More than 100 years old and spanning the Lot river in southwestern France, the Pont de la Libération is made of brick and unreinforced concrete—technically very small stones and mortar. The bridges of Madison County have nothing on this 112-year-old National Historic Site of Canada, which became the world’s longest covered bridge only after two spans were destroyed by river ice in 1920, prompting replacement and a roof (covering helps prevent rot on the central wooden trusses).
From the ice roads of Arctic Alaska to a cable-stayed controversy on the other side of the Bering Strait—stretching over cities, seas, and even the jungle canopy—the world’s longest bridges exist on a scale that can only be described as stupefying. Not that the world’s longest suspension bridge has it any easier: every day, 23,000 cars pass over a structure that must withstand earthquakes (a 7.2 magnitude earthquake hit in 1995), consistently strong tidal currents (9 knots), and wind gusts up to 179 mph.A three-day ritual celebrating the weave includes traditional dance and food and usually ends on the second Sunday in June. The problem: how to connect a train from Elizabethport, NJ, to a marine terminal in Staten Island while still allowing shipping barges to access the busy Port of New York and New Jersey.The solution: a massive vertical-lift bridge that clears the high water mark by 135 feet when open and allows trains to move seamlessly from one state to the other when lowered (usually only three times a day).Finally, in December 1919, the 94-foot-wide, 1,800-foot-long central span was jacked 150 feet into place, and it has remained the record-holder ever since.Today, it has a famous neighbor to the west, the Pierre Laporte Bridge, the longest suspension-bridge span in Canada. A common feature on bridges built before the turn of the century is the truss, a triangular unit used to distribute a bridge’s weight.