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The Art of Demolition

The following article was authored by Ed Davidson with Long Foundation Drilling Co. and originally published on LinkedIn.


There ya have it folks...

This looks eerily familiar, but I digress...

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.

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, the weather conditions, the materials, the mass and the physics of it – people have no idea how many considerations go into bringing a building down and sometimes needing to do so fast without breaking a window of its neighbours.

Indeed, for these jobs, some engineers might argue that rather than blow-up a building – or "blow-down", as they prefer to call it – a more piecemeal, floor-by-floor approach is preferable. And it is in technological advances of the last 20 or so years that the two approaches are going head to head. In the blow-down camp, is a system called the HotShot. The skill in implosion is in knowing how much and where to put so-called "kicking" and "cutting" explosives – typically weapons-grade dynamite and Semtex respectively, the former used to take out supporting columns and dictate the direction of fall, the latter, much hotter explosive to burn through the structure – and then knowing the required millisecond differences in detonation times to get all of them to work in accord; HotShot, " one of the world's first auto-programmable electronic initiation system", allows for an even finer calibration of the delay between and sequencing of charges.

On the other hand, In the break-down camp, there is a Super High Reach, a £2m-a-piece mega-dinosaur of a machine, the largest in the world, weighing in at 140 tons and with a 67m-long telescopic excavation arm, on which is mounted a "hydraulic muncher that effectively eats a building.

You don't see many of the old hand-held jack hammers at work these days. The more inner-city projects there are – and there are more and more of them – the greater the demand for cleverer, cleaner means of demolition.