Bridges of Lyon, France: Passerelle du College across the Rhone River

September 2016 (45.7643, 4.8397) Passerelle du College

The Passerelle du College is a pedestrian bridge that was built to carry children to school. It was almost completed when a cable swage broke, sending workers into the Rhone where 8 people drowned. After the accident, the bridge was quickly completed (in 1845). During WWII, the bridge was determined to be a danger to the retreating German Army and one of the piers was destroyed. The bridge was carefully rebuilt after the war (in 1945).

The Passerelle du College is a three span bridge with suspension cables and stays supporting the main and back spans and additional cables without stays to help support the main span (see above photo).

Looking west across the Rhone, we can see that the piers are protected by tiny islands that have trees and perhaps a garden? The closer pier has an inscription on top commemorating its reconstruction after WWII.

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Butte County, California Bridges: Old Bidwell Bar Bridge

August 2015 (39.53747 Degrees, -121.45417 Degrees) Old Bidwell Bar Bridge

The first suspension bridge (ropes hung above an obstacle) predates recorded history. The first iron suspension bridge was built (appropriately) by the Tibetan bridge engineer Thangtong Gyalpo in the 15th century. The first US suspension bridge was the Jacob's Creek Bridge in Pennsylvania built in 1801. The first California suspension bridge was the Bidwell Bar Bridge built across the Middle Fork of the Feather River in 1855 (see photo below).

Bidwell Bar was a gold rush town that was founded after John Bidwell discovered gold there in 1848. The town experienced a rapid boom and an equally rapid bust until the bridge was just about all that remained. When the Oroville Dam was built in 1965, the town was submerged and the bridge (along with a historic orange tree and toll building) was moved to its present location (Kelly Ridge Park) in a state boat launch facility about a mile west of its original location.

When I drove to the park entrance in August, the ranger told me the bridge was inaccessible because the road had been blocked by fencing surrounding houseboats in dry dock. I was irritated that after all of the trouble to move the bridge the park had closed it to the public. However, the bridge turned out to be readily accessible to anyone willing to hike up a hill (although photos suggest the bridge was less accessible before the drought). Another thing that bothered me is that timber piles now supported the bridge rather than having the suspension cables carry the 240 ft long span.

The Bidwell Bar Bridge was fabricated in Troy, New York and shipped around the southern tip of Chile to California. The towers are atop stone abutments and composed of four iron pipes stamped with 'Starbuck's Metal Works of Troy, NY. The pipes at each tower form a pyramid with saddles on the top that support two suspension cables. Regularly spaced hangers support timber floor beams that carry the deck. The bridge is a California Historical Landmark and a Historical Civil Engineering Landmark.

Butte County, California Bridges: Old Bidwell Bar Bridge by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Butte County, California Bridges: Route 162 Bridge across the Middle Fork of the Feather River

August 2015 (39.54987 Degrees, -121.42988 Degrees) Lake Oroville Bridge

This week's bridge crosses over the Middle Fork of the Feather River. The water level is so low now that the bridge looks like it did when it was first built. It's a suspension bridge, which is one of the easier long span bridges to build. Once you drape the cables over the towers (and anchor them) you can just work from each end hanging the superstructure until they meet in the middle.

Chico State University has archived many photos that were taken during construction of the bridge and the dam. It's surprising how many long span bridges were designed and built during the period when the dams were being constructed. Sepulveda Dam was completed by the USACE in 1941, Shasta Dam was built by the USBR in 1945, Oroville Dam was built by the CDWR in 1965, etc. Who were all these bridge engineers?  There seems to be a boom period for different places when money is available and amazing infrastructure is created.

This week's bridge has several names. It's called the Bidwell Bar Bridge because it replaced an old bridge by that name (that we'll look at next week). It's called the Lake Oroville Bridge because its the most impressive of the bridges over Lake Oroville. Caltrans calls it the Middle Fork of the Feather River Bridge (12 0188) after the obstacle that it crosses. It carries the Olive Highway, which is also called the Oroville-Quincy Highway and it's officially called California Route 162.

The main span is 1108 ft long and the entire bridge is 1793 ft long. The roadway is 28 ft wide with sidewalks on both sides of the roadway. It's an interesting bridge because it is on a horizontal curve with the suspension cables anchored to the side of the deck. Note how there are no back stays on the bridge. Instead, there are concrete piers to support the back spans on both ends of the bridge. Eric Sakowski writes that it's the highest reservoir bridge in the US. The towers are 350 ft tall and were built about 300 ft above the bottom of the river.

Butte County, California Bridges: Route 162 Bridge across the Middle Fork of the Feather River by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Los Angeles County, California Bridges: San Pedro Bay Bridges

(33.7580 Degrees, -118.2475 Degrees) San Pedro Bay Bridges

After passing under the Queensway Drive Bridges we leave the Los Angeles River and enter San Pedro Bay. The Bay is dominated by Terminal Island and the Ports of Los Angeles and Long Beach. The Ports rely on three bridges to move goods in and out of Terminal Island. The Vincent Thomas Bridge is a suspension bridge designed by Jim Jurkovich at Caltrans in the 1950s. The Schuyler Heim Bridge is an old lift bridge that is currently being replaced with a cast-in-place box girder bridge. The Gerald Desmond Bridge is a truss arch bridge that is being replaced with a cable-stayed bridge. We'll spend the next few days studying these bridges.

Los Angeles County, California Bridges: San Pedro Bay Bridges by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Los Angeles County, California Bridges: Interstate I-405/I-710 Interchange across the Los Angeles River

August 1999 (33.8258 Degrees, -118.2053 Degrees) Los Angeles River Bridges

About four miles south of the Artesia Blvd Bridge is the I-405 (San Diego) Freeway Bridges (53 1209) and a little south of that is a utility suspension bridge. The I-405 Bridges are eight-span steel girder bridges on very wide pier walls that were built in 1963 and retrofit in 1993.

Los Angeles County, California Bridges: Interstate I-405/I-710 Interchange across the Los Angeles River by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

San Francisco County, California Bridges: Golden Gate Bridge (2)

July 2014 (37.80482°, -122.46757°) Golden Gate Bridge

Here's the view while driving across the Golden Gate Bridge. We drove south from Marin County, which is the toll-paying direction, except there are no longer any toll booths. Either you have a FasTrak tag on your vehicle or they photograph your license plate and send you the bill. The sidewalks are packed with bicyclists, runners, and tourists all trying to avoid each other. 

They recently voted to put a suicide net under the bridge, which I think is a good idea. When they were putting a new deck on  the bridge 25 years ago, a friend who was working on the project said that people would slam on their brakes, run out of their car, and jump before anyone could stop them.

San Francisco County, California Bridges: Golden Gate Bridge (2) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

San Francisco County, California Bridges: Golden Gate Bridge (1)

July 2014 (37.80482°, -122.46757°) Golden Gate Bridge

The Golden Gate Strait flows between the headlands of the San Francisco and Marin Peninsulas. Powerful tidal currents and dense fog made the strait difficult to cross before the construction of the Golden Gate Bridge (in 1937). This photo is taken from Crissy Field, which used to be a U.S. Army airfield and is now part of the Golden Gate National Recreation Area. The buildings on the left were airplane hangars that were converted into gyms with rock walls, swimming pools, and bike rental facilities. The buildings on the right belonging to the Gulf of the Farallones National Wildlife Sanctuary.  The Farallones are islands just outside the Golden Gate in the Pacific. 

San Francisco County, California Bridges: Golden Gate Bridge (1) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Solano County, California Bridges: I-80 Bridges across the Carquinez Straits

January 2014 (38.064 Degrees, -122.225 Degrees) Carquinez Bridges

Yesterday we looked at the Napa River Bridge and the Mare Island Lift Bridge from the tower of the Carquinez Suspension Bridge. Today we are looking at the Carquinez Bridges from the deck of the Mare Island Lift Bridge.

The Carquinez Bridges include a 1950s era truss bridge and a new suspension bridge. We studied these bridges previously when they were building the suspension bridge, retrofitting the truss bridge, and removing the 1920s era riveted truss bridge.

The remaining truss bridge got an interesting seismic retrofit in the1990s that included shock absorbers at the expansion joints to prevent unseating at the ends of the cantilevers (above) and supports at the bottom of the towers to facilitate rocking (below).

The bridges carry westbound and eastbound I-80 traffic across the strait that connects San Pablo Bay (on the west) to Suisun Bay (on the east).

The photo shown below was taken before they completed the suspension bridge and before they removed the 1920s truss bridge. On the north (far) side of the bridges is the city of Vallejo and on the south (near) side is the town of Crockett that includes the big C and H (California and Hawaii) Sugar Refinery.

Solano County, California Bridges: I-80 Bridges across the Carquinez Straits by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Tokushima Prefecture, Japan Bridges: Ōnaruto Bridge across the Naruto Strait (2)

November 2013 (34.2461 Degrees, 134.6670 Degrees) Ōnaruto Bridge

Continuing north we arrived at the Naruto Strait and the Ōnaruto Bridge. The Naruto Strait (鳴門海峡) has dangerous whirlpools and eddies, which are imaginatively rendered in the folk dances of the region. The Strait separates Shikoku Island from Awaji Island and it's crossed by the Ōnaruto Bridge.

Originally, they were planning to carry the Shinkansen (bullet train) on the bottom bridge decks of the Kobe-Awaji-Naruto Expressway. Eventually it was decided to carry trains on the Seto-Chuo Expressway instead and the bottom deck is used to carry maintenance crews and visitors under the bridge. Tourists can watch ships navigating around the rocks and swift current under the bridge. However, the bridge was designed so it could still carry the Shinkansen in the future. Also, the number of traffic lanes could be increased from four to six lanes, but as can be seen in the photo above, there is almost no traffic on this bridge.

Because of the hostile environment at the Naruto Strait, everything about this bridge was made extra strong. For instance, instead of two suspenders hanging from the suspension cable at each floor beam, the Ōnaruto Bridge has four suspenders so that two can be replaced at a time. Because of the hard rock and swift current under the Naruto Strait, the towers and pier are supported on large diameter pile caps instead of caissons.

The suspension cables were constructed with extra strands to balance the tension in the side tower that supports the short truss span at the end of the bridge. Also, larger diameter wires (5.37mm) were used for the suspension cables.

Tokushima Prefecture, Japan Bridges: Ōnaruto Bridge across the Naruto Strait (2) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

Tokushima Prefecture, Japan Bridges; Bridges across Konaruto Channel (2)

November 2013 (34.1892 Degrees, 134.6125 Degrees) Konaruto Channel Bridges

Three bridges cross the Konaruto Channel in northeastern Shikoku. Furthest to the east is the Muya Bridge, a big steel box girder bridge on hammerhead pier walls that carries the Kobe-Awaji-Naruto Expressway. This bridge is 536 meters long with four lanes, and it was built in 1987.

Just west of the Muya Bridge is the Small Naruto Bridge, a four span suspension bridge with an interesting 'A' shaped tower supporting the middle of the bridge. This bridge is 441 meters long with 160 m long middle spans and it was opened to traffic in 1961.

The westernmost bridge across the Konaruto Channel is a 530 meter long three span cable-stayed bridge (also called the Small Naruto Ohashi) with a 280 meter long center span that was built in 1998. I wasn't able to photograph it, but interested readers can view it by using the following link to another website. 

Tokushima Prefecture, Japan Bridge; Bridges across Konaruto Channel (2) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

Tokushima Prefecture, Japan Bridges; Bridges across Konaruto Channel (1)

November 2013 (34.1892 Degrees, 134.6125 Degrees) Konaruto Channel Bridges

Shikoku Island is separated from Honshu Island by the Seto Inland Sea. The three routes of the Honshu-Shikoku Bridge Project were built to connect Shikoku Island to the more developed Honshu Island and allow Shikoku to better participate in the social and economic life of the country. 

There are three long routes on the Honshu-Shikoku Bridge Project. The westernmost route is the Nishi-Seto Expressway, which includes nine long span bridges and connects Imabari to Onomichi. We studied the construction of several of these bridges in my blog in July of 2009. The middle route is the Seto-Chuo Expressway which carries both highways and railways and includes six long span bridges. The eastern route is the Kobe-Awaji-Naruto Expressway, which is 89 km long and includes some of the longest and most difficult bridges to construct.

Today's bridges are at the southern end of the Kobe-Awaji-Naruto Expressway on Shikoku Island. We'll take a closer look at these bridges tomorrow.

Tokushima Prefecture, Japan Bridge; Bridges across Konaruto Channel (1) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

Tokushima Prefecture, Japan Bridges: Ōnaruto Bridge across the Naruto Strait (1)

November 2013 (34.2461 Degrees, 134.6670 Degrees) Ōnaruto Bridge

Greetings from Shikoku Island. The bridge in the distance is the Onaruto Bridge, part of the Honshu-Shikoku Expressway. I have to continue on the US-Japan Bridge Tour, so I will write more about this and other bridges later.

Tokushima Prefecture, Japan Bridges: Ōnaruto Bridge across the Naruto Strait (1) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

El Dorado County, California's Bridges: Mosquito Road Bridge across the South Fork of the American River (4)

January 2013 (38.776 Degrees, -120.749 Degrees) Mosquito Road Bridge

The Mosquito Road Bridge is almost perpendicular to the river. The deck sits on timber floor beams with ramps at each end that go from the floor beams to concrete abutments. The far end (in the photo above) is fixed while the near end has an expansion joint for temperature movement.

Each suspension cable is actually three cables bundled together with separate anchorages. In the photo above and in a previous photo of the tower we could see that the towers are much older than the bridge and are made from concrete filled with rubble.

El Dorado County, California's Bridges: Mosquito Road Bridge across the South Fork of the American River (4) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

El Dorado County, California's Bridges: Mosquito Road Bridge across the South Fork of the American River (3)

January 2013 (38.776 Degrees, -120.749 Degrees) Mosquito Road Bridge

Despite the many restrictions posted on the Mosquito Road Bridge and despite its rural location, the bridge is in constant use. However, the bridge appears to be very well maintained and is in good shape for a 70 year old structure. The combination of an attractive landscape and an attractive bridge provides for a near ideal aesthetic experience. Civilization living in harmony with nature.

El Dorado County, California's Bridges: Mosquito Road Bridge across the South Fork of the American River (3) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.