Saturday, October 31, 2009

American River Bridges: Western Pacific Railroad Bridge

Although it's hard to tell from this photo, we are approaching downtown Sacramento on our trip down the American River. I took many of these photos from my kayak, which was difficult as the boat tended to rotate whenever I put down my paddle.

The Western Pacific Railroad Bridge is a three span, steel through truss structure supported on pier walls and seat-type abutments. Although the bridge crosses the river at a high skew, the piers were built perpendicular to the bridge (rather than parallel to the river) and so the designer didn't have to adjust the ends of the truss spans to match the skew. On the north end of the bridge is a short, timber trestle section that allows bicyclists to go under the two sets of railway tracks carried on the bridge. The pier foundations are clearly visible, even at high tide above the river's surface. When the bridge was built (at the beginning of the 20th century) the riverbed was much higher then it is now and the resulting lower river leaves the pier foundations exposed.

The Western Pacific Railroad was formed in 1903 to build a standard gauge track connection to the Pacific. The company was acquired by the Union Pacific Corporation in 1983.
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American River Bridges: Western Pacific Railroad Bridge by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Friday, October 30, 2009

American River Bridges: Union Pacific Bridge (3)

In just eleven days, Union Pacific managed to replace the 1440 ft long, fire damaged timber trestle structure with a precast concrete superstructure supported on two steel H pile bents with concrete bent caps.
The trestle carries two sets of railroad tracks on ballast.

Eleven days has to be a world's record for building a quarter-mile-long bridge. Union Pacific must have had all the material in a nearby yard. Even so, they must have had three or four pile driving units working at the same time to have driven 200 piles in a week. Then there was less than a week to install the bent caps, place the precast superstructure, put down the ballast, and lay down a quarter mile of track. There must have been so many workers, that its amazing they didn't get in each others' way!
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Thursday, October 29, 2009

American River Bridges: Union Pacific Bridge (2)

This timber trestle acted as an approach structure for the steel truss railroad bridge over the American River we saw yesterday. I have often wondered whether an embankment or a bridge makes a less expensive approach for a river crossing. At this location however, a bike trail had to pass under the railroad tracks.

This timber trestle structure must be as cheap a bridge as it's possible to build. Lateral (and longitudinal) stability is provided by a pair of diagonal braces. The axial members are slightly battered to provide a little more stability. The axial members are anchored to the top and bottom beams by metal plates with narrow rims. Still, it must have been a remarkably strong structure to carry the dozens of freight and passenger trains that rumbled over it every day.

I wasn't aware of the difference between timber preserved with resin from the creosote bush and timber preserved with resin made from petroleum products, until I did some research for this article. It must have petroleum-based creosote that made this timber structure so combustible. Someone set fire to the bridge and it made a tremendous blaze with a dense cloud of smoke that could be seen from 50 miles away. In hindsight, an embankment supported by retaining walls seems like a cheaper investment, but Union Pacific replaced this structure with a steel trestle bridge in less than two weeks. We'll look at this new structure tomorrow.
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Wednesday, October 28, 2009

American River Bridges: Union Pacific Bridge

We're going to spend a couple of days studying a long viaduct that carries Amtrak and Union Pacific trains across the American River, just downstream from the Business 80 Expressway Bridge. This bridge includes a quarter mile long viaduct north of the river and a highly-skewed, five span steel Warren truss across the river.

I hadn't really thought about skewed truss bridges before. Because the trusses rest on skewed pier walls, the middle of each truss is built normal but the ends have triangular segments to match the skew.  Only the spans over the river are skewed. The rest of the bridge, including the trestle, have perpendicular supports.

A couple of years ago (on March 15, 2007) the timber trestle on the north side of the truss spans caught on fire. Sacramento had a couple of fire boats that raced to the truss bridge and sprayed it continuously while other firefighters concentrated on putting out the trestle fire. I guess the Sacramento Fire Department wasn't used to having fire boats because there were so many safety violations that the boats were taken out of service for three weeks after the fire. Apparently there was no oxygen tanks on the boat and so the firefighters were breathing toxic fumes for several hours. Also, the firefighters couldn't get their life vests on over their other equipment.  Fuel cans for the boat were sitting on the deck while they fought the fire. Also, the water pump for one boat was broken and the starter motor on the other boat was broken. Still, quick action by the firefighters probably saved the steel trusses and allowed Union Pacific to reopen the bridge eleven days after the fire.

We'll look at the timber trestle tomorrow.
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Tuesday, October 27, 2009

American River Bridges: Business 80 Expressway Bridge

About two miles further downstream is the Business 80 Bridge. It's an eight-span steel plate girder bridge on oddly-shaped two column bents. The tops of the columns have pedestals that support the girders. The bridge was built in 1954 and renovated (and seismically retrofitted) in 1996.

This is a very busy bridge and expressway, and it's usually stop and go during rush hour. Its also quite noisy and you can hear the traffic from a mile away. I think steel plate girders must be noisier than concrete box girders.
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Monday, October 26, 2009

American River Bridges: Fair Oaks Blvd. Bridge


Half a mile downstream from the Guy West Bridge is the three camelback truss spans of the Fair Oaks Boulevard Bridge. It is a three-span steel, through truss bridge supported on pier walls and seat-type abutments.

On the east end of the bridge is Fair Oaks Blvd. and on the west end of the bridge the road splits into residential 'H' Street and commercial 'J' Street and the entrance to California State University.

There's no room for bikes along the shoulders of this bridge and the sidewalks are so narrow that there's not enough room for cyclists to pass each other.

The bridge got a major renovation and repainting a few years ago. The entire bridge was wrapped up tight to prevent any of the lead-based paint from falling into the river. It must have been very unpleasant to work inside that cage of steel trusses and plastic tarp.
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Sunday, October 25, 2009

American River Bridges: Guy West Pedestrian Bridge

Less than a mile downstream from the Howe Avenue Bridges is the Guy West Pedestrian Bridge across the American River. This is the main pedestrian entrance into California State University in Sacramento. The bridge was named after Guy West, who was the founding president (in 1947) of what was then Sacramento State College.

The bridge is said to have been designed to have the same relative dimensions as the Golden Gate Bridge, which has a span of 6500 ft. That makes this bridge about 1/10 the size of the Golden Gate Bridge.

the Guy West Bridge was built in 1966 at a cost of $636,000. It's owned by the University who has been trying to give it to the city or the state since it doesn't have the resources to maintain it and it needs to be repainted, which will cost millions of dollars.
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Saturday, October 24, 2009

American River Bridges: Howe Avenue Bridges

Just a couple miles further downstream are the Howe Avenue Bridges. Each bridge is an eleven span, reinforced concrete box girder bridge carrying two traffic lanes and a sidewalk. This is the most popular kind of bridge built in California and the industry is very competitive for cast-in-place construction. The bridges are supported on tall, thin pier walls and they were built in 1969 and never widened or seismically retrofitted.
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Friday, October 23, 2009

American River Bridges: Watt Avenue Bridge

When I do kayak through the rapids downstream of the Harold M Richey Memorial Bridge, it takes over an hour to get to the next bridge which is about four miles further down the American River.

The Watt Avenue Bridge is a thirteen span, continuous, reinforced concrete T-beam structure supported on pier walls. It was built in 1961 and widened to eight lanes in 2002. The widening included better accommodations for bicyclists and large balconies for people to congregate and look down at the river. It even has a water motif that was embossed and painted on the bridge.

It seems to me that the current is quite strong, and I have to slow down the kayak and aim for the bank or get swept downstream. You may also notice that there are no boats on the river. There is a speed limit of only a few knots and the river gets shallow and so most of the boats are further downstream.
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Thursday, October 22, 2009

American River Bridges: Harold M. Richey Memorial Bridge


There's a park with river access near my house. I like to wheel my kayak to the park and kayak up and down the American River. However, I must remember to turn around under this bridge or else I'll be pulled into the rapids downstream and I won't be able to paddle back upstream. Kayaking on the river is strange because there are enormous rocks in the water that suddenly come almost to the surface and give me a sharp attack of vertigo.

This bridge's columns have that nice texture that they glue onto the concrete forms before they pour the concrete. The column's style seems very 1960's to me, but I don't have any information about when it was built. I do know that it is a six span, reinforced concrete box girder bridge on single column bents and its about 1000 ft long. Like yesterday's Fair Oaks Bridge, the Harold Richey Bridge is owned by the Sacramento County Parks and Recreation Department.

This bridge is usually crowded with families and cyclists, especially on the weekends. There are elaborate rules on the bridge deck about the right-of-way for pedestrians, equestrians, cyclists, etc. that I've never quite figured out. The bridge is named after Harold M. Richey and it was dedicated to him in 1987. I think that Richey was a county commission who was a strong supporter of the bike trail, and the bridge was dedicated to him after he died.

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Wednesday, October 21, 2009

American River Bridges: Fair Oaks and Sunrise Bridges

Continuing downstream along the American River we come to the Fair Oaks Pedestrian Bridge. In the distance we can see the Sunrise Boulevard Bridge.

Wikipedia says that the Fair Oaks Bridge is a Pratt Truss since the diagonals all move downward towards the center of the bridge. The Wikepedia article has the best description on the Internet of the different kind of truss bridges.

There is also a long article about the Fair Oaks Bridge. Apparently several bridges were built at this site that were washed away by floods. The dams across the river eventually reduced the occurrence of flooding. The current bridge was built in 1907. It has two 220 ft long truss spans supported on a tall masonry pier in the center of the river. It was closed to traffic in 1967 and ownership was transferred to the Sacramento County Parks and Recreation Department. It was listed as a National Historic Site in 2006. More information on this bridge is available on another Wikepedia Website.

The Fair Oaks Bridge was another favorite location for rope climbing practice, although one had to be patient with all the questions that were asked (and we had to keep our equipment out of the way of cyclists). As I mentioned the Sunrise Bridge, a five span steel stringer bridge that was built in 1955, can be seen in the distance. The Sunrise and Hazel Bridges carry most of the vehicle traffic across this part of the American River. The next vehicle crossing is about fourteen miles downstream.
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Tuesday, October 20, 2009

American River Bridges: Hazel Avenue Bridge

This is actually called the American River Bridge but to avoid confusion with the many other bridges with the same name, I'm renaming it after the road that it carries.

Continuing the themes of the tremendous demand that growing communities place on more highway capacity, we can see the Hazel Avenue Bridge is getting widened. The bridge is just downstream from the Nimbus Dam and about four miles downstream from the Lake Natoma Crossing (and three miles upstream from the Sunrise Blvd Crossing). Moreover, this is where the American River Bike Trail (a much used recreational and alternative commuter resource) crosses the river. The widening will increase the capacity of the road and provide better safety for cyclists.

The existing bridge is a four span reinforced concrete box girder structure on single column piers built in 1966 (see below).  The widening will increase the deck from four to six lanes and support it on two column piers. The widening will also provide little bastions for cyclists and pedestrians to move off the traveled way and enjoy the view.

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Monday, October 19, 2009

American River Bridges: Historic Truss, Rainbow, and Lake Natoma Bridges

I thought we'd take one last look at the three American River/Lake Natoma Crossings in the City of Folsom.

These bridges reflect the pride and wealth of a community that can build new bridges while maintaining and even restoring bridges that reflect Folsom's past. It also reflects a willingness on the part of the community to solve problems and make compromises for the greater good.

I live about ten miles downstream where there are few bridges and I have to drive several miles to get across the American River. At one time, they discussed building a bridge very close to my house but I'm glad the plan fell through. I wouldn't want all the cars and noise in my little neighborhood.
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Sunday, October 18, 2009

American River Bridges: Lake Natoma Crossing

Because of all the traffic problems on the Rainbow Bridge, the City of Folsom built the Lake Natoma Crossing just downstream in 1999. It is a 2300 ft long prestressed concrete box girder bridge. It includes three 328 ft long haunched girder spans over Lake Natoma, which was formed by Nimbus Dam just downstream from Folsom Dam. It provides four vehicle lanes, two bike lanes, and pedestrian walkways, and takes some of the traffic off the Rainbow Bridge.

There are several interesting features on this bridge. For one thing it was designed with a lot of community input, which included the appearance of the bridge. There are a lot of embellishments reflecting the City of Folsom's 19th century appearance (brackets supporting the bridge overhangs and Victorian bridge columns). However, the most controversial element is the decorative arches that serve no purpose except to resemble the arch on the Rainbow Bridge just upstream. To me this is intellectually dishonest and gives the bridge an overdecorated appearance. Apparently HDR (the designers) couldn't get a real arch bridge to work with the seismic and other restraints and offered this as a solution. It does match the overdecorated style of the Victorian era, although the parabolic shape seems more modern.

The other interesting feature is the seismic design. The columns are supported on large-diameter pile shafts embedded into rock. The top of the columns have isolation bearings that allow the superstructure to move during an earthquake without putting large demands on the columns. Moreover, the superstructure was made with lightweight concrete to reduce the inertial force to the bearings.

The bridge reflects the needs of the community and the various compromises that had to be made between the demands of nature and society. However, I don't think that Ayn Rand/ Howard Roark would approve.
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Saturday, October 17, 2009

American River Bridges: Folsom Rainbow Bridge

Just downstream from the Historic Folsom Truss Bridge is the Rainbow Bridge, which carries Greenback Lane over the American River. For many years, this was the only bridge across the American River, which must have been a real hassle in such a highly populated area. Even today, it has too much traffic on an antiquated structure that needs to be replaced.

The Rainbow Bridge was built in 1917 and was widened from 23.33 ft to 31.0 ft in 1969. It has a 209 ft long open spandrel arch span over the river, seven T-girder approach spans to the north of the river and four T-girder approach to the south of the river for a total length of 511 ft.

The bridge only has one lane of traffic in each direction, narrow shoulders, and a 4 ft sidewalk but it carries about 38,000 vehicles a day. Also, the bridge is eligible to be on the list of Historic Places. The city of Folsom will have to make some hard choices whether they should keep this historic structure or replace it with a new, wider bridge.
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Friday, October 16, 2009

American River Bridges: Historic Folsom Truss Bridge

A couple of miles downstream from Folsom Dam are three bridges clustered together across the American River. The first bridge is a truss structure that replaced a suspension bridge at this site in 1893. However, it wasn't built to handle automobiles and it was closed after another bridge was built alongside of it. It was eventually moved to Northern California where it was used to cross the Klamath River. In the 1990's, it was brought back to Folsom, renovated, set back on it's original foundations, and used as a pedestrian and bicycle bridge across the American River.

My first impression was that this bridge was very tall. It has about a 330 ft span and it's about 30 ft tall, so maybe this kind of truss requires a 1 to 10 ratio between its depth and its span. I would guess that its a Pratt Truss with all the diagonals in tension, but I'm not an expert on truss bridges. If you know what type of truss this is, please let us know.

Truss bridges must have seemed the height of scientific progress in the 19th century, but now they are seldom used. Before computers, it was relatively easy to determine the forces on these structures that have no flexural members, just compression and tension members with pinned connections. They still seem to be a very efficient method of spanning long distances with a minimum of steel. Maybe some innovation in truss bridge design will bring them back into fashion or maybe they'll eventually disappear.
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Thursday, October 15, 2009

American River Bridges: Folsom Dam Bridge


We must travel about sixteen miles downstream from the No Hands Bridge along the American River and past Folsom Lake to reach the next bridge, which was just completed a few months ago. The Folsom Dam Bridge was built because Homeland Security didn't want the public to drive on large dams after 9/11.

A friend just sent me some photos of a new bridge they're building across the Colorado River so that no one drives over the Hoover Dam. Similarly, after 9/11, people were prevented from driving over Folsom Dam, creating a traffic nightmare, that was eventually solved when the Folsom Dam Bridge was build a few hundred yards downstream.

I'm in no position to judge how serious a threat terrorists blowing up a dam is to U.S. security. I know that after 9/11, people came up to me occasionally and asked me why I was photographing a bridge, as if I was planning to blow it up! I thought that was being a little paranoid, but I'm probably in the minority. Anyway, more bridges means more work for bridge engineers!

I photographed this bridge (without a tripod) using auto-bracketing to create three images that were merged together in Photoshop to create a high-density-range (HDR) photo. However, I think the color looks a little strange. I rode my bike seventeen miles from my house along the American River Bike Trail to the bridge last Saturday. I was surprised by the razor wire on top of the fence (that ruined the photograph) but that's a small price to pay to be secure I guess.

As you can see, its a continuous, three-span, prestressed concrete box girder bridge on squat columns that look like an unfortunate choice for earthquake country. Caltrans requires spirals or hoops for transverse reinforcement, but these columns look like they're built with stirrups and ties. Well, this isn't a highly seismic area, and the bridge had to be reviewed by Caltrans, so it's probably okay.

In the computer graphics used as public relations for the bridge they show hikers and cyclists along the bike trail without any fences or razor wire to obscure the view.
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Wednesday, October 14, 2009

American River Bridges: No Hands Bridge

I don't have a photo of the next bridge downstream, which is the Highway 49 bridge over the North Fork of the American River. It is a three-span steel girder bridge that was built in 1948.

Although I can't find a photo of the bridge, I remember standing on it to photograph today's bridge, which is a railroad bridge built by the Pacific Portland Cement Company in 1912 to haul limestone out of a quarry. The quarry is no longer in use, the trestle approaches are gone (used as materials for the war effort), but the bridge is still used by hikers and equestrians along the Western Pioneer Express Recreation Trail. Moreover, the bridge is so strong, that it remained in service (and was used by cars) after the Highway 49 bridge was damaged during a flood in 1964.

It's a closed-spandrel reinforced concrete arch bridge with a deck 150 ft above the American River. It cost $300,000 and the labor of 800 workers to build and was claimed to be the longest reinforced concrete arch bridge in the world when it was completed in 1912. There's an excellent article about this bridge on a website provided by El Dorado County. It was originally called the Mountain Quarry Bridge but it's name changed to the No Hands Bridge because at one time it lacked a railing.
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Tuesday, October 13, 2009

American River Bridges: Old Foresthill Road Bridge

After spending several days looking at the new Foresthill Bridge, I thought we'd take a quick look at the original Foresthill Bridge across the North Fork of the American River.

This photo was taken from the bottom chord of the new bridge (while I was rope climbing). You can see it is a five span steel girder bridge on single column bents with hammerhead bent caps. It is a locally-owned bridge that was built in 1955 on a small radius horizontal curve. I like how the road hugs the hills and forms a horseshoe with the bridge over the river. If the Auburn Dam had been built, it would be sitting under hundreds of feet of water.

There are a lot of bridges in this sparsely populated region, some of them from the the beginning of the 20th century. It's close to where gold was first discovered (in nearby Coloma in 1849) which may explain why so much infrastructure was needed. People still pan for gold today, but most of it's gone. The miners built water cannons that altered much of the landscape in the region.
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Monday, October 12, 2009

American River Bridges: Foresthill Bridge (4)

One more photo of the Foresthill Bridge before we move on. I read that this is the tallest bridge in California, but I think it depends on what you're measuring. The Golden Gate Bridge has taller towers but the Foresthill Bridge has a higher deck.

The bridge is scheduled to be repainted, get a center deck placed between the two existing decks, and be seismically retrofitted next year at a cost of $70 million. The bridge was built 36 years ago at a cost $13 million. It was originally painted with lead-based paint and so it will cost $27 million to carefully remove the existing paint, prime the bridge, and repaint it a similar shade of green.

I guess they weren't thinking about earthquakes when they built the bridge, although it was an earthquake up north in Oroville that eventually stopped them from building a dam under the bridge. I know there are some M6.5 faults in the foothills, but I can't remember how far away they are from the bridge.

Such a tall, flexible structure wouldn't be damaged by shear forces, but the large displacements might be a problem. I recall that they are going to install buckling-restrained braces to act as dampers and reduce the displacement of the superstructure during earthquakes.
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Sunday, October 11, 2009

American River Bridges: Foresthill Bridge (3)

We have been studying the Foresthill Bridge over the last few days. The truss is under the deck, which makes it a deck truss bridge. Deck trusses are less of a headache to bridge owners since we don't have to worry so much about high hits, that occur on through truss bridges. On this bridge, the truss carries two separate decks with a drop of 700 ft between them.

The construction of such a tall bridge must have been challenging. First the abutments and the enormous towers were built and then the superstructure was started from the ends and eventually met in middle. For some reason, people are often surprised that engineers can design something precise enough so the bolt holes meet when the two sides come together. However, the displacement due to temperature and gravity is well known, and besides, steel is pretty flexible and can be stretched easily to bring the holes together for the final bolts.

There are several blogs that discuss the construction of the bridge. One is a short article from the Placer County Historical Society, but it includes a nice photo of the bridge being constructed. There's also a longer article about the politics of the bridge and the Auburn Dam.

Placer County must be sick of this bridge because there are so many requests to film movies with cars driving off the deck. There are requests from enthusiasts who want to bungee jump or parachute off the bridge. And there are the many terribly depressed people who want to end their lives by jumping off the bridge.

Maybe we'll spend one more day at the Foresthill Bridge, and then we'll look at the many other interesting bridge that cross the American River.
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Saturday, October 10, 2009

American River Bridges: Foresthill Bridge (2)

I'm familiar with the Foresthill Bridge because that's where we used to practice our rope climbing techniques. There's a door in the west abutment that leads you down a  corridor (that smells strongly of bat guano) and you end up on the painter's walkway above the bottom chord of the bridge.

Its a good place to work because you are away from traffic and you don't have to interrupt your concentration to explain what you''re doing to passing pedestrians or cyclists. However, since 9/11 you better alert someone from Homeland Security that you'll be on the bridge or you'll find yourself surrounded by police in helicopters trying to find out what you're up to.

It's here that we practiced setting a traverse, different methods of getting off one tension line and onto another, and rescue techniques. Rope climbing is the only way that bridge engineers can inspect very tall towers, deep superstructures, and other places where a snooper truck or person-lift can't go.

Actually, rope climbing equipment and rope climbing techniques have changed a lot since this photo was taken. Nowadays, each climber belays him or herself and the harness is much lighter and less painful to wear. Still, the basics are the same. Each climber must always be securely attached to two ropes at all times.

We stopped climbing because we lost our leader (he took another job). I guess we were a bunch of followers and when our leader left, no one was willing to take over maintaining the equipment, planning the exercises, etc. Also, I stopped because as I got older, I lost the ability to lift myself up onto bridge members by just using my arms.
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Friday, October 9, 2009

American River Bridges: Foresthill Bridge

The American River flows out of the Sierra Mountains in California in three fast-moving streams. Just north of the confluence sits the Foresthill Bridge.

This bridge carries a local road (the new Foresthill Road) across the north fork of the American River. It was built in 1973 by the US Bureau of Reclamation at a cost of $13 million. The deck is 730 ft above the river and the 2429 ft long superstructure was supposed to span over a reservoir formed by the Auburn Dam, which was never built. The concerns of environmentalists and others eventually stopped this dam project.

It wasn't as if this victory stopped the damming of the American River. The Lake Clementine Dam is just upstream and the Folsom Dam is just downstream and there are probably a dozen other dams built across forks of the American River. In fact, I think that only one river coming out of the Sierras in California (maybe the Smith River up north) has not been dammed.

I feel somewhat ambivalent about dams. Some of my best friends are dam engineers, including the late, great Leval Lund from LA Water and Power. Still, I think that we would be better off in the long run without them. Eventually, the Folsom Dam will fail, and over a million people live downstream.

I seem to be interjecting  a lot of my personal thoughts into this blog lately. I guess I'm really just trying to engage you, dear reader to respond to my blog. Google informs me that there are about 400 people a week reading this blog, but the only comments come from the kind and omniscient Happy Pontist.

I was reading in Bridge Design and Engineering about a bridge in Canada that was built to carry earthmoving equipment that would tear up the landscape in the search for oil sands. I was also reading about the building of roads into the habitat of the last tribes in Amazonia still untouched by our culture.

I guess we all feel a little guilty about the uses our bridges are put to, even though we are just trying to build something useful. I think that's why the Happy Pontist was writing about Bridges to Prosperity, Helvetas, etc. whose bridges are meant to help the poorest people (although they may be most helpful to the farmers and ranchers who live nearby). Anyway, over the next few weeks, we'll look some more at the Foresthill Bridge as well as at other bridges crossing the American River.
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Thursday, October 8, 2009

Vancouver's Bridges: Patullo Bridge (2)

One last photo of the Patullo Bridge and then I'll have to find another city's bridges to put in my blog. There are so many new and interesting bridges in Vancouver that I'd like to come back one day. In particular, I'd like to study the extradosed bridges that were recently built.

An extradosed bridge is a cable-stayed bridge with short towers. Since the cables have a smaller vertical component, they are much less effective and it's more like a prestressed girder bridge.

Just 72 years ago, the Patullo Bridge was a brand new structure and considered the height of modernity. Now, with its 10 ft traffic lanes and aging structural members, it's considered antiquated and will shortly be replaced. In 1937, it cost $4 million to build and was named after the premier of British Columbia. I wonder if the works of Calatrava will prove to be equally short lived? Most bridges have about a 75 year life-span, unless the public is willing to make a special effort to preserve them.

In 2009, the Burnaby Village Museum celebrated the bridge's 1937 grand opening with a special show and luncheon. Information from the museum's show is available online.
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Wednesday, October 7, 2009

Vancouver's Bridges: Skytrain, Patullo, and New Westminster Bridges

We looked at the Skytrain Bridge yesterday. It's a cable-stayed bridge (built in 1990) that carries automated trains over the Fraser River.

A few hundred meters to the east is the Patullo Bridge that we looked at back in March 2, 2009. It is a suspended deck truss arch bridge that was built in 1937. Because of the narrow lanes and the lack of a median barrier, there are frequent accidents on the bridge and it's expected to be replaced in a few years with a toll bridge. In 2009 vandals set fire to the wooden trestle on the south end of the bridge but it was quickly repaired.

A couple hundred meters further to the east is the New Westminster (or CNR) Bridge. It is a long truss bridge that was built in 1904 with a swing span in the middle of the Fraser River. Like the Patullo Bridge, it is frequently the target of vandals and they have stopped using open car vehicle transporters on this bridge.

Six kilometers further to the east along the Fraser River is the Port Mann Bridge (completed in 1964) that closely resembles the Patullo Bridge. I never had time to photograph this bridge, but photos are available at Wikipedia. The bridge carries an amazing 126,000 vehicles a day. Although the bridge is only 45 years old, there are plans to build another bridge with a larger capacity and to tear the Port Mann Bridge down. As can be expected in a politically active city like Vancouver, there have been protests to improve mass transit instead of building more ways for people to drive cars into the city. Perhaps the Golden Ears Bridge was built to carry some of the excess traffic?

With its broad rivers and growing population, I guess Vancouver is a good city for bridge engineers.
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Vancouver's Bridges: Skytrain, Patullo, and New Westminster Bridges by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.