The Geek Atlas

Japan

027

Akashi-Kaikyo Bridge, Kobe, Japan

34° 36′ 59″ N, 135° 1′ 13″ E

The World’s Longest Suspension Bridge

There are suspension bridges all over the world, from the Clifton Suspension Bridge in Bristol, UK, to the Golden Gate Bridge in San Francisco, California. But only one can be the longest, and that honor goes to the Akashi-Kaikyō Bridge in Japan, which links the city of Kobe on the main Japanese island of Honshu with Awaji Island across the Inland Sea. The bridge was built to cross a dangerous waterway that had previously been plied by ferries and was the site of tragic sinkings in stormy weather.

The Akashi-Kaikyō Bridge has a main span of 1991 meters (by contrast, the main span of the Clifton Suspension Bridge is 214 meters, and that of the Golden Gate Bridge is 1,280 meters). The original plan was for a main span of 1,990 meters, but in 1995, after the main pillars were built but before the bridge was installed, a large earthquake hit the Kobe area and moved the pillars apart by an extra meter. Overall, the bridge is 3,911 meters long.

To help prevent swaying (especially in an earthquake), the bridge has pendulums inside the towers that act to dampen any movement (more on damping via pendulums in Chapter 34).

Avoiding corrosion is an important concern because of the salty air. The main cables consist of multiple cables bunched together, and dry air is ...