Inside Guniuhe Grand Bridge: How China Built a 520m Arch That Couldn't Support Itself

A 520-meter steel arch over a canyon in Guizhou, China. And for months, it had nothing to stand on. Arches are famous for their strength, but only once they're whole. Until the last piece goes in, half an arch is just steel hanging over a void, getting heavier with every lift. No scaffolding from the valley floor. Barely a flat meter of ground on the cliffs. And when the two sides finally reach for each other, the gap between them won't hold still. So what kept the Guniuhe Grand Bridge from falling before it was even a bridge? And how do you hit a moving target with the final piece of steel? Subscribe:    / @inside_megaprojects