Marin County, California Bridges: The Richmond-San Rafael Bridge across San Francisco Bay

December 2015 (37.9440, -122.4802) Richmond-San Rafael Bridge

This week we'll begin studying the bridges in Marin County, California, a scenic and affluent region just north of San Francisco.

Today's structure is the Richmond-San Rafael Bridge, which carries Interstate 580 between Contra Costa and Marin Counties across San Francisco Bay. It's a double cantilever through truss with a sway back section between the two cantilever frames. I previously showed this bridge from Contra Costa County. Today we see it from Marin County just north of San Quentin State Prison.

The bridge has two decks, each carrying two lanes of traffic and a break-down lane. It was built in 1955 and was considered to be the ugly duckling of the Bay Toll Bridges. However, I like it's unusual appearance. Also, I prefer driving over this bridge in order to avoid all the traffic on the San Francisco-Oakland Bay Bridge.

After the 1989 Loma Prieta earthquake the Bay Bridge was closed for a month for repairs while the Richmond-San Rafael Bridge remained in service. Both bridges were recently retrofit, but unlike the Bay Bridge, the Richmond-San Rafael Bridge wasn't retrofit to remain in service following a large earthquake.

Marin County, California Bridges: The Richmond-San Rafael Bridge across San Francisco Bay by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Plumas County, California Bridges: Jamison Creek Bridge

November 2015 (40.7587, -120.6951) Jamison Creek Bridge

We'll finish our study of Plumas County bridges with a two span reinforced concrete box girder bridge that was built in 2003. The Jamison Creek Bridge (09C0045) crosses the creek on Johnsville Road in the town of Johnsville. The bridge is in Plumas Eureka State Park, which is a pretty environment, and was the incentive to make an ordinary bridge a little less ordinary with a stone facade. However, the rocky creek and the rocky bridge may be too much of a good thing.

Plumas County, California Bridges: Jamison Creek Bridge by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Plumas County, California Bridges, Union Pacific Railroad Bridges

November 2015 (39.8080, -120.4678) Union Pacific Railroad Bridges

The Union Pacific Railroad follows the Middle Fork of the Feather River east from Blairsden, across the Clio Trestle, through the Portola Railroad Depot, and into Reno, Nevada. The photo above shows the tracks crossing State Route 89 in Blairsden. The Blairsden Underpass (09 0031) is a single span through plate girder bridge on concrete abutments that was built in 1908. These through girder bridges are a favorite choice of the railroad since the girders are high enough to avoid vertical clearance problems (15 ft 3 inches) on the roadway below.

Continuing east of Blairsden the tracks cross over Willow Creek before going under North Gulling Street on the Portola Overhead (09 0100) (see photo below). Underpasses allow roads to go 'under' railroads and overheads allow roads to go 'over' railroads in Caltrans' parlance (railways probably have their own nomenclature).

The Portola Overhead is a 3 span steel girder bridge that was built in 1954. Note the well cars, with a well or depression that can carry double stacked shipping containers closer to the rails than the traditional flat car so they can go under bridges. Whoever invented shipping containers revolutionized commerce. The same container can be carried on a truck, a ship, or a train and it can be tracked with GPS software whether it's moving or stacked in a port.

Plumas County, California Bridges, Union Pacific Railroad Bridges by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.