Alameda County, California Bridges: Fruitvale Avenue Bridges across the Oakland Estuary

June 2014 (37.76889 Degrees, -122.23000 Degrees) Fruitvale Avenue Bridges

The Fruitvale Avenue Bridges include a railroad lift bridge and a single leaf bascule bridge (also called the Miller Sweeney Bridge). Both bridges connect Alameda Island to Oakland. 

The Fruitvale Railroad Bridge was built in 1951 by the United States Army Corps of Engineers (USACE). The contractors included Ben Gerwick and Southern Pacific. It cost just under a million dollars to build. The USACE owns the bridge but it is operated and maintained by Alameda County. The bridge includes 185 ft tall towers and a 200 ft long lift span. Although it provides 13 ft of vertical clearance when closed, it is normally kept at 65 ft (mid-open), and can be raised to 135 ft if necessary. The bridge usually carries only one or two trains a day.

The Fruitvale Avenue Road Bridge was built in 1973 by the USACE and it won several awards. The contractor was Hensel Phelps Construction and the designer was McCerary-Koretsky with material and technical support from Kaiser Steel. The bridge is 395 ft long with a 128 ft long bascule span and carries about 14,000 vehicles a day. 

Alameda County, California Bridges: Fruitvale Avenue Bridges across the Oakland Estuary by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Movable Bridges - Brickell Avenue Bridge

The Intercoastal Waterway (a 3000 mile channel along the Atlantic and Gulf Coasts) is a good place to find movable bridges. Its safer than traveling on the open ocean and so ships travel on it and movable bridges are needed for people wanting to get to the beach. These bridges seem to open and close more often than the other movable bridges we've been studying.

The Brickell Avenue Bridge actually crosses over the Miami River just before it empties into the Intercoastal Waterway in Miami Beach, Florida. The bridge is decorated with sculptures, sconces, and a pretty tender house. It's a bascule bridge built in 1995 that replaced a 64 year old structure. It was recently widened to three lanes in each direction but it still gets backed up with traffic during rush hour. The bridge has a higher vertical clearance and the river was dredged so it doesn't have to open quite so often.

Movable Bridges - Brickell Avenue Bridge by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Movable Bridges - Popps Ferry Bridge

As we continued east along Mississippi's coastline into Biloxi's Back Bay we came to the Popps Ferry Bridge.

It seems like bridges along the Gulf Coast are in a constant state of disrepair. In this photo the bridge is being put back together after Hurricane Katrina came through (in August 2005). I was reviewing my trip on Google Earth and found a photo of the bridge being repaired again after being hit by a tugboat pulling eight barges in 2009. The bridge tender opened the double-leaf bascule spans for the tugboat, but the operator must have had trouble with the current because he knocked out a bridge span instead. If it's not hurricanes, or errant vessels, its oil spills for the ill-fated residents of Biloxi's Back Bay.

The Popps Ferry Bridge has long and short precast I girder approaches and a 180 ft wide channel opening. The bridge was originally built in 1979 but its been rebuilt several times.

I'm afraid we are going to see a lot more damaged movable bridges before we get out of the Gulf. We estimated there was over $2 billion in bridge damage from Hurricane Katrina and many of these bridges have movable spans.

Movable Bridges - Popps Ferry Bridge by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Movable Bridges - Meridian Bridge (2)

I'm standing on the deck of the Meridian Bridge. In the distance you can see the Sutter Buttes, which are the remains of some old volcanos.

The steel tower supporting the swing span is a model of simplicity. The tubular legs on each side of the deck come together at the top and are braced with a strut. The cables come up from two floor beams, through the top of the tower, and then are attached to two floor beams on the other side.

I often wondered why the swing span of this type of bridge doesn't bang into the corners of the side spans when it moves. I looked closely at the gap between them and saw that it was curved, probably to the circumference of the circle the swing span makes as it rotates about the pivot span.

Movable Bridges - Meridian Bridge (2) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Movable Bridges - Meridian Bridge

This is the last movable bridge I have photos of on the Sacramento River. However, there are a few more movable bridges up north that I hope to photograph (maybe during the summer).

Bridge engineers are faced with a challenge providing a big enough channel opening with a swing bridge. Because the support is in the center, it's difficult to make the cantilever spans on each side large enough for ships to pass. We saw that the Spokane Street Bridge (April 28th and 29th) has a swing span on each side of the channel so that a very large opening can be created. The other swing bridges we looked at had truss superstructures to provide long stiff cantilever spans. The Meridian Bridge solves the problem in a different way, with a central tower and a cable stays to support the cantilever spans.

This bridge carries State Route 20 across the Sacramento River a little south of Colusa and a little west of Marysville. It was built in the 1970s (and along with the Spokane Street Bridge) provides a good example of how engineers can develop new solutions to address some of the disadvantages inherent with swing bridges. The tower is 50 ft tall and the leaves are about 180 ft long, providing a suitable opening for ships to pass.

We'll take a closer look at this interesting bridge tomorrow.

Movable Bridges - Meridian Bridge by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Movable Bridges - Knights Landing Bridge (3)

A last look at the Knights Landing Bridge. Its a double leaf simple trunnion bascule bridge that carries State Route 113 over the Sacramento River. The counterweights are enclosed in the large bin-type abutments.

Balancing the bridge leafs with the counterweight requires careful planning. Because traffic travels on approach spans rather than directly on the counterweights, this bridge is more stable in the closed position. When the locks are opened at midspan, the bridge can be raised with a smaller motor than would be needed if the deck had been made heavier to resist the counterweight and live load behind the trunnion.

I believe this bridge can still be operated. At least, it looks in good shape. Perhaps it is only opened when a request is made to the U.S. Coast Guard several days in advance.

Movable Bridges - Knights Landing Bridge (3) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Movable Bridges - Knights Landing Bridge (2)

A view from the deck of the Knights Landing Bridge. In this view, we can see the top chord of the bascule span going through a slotted hole in the approach slab.  The trunnion must be a little bit in front of the approach slab, the counterweight sits below the slab, and it descends into the bin-like abutment when the operator raises the bridge.

This area has changed a lot over the years. When Dr. Knight first came here, this was a meeting place of Native Americans living along the Sacramento River and Cache Creek. A town and ferry were built to handle all the traffic moving along the river, but now its like a ghost town.

Movable Bridges - Knights Landing Bridge (2) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Movable Bridges - Knights Landing Bridge (1)

North of Sacramento are several interesting movable bridges across the Sacramento River.

The Knights Landing Bridge is the first double leaf bascule bridge across the river that isn't a through truss. I'm actually not sure what kind of structure it is. Are those pony girders with rectangular openings or is it some kind of Vierendeel truss?

I'm also not sure what kind of bascule bridge it is. Is it a double leaf simple trunnion bridge or is it a Scherzer rolling lift double leaf bascule bridge? I vote for the latter since the bridge is high up with counterweights that can pivot into the concrete boxes at the far ends.

The bridge carries State Route 113 over the Sacramento River in the town named after Dr. William Knight, a physician who founded the town of Knights Landing on an ancient Native American mound in 1842.

We'll take another look at this unusual bridge tomorrow.

Movable Bridges - Knights Landing Bridge (1) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Movable Bridges - Spokane Street Swing Bridge (2)

Another view of the Spokane Street Bridge. Note the old bascule railroad bridge in the background. This area is part of a huge port. The Spokane Bridge carries container trucks into the harbor while also allowing container ships through the channel.


The previous bridge restricted access to the channel and so it was replaced with a double leaf swing bridge that can rotate completely out of the way. Each leaf is 450 ft from end to end and the bridge  provides about 350 ft  of channel clearance.


The tower that controls the bridge can be seen on the right side of the photo. Each leaf rests on a 103 inch diameter steel piston. To move the bridge the operator disengages locks that hold the two leafs in place, turns on a pump that raises the two pistons on hydraulic fluid, and then activates two arms that turn the leaves in opposite directions. That was the case until after the 2001 earthquake when one piston was found to be damaged. The City of Seattle had more pistons sitting on the site and replaced the damaged cylinder in a few days. Eventually KPFF, who acted as a sub-consultant to URS, designed a new cylinder that was less likely to suffer fatigue.


A concrete swing bridge is an innovative idea and this attractive bridge won a number of awards.

Movable Bridges - Spokane Street Bridge (2) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Movable Bridges - Spokane Street Swing Bridge

This is our second look at these bridges (first shown in my May 20, 2009 blog). This is a more detailed examination of the lower, double leaf swing bridge that crosses the Duwamish River and carries traffic between Harbor Island and West Seattle.

I find it strange that the two leafs can swing past each other without touching. The two (7500 ton) leafs are supported on hydraulic cylinders that lift them up an inch and then swing them out of the way. The operation is performed eight times a day and takes ten minutes.

I'm standing in the control tower where a bridge operator moves the bridge. I was there to inspect bridge damage after the 2001 Nisqually earthquake. However, it was never clear whether one of the cylinders became damaged from the earthquake or because of the strain of lifting such a heavy structure. The bridge was quickly repaired and put back in service. We'll take another look at this structure tomorrow.

Movable Bridges - Spokane Street Swing Bridge by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Oregon's Bridges: Siuslaw River Bridge

Continuing south along the Oregon coast is the city of Florence and the Siuslaw River Bridge. This is one of Conde McCullough's most ornate creations. A 140 ft long steel, bascule bridge was built between two 154 ft reinforced concrete bow string arches, which are connected to 20 concrete girder approach spans. Among the decorative features on this bridge are obelisks that support the movable span, pylons at the far ends of the arch spans, an ornamental railing, arch shaped two-column piers, X-bracing connecting the arch ribs, and haunched girders on the approach spans.

The Siuslaw Bridge has a total length of 1568 ft and it was built in 1936 by the Mercer-Fraser Company of Eureka, California. The bridge would be at the mouth of the Siuslaw River except there is a giant sandbar that makes it flow another four miles before it finds the Pacific. The city of Florence is on the north side of the river and has a population of about 8000 people. The economy used to be based on logging and fishing but now its mostly supported by tourism and by retired people moving into the area. Perhaps the movable bridge span was to allow the passage of boats loaded with timber from Oregon's interior.

We can see timber piles sticking out the river where a dock once stood. The river was crossed by a ferry before the bridge was built.

Oregon's Bridges: Siuslaw River Bridge by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Portland's Bridges: Morrison Bridge (2)

One more look downstream at the Morrison Bridge from the deck of the Hawthorne Bridge. The side spans are deck trusses and the approach spans are steel girders. As I mentioned, there are several ramps and connectors that carry vehicles from streets and expressways on and off this bridge. Like the other movable (non-railroad) Willamette River crossings, this bridge is owned by Multnomah County.

The bascule span is usually opened once a day, which is fortunate since the roadway is so heavily traveled. There's about 69 ft of vertical clearance with the bridge closed. The machinery that performs this operation was manufactured by Northwest Marine and Iron Works of Portland and installed in 1957 by US Steel.

It seems like movable bridges aren't built as often anymore, although some unusual movable footbridges have been built lately. Most bridge owners aren't willing to invest in the much higher operating and maintenance costs. The alternative would be long retaining walls or approach spans to lift the crossing high above the water. I'm not sure whether retaining walls or approach spans would be more expensive. It probably varies from place to place. Still, an approach span would be required whenever there are streets that must be crossed over.

As I've previously mentioned, bridge building is a dangerous occupation. Construction of the Morrison Bridge took the life of a Mr. Davies when he was buried by a slide while checking footing reinforcement.

Portland's Bridges: Morrison Bridge (2) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Portland's Bridges: Morrison Bridge

There have been three Morrison Bridges at this location. The first bridge was designed and built by Charles Swigert of the Pacific Bridge Company in 1887. It was a timber truss bridge with a steel swing span and it was the first bridge in Portland across the Willamette River. It survived the flood of 1894 which rose to the bridge's deck and damaged the motor and railing. It was replaced with a wrought iron and steel swing bridge in 1905. It had a timber deck and carried street cars but no automobiles.

The current Morrison Bridge was built in 1958 at a cost of $13 million. It included an elaborate interchange with ramps for the I-5 and the I-84 expressways. It's a double leaf bascule bridge, similar in appearance to the Burnside Bridge, but with an airport motif instead of medieval battlements. It was designed by Sverdrup of St. Louis and by Moffat and Nichol of Portland and built by the American Bridge Division of US Steel.

Large cofferdams were build for the two main piers. While the east cofferdam was being de-watered, several struts buckled from the increased stress but adjacent struts prevented collapse of the cofferdam. While the new bridge was being built, the east side of the existing bridge was moved to the south and continued carrying traffic. Because the second bridge was kept in service, the west side of the third bridge doesn't connect to Morrison Street.

The third Morrison bridge is 760 ft long, 90 ft wide, and with a  284 ft long double leaf bascule span. The deck of the bascule span was made of grated steel to reduce its weight. The bridge is the largest machine in Oregon with 36 ft tall gears driving the 940 US ton counterweights inside each pier. It carries 50,000 vehicles a day as well as bicycle and pedestrian traffic. Its scheduled for a seismic upgrade in the near future.

Portland's Bridges: Morrison Bridge by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Portland's Bridges: Burnside, Morrison, and Hawthorne Bridges

This photo was taken from the Oregon Health and Science University (OHSU) on a hill west of the Willamette River. You take the Portland Tram up to the University Hospital.  I wondered how they handled emergencies, especially if the tram were to lose power, but apparently they have adequate back-up systems. In the foreground are three moveable bridges and above the horizon is Mount St. Helens, which was cone shaped before it erupted in 1980.

We studied the Burnside Bascule Bridge yesterday. The Morrison Bridge is also a bascule bridge, which means the center leaf spans meet at midspan and swing up and down with the help of motors and counterweights (behind the pivot point). The Hawthorne Bridge is the oldest vertical lift bridge still in operation in the United States. We will take a closer look at these two bridges in the next few days.

Portland's Bridges: Burnside, Morrison, and Hawthorne Bridges by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Portland's Bridges: Steel Bridge

The Steel Bridge (over the Willamette River in Portland, Oregon) is a very unusual 'telescoping lift bridge' that can raise its lower deck without disturbing traffic on its upper deck and it can raise both decks to allow for the passage of large vessels. In the closed position it provides about 26 ft of vertical clearance. With the lower deck raised it provides 72 ft of vertical clearance. With both decks raised it provides 162 ft of vertical clearance. It has independent counterweights to lift each span.

The Steel Bridge is also unusual for the variety of vehicles that it can accommodate on its two decks. In this photo we can see a light rail train traveling on the upper deck while three diesel locomotives are crossing on the lower deck. The average daily traffic includes 23000 trucks, buses, cars, and motorcycles, 200 light rail trains and trolleys, 40 freight and Amtrak trains, over 2000 bicycles, and uncounted pedestrians. It carries railroad, pedestrian, and bicycle traffic on the lower deck and highway, light rail, and streetcar traffic on its upper deck.

The Steel Bridge was designed by Waddel and Harrington (consultants from Kansas City) with support from the Oregon Railway and Navigation Company and the Union Pacific Railroad. The two railroad companies also built the bridge, which was completed in 1912. It replaced the previous Steel Bridge from 1888 that was so named because it had replaced an even earlier wrought iron bridge.

The Steel Bridge is composed of a 290 ft long steel Pratt truss on each side of the 211 ft long lift span. The superstructure is supported on short concrete piers on caisson foundations. Wikipedia has a nice website for this bridge that includes several drawings of the structure and the lift mechanism.

Portland's Bridges: Steel Bridge by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Portland's Bridges: Broadway Bridge

About half a mile upstream from the Fremont Bridge (across the Willamette River) is the Broadway Bridge. It is an unusual Rall-type bascule bridge, which was chosen as the low bidder in a competition. However, the complex mechanism (it rolls back on rails as it lifts) has required frequent repairs and has been more expensive in the long run.

The bridge was designed by Ralph Modjeski and built by the Pennsylvania Steel Company over two years at a cost of $1.6 million. It had the world's longest double leaf bascule span when it was completed in 1913.

The main piers are reinforced concrete faced and topped with granite. The approach piers are 12 ft diameter concrete-filled steel pipes tied together with cross-bracing. A 278 ft double-leaf bascule span is supported on the main piers and crosses over the shipping channel. It provides 70 ft vertical clearance when closed and is opened about once a day. An operator's house is above each of the main piers (on the other side of the bridge). The approach spans are steel, camelback trusses. A reinforced concrete ramp on the west side goes over Union Station and carries traffic on and off the bridge. A similar ramp on the east side goes over Highway 99 and light rail tracks.

The bridge is 1742 ft long and 70 ft wide. It has two lanes of traffic in each direction and two broad sidewalks. It carries about 2700 vehicles and 1200 bicycles a day. It has been frequently repaired and renovated over the years. The concrete deck was replaced with a steel grating in 1948 to make it easier to lift. The steel deck was replaced with a fiber-reiforced composite material in 2005.

I'll just mention that Portland, Oregon is a very nice, attractive city with a very efficient transportation system. The area around the Willamette River is particularly pleasant and attracts large crowds on the weekends.

Portland's Bridges: Broadway Bridge by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

New York City's Bridges: Broadway Bridge

The Broadway Bridge crosses over the Harlem River Ship Canal, which connects the Harlem River to the east with the Hudson River to the west. The bridge has a double deck with four traffic lanes and two sidewalks on the bottom and three sets of subway tracks on the top. The bridge provides 304 ft of horizontal clearance through the canal, 136 ft of vertical clearance when the bridge is open, and 24 ft of vertical clearance when the bridge is closed.

The current lift bridge was opened to subways in 1960, to vehicular traffic in 1962, but it couldn't be raised until 1964. Apparently, the need for tall vessels to navigate the Harlem River isn't very acute. I read that they only allow one bridge to open at a time, and during the summer several of the bridges have difficulty opening due to thermal expansion of the decks. One would need a very compelling reason (and a great deal of patience) to take a ship taller than 24 ft any distance along the river.

New York City's Bridges: Broadway Bridge by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

New York City's Bridges: University Heights Bridge

Another swing bridge. This structure started it's life upstream in 1895 as the Broadway Bridge and was moved to University Heights (West 207th Street) in 1906. The swing span was eventually replaced in 1992. This bridge connects the University Heights section of the Bronx with the Inwood section of Manhattan. It is another highly ornamented bridge designed by Alfred P. Boller.

Gustav Linderhal, the newly elected chief bridge commissioner, wanted a lift bridge at this location, but the other commissioners were leery of the expense. A lift bridge was a new concept at the beginning of the last century. It really is a better idea since ships were routinely smashing into the pivot pier of the Harlem River swing bridges. A lift bridge would give these ships much greater horizontal clearance. However, the city jumped at the chance of using the discarded swing span of the Broadway Bridge instead.

New York City's Bridges: University Heights Bridge by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

New York City's Bridges: Macombs Dam Bridge

This bridge's name derives from an earlier bridge and dam that Alexander Macomb (a farmer and landowner) built on this site in 1814. The current bridge was designed by Alfred P Boller and it was completed in 1895. The main span is 412 ft long over two 150 ft wide channels. Thus, it is the biggest of Boller's Harlem River swing bridges and it's considered the most attractive of his Gothic Revival designs. Like his other bridges, the Macombs Dam Bridge consists of an oddly-shaped through truss due to the tower above the center pier. It was recently rehabilitated (as shown in photo) with new trusses, a new deck, and a new motor. In fact plans have also begun to retrofit this bridge to resist an earthquake that is likely to occur in the area.

As usual, much more information on this bridge is available from New York City Roads.

New York City's Bridges: Macombs Dam Bridge by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

New York City's Bridges: 145th Street Bridge

Another Alfred P. Boller swing bridge very much like his Madison Avenue and Macombs Dam Bridges over the Harlem River. The 145th Street Bridge was built between 1901 and 1905 with a 300 ft long swing span. A great deal of information about this bridge is provided online by the City of New York Roads.

On a modern swing bridge, the center span is supported on a piston that is lifted up by hydraulics and then swung around with an arm (there are also locking devices at the ends of the swing span). The machinery that drives these early 20th century swing bridges are similar. As a bridge engineer, I rely on a mechanical engineer to design this machinery, although I suppose there may be some engineers who can design a movable bridge on their own. The operation of these bridges also relies on the Coast Guard who maintain the safety of waterways as well as with municipal authorities who periodically inspect the bridge (and the bridge operator). Thus, a movable bridge is a kind of hybrid which requires close cooperation between many different disciplines.

New York City's Bridges: 145th Street Bridge by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.