Tokyo Bay Bridges: Rainbow Bridge (2)

At 570 m, the Rainbow Bridge is very short for a suspension structure. The Tatara (cable-stayed) Bridge is 890 m. The Lupu (arch) Bridge is 550 m. Perhaps the engineers felt obligated to build a suspension bridge because the nearby long-span structures are cable-stayed bridges.

The Rainbow Bridge spans between Shibauru Wharf and the Daiba District. Considering the span length is so short, it's surprising that the east tower sits in Tokyo Bay. Maybe there was no place to put the tower on land, since the bridge swings to the north from the eastern tower before reaching Daiba.

Tokyo Bay Bridges: Rainbow Bridge (2) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Tokyo Bay Bridges: Rainbow Bridge

In 1991, we were taken to see a new bridge being built a little downstream from the mouth of the  Sumida River in Tokyo Bay. The Rainbow Bridge is a double-deck truss suspension bridge supported on steel, two-legged towers. The upper deck carries the Metropolitan Expressway and the lower deck carries mass transit, pedestrians, and port traffic.

The name 'Rainbow Bridge' is because of an automated lighting system that continuously changes the bridge's color depending on the day of the week and the time of the day. We'll look at the completed bridge tomorrow.

Tokyo Bay Bridges: Rainbow Bridge by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Tokyo's River Crossings: Ryogoku Bridge across the Sumida River (1)

Continuing downstream on the Sumida River we come to the Ryogoku Bridge. This structure was built in 1932 to replace a timber bridge from 1659. Many timber structures were rebuilt in the 1930s, due to the devastating fire that followed the 1923 Great Kanto Earthquake.

The original Ryogoku Bridge has been depicted by Hiroshige, Hokusai, and other artists and writers. The name Ryogoku means two provinces because the original bridge joined Edo and Shimosa. Eventually, the surrounding neighborhood was named after the bridge. The following link shows a print of the Ryogoku Bridge from 1830.  The Sumida River looks so wide in this print that we can barely see the opposite bank. This must have been before the Arakawa River was diverted from the Sumida River for flood control. Also, Mt. Fuji can be seen quite clearly behind the bridge. I've noticed that this custom of putting Mt Fuji behind depictions of bridges continues on new Japanese bridge projects.

The current bridge is a three-span steel haunched girder bridge with a dropped-in section on the center span. The bridge is 164.5 m long and 24 m wide. It is highly decorated with concentric circles at the bastions, spheres on pedestals at the abutments, and a wave-like motif on the interior railing. This is very similar to the Art Deco style that was being used in Europe and the United States in the 1930s.

Tokyo's River Crossings: Ryogoku Bridge across the Sumida River (1) by Mark Yashinsky is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 United States License.