John Metcalfe was CityLab’s Bay Area bureau chief, covering climate change and the science of cities.
There's fun and profit in having giant shredding rotors tear the flesh off deceased vehicles.
When a car dies, the last thing its owner often sees of it is its bumper bouncing down the street behind a tow truck.
But the car's journey is not over, not by far. Auto carcasses are ultimately destined for a more violent end, as rapacious humans tear their guts apart to salvage every useful hunk of material.
A defunct vehicle can wind up in an impound lot, if the owner has decided to abandon it to whatever fate a municipality deems fit. There, it will either go up for auction to fix-it-minded used-car dealers, or else sit in the weeds growing a healthy coat of rust. This is simply a pit stop in the eventual demise of an auto. When the lot manager gets tired of staring at its oxidized hide, or its stay has run out, the machine transfers into the hands of a salvage business. This is where things get brutal.
The salvager methodically takes apart the vehicle for any bits and pieces that can be resold. Tires and batteries are stripped out. When all that remains is cold metal, the naked car is hauled out to a scrapyard to meet the shredder.
Car recycling is a widespread but nearly invisible practice across the world. It generates billions of dollars each year. Here's how it goes down: The decrepit ride is thrown into a powerful machine with two sets of gnashing rollers. These spinning maws whirl as fast as 175 m.p.h. and can consume a vehicle in as little time as 45 seconds, according to Earth 911. They eat the car foot by foot, sometimes biting off so much they're forced to regurgitate a mouthful and then start chewing anew.
Beneath this gnarly shredder accumulates a pile of pulp that is next separated into components: steel and iron, nonferrous metal and everything else. Iron and steel fetch nice prices on the metals market and eventually become the skeletons of new cars. The remaining jambalaya of torn-up foam, plastic and glass will go occupy space in a landfill. Green-minded scrappers might choose a more eco-friendly destination, though, like donating it for use as carpet padding and auto cushions. Or maybe they'll give it to designers to make colorful baby pillows.