Marin County, California Bridges: NWPRR Corte Madera Creek Bridge

January 2016 (37.94332, -122.51351) NWPRR Bridge 

There used to be several movable bridges in Marin County but only two remain. The Petaluma River Railroad Bridge is on the border with Sonoma County and it was covered in a 2014 blog. The Corte Madera Creek Bridge was made famous by Clint Eastwood who jumped off the trestle portion onto a school bus (without a stunt double) in the film 'Dirty Harry.'  The section Clint Eastwood jumped from (over Sir Francis Drake Blvd) was removed in 2003.

Terry Koglin in his book 'Movable Bridges' managed to provide data on every movable bridge in the U.S. He wrote that today's bridge was built in 1930. It includes an 80 ft long bascule span. It was owned by the Northwest Pacific Railroad but it's currently abandoned. The bascule span provided 10.5 ft of vertical clearance in the closed position but it has remained open for many years and is covered with rust.

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

Santa Cruz County, California Bridges: State Route 9 Highway Bridge and SCBG Railway Bridge across Rincon Gulch

March 2014 (37.00556, -122.04500) Rincon Gulch Bridges

A concrete T girder highway bridge and a timber trestle railway bridge were built side by side across Rincon Gulch in Big Trees State Park. 

The Rincon Gulch Highway Bridge (36 0037) carries State Route 9 on a three span T girder superstructure with two column bents that were built in 1930 and retrofitted with infill walls in 1996.

The timber trestle bridge includes a steel girder span over a dirt road that rests on a steel tower pier to help support the near side. 

Santa Cruz County, California Bridges: State Route 9 Highway Bridge and SCBG Railway Bridge across Rincon Gulch by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Calaveras County, California Bridges; Cement Plant Road Bridge across Calaveritas Road

June 2013 (38.15889 Degrees, -120.61246 Degrees) Cement Plant Road Bridge

Readers may recall the iconic Cement Plant Road Bridge across State Route 49 from an earlier blog.  Cement Plant Road becomes a surface road a little east of the Golden Chain Highway but becomes a timber trestle bridge again to cross over Calaveritas Road (two miles to the east). Two miles further to the east Cement Plant Road reaches a dead end by an old quarry. My feeling is that this road used to be a railroad spur, maybe to a railway yard in the town of San Andreas. For some reason these old timber trestles provide a way for local traffic to drive over a busy highway and a much less busy road.

These trestles look a lot like the timber falsework we build to support concrete forms for bridge construction. They are only designed for a small lateral force, so it is fortunate that they haven't been knocked down by an earthquake. Of course, railroad engineers like to say that the large impact forces of a locomotive make these bridges less vulnerable to ground shaking.

Calaveras County, California Bridges; Cement Plant Road Bridge across Calaveritas Road by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Calaveras County, California Bridges: Calaveras Cement Company Underpass

March 2013 (38.16194 Degrees, -120.64972 Degrees) Calaveras Cement Company Underpass

Today's bridge is the most iconic structure in Calaveras County. Its a long timber trestle bridge with a single span T girder frame over State Route 49. The bridge was once part of a railway line that carried the Southern Pacific railroad from Valley Springs to the cement plant south of San Andreas. More information on the cement plant can be found at the Stone Quarries and Beyond Website.

The Calaveras Cement Company Underpass (30 0039Z) has a 40 ft long span over the highway and it was built in 1935. The National Bridge Inventory/Uglybridges Website reports that it currently carries 6950 vehicles a day which seems much too high. That must be the number of vehicles that go under the bridge each day.

Calaveras County, California Bridges: Calaveras Cement Company Underpass by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.