'You can't really test explosives' – why demolitions go wrong
|
Version 0 of 1. In the explosive business of controlled demolition, a building that doesn’t go down in the way it was supposed to is known as a “standup”. And on Sunday, Glasgow got a double act as mortifying as the Krankies when thousands gathered to watch as the six remaining tower blocks of the historic Red Road flats were razed to the ground. As the dust settled and the two-year clear-up was pondered, it became clear. Two were still partially standing. What went wrong? Too much tower? Too little explosive? The demolition organisers (who in 2013 successfully razed another Red Road block that, at 28 storeys high, was the biggest structure imploded in the UK) admitted the final phase had not gone “completely to plan”. But how exactly do you plan to blow up half a dozen high-rises that were once the tallest buildings in Europe? “We’re talking months to prepare for a demolition like the one at Red Road,” explains Emma Thompson, a safety officer at DSR Demolition in South Yorkshire. Although the family firm hasn’t worked on a project as big as Red Road, they have a long history in explosive demolition. Or, as Thompson puts it, “explosives are in our blood”. “It begins with investigatory work,” she continues, “looking at the actual fabric of the building and which areas you are going to isolate for placing the explosives. You might do some pre-weakening, which involves taking out walls. You need to drill holes to place explosives, and the depth and angle of each one has to be checked. At Red Road, you’re talking about a steel structure, which requires more explosives of a higher charge weight. Then you wrap everything in geotextile membrane and chain-link to prevent the spillage of debris. As my boss says, the building looks like a bag of sprouts when it’s ready to go.” Still standups happen. In 2009, a 24m (80ft) building in Çankırı, Turkey, toppled into a full somersault instead of collapsing back to its footprint. The same year, a 22-floor residential building in Liuzhou, southern China, split in two when it was exploded, one half crashing sideways to the ground, the other left leaning into the cityscape. Our desire to build up continues nonetheless, accompanied by the need to bring down. The question remains: can an explosion ever be truly controlled? “There is always the possibility of malfunctioning because you can’t really test explosives,” Thompson admits. “You can have all the knowledge in the world, and even with identical towers such as Red Road and a contractor that has extensive experience working in the area, there is the chance of an anomaly in the building. Things might not pan out as you planned them. It’s a nerve-racking job,” she concludes. “The building does what it wants to do in the end.” |