Alameda County, California Bridges: East Bay Skyway Bridge across San Francisco Bay (2)

September 2013 ( 37.8168 Degrees, -122.3562 Degrees) East Bay Bridge

I was disappointed by my attempt to photograph the new East Bay Bridge on our way to SFO and Japan (see previous blog). On our way home, my son was too tired to drive and so I asked him to photograph the bridge and his photos were much better than mine.

The old truss bridge will eventually be removed, which should allow for better views of the bay. Tall light posts appear to compete vertically with the bridge tower (composed of four legs and connected by shear links). Pairs of stay cables wrap around the suspension cable and are kept from banging against each other with spacers (dampers?).

Alameda County, California Bridges: East Bay Skyway Bridge across San Francisco Bay (2) by Aaron Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

Alameda County, California Bridges: East Bay Skyway across San Francisco Bay (1)

September 2013 ( 37.8168 Degrees, -122.3562 Degrees) East Bay Bridge

I wanted to post a photo of the newly opened East Bay Skyway (34 0007L/R), which is part of the San Francisco Oakland Bay Bridge. Unfortunately, going 60 mph in the early morning light didn't provide the ideal conditions for photography.

The photo is of the self-anchored suspension spans at the west end of the East Bay Section of the Bay Bridge next to Yerba Buena Island. The tower is made up of four steel legs, tied together with shear links, which are designed to yield and protect the tower during earthquakes. We are on our way to Japan for a week and I'm hoping to send some blogs about bridges across the Edogawa.

Alameda County, California Bridges: East Bay Skyway Bridge across San Francisco Bay (1) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

Tokyo, Japan's Bridges: Kiyosu Bridge across the Sumida River (2)

June 2011 (35.682 Degrees, 139.792 Degrees) Kiyosu Bridge

Here's a closer look at the Kiyosu Bridge. The towers are short and supported on pinned bearings. 'Spined' box girders carry the suspension link forces between the ends of the bridge. The bridge functions like a continuous prestressed girder with the suspension links performing the role of the prestressing tendons.

Tokyo, Japan's Bridges: Kiyosu Bridge across the Sumida River (2) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Tokyo, Japan's Bridges: Kiyosu Bridge across the Sumida RIver (1)

June 2011 (35.682 Degrees, 139.792 Degrees) Kiyosu Bridge

Continuing upstream on the Sumida River we arrive at a three span self-anchored suspension bridge. The Kiyosu Bridge is another steel structure built after the Great Kanto Earthquake. It was completed in 1928, it's 183 m long, and 22 m wide (according to the Structurae Website).

Self-anchored suspension bridges are uncommon but several have been built in Japan (For instance, the Konohana Bridge in Osaka Bay from my blog of June 11, 2009). However, the Kiyosu Bridge is of an older style with steel links instead of cables. It must be an attractive choice, similar to an arch, when you need a medium length bridge but you don't want to build costly anchors. This bridge must have members under the deck, only to carry compression rather than the tension of a tied arch.

Tokyo, Japan's Bridges: Kiyosu Bridge across the Sumida River (1) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.