Topping-out ceremony for injector building
It’s half-time for the construction of the injector complex: the first topping-out ceremony for one of the underground buildings of the European XFEL facility was celebrated on 22 June on the DESY-Bahrenfeld construction site.
The European XFEL facility comprises eight underground shafts and buildings, seven halls above ground, and the main building on the Schenefeld campus—there will thus be plenty of occasions in future to hang a topping-out wreath off a crane. One day after the summer solstice, the first topping-out ceremony of the series was celebrated: the shell of the underground injector complex, which is 100 metres long and seven storeys deep, has reached the surface. The construction work for the huge building, which consists of two shafts and two 20-metre connecting tunnels lying on top of each other, started in May 2010. It is to be handed over to the building owner in spring 2012.
“A topping-out ceremony is normally held to celebrate the completion of the roof structure, and the participants are looking up. Today, we are more or less standing on the roof and looking down 37 metres onto the floor of the second injector shaft,” said Helmut Dosch, the chairman of the DESY Board of Directors, in his short address. Standing between the two foremen of the companies Züblin and Aug. Prien, he thanked the construction workers for their dedication in realizing the building shell. During their work, they had to master a range of challenges, such as the extremely cold and long past winter or the stable bridge carrying the cables for the energy supply of neighbouring quarters, which lies right across the building pit and blocks the free access of the crane.
In the past months, around 22 500 cubic metres of concrete flowed into the more than one metre thick walls and floors. The workers are now adding the finishing touches—for example installing the doors, stairs and lifts or constructing the partition walls.