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In late 1884, two corporations submitted a request to Congress for authorization to build a railroad bridge across the river at Memphis, Tennessee. At the time the closest bridge across the Mississippi was the Eads Bridge at St. Louis, Missouri, and that was 400 miles north of Memphis. Ten railroad lines were already entering the city from the west and east. The lines on the easterly side of the river converging on Memphis were the Louisville and Nashville (L & N), the Southern, the Nashville, Chattanooga and St. Louis, the St. Louis and San Francisco, and the Illinois Central Railroads. Across the river the largest lines entering from the west were the Kansas City, Memphis and Birmingham, the Kansas City, Ft. Scott and Memphis, the St. Louis, Iron Mountain and Southern, and the Little Rock and Memphis Railroads. Car ferries were used to carry trains across the river. An act called the “Casey Young Bridge Bill” was passed and granted the two separate private companies, the Tennessee and Arkansas Bridge Company and the Tennessee Construction and Contracting Company, right to build a bridge. The authorization was approved February 26, 1885, with the following conditions:
- The bridge is to be built with unbroken and continuous spans (in other words no swing spans).
- The length of the channel spans (two in number) is not to be less than 550 feet.
- No span shall be less than 300 feet.
- The lowest part of the superstructure shall be no less than 65 feet above extreme high water.
- And the bridge shall not at any time substantially or materially obstruct the free navigation of the river.
Once again, the Federal Government changed the horizontal and vertical clearances required to 55 feet and 65 feet. The Eads Bridge upstream required 500 feet and 50 feet clearances. The legislation did not allow for the companies to consolidate so a new company was formed, The Kansas City, Fort Scott, and Memphis Railroad Company and charted in 1887, to construct a bridge and railroad tracks over the Mississippi River from Marion, Arkansas, to Memphis, Tennessee. The three-mile line was controlled, and its mortgage guaranteed, by the Kansas City, Fort Scott, and Memphis Railroad Company. When they went back to Congress, the clearances were once again changed. The House approved HR 2927 on May 24, 1886, with amendments of July 17, 1886. They recommended two spans of 600 feet and others at 450 feet and a vertical clearance of 65 feet and sent it the Senate where a long debate took place on April 2, 1888. Some senators wanted to make the clearance 1,000 feet horizontally and up to 100 feet vertically and an official minority report of the Committee on Commerce on January 17, 1888, recommended 1,000 feet and 85 feet above extreme high water. The Mississippi River Commission had earlier recommended 1,000 feet and 75 feet clearances. The Bill, An act to authorize the construction of a bridge across the Mississippi River at Memphis, Tennessee, was finally approved on April 24, 1888 with the following requirements:
Provided, That the main channel span shall in no event be less than seven hundred feet in length, or the other spans less than six hundred feet each in length; and if the report of said officers shall be approved by the Secretary of War, the spans of said bridge shall be of the length so required. The lowest part of the superstructure of said bridge shall be at least seventy-five feet above extreme high-water mark, as understood at the point of location, and the bridge shall be at right angles to and its piers parallel with the current of the river.
George Morison was selected as Chief Engineer in 1886, and while negotiations were underway in Congress, he prepared preliminary plans based upon a site survey and borings. In February 1887 he submitted a report to the bridge company for a bridge with three 660-foot simple spans as well as a preliminary plan for a 1,300-foot cantilever span. The Act as passed also stated, “three engineer officers from the Engineers Bureau to be detailed to the duty of examining, by actual inspection, the locality where said bridge is to be built and to report what shall be the length of the main channel span and of the other spans.” The Board was split with some wanting 1000 feet and others 700 feet, but Secretary of War William Endicott wanted 770 feet. Based upon this, Morison, against his best wishes, made his easterly channel span 790 feet cantilever span with two side spans of 621 feet 6 inches and added provisions for wagons and animals.
The span lengths from east to west (Memphis on right) were:
- Anchor arm………… 255.83 feet
- Cantilever span………790.42 feet (cantilever arms 169. 38 feet, 451.66 feet suspended span)
- Anchor span………….621.00 feet
- Cantilever span………621.06 feet (cantilever arm 169. 38)
- Deck span……………338.75 feet
The 790-foot span was the longest in the United States when built.
Morison made the width, center to center, of his spans 30 feet with a depth of truss over his piers 77-feet, 7 inches with the depths of his suspended spans of 56 feet, 5 ¼ inches. The truss style was a double intersection Warren. The westerly viaduct consisted of 59 feet plate girder spans with 29.5 feet braced steel bents (three masonry bents when crossing railroads) for a total length of 2,290.6 feet and followed by a wooden trestle 3,097.5 feet long on a 1.25% grade.
Preliminary work started in late 1888 but full-scale work was not authorized until January 1, 1889. The foundations were placed using pneumatic caissons with a maximum depth of 130 feet.
The superstructure was fabricated by the Union Bridge Company under Charles Macdonald and the erection by the Baird Brothers. They had a difficult time closing the cantilever span that was described thoroughly in Morison’s A REPORT, GEORGE H. NETTLETON, PRESIDENT OF THE KANSAS CITY AND MEMPHIS RAILWAY AND BRIDGE COMPANY written in 1894. Morison was in the habit of writing similar reports on the bridges he built in the last third of the 19th century.
The bridge opened for traffic on May 12, 1892. The bridge still serves today with the westerly viaduct replaced in 2017. It now has two neighboring bridges, the Memphis and Arkansas and the Harahan Bridges. Upstream is the Hernando De Soto vehicular bridge. ■
About the Author
Dr. Frank Griggs, Dist.M. ASCE, specializes in the restoration of historic bridges, having restored many 19th Century cast and wrought iron bridges. He is now an Independent Consulting Engineer (fgriggsjr@verizon.net).
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