The end of a vision in precast concrete
“Topography of Terror” victim of wrecking ball
In addition to the memorial to the murdered Jews of Europe, which will open in Berlin next May, the German capital was to have been given a second significant monument erected of precast concrete components: the “Topography of Terror” memorial by Swiss architect Peter Zumthor. The demolition of the partially completed shell construction started in December, after this prestigious project was finally called off after almost twelve years. This is not only a sad loss for the collective remembrance and the German cultural landscape, but it also means the loss of a major opportunity for the precast concrete industry to demonstrate its special capabilities.
When the field of steles by Peter Eisenman opens next May and these dark slate-coloured concrete slabs, so unreal in their perfection, will remind us all of the death of millions of European Jews, another memorial will already have become history not far from the same site. Last month demolition work started on the basic parts of the “Topography of Terror” shell construction on the Prinz- Albrecht site, the location of the Gestapo’s administrative and torture headquarters during the Nazi regime. The three stairwells already constructed for this highly visible project by Swiss architect Peter Zumthor are being cleared away at this moment. This act of destruction was preceded by almost six years of interruption to the building works caused by the insolvency of the first building contractor. After the second building company succumbed to the same fate, and after many years of controversy, the Berlin Senate last summer decided officially to cancel the project, which was not very popular and was, as many suspect, deliberately delayed. But before the demolishers could move in, the federal constitutional court had to give its verdict, and in November it determined that the decision by the Berlin government did not represent an affront to the architect’s reputation. Even an appeal signed at the last minute by 25 well-known architects from all over the world (including Sir Norman Foster, Renzo Piano and Richard Meier) could not stop the wreckers.
The intention now is to stage the “Topography of Terror” in a different way – and with a better chance of success. The authorities are planning to hold a new competition, and the previously budgeted
19.4 million euros have been promised again to make it happen.
What we have lost is a daring building in precast concrete, whose construction could have been of extraordinary significance for the whole of the precast concrete industry.
The design featured a nearly 120 m long and about 20 m high block which was intended to protect the excavated foundation walls and cellar remains of the Prinz- Albrecht- Palais, and its visitors, from the weather. It was intended for the ruins to be freely accessible from the ground floor. The building’s structure was to have the character of a shell, albeit with administration facilities and special exhibition rooms on the upper floor.
From a structural point of view, the building would have consisted of an almost infinite number of precast members with a 24 x 34 cm base to be used both vertically as supports and horizontally as beams. The horizontal and vertical parts of the structure would have interlocked like two combs pushed into each other. To start with, the individual pre-drilled precast members would have been connected in the intersecting axis with a special hollow bolting system. Finally, tensile pressure would have been applied to all intersecting nodes by means of a continuous 120-m long tensioning cable. According to structural engineer Jörg Schlaich’s calculations, the pressure from the tensioned cable acting on the contact surfaces (roughened by grinding) would have been sufficient to connect all concrete members rigidly with each other, just as a result of friction. Thus it would have been just the detailing of the node construction that would have provided the stability for the whole framework and would have rendered the ceiling construction, which had been calculated as Vierendel girder, structurally effective. The width of the ceiling beams, measuring just 24 cm, would have dictated the width of the openings between the vertical concrete columns. These would have been closed with glazing. Although from the outside the building would be a monolithic cube without windows, the interior would have been surprisingly light since the proportion of glass in the building façade would have been 50 %.
The project failed – according to some – because of the unrealistic nature of the design, which caused costs to go through the roof. The architect, on the other hand, insists that he would have been able to keep to the original cost estimate of 38.9 million euros right through to the end. Unfortunately, the city-state of Berlin had never been seriously prepared to put up this amount of money, which was what was actually required. The State had made its selection of companies solely on the grounds of costs and completely failed to take into account whether the chosen companies had the necessary expertise to realize a structure of this kind. This meant that competent bidders would have been edged out of the tendering process.
Robert Mehl, Aachen