Photograph by Washington State Department of Transportation via Getty

Until last Monday, when engineers began hoisting its two-thousand-ton cutterhead to the surface, Bertha, the world’s largest tunnel-boring machine, was stuck a hundred and twenty feet below the streets of Seattle, too damaged to move far forward and incapable of going in reverse. The machine, which weighs some seven thousand tons and is about as long as a football field, is the centerpiece of a two-billion-dollar project to build a stretch of underground highway two miles long, two lanes wide, and two levels high. But, in December of 2013, after only four months and a thousand feet of digging, Bertha overheated and was shut down. Attempts to fix it set off a cascade of other construction problems, helping to secure the tunnel’s reputation as one of the biggest megaproject fiascoes in history.

The extravagant scale of the disarray in Seattle may seem exceptional, but among megaprojects—commonly understood to be projects that cost at least a billion dollars—the size of the undertaking is nothing special. According to Bent Flyvbjerg, a management professor at the University of Oxford’s Saïd Business School, megaprojects have come to constitute eight per cent of global gross domestic product. China is most responsible for this explosion—according to the scientist Vaclav Smil, the country used more cement between 2011 and 2013 than the United States did during the entire twentieth century—but many nations have contributed. The projects include not only tunnels, bridges, dams, and highways but also airports, hospitals, skyscrapers, cruise ships, wind farms, offshore oil and gas rigs, aluminum smelters, communications systems, Olympic Games, aerospace missions, particle accelerators, the Affordable Care Act Web site, entire cities—the list goes on and on.

Jacques Leslie

The Trouble with Megaprojects