Akashi Kaikyo Bridge

Japan / Hyogo / Akashi /
 bridge, road bridge, toll bridge, suspension bridge

The Akashi Kaikyo Bridge (Akashi Kaikyo Ohashi), also known as the Pearl Bridge in Japan is the world's longest suspension bridge (measured by the length of the center span of 1,991 metres/6,532 feet). It links the city of Kobe on the mainland of Honshu to Iwaya on Awaji Island by crossing the busy Akashi Strait. It carries the part of the Honshu-Shikoku Highway. The bridge is one of the key links of the Honshu-Shikoku Bridge Project, which created three routes across the Inland Sea.

Before the Akashi Kaikyo Bridge was built, ferries carried passengers across the Akashi Strait in Japan. This dangerous waterway often experiences severe storms, and in 1955, two ferries sank during a storm, killing 168 children. The ensuing shock and public outrage convinced the Japanese government to develop plans for a suspension bridge to cross the strait. The original plan called for a mixed railway-road bridge, but when construction began in April 1986, the construction was restricted to road-only, with six lanes. Actual construction did not begin until May 1986, and the bridge was opened for traffic on April 5, 1998. The Akashi Strait is an international waterway that necessitated the provision of a 1,500-metre (4,291 ft) wide shipping lane.

The Akashi-Kaikyo Bridge has three spans. The central span is 1,991 m (6,532 ft) and the two other sections are each 960 m (3,150 ft). The bridge is 3,911 m (12,831 ft) overall. The central span was originally only 1,990 m (6,529 ft), but the Kobe Earthquake on January 17, 1995 moved the two towers sufficiently (only the towers had been erected at the time) so that it had to be increased by 1 m (3.3 ft).

The bridge was designed with a two-hinged stiffening girder system, allowing the structure to withstand winds of 286 kilometres per hour (178 mph), earthquakes measuring to 8.5 on the Richter scale, and harsh sea currents. The bridge also contains pendulums that are designed to operate at the resonance frequency of the bridge to damp forces. The two main supporting towers rise 298 m (978 ft) above sea level, and the bridge can expand because of heating up to 2 metres (7 ft) over the course of a day. Each anchorage required 350,000 metric tons of concrete. The steel cables have 300,000 km of wire: Each cable is 112 cm in diameter and contains 36,830 strands of wire.

The total cost of the bridge is estimated at 500,000,000,000 Yen (US $5,000,000,000), and is expected to be defrayed by charging commuters a toll to cross the bridge. The toll is 2,300 Yen (US$20.00) and is used by approximately 23,000 cars a day.

Two parks in proximity of the bridge have been built for tourists, one in Maiko (including a small museum) and one in Asagiri. Both are accessible by the coastal train line.
Nearby cities:
Coordinates:   34°37'2"N   135°1'17"E

Comments

  • wow magnificent bridge!
  • It came in second place on the Travel Channel's "Top Ten Bridges"
  • Powerful tidal currents pass under the span. Tour boats venture to the towers to see the huge whirlpools formed by interactions between the currents and the tower bases.