Contra Costa County, California Bridges: Indian Slough Bridges

February 2014 (37.93889 Degrees, -121.61000 Degrees) Indian Slough Bridges

Around the Antioch Bridge is the California Delta, a maze of sloughs and swampy islands. California's Delta has similar problems to the ones that plague the Mississippi Delta. It's below sea level and protected by gates and levees. The state government wants to divert some of the water into tunnels for farmers and wildlife habitats, but this plan is fiercely opposed by the people who live in the Delta.

We'll spend the next few days studying a few of the bridges that cross the Delta in Contra Costa County.

Indian Slough is crossed by several bridges at Orwood Road a little north of the waterfront community of Discovery Bay.  A squat concrete trestle bridge carries Amtrak and BNSF trains across the slough (top photo). Three large diameter utility bridges cross the slough to bring fresh water to communities in the Bay (see photo above). The utility bridge to the north has a seismic retrofit with lead rubber bearings supporting a steel eccentrically braced frame that will act as a fuse for transverse displacement (see photo below).

Just south of the utility bridges, the Orwood Road Bridge (28C0024) crosses Indian Slough. It's a twelve span timber trestle bridge with a reinforced concrete deck (see photo below). This road bridge is 230 ft long, 22 ft wide, and it was built in 1947.

Contra Costa County, California Bridges: Indian Slough Bridges by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Tokyo Prefecture, Japan's Bridge's: Utility and Railroad Bridges across the Edogawa

September 2013 (35.6970 Degrees, 139.9329 Degrees) Utility and Railroad Bridges

The next three bridges across the Edogawa are two utility bridges with a railway bridge between them. The first utility bridge carries a single pipeline across the river. However, the next utility bridge carries two pipelines and so it switches from a truss segments to steel arches to carry the bigger load across the river.

The railroad bridge is made up of Warren Truss segments sitting on two column bents. They probably build these trusses in a yard and bring them downstream on crane barges that lift them into place. A top chord piece is placed between the segments to make a continuous superstructure.

The Google Earth photo below shows the location of these three steel bridges. The Edogawa has become a salt water estuary as we get closer to Tokyo Bay.

Tokyo Prefecture, Japan's Bridge's: Utility and Railroad Bridges across the Edogawa by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

Niigata Japan's Bridges: Utility Bridges across the U River (2)

August 2007 (37.360 Degrees, 138.550 Degrees) Utility Bridges

More photos of the utility bridges across the U River just upstream of the Highway 8 Bridge. It looks like these utility truss bridges carry a variety of pipes and cables. We don't seem to have as many in California. Instead, the utility companies put their pipes, cables, etc into our highway bridges. The utility companies must keep a bunch of these truss members available in different lengths to cross over rivers. 

As we traveled inland, the river lost its high levees and slope paving. We have also traveled past most of the damage from the 2007 earthquake.

Niigata Japan's Bridges: Utility Bridges across the U River (2) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Niigata Japan's Bridges: Utility Bridges across the U River (1)

August 2007 (37.360 Degrees, 138.550 Degrees) Utility Bridges

We are slowly traveling out of the city and into the countryside. In the photo above I'm standing on the Highway 8 bridge looking upstream at the U River, two utility bridges, and at distant mountains. Both bridges are composed of Warren trusses that are firmly anchored to abutments and a hammerhead bent.

Niigata Japan's Bridges: Utility Bridges across the U River (1) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Tokyo, Japan's Bridges: Senju Bridges over the Sumida River (2)

March 2012 (35.740 Degrees, 139.797 Degrees) Senju Bridges

A view looking downstream at two utility bridges in front of the Senju Bridges. The river was once heavily travelled but now it's almost empty. We are past the area covered in my book on Tokyo River Walks and just a few miles from the river's beginning.

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

Japan's Bridges: Higashimatsushima River Bridges in Miyagi Prefecture

June 2011 (38.4383 Degrees, 141.2281 Degrees) Higashimatsushima River Bridges

Many rivers flow into Ishinomaki Bay. To the south, the Higashimatsushima River is crossed by dozens of bridges. In this photo we can see utility and steel girder roadway bridges crossing the river in this residential neighborhood. We are a little bit upstream of the tsunami damage, but we'll look at a damaged bridge tomorrow.

Japan's Bridges: Higashimatsushima River Bridges in Miyagi Prefecture by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

Japan's Bridges: Sendai Port Bridges

June 2011 (38.286 Degrees, 141.032 Degrees) Sendai Port Bridges

Some utility bridges in Sendai Port. The port was badly damaged by the tsunami. Row after row of newly built Hondas and Toyotas were sitting in vast parking lots around the port and they were picked up and destroyed by the waves.

In the photo above, several utility lines hang from a Warren truss bridge that had some damage to its left approach. Behind it is a girder bridge that is arched to help support its load. Around the bridges are damaged slope paving and embankments. Just outside of the photo are rows of gas and liquid tanks. One of them must have caught fire after the tsunami because photos and videos showed it burning through the night.

Behind me were the cranes used to load and unload shipping containers. Many of them were off their rails or their mechanisms had been contaminated by seawater. Damaged shipping containers had been picked up and re-stacked. Container ships were also picked up by the waves and now sat among the debris. They said it would be a year before the port could be repaired. So how are all the new cars getting to the dealers?

Japan's Bridges: Sendai Port Bridges by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.