added the Südhalle with large arched windows facing the canal. Ludwig Leo designed the pink circulation tank built in 1968–1974, and the plant went into operation in 1975.

Locals call the building Rosa Röhre, pink pipe, after the colour Ludwig Leo chose for the 17 mm steel shell of the circulation tank. The tube pierces a blue-clad laboratory cube, and the interior decks, with dark green floors and white walls, recall ship engine rooms. The Deutschlandfunk called it an icon of Pop Art architecture.

The building stands on the Schleuseninsel in the Landwehrkanal at Müller-Breslau-Straße, on the western tip of the Tiergarten in Charlottenburg. It is not open to the public; the pink tube and blue-clad laboratory block can be seen from the canal bank and the adjacent streets. The structure was closed around 2001/02, with running contracts wound up by summer 2007.

The narrow plot was already fully built over before Ludwig Leo's extension, so he turned the circulation pipe vertical instead of horizontal. That decision gave the building its look as an urban sculpture. The pipe's 17 mm steel skin is coated with 4 cm of pink-sprayed PU foam, insulation that still worked even after it began peeling from the steel.