The Akashi Kaikyo Bridge is a suspension bridge in Japan. It crosses a strait open to earthquakes and heavy sea storms.
Traffic started in 1998. The central span measures 6,532 feet (1,991 meters).
It was then the longest span of any suspension bridge in the world.
The drawing had called for about 3 feet less.
The towers were already standing, the only finished parts of the bridge, when a 1995 earthquake pushed them apart.
Engineers lengthened the opening by about 3 feet.
Those finished towers never moved back to the line on the drawing.
Then came the other work.
Counterweights, pendulums, and steel trusses went into the structure. A pendulum is a heavy swinging mass that damps the sway instead of letting it grow. The bridge is built to withstand earthquakes up to magnitude 8.5.
It still does not hold still.
In a single day the span can grow and shrink by up to 6.5 feet, only because the temperature changes.
How long is that span on the ground?
Almost 22 football fields, laid end to end.
Length makes the record.
Movement shows the math.
Enjoyed the story?
Follow Colossal Facts for a new story every day.
Or watch them as short videos on Facebook →
