Showing posts with label Warren Truss Railway Bridge. Show all posts
Showing posts with label Warren Truss Railway Bridge. Show all posts

Sunday, October 11, 2015

Plumas County, California Bridges: Rock Creek Bridges

September 2015 (39.8988 Degrees, -121.3589 Degrees) Rock Creek Bridges
The Union Pacific Railroad and California Route 70 run parallel to each other for about 50 miles along the North Fork of the Feather River. A few miles past the Pulga Bridges (where Rock Creek flows into the North Fork) is another juxtaposition of highway and railway bridges.

The highway bridge (09 0002) is a 330 ft long, three span river crossing with a 180 ft long Parker through truss center span across the North Fork. It was built in 1936 but the substructure was rebuilt on 2000. Those extra long bent caps look like they were built to carry a future widening (see photo below).
The railroad crosses Rock Creek with a steel trestle bridge that includes a Warren truss main span. We are going to see a similar style of adjacent railway and highway bridges as we continue to travel upstream along the Feather River through Plumas County.
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Plumas County, California Bridges: Rock Creek Bridges by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Sunday, September 13, 2015

Butte County, California Bridges: Pulga Bridges over the North Fork of the Feather River

August 2015 (39.79418, -121.45297) Pulga Bridges
The two Pulga Bridges are far enough upstream across the North Fork of the Feather River to not have been impacted by the construction of the Oroville Dam. The taller bridge is a truss arch that was built in 1932 and got some repairs and a seismic retrofit in 2002. It carries State Route 70 over the river and over the Western Pacific (now Union Pacific) Railroad Bridge 170 ft below. This portion of State Route 70 was established as the 'Feather River Scenic Byway' by the USDA Forest Service and includes about 130 miles of road carved out of the Feather River Gorge through the Sierra Nevada.
The photo above was taken in 1937 just after the new highway was completed (courtesy of the UC Davis 'Eastman's Originals Collection') . It looks very similar to the photo I took 78 years later. The bridges were named after the nearby town of Pulga (Spanish for flea) which was also called Big Bar.
The railway crossing is a 435 ft long three span through truss bridge on concrete piers. The bridge was built at this location so the grade could be maintained at 1.0 percent all the way to Beckwourth Pass near Nevada. The railway line was completed in 1909 and it's only half as steep as Southern Pacific's Donner Pass Line to the south.
The highway crossing (12 0038) has a 350 ft long main span and a 684 ft long total length. The approach spans are steel girders on steel towers and the main span is a truss arch on concrete piers. Large 'deadmen' supported the ends of the arch while it was assembled. It took 3 1/2 years to build. The bridge deck is on reverse horizontal curves and it also has a twisting superelevation (see photo above).
My friend Steve designed the retrofit/repairs. He said there weren't any shop drawings so he had to measure everything on the bridge (especially all the gusset plates). They built a timber walkway on one side of the bridge so they could work on the retrofit/repairs. Rope climbing teams used to do the biannual bridge inspection but now they use a snooper truck instead (see photo above).
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Butte County, California Bridges: Pulga Bridges over the North Fork of the Feather River by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Sunday, May 13, 2012

Tokyo, Japan's Bridges: Arakawa Railway Bridges (3)

March 2012 (35.746 Degrees, 139.822 Degrees) Keisei Line Bridge
Continuing downstream we come to the Keisei Line Bridge. It is a long steel plate girder bridge with three Warren Truss spans over the Arakawa. The bridge is about 1475 ft long and built in 1931. It's next to the Horikiribashi, which we'll look at tomorrow.
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Tokyo, Japan's Bridges: Arakawa Railway Bridges (3) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Sunday, April 22, 2012

Tokyo, Japan's Bridges: Kesei Railway Bridge across the Sumida River

March 2012 (35.744 Degrees, 139.789 Degrees) Kesei Railway Bridge
The next river crossing is a railway bridge that carries the Kesei Main Line, which is a private railway that goes between Tokyo and Narita Airport. I usually take the JR Express to and from the airport, but the Kesei Line provides a pretty trip through Chiba Prefecture.

This is a two span Warren Truss with vertical members and rounded top chords, similar to thousands of other railroad bridges all over the world.
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Tokyo, Japan's Bridges: Kesei Railway Bridge across the Sumida River by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.