BONN The demolition work for a new hotel close to the Beethovenhalle in Bonn is continuing after a forced break. An excavator with a huge bit had caused gas pipes to vibrate to such an extent that the pipes could have leaked.
This bunker is tougher than expected. In the middle of February, the Becker construction company from Oberhausen had to temporarily stop demolition for a new hotel building at Erzbergeufer. Site manager Uwe Groh and his team have been back on the site next to the Beethovenhalle since 13 May. The forced break was for the following reason: further demolition works heading away from the Rhine bank by an excavator with a huge bit had caused nearby gas pipelines belonging to Stadtwerke Bonn to vibrate to such an extent that SWB employees, who carried out continual measurements, declared a pipe could leak.
The replanning took three months. Now there is a new man at the construction site between the riverbank, Theaterstraße, Windmühlenstraße and An der Windmühle. Rolf Wunderlich, an explosives expert from the German Explosives Union based in Hückeswagen, is a key part of the new concept. Twice a day, with the help of construction workers, he drills holes in the uppermost ceiling of the former air-raid shelter. The steel-reinforced concrete is 1.30 metres thick. Then Wunderlich pushes sticks of dynamite, delivered daily from a secure location, into the holes.
On this day, he fills eleven holes with 6.6 kilogrammes of explosives. The excavator then lays 1.5 tonne rubber mats made from used car tyres over the explosive contents. You can see the reason for this protective cover daily at 10am and 2pm. At these times there is a rumbling after Wunderlich has first given the signal with a horn and the traffic in the immediately adjacent streets has been halted for a short time.
The heavy rubber mats lift a little with the detonation and then the construction workers can again remove blown up pieces of the ceiling. Groh estimates this will continue until July: twice daily explosions on workdays, clear construction rubble and so on until the upper ceiling is removed.
Residents were informed of the detonations after consultation with the city. According to Groh and the press office, there have been no complaints so far. The former bunker builders cast a false ceiling underneath, but the demolition company can cut through the 35 centimetres with so-called shears. The foundation of the bunker will remain. “Also the outer walls,” says Groh. The future hotel building that Landmarken AG plans to construct in time for the Beethoven Anniversary 2020 will be built on top of it. According to Landmarken’s press officer Kolja Linden, the third quarter remains the target despite the delays.
(Original text: Philipp Königs. Translation: kc)