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Why don't more Chicago buildings get blown up?
May 6, 2010

Dear Cecil:

You have been a great source of information for almost 30 years. Here's something I've been pondering something for almost that long. As I walk down the hallowed and dirty streets of Chicago I see buildings being torn down by man and machine. On PBS and various cable programs I see buildings in other cities being blown up. Howcumzit Chicago doesn't use explosive demolition? Is it too quick, not enough union members, why?

— Dave

Cecil replies:

Dave, on a gut level, I'm one hundred percent with you. Already we've got firecrackers and gunshots, vehicles with no mufflers, those wacky car sound systems where the bass seems to emanate from the center of the earth. Exploding buildings would fit right in. (Yes, I know the preferred term is imploding, but that's a misnomer. More on that by and by.) We certainly don't lack for suitable candidates — why, I can think of dozens, maybe hundreds of priceless architectural gems we haven't yet reduced to rubble. And imagine the opportunities for urban catharsis! Cubs blow another one in the late innings, tension rises. Ancient tower is blasted to flinders, everybody calms down. Granted, after a couple typical seasons the town will look like Kearney, Nebraska. Just saying, explosive demolition could make urban life even more exciting than it is now. 

Nonetheless, Dave — and in your heart you knew this was coming — these are immature thoughts. I arrive at this conclusion after lengthy colloquy with demolition industry sources, an implosion specialist, and most important, the city's single largest flattener of buildings, some of which which it knocked down with explosives, but most the old-fashioned way. Turns out there are reasons we don't implode many buildings here. Those flashy demolitions you see in Las Vegas, Texas, and other shallow localities? Some claim they're done partly for show.

Our case study here is the Chicago Housing Authority, which has knocked down 79 highrises over the past dozen years, most as part of its Plan for Transformation — the major transformation being to replace its misbegotten "family" highrises with more suitable dwellings. The CHA took down a half-dozen buildings with explosives, starting with four 16-story structures in its Lakefront Properties development in 1998 (see video), followed by two more at Washington Park Homes the next year. After that it went back to traditional methods. The question to be studied: why?

We'll get to that. First some background on the fine art of explosive demolition, commonly — but wrongly — known as implosion. An implosion is when the force of an external blast crushes an object in on itself, a standard method of detonating an atomic bomb. Strictly speaking, that's not what happens here. Shrewdly-placed charges knock out the internal supports; the building then collapses on itself by gravity (at least that's the idea). "Implosion" is PR to assure fretful clients that debris won't go ricocheting all over. Nonetheless, since that's the term everyone uses, I'll use it here.

The leading expert in implosion is Controlled Demolition, Inc. (CDI) of Maryland, which has blown up more than 7,000 structures worldwide, including the six CHA highrises and, more recently, the Brach Candy building on the west side for the movie The Dark Knight. (CDI provided the cool Brach Candy photo above.) The company has its own YouTube channel with spectacular videos of dozens of shots. Months of careful planning and prep work are needed to ensure the building falls like it's supposed to, but the actual implosion generally takes less than a minute. If all goes well, you wind up with a well-pulverized pile of debris confined to the building's original footprint, or in reasonable proximity thereto. All you have to do is haul it away.

So — getting back to your question, Dave — why don't we do more implosions here? Let's review a few theories.

1. It's too dangerous in a densely built-up city.

It's dangerous all right. Browse around on YouTube and you can find plenty of examples of implosions gone disastrously if sometimes hilariously wrong, most of them outside the U.S. (In one case in Turkey — I'm guessing this was an implosion, but it's hard to tell what these guys were up to — the building rolled through the neighborhood for a good block.) Under the best of circumstances nearby windows can get blown out, utilities may be damaged, and massive clouds of dust are thrown up.

Nonetheless, urban implosions are common. The most impressive in my opinion is CDI's 1998 implosion of the old Hudson's department store in downtown Detroit, said to be the tallest structure ever dropped with explosives. But you can find precision takedowns of big buildings in close quarters in many cities. CDI says it has imploded buildings that were touching other structures. Public housing towers are comparatively easy, since they're usually surrounded by open space.

2. The unions don't like it.

Let's put it this way. Various parties have a vested interest in doing things the traditional way — and they're not necessarily all unions trying to preserve jobs. Stacey Loizeaux of CDI says:

The big demolition companies own large fleets of heavy equipment. These machines must be kept busy as much as possible to pay for themselves. If a project can be safely approached via conventional wrecking methods and time allows for it, these contractors will always opt to keep their machines working using conventional techniques.

I couldn't get anybody in Chicago to comment on this issue directly. Still, an implosion hardly means union workers operating heavy equipment lack for things to do. More on this below.

3. Implosions are for entertainment. 

This is a touchy subject. Let's acknowledge the obvious: for most people, an implosion is the closest they'll ever get to the ultimate holy-shit experience. In the 1980s, reality TV shows about implosion fueled public interest, and by the early 1990s some explosive demolitions had become big events, drawing news coverage and massive crowds. One source in the wrecking industry, noting that fewer than one percent of buildings were brought down by implosion, suggested some clients decided to blast in order to put on a good show. In Las Vegas, where implosion sometimes seems to be the default method of demolition for old hotels and casinos, dropping a building is often accompanied by fireworks and a carnival atmosphere. When Texas Stadium was detonated last month, the city of Irving sold naming rights to Kraft Foods to promote its "Cheddar Explosion" and charged spectators $25 per car. On occasion hosting a crowd can have disastrous consequences — in 1997, a 13-year-old girl was killed by flying debris during a much-publicized implosion in Australia.

The preceding notwithstanding, Stacey Loizeaux bridled at the notion that she's in the amusement business. Many implosions are in isolated locations with only a handful of spectators; others in urban areas are purposely scheduled for times when few people are on the street. Placement and timing of charges is intended solely to flatten the building, not dazzle the multitudes. Considering the utter devastation typically achieved, implosions are astonishingly economical, not only in terms of explosives but resultant showy effects — the average Fourth of July fireworks display produces more light and noise.

When the avowed goal is spectacle, implosion specialists team up with special effects experts to generate more flash — for example, when CDI blew up the Brach Candy building for The Dark Knight. Of this project Loizeaux says:

Total set-up time was about two months of meetings, planning, etc., a week or so of preparation and about four days of actual loading, wiring, coordinating with the special effects team/director, rehearsals, and so on. Total explosives used consisted of 24.8 pounds of linear shaped charges, detonating cord and detonators. The SFX crew was behind the brilliant fireball, shattering windows, and fake debris raining out of the building. I worked side by side with Ian Lowe of the SFX team to carefully time and coordinate our completely separate yet overlapping initiation systems to ensure safety of operations.

So yes, entertainment is a factor sometimes. But except in the odd case it's not the main point.    

4. Implosion doesn't necessarily save money.

This was the central issue in the minds of people I spoke to in Chicago, both in the wrecking business and at the Chicago Housing Authority — in particular, Sanjiv Jain, CHA's vice president for capital construction. Preparation for an implosion can take months. In addition to working out the technical details of the blast, nervous neighbors must by consulted, nearby structures and utilities assessed, protective measures put in place. Demolition crews using conventional equipment must remove windows and such from the target building to minimize flying shards. Interiors are generally gutted, both to recover salvageable material (upwards of 90 percent of the structure may be recycled) and to expose structural elements, some of which may be weakened or removed to ensure the final collapse. Nearby low structures may be demolished by machine ahead of time. (Small buildings are seldom imploded, in part because they don't drop far enough to thoroughly smash the wreckage.)

Setting up the implosion may take a week or two, and the implosion itself is over in seconds. But it's not as though all that's left is a pile of dust you can shovel into a dumpster. Although an adroitly imploded building may be shattered into remarkably small bits, generally you're faced with a tangled heap of rubble that can be 50 or more feet high. Additional months of labor — involving, it ought to be said, lots of machines, trucks and workers — are needed to separate the junk, break up the remaining large chunks, and haul it all away. Jain says:

When you add up all the costs, it's really not that much cheaper — if anything five or ten percent. When you consider the staff time required, I don't see the savings. A tremendous amount of close coordination is required with the public and private sectors. It's a very stressful project.

Plus there's the liability, Jain says. Slight though the chance may be, God forbid all the charges don't go off and the building doesn't collapse completely;  now you've got a structurally unstable building with live explosives in it.

Hard to argue with — clearly ball-and-crane demo was the conservative choice. Then again, Jain concedes the CHA never sat down with accountants and spreadsheets to do a cost-benefit comparison of wrecking methods, which the agency was in a unique position to do, having knocked down buildings both ways. No point now; the CHA's demolition program is near its end.

All in all, Dave, I'm not seeing an imminent uptick in implosions in Chicago. But who knows? The city has oodles of tall buildings, all of which will need to come down someday. Maybe someone will do the as-yet-undone analysis and discover explosive demolition really does make economic sense. 

I'll tell you one thing. If they ever decide to implode the Hancock or the building currently known as Willis Tower, I don't care if I'm pushing a walker or in an oxygen tent. I want to be there for that.

— Cecil Adams
Photo courtesy of Controlled Demolition, Inc. — Phoenix, Maryland

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