The Great Seto Bridge or Seto Ohashi Bridge connects Honshu and Shikoku and spans the Seto Inland Sea. The whole bridge is connected by several suspension bridges, cable-stayed bridges, and girder bridges, forming a spectacular bridge group. The bridge started on October 10, 1978, and was finally opened to traffic on April 10, 1988.
In 1955, a ferry overturned and killed more than 160 people in the Seto Inland Sea, prompting the Japanese government to decide to build a bridge. The construction of this bridge took nine years and six months, an unprecedented masterpiece in the history of bridges in the world.
In order to prevent the ship from colliding with the piers and causing mutual damage, the outer layer of the piers is made of materials that are neither soft nor hard and resistant to seawater corrosion. A total of 700,000 tons of steel, 2.8 million cubic meters of concrete and 290,600 kilometers of steel cables were used to build the Great Seto Bridge. Let's find out more details about the size and design of this bridge.
Size and Design of the Great Seto Bridge
The Great Seto Bridge is a dual-use railway and highway bridge, with a 4-lane expressway (Seto Chuo Expressway) on the upper level and the JR Shikoku Seto Bridge Line on the lower level. It consists of two cable-stayed bridges, three suspension bridges, and one truss bridge. It is currently the largest sea-crossing bridge in the world. The bridge starts from Okayama Prefecture in Honshu in the north, like a gray-white steel dragon across the ocean, heading south to Kagawa Prefecture in Shikoku. The bridge crosses five islands in the sea, like five bright green pearls strung together by a silver thread.
The team of architects overcame many unimaginable difficulties and finally built this modern steel bridge with advanced technology and a beautiful appearance. According to the design, the bridge is resistant to earthquakes measuring 8.5 on the Richter scale and winds of 60 meters per second.
Dimensions of the Great Seto Bridge
The total length of the Great Seto Bridge is 13.1 kilometers, and the sea-crossing section is 9.4 kilometers long. As a dual-use railway and roadway bridge, it is the second-longest in the world. The longest bridge among the six bridge sections is the Nanbeizan Seto Bridge. Its two bridge towers are 194 meters high and 1,100 meters in span. The steel cables used are 1.07 meters in diameter and 1,780 meters long and can withstand 90,000 tons of tension; the bridge is 65 meters above the water, and a 500,000-ton ship can smoothly pass under the bridge.
|Total Length||13.1 km|
|Longest Section||Nanbeizan Seto Bridge, 1,100 m|
|Highest Tower||194 m|
|Longest Span||1,100 m|
|Navigable Clearance||65 m|
In the past, it took more than 2 hours for vehicles to cross the sea by boat. It only takes 40 minutes after the bridge is built, and it is not affected by the weather, which has greatly promoted the exchange of economy, culture, and various information between the Honshu and Shikoku islands. The upper layer of the bridge is a 4-lane highway, which can pass 25,000 vehicles daily; the lower layer is a double railway line, and 120 electrified trains pass through every day. There are many attractions nearby for tourists. One of the featured attractions is the Seto Bridge Memorial Park, a large recreational area where visitors can enjoy spectacular views of the bridge.