9/24/12

BRIDGES: Across the Gila River at the Gillespie Dam


What is it about bridges? There's something wonderful about them no matter the size.

I can remember crossing a tiny bridge in England that had a toll keeper. The problem was that the bridge was so small the backend of the car was almost still on the other side when the front was almost off the bridge. I still wonder if the guy built the bridge himself and was just pulling a fast one.

Then there's the Golden Gate bridge. A stunning bridge with magnificent views. However, more than once as I've crossed it I've suddenly had the passing thought of, "Oh geez, what if the big one hits right now?" You can't live in California without occasionally wondering if the next moment is IT. I hope to not be on any of the bridges when it happens.




Click on either image to see them larger.

This bridge in Arizona has an interesting history. The post card is from the 1920s. The following is from a marker placed at the dam.
In 1909, Arizona's Territorial Legislature created the Office of the Territorial Engineer to develop a system of roads connecting Arizona's major cities and towns and improve the delivery of the US Mail. The automobile was steadily gaining in popularity and rutted, dirt wagon roads were no longer suitable for this new means of transportation. Shortly after Arizona Statehood in 1912, the State Engineer surveyed a major East-West transportation route across Southern Arizona between the towns of Clifton and Yuma. This early highway route followed the Gila River west from Phoenix, turning south near the small town of Arlington where the Hassayampa River and Gila River meet. The original highway route then turned westerly through the then popular hot spring resort town of Agua Caliente and forded the Gila River near the town of Dome until 1915, when a bridged crossing was constructed further upstream at Antelope Hill. This highway route, however, proved to be unreliable due to frequent washouts during heavy rains and flooding.

In 1921, the highway route was realigned to ford the Gila River just below the newly constructed Gillespie Dam. Heading south toward Gila Bend, the new route was known as the Phoenix-Yuma Highway. The following year, the Arizona Highway Department built a concrete apron on the downstream side of the Gillespie Dam to help automobiles to cross the Gila River. This crossing point also provide to be unreliable, as high water often made passage difficult. Between 1922 and 1926, large trucks, tractors and horse teams were frequently used to pull automobiles across the apron of the dam.

The Arizona Highway Department set about designing an all-weather bridged structure in 1925 to span the Gila River at this location. Construction of the Gillespie Dam Bridge began in February 1926 and later that same year, the American Association of State Highway Officials adopted our present day highway numbering system. When the new Gillespie Dam Bridge opened to traffic on August 1, 1927, it was officially designated part of the early southern continental US 80 Highway.

Lee Moor Construction of El Paso, Texas built the nine-span steel truss bridged crossing of the Gila River for a cost of $320,000. The 1,662-foot-long Gillespie Dam Bridge was unique for its time and one of the longest bridges and the largest steel structure in the state. All of Arizona's major bridges before this were built using reinforced concrete arches which proved to be no match for swollen, flooding rivers. The new design produced a more durable and flexible bridge that could better withstand the force of flood waters.

Bridge design elements include a connected series of rigid through trusses weighing 2.3 million pounds. The bridge has a total of nine steel truss spans - five 200-foot-long trusses centered over the river channel, flanked by two 160-foot-long trusses at each end. Each steel truss features a camelback web configuration with a built-up box beam for the upper and lower steel members. The trusses are supported by solid concrete abutments and pier columns placed on bedrock at a depth of 25 feet, with the deepest pier extending 43 feet below the riverbed.

The new bridge and US 80 Highway through the Arlington Valley became part of the National "Ocean-to-Ocean Highway". Gillespie Dam Bridge carried US 80 transcontinental traffic from 1927 to 1956, when US 80 Highway was shifted east to Rainbow Valley and the Arlington Valley stretch was decommissioned as an interstate route. The operation, care and ownership of the bridge were then transferred from the State of Arizona to Maricopa County. (SOURCE: HMdb.org)
To read more visit The Historical Marker Database.

When you traveled this road there was no fancy motel awaiting you. There was no nauseating fast food joint with corporate ownership. There might be a flea bag and a greasy spoon somewhere down the road. Travel was an adventure and a bumpy ride was had by all.

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