Engineering
The Structural Secret of Long-Span Cable-Stayed Bridges
Quick fact
In a cable-stayed bridge, every stay cable is tensioned so that the deck is kept in compression along its length, much like the string of a bow. This pre-stressing effectively turns the deck into a continuous beam that rests on elastic supports provided by the cables, allowing spans of over a kilometer with a surprisingly thin deck.
Why this is interesting
You’ve probably crossed a cable-stayed bridge without a second thought, but the way it lets a thin ribbon of concrete and steel leap across a vast river is almost magical. How can those slender cables hold up an entire roadway?