Watch a video of the girder being put into place
For the first time in Denmark, 85-metre long steel girders are being installed from the water. The girders have been welded together in quarters in Latvia, and then transported to the B&W dockyard close to the playhouse site in Copenhagen harbour for final assembly. Installation takes about eight hours per girder. And so this highly distinctive building is beginning to take shape.
"It is very unusual to install such massive steel girders in a single operation," comments COWI Head of Department René M. Kræmer, "and I don’t think it has ever been done before from the water." "The size and span of the girders stand comparison with those of a bridge. On completion of the construction, the free span will be of such dimensions that the girders will appear to be suspended in the air with no supporting structure."
The steel girders, which will support the actors’ canteen and wardrobe, form a prominent part of the building. By day people will clearly see the pattern formed by the long girders through the glass façades of the top floor. And in the evening the roof will appear as a belt of light right around the playhouse.
In order to create the feeling that the entire top floor seems almost to be suspended above the rest of the building, the roof has a very large free span. The biggest freely suspended cantilever, at the corner of the playhouse, is 26 metres – the equivalent of a seven-floor building. The construction is similar to the roof of Copenhagen’s new Opera House, which can be seen on the other side of the harbour.
To compensate for the heavy load, the end of the grey steel lattice above the water has been raised about 10 cm. But by the time the building is completed, the structure will have settled and the entire floor will be level. "The grey steel lattices have been made with a built-in skew – because when they are subject to the full pressure of the roof, they will level out. You can compare it to the pylons of Denmark’s Great Belt Bridge. They were also installed slightly skewed – deliberately so, I might add. Because the subsequent load exerted by the bridge girders caused them to recede and stand straight," explains COWI Senior Project Manager Kim Bundgaard. By Christina Tækker, cht@cowi.com Published: 8.5.2006