Akashi-Kaikyō Bridge

Infobox_Bridge
bridge_name= nihongo|Akashi Kaikyo Bridge
|明石海峡大橋|Akashi Kaikyō Ō-hashi


caption= Akashi Kaikyō Bridge from the air.
official_name=
also_known_as=
carries= 6 lanes of roadway
crosses= Akashi Strait
locale= Awaji Island and Kobe
maint= Honshū-Shikoku Bridge Authority
id=
design= Suspension bridge
mainspan= 1,991 metres (6,532 ft)
length= 3,911 metres (12,831 ft)
width=
clearance=
below= 65.72 meters
traffic=
open= April 5, 1998
closed=
toll= 2,300 Yen or US$20
map_cue=
map_

map_text=
map_width=
coordinates= coord|34|36|59|N|135|01|13|E|region:JP_type:landmark|display=inline,title
lat=
long=

The nihongo|Akashi Kaikyō Bridge|明石海峡大橋|Akashi Kaikyō Ō-hashi, also known as Marcus Bridge in Japan was completed in 1998 and is the world's longest suspension bridge (measured by the length of the center span of convert|1991|m|ft|0|disp=s). It links the city of Kobe on the mainland of Honshū to Iwaya on Awaji Island by crossing the busy Akashi Strait. It carries the part of the Honshū-Shikoku Highway.

The bridge is one of the key links of the Honshū-Shikoku Bridge Project, which created three routes across the Inland Sea.

History

Before the Akashi Kaikyō 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 in the strait 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 on the bridge 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 convert|1500|m|ft|0|adj=on-wide shipping lane.

Architecture

The bridge has three spans. The central span is convert|1991|m|ft|0|abbr=on, and the two other sections are each convert|960|m|ft|0|abbr=on. The bridge is convert|3911|m|ft|0|abbr=on long overall. The central span was originally only convert|1990|m|ft|0|abbr=on, 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 convert|1|m|ft|1|abbr=on.

The bridge was designed with a two-hinged stiffening girder system, allowing the structure to withstand winds of convert|286|km/h|mph|0, 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 convert|298|m|ft|0|abbr=on above sea level, and the bridge can expand because of heating up to convert|2|m|ft|0 over the course of a day. The cables are in 350,000 tons of concrete and are one meter in diameter.

Use

The total cost is estimated at ¥500 billion (~US$5 billion), and is expected to be defrayed by charging commuters a toll to cross the bridge. The toll is ¥2,300 (US$20.00) and is used by approximately 23,000 cars/day. [Megastructures. National Geographic for Channel Five.]

Nearby attractions

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.

Photos

See also

* Honshū-Shikoku Bridge Project
* Kurushima-Kaikyo Bridge
* Great Seto Bridge
* List of longest suspension bridges

External links

*

References

Crossings navbox
structure = Crossings
place = Kobe-Awaji-Naruto Expressway
bridge = Akashi Kaikyō Bridge
bridge signs =
upstream text = North
upstream = Honshū
upstream signs =
downstream text = South
downstream = Ōnaruto Bridge
downstream signs = LongestBridge
type = suspension
start = 1998
end = Present
previous = Humber Bridge
current = Akashi Kaikyō Bridge
next = None