1872 or 1874 (
Bridge Hunter, no Historic Bridges, lost)
1887 (
Bridge Hunter,
HAER, no Historic Bridges, lost)
1916 (
Bridge Hunter, no Historic Bridges,
3D Satellite)
The bottom chord was fifty-feet above high water, which allowed steamboats to pass under it. Each pier column was made with cast iron 8.5' diameter sections that were 10' high. Some columns went down 82' below low water to reach bedrock. The cylinders where filled with masonry laid in hydraulic mortar and cross braced. Most members in the truss spans were made with wrought iron. Those members that were strictly in compression were made with cast iron. Each span was 250' long. The bridge cost $2,000,000. [
English American Bridges] The present-day value of $2m is $44,400,000. [
MeasuringWorth]
I have always heard of the driving of the golden spike at Promontory in 1869 as the completion of a transcontinental railroad. But I see the transcontinental railroad was really not completed until this bridge was finished a few years later. (During the first year of transcontinental service, 1869, passengers from the East arrived in Chicago on the Michigan Central, but by the mid-1870's they had their choice of connections from the Pennsylvania, Erie, or New York Central. The trip took 8-10 days and some people took it simply for the adventure. To get to Omaha, the passenger had the choice of a direct route with the C&NW or Rock Island or an indirect route with the CB&Q. Until the bridge was built, the passengers had to use a ferry boat. But even after the bridge was built, passenger rail cars did not use it. The passengers had to struggle with ground transportation to make their connection just as they had to in Chicago. [
AmericanHeritage]
Note that the 1887 bridge (below) was made with more typical solid masonry piers down to bedrock and with steel Whipple trusses. It was double-track. The longest span was 246'. Ralph Modjeski was the Assistant Engineer.
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Photo from HAER NEB,28-OMAH,4--1 from ne0056
Photocopy of photograph, original negative in the possession of John R. Morison, Peterborough, New Hampshire. Photographer unknown, circa 1887. SOUTH WEB AND WEST PORTAL OF BRIDGE - Omaha Bridge, Spanning Missouri River, Omaha, Douglas County, NE
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The superstructure became too small and weak to handle the growing size and weight of locomotives and freight cars. But the piers were still more than adequate for the new traffic loads. To avoid disrupting traffic, they built temporary wood piers on both sides of the permanent piers. Then they built the new spans on the downstream (South) temporary piers. They also had to build falsework under the new spans because back then trusses were built in place. (Now trusses are built on the shore and floated into place.)
In one day, they winched the old spans onto the upstream piers and winched the new spans onto the permanent piers.
Five hoisting engines were used so that the spans were winched in unison. The spans were moved in about 15 minutes. Much of the outage between 11:00am and 9:40pm was spent jacking up the approach spans two feet to meet the deck height of the new spans. A travelling crane on the top cord of the new spans was then used to dismantle the old spans. "The operation will be carried on without the use of false work by cantilevering from the new bridge." [
Railway Review..., Volume 60]
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