Demolition has demoted wrecking balls when bringing down buildings
In my two-year-old’s quest to learn the names of every piece of motorized construction equipment possible, wrecking balls seem to hold a special place in his imagination. Possibly it was due to the villainous wrecking ball in the Three Little Rigs, but he’s a touch fearful of the 12,000 pound hunks of swinging metal. Luckily for him, he’s not likely to ever encounter one in person, as they’re now used in fiction much more than at any demolition site. The dramatic spectacle that makes them great on a screen or in a book also makes them increasingly impractical in real life.
The functionality of a wrecking ball is pretty obvious. The ball is made of forged steel, which compresses the semi-molten metal as it is shaped. The higher density in the resulting ball then heavier and stronger, allowing it to survive repeated encounters with bricks, mortar, wood, etc. The balls are either ratcheted back and released to swing into a building, dropped onto the targeted structure, or swung by spinning the crane itself. The building is then smashed, crushed, and shattered to make way for new construction.
The problem with the smashing and crashing is that it makes a mess. Whereas previous demolition was actually deconstruction, taking apart a building piece by piece so that materials could reused, a wrecking ball, well, wrecks everything. With growing concerns over potential hazards like asbestos in the 1960s, the speed and low cost of swinging a metal ball weren’t enough to sustain their practicality. What had previously been a proud symbol of rapid, modern progress wiping out old structures to make way for the new started being replaced only 20 years after its introduction.
Options for contemporary construction
Modern demolition has grown to two extremes. For large structures, well placed explosives make quick but controlled implosions possible. For slower projects, deconstruction has come back into play thanks to tools like impact hammers, which can be mounted on excavators and backhoes. These tools can break apart structures carefully enough to allow for salvageable materials, creating less mess and less waste. They don’t provide the quick, visual spectacle of a huge metal ball slamming into a wall, they can still make for a decent show as long as you like the deafening soundtrack of over 1000 strikes per minute at 1000 feet per pound-foot. It’s enough to entertain my two-year-old anyway.
Source: The Indestructible Appeal of the Wrecking Ball by Eric Grundhauser, Atlas Obscura