Nothing grabs people’s attention or draws crazed male wolf calls quite like the sight of some old Las Vegas highrise being imploded. While Americans may never again view such events without eerie flashbacks to 9/11, bringing down a large building predictably, and above all safely, ironically remains a calling that demands both skill and finesse.
The few seconds it takes to carry out a graceful, seemingly slow-motion building implosion makes this kind of work look simple--even effortless. In fact though, it requires weeks and often months of planning and preparatory work. The engineering involved can be nearly as complex as that used to design the building in the first place.
First, highrise demoliton engineers or “blasters” study the original building plans and decide how to persuade the structure to fall how and where they want it to. Nonstructural portions are often removed by conventional methods so that they won’t impede the collapse, and columns or beams may be weakened so that they’ll fail in predictable locations--something like scoring cardboard to make it fold where you want it to.
Despite the well-known use of explosives in this profession, it’s gravity that really does the job. After all, the energy it took to hoist every single beam and brick into place is locked up in the structure, waiting for Mother Nature to reclaim it. The taller the building, moreover, the more stored energy it contains. Using explosives just gives gravity a little nudge and lets it go to work.
Often, the presence of nearby structures requires a building to be brought down in a certain direction, or even within the space of its own footprint. To accomplish this, blasters use a carefully choreographed sequence of explosions, each of them relatively small, to induce a predictable and orderly collapse. For example, in a typical highrise implosion, the bottom center support columns will be blasted first, followed a few seconds later by the columns further out, so that the sinking middle portion will pull the building walls inward after it.
In a reinforced concrete building, the blasters may choose a grade of explosive that will pulverize the concrete but leave the reinforcing bars intact, so that the steel strands will help guide the building down in the right direction.
While there are countless outfits who demolish buildings, in the realm of highrise demolition, there’s only one superstar. Controlled Demolition, Inc., is a Maryland company run by the Loizeaux family, the Flying Wallendas of building implosion. Through three generations, the Loizeauxs have demolished skyscrapers, stadiums, smokestacks, bridges, radio towers and just about every other kind of large structure imaginable. They’re even listed in the Guinness Book of World Records for the most buildings to be imploded at the same time--seventeen--handily beating their own previous Guiness record of twelve.
It’s a tribute to the family's skill that the public almost nonchalantly expects buildings weighing many millions of pounds to obediently crumble into a tidy little pile at the push of a button. Making it so isn’t quite as easy as it looks.