Vienna is famous for its historic architecture, with notable buildings by the Secessonist architects Josef Hoffmann, Joseph Maria Olbrich, Otto Wagner and others. There are other surprising buildings such as the gasometers in Simmering and surprisingly, in the leafy Arenbergpark, two immense concrete second world war Flak towers rising above the trees, among the largest such towers ever constructed.
Flak towers (Flaktürme) were complexes of tall anti-aircraft gun towers and air raid bunkers for civilians constructed in Berlin, Hamburg and Vienna. There are three such complexes in Vienna, each with two towers, an L-Tower (Leitturm or Lead Tower) and a G-Tower (Gefechtsturm or Combat Tower), unique reminders of the Second World War.
The towers were ordered to be constructed by Adolf Hitler after the RAF air raid on Berlin in 1940. It is said that he himself made sketches for them and they were such a priority that the national rail schedule was altered to enable construction materials to be shipped as a priority to the sites for fast construction. Speed does not mean quality and the concrete of these towers is deteriorating. The towers in Vienna are almost impossible to demolish, given the walls are up to 3.5 m thick and they are located in dense urban areas so cannot be blown up.
In Arenbergpark, the L-Tower is empty, with steel rods exposed and protection in place to catch falling concrete. The G-Tower became an outpost of the MAK (The Austrian Museum of Applied Arts/Contemporary Art) in 1995 when most of the MAK Collection of Contemporary Art moved there. It is currently closed for repair and refurbishment with the aim of opening up the permanent collections and providing new special exhibition areas.
“In the coming years, the MAK Tower will be reopened as a platform and site of experimentation for contemporary art, design, and architecture to be successively developed into one of the largest and most high-profile institutional art centers in Vienna and a laboratory of contemporary art.” (MAK website)
In the main MAK building in Stubenring there is a model of a proposal including a new lift and stair, without compromising the historic tower. Funding appears to be uncertain and it also leaves the other tower awaiting its future.
One imaginative idea has been carried out in Hamburg where a 42 metre high concrete Second World War bunker has been converted into a renewable energy plant which provides heat and electricity to the surrounding neighbourhood by the urban development company IBA Hamburg and also includes a visitor centre, so it becomes a real community asset.
“After standing empty for more than sixty years, followed by a seven-year project development and construction phase, this war monument has been transformed into a sign of the dawn of a climate-friendly future,” (IBA director Uli Hellweg).
The project included a public cafe and an event space on the upper level, reached by a new lift and staircase. The renewable energy centre comprises a two-million-litre water reservoir which acts as large heat sink for heat from a biomass thermal power plant, a wood burning unit, a solar thermal system on the roof and waste heat from a nearby industrial plant. The heat is then redistributed to neighbouring buildings while rows of photovoltaic panels cover the south facade, adding a contemporary design element to the tower, and feeds power into the electricity grid.
An imaginative idea which gives the tower a sustainable and community future. Perhaps art and science could combine together in some way for the two towers in Arenbergpark?