Friday, May 7, 2010

Movable Bridges - Steamboat Slough Bridge

All the bridges at the southern end of the Sacramento River (north of the Rio Vista lift bridge) are heel trunnion double leaf bascule structures. They must have put a half dozen of these movable bridges between Sacramento and Rio Vista during the 1920s. Perhaps there was more ship traffic in those days. Riding my bike along the river today, all I see are a few speedboats. I wonder if a bridge operator is always on duty just in case?

Steamboat Slough Bridge doesn't actually cross the Sacramento River. It carries State Route 160 traffic over Steamboat Slough on the west side of the river. It's a 68.9 m long bridge that was built in 1924.

All of these bridges have height restrictions due to the huge, concrete counterweights (and low cross-beams). The bridges are almost identical with short spans to support the counterweights and long through truss movable spans. They just have different approach spans when a longer bridge is needed.
Creative Commons License
Movable Bridges - Steamboat Slough Bridge by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

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