On July 20, 1934 construction began on a bridge across the Sacramento River to connect Sacramento, the state capital of California (which is in Sacramento County) with the city of West Sacramento (which is in Yolo County).
Why build a new bridge?
The new bridge was built to replace the M Street Bridge, which was built in 1911 and was a swing-through truss railroad bridge owned by the Sacramento Northern Railway.
The M Street bridge had a superstructure composed of triangular units known as trusses, and could be rotated horizontally to allow the passage of maritime traffic on the Sacramento River below. The M Street Bridge was later modified to also allow motor vehicles to travel across it. Nine-foot roadway sections were added as cantilevered sections on both sides of the existing rail bridge.
Sacramento’s population more than doubled between 1910 and 1935, and by the early 1930s, the M Street Bridge was inadequate for the ever-growing volume of automotive traffic. In 1933, the city realized that it needed a better crossing over the Sacramento River.
Beginning on December 22, 1933, the State of California, Sacramento County, and the Sacramento Northern Railway held meetings to plan the new bridge. An agreement was reached among the parties on March 8, 1934. Under the terms of that agreement, Sacramento Northern Railway gave up its rights to the M Street Bridge in return for the rights to rail traffic over the new bridge until March 21, 1960 (the original expiration date of its franchise to operate rail traffic over the M Street bridge).
The design of the new bridge
The new bridge was designed as a span-driven vertical lift bridge. This bridge type is movable – designed for areas through which large ships travel on a regular basis. A vertical lift bridge’s span can be elevated vertically while remaining parallel with the structure’s deck.
The bridge’s towers are 160 feet high. From east to west, the bridge consists of a 30-foot-long girder span, a 167-foot long eastern truss approach span, a central lift span that is 209 feet long, a 193-foot-long western approach span and four 34-foot-long girder spans. With the draw up, there is “100 feet of vertical clearance above high water with a 172-foot-wide navigation channel between the timber pier fenders.” The bridge’s lift span weighs 1,040 tons; however, the use of an equal amount of counterweights (which are located in each tower) allows the span to be operated with two relatively small 100-horsepower electric motors.
The bridge was initially designed with a 52-feet wide roadway with sidewalks, with single lanes for vehicles that flanked the 13-foot center lane for rail traffic.
According to Historicbridges.org, the bridge is among the most beautiful and unique vertical lift bridges to be found. However, that has more to do with the bridge’s appearance rather than its design.
What makes the Tower Bridge unique is that it was designed under the guidance and supervision of architect Alfred Eichler. He developed the bridge’s appearance, which bridge engineers then designed. “The effect of having an architect guiding the design process is strikingly obvious with this bridge’s unique and pleasing appearance, that has a strong Streamline Moderne influence, which is a form of Art Deco.”
Eichler’s design elements included completely hiding the bracing on the tower posts by using decorative solid metal panels. These panels also hide the counterweight and the counter chains. According to Historic Bridges, “the faces of the towers have an ‘x-bracing’ that functions” similarly to many other lift bridges, “but has been carefully designed so that from the exterior, a flat surface is visible, hiding the flanges and webs of the actual bracing. The top of the tower face has vertical openings. The very tops of the tower are capped with steel that hides most of the sheaves and matches up with the other covers on the towers.” The bridge’s tender house “also doubles as the machinery room” and “is a low-lying structure with a decorative cupola,” positioned on top of the lift span. “The lift span and approach truss spans are distinguished by a minimalized use of lattice and v-lacing, likely an attempt to maintain the clean, streamlined appearance found in the towers. The other key distinguishing feature in the trusses is the portal and sway bracing that is a unique arched design. Original ornate riveted lighting is present on the bridge. The approaches to the bridge have two pairs of concrete pillars, with the outermost pair bearing a casting of ‘1935’ at the top.”
As noted above, the bridge is a rare use of Streamline Moderne architectural styling in a lift bridge. The Streamline Moderne architectural style adds a sleek appearance to an otherwise utilitarian design, and is characterized by such features as curving forms and long horizontal lines. The Tower Bridge is a rare example of this style used on a bridge; this style was more commonly used in buildings and on vehicles.
This makes it “an outstanding expression of the social and architectural climate of the period of construction.” The American Institute of Steel Construction gave the Tower Bridge an honorable mention for its Class B prize bridge award in 1935.
The Tower Bridge is often compared to the much longer Golden Gate Bridge. Both bridges have towers whose bracing is covered up and/or carefully designed to maintain the Art Deco appearance. Although the Tower Bridge was constructed of steel, in keeping with its Streamline Moderne styling, it was originally painted silver to represent aluminum.
Opening of the bridge and its dedication ceremony
Construction of the bridge began on July 20, 1934 and it was finished less than 18 months later. On November 7, 1935 the first train crossed the Tower Bridge. On Sunday, December 15, 1935, California Governor Frank F. Merriam dedicated the bridge, and used his car to lead the inaugural parade across it.
The California Department of Highways and Public Works magazine reported, “As the radiator of his automobile broke the ribbon stretched across the eastern bridge entrance, the siren on the central towers announced the opening of the structure to traffic and factory whistles throughout the city, automobile horns and sirens on river craft joined in the chorus.” Concurrently, 1,000 homing pigeons were released at the site to fly throughout California with messages about the opening of the bridge.
Tower Bridge’s roadway leads directly to the State Capitol building. This may account for the effort to build an aesthetically pleasing bridge. The bridge was formally accepted by the state on January 11, 1936. Therefore, Tower Bridge was the first vertical lift bridge in California’s highway system.
The bridge’s railroad tracks
The bridge’s railroad tracks were removed in 1963. Following their removal, the roadway was renovated to four lanes of automotive traffic.
Because of the nearby railroad tracks, the bridge’s east grade crossing is designed as a secondary barrier to exclude vehicular traffic while the bridge is raised. When the warning siren sounds, the crossing activates, blocking traffic until the bridge is safe for use.
From 1963 until 2007, the bridge was used for pedestrian and vehicle traffic only. In 2007, the area’s regional transportation agencies considered adding trolley traffic across the bridge. However, no action was taken until 2020, when those plans were changed. On September 15, 2020 the board of directors of the Sacramento Regional Transit District voted in favor of using Tower Bridge to extend the light rail system to provide service to West Sacramento.
The bridge’s designation
For many years Tower Bridge was both a major link for U.S. Highway 40 traffic and the main gateway to Sacramento.
When U.S. Route 40 was truncated east of Salt Lake City, Utah, the bridge became part of California State Route 275. It is maintained by the California Department of Transportation. At 738 feet long, it is the shortest state highway in California.
The bridge connects West Capitol Avenue and Tower Bridge Gateway in West Sacramento with the Capitol Mall in Sacramento.
In 1982, Tower Bridge was added to the National Register of Historic Places.
The bridge’s paint job
From its opening in 1935 until 1976, the bridge was painted with a silver aluminum paint under a special work order. During that time, some people complained about glare from the bridge. Initially, the bridge’s concrete pylons were painted a sky-blue color.
As part of the state’s projects to acknowledge the bicentennial of the United States, Tower Bridge was painted a yellow-ochre color to match the gold-leafed cupola on the nearby State Capitol.
Some 25 years later – in 2001– the paint job was in poor condition. Residents who lived within 35 miles of the capital were eligible to vote on a new color scheme. Their choices included all-gold; green, gold and silver; or burgundy, silver and gold. The winning choice was all-gold, and the bridge was repainted in 2002. The new paint job is expected to last 30 years.
According to Historicbridges.org, the gold “suits the impressive landmark appearance of the bridge quite well.” Meanwhile, the concrete pillars on the bridge’s approaches (which as noted above were originally painted sky-blue) are now the color of plain concrete.
FreightWaves Classics thanks Historicbridges.org, bridgehunter.com and Wikipedia for information that was used in this article.