Japan's Bridges: JR Natori River Bridge in Miyagi Prefecture (2)

June 2011 (38.206 Degrees, 140.883 Degrees) JR Natori River Bridge

A less successful photo of the Natori River Bridge (I couldn't find a good place to take a picture). Still, we can see the varying height of the towers. A nice asymmetric touch.

The first time I saw this kind of bridge was in a photo of Christian Menn's Ganter Bridge in Switzerland. However, that bridge stands dramatically 150 meters over a mountain valley. Still, both bridges are similar with concrete diagonal elements that taper towards the towers. However, the Ganter Bridge's tower legs more closely resemble the tops of the towers above the deck. It looks like they painted the tops of the towers (and the stays) on the Natori River Bridge. I prefer the natural color of the concrete girders and tower legs.

The Shinkansen Bridge is in the background and both bridges have cantenary electric lines to power the trains. However, the JR Natori River Bridge has the electric lines attached to the towers. There is some controversy whether extradosed bridges are an economical design. However, I don't see why they shouldn't be. They seem easier to build than an arch or a truss for bridges between 100 and 300 meters in length.

Japan's Bridges: JR Natori River Bridge in Miyagi Prefecture (2) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

Japan's Bridges: JR Natori RIver Bridge in Miyagi Prefecture (1)

June 2011 (38.206 Degrees, 140.883 Degrees) JR Natori River Bridge

A nice thing about Japanese bridge owners and engineers is that they are often adventurous in their choice of bridges. For instance, this railway bridge over the Natori River in Sendai is a five span, 512.2 m long extradosed bridge with a 108.2 m main span. The diagonal elements are prestressed and support the girders in tension, allowing for spans that are a little longer than a girder bridge and a little shorter than an arch bridge.

I think I must have taken this photo from the bullet train on the adjacent bridge. Note the many other bridges crossing the Natori River. Japan seems eager to spend money on their infrastructure.

Japan's Bridges: JR Natori River Bridge in Miyagi Prefecture (1) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License.