Hordes heading for a fall

Texas Stadium, the former home of the Dallas Cowboys was imploded in April 2010. Photo / AP

When Glencairn Tower went down in November, 64 charges - 100kg of the latest explosives placed with scientific precision - brought all 17 storeys down in just five seconds.

The demolition job at Motherwell, near Glasgow in Scotland, was unusual for two reasons. It was the first steel-structured building in Europe to be imploded and the crowd of several thousand that turned up to watch its demise may well have set a British record for attendance at a demolition.

Watching buildings bite the dust has become something of a spectator sport: inevitably, perhaps, crowds gathered to see a trio of housing blocks in Sighthill, Edinburgh, go down in September and two student accommodation blocks at Aston University in Birmingham, England, tumble last spring.

Thousands also turned up to see the Deutschlandhalle arena in Berlin go down last month. In the United States, local authorities have even advertised implosions. The sense in that is debatable. When the Royal Canberra Hospital, in Australia, was imploded in 1997, shrapnel and concrete chunks rocketed 600m into the "safety zone", killing one spectator and injuring nine.

In November 2011, an 80m tower being demolished at the old Mad River Power Plant in Ohio toppled the wrong way, crushing a building below, taking down electricity lines and causing spectators to run for their lives.

Apparently an undetected crack in one side of the tower had pulled it in a different direction to one designated by the positioning of the explosives. That suggests just how precise calculations must be in ensuring a safe and successful implosion.

"Demolition is 50 per cent joining the dots and 50 per cent creativity, because you're dealing with a structure that's full of unknowns. If demolition was easy there would be more companies doing it. But it's an art and art isn't easy," says Mark Loiseaux, of Phoenix-based Controlled Demolition, widely acknowledged as the king of demolition.

It was Loiseaux who was the first to bring down decommissioned cooling towers at an active nuclear power station, Sellafield, on the Irish Sea coast in the north of England; who devised the plan for the demolition of structurally unsound buildings around the twin towers in New York; who led the US mission to Christchurch after the earthquakes and whose experience of explosives more recently won his company a contract for the elimination of weapons in post-Gaddafi Libya. His father even pioneered the whole idea of demolition by implosion.

"Architecture is about plugging info into software and watching it spit out all the specs - and I speak as a trained architect," says Loiseaux, who might be seen in action in Glasgow in April when the first two of six 31-storey blocks of flats are due to be imploded.

"But they don't teach what we do. With demolition it's you versus the building: you have to divine what's holding the building up and that's especially hard with buildings that have technically failed but are still standing. The angle of repose, the volume of debris ... and sometimes needing to do it without breaking a window of its neighbours."

- Independent