Cincinnati Southern Bridge

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Coordinates: 39 ° 5 ′ 53 ″  N , 84 ° 32 ′ 31 ″  W.

Cincinnati Southern Bridge
Cincinnati Southern Bridge
use Railway bridge
Crossing of Ohio River
place Cincinnati ( Ohio ) and
Ludlow (Kentucky)
Entertained by Norfolk Southern Railway
( Cincinnati, New Orleans and Texas Pacific Railway )
construction Truss bridge
overall length 988 m
Longest span 157 m
Clear height 31 m (low water)
12 m (high water)
opening 1877, 1922
planner JH Linville (1870)
Ralph Modjeski (1922)
location
Cincinnati Southern Bridge (USA)
Cincinnati Southern Bridge

The Cincinnati Southern Bridge is a double-track railroad bridge over the Ohio River between Cincinnati , Ohio and Ludlow , Kentucky . It goes back to one of the first bridges over the Ohio, which was built by the city of Cincinnati until 1877 as part of the Cincinnati Southern Railway . With the increase in rail traffic at the beginning of the 20th century, the single - track truss bridge made of wrought iron reached its load limit. The bridge construction engineer Ralph Modjeski provided the bridge with a new double-track superstructure in 1921–1922 , for which he had the existing bridge piers reinforced and the new steel structure erected around the old trusses while operations continued . The old swing bridge over the shipping channel was replaced by a lift bridge, the lifting mechanism of which is no longer available today. The railway line from the city of Cincinnati to Chattanooga , Tennessee , including the bridge, has been leased to the Cincinnati, New Orleans and Texas Pacific Railway since 1881 , a subsidiary and part of an important north-south connection of the Norfolk Southern Railway .

history

First bridge in 1877

With the expansion of the railroad companies in North America in the second half of the 19th century, transportation on the southern trade routes along the great Ohio and Mississippi rivers increasingly shifted to rail. In addition, the fear of competition in trade with the south through Louisville , 160 km away , grew in Cincinnati , where the first railway bridge was built over the Ohio in Kentucky from 1867 . Businessmen from Cincinnati therefore forced the construction of their own railway line, which should run south to Chattanooga in Tennessee , about 540 km away . The city decided in 1869 to finance it by issuing a municipal loan , after which the Cincinnati Southern Railway could be completed by 1880. The route required the construction of 27 tunnels and 105 bridges. The two largest projects were the High Bridge over the Kentucky River and the bridge over the Ohio River in south Cincinnati, both of which were built by 1877.

and display information about the image
The first bridge over the Ohio of the Cincinnati Southern Railway from 1877. The largest Whipple truss next to the swing bridge (left) was the longest single-span girder in the USA at the time (picture from 1883)

The truss bridge designed by JH Linville in Cincinnati consisted largely of parallel- belted Whipple trusses with an underlying track (English whipple truss , after its inventor Squire Whipple , 1804-1888), the largest with a span of 157 meters, the longest single-span girder in the USA was. The wrought iron superstructure rested on sandstone pillars that rose more than 30 meters from the water at low tide . A 113-meter-long swing bridge was integrated on the Kentucky side to enable steamships with their high chimneys to pass through during floods .

The city of Cincinnati leased the Cincinnati Southern Railway in September 1881 until 1901 to the Cincinnati, New Orleans and Texas Pacific Railway , which at that time belonged to the railway empire of Frédéric Emile Baron d'Erlanger and became part of the Southern Railway in 1894 . The lease contract was extended to 1966 in 1901 and, after renewed negotiations, extended to 2026 in 1928.

Second bridge in 1922

Construction of the new steel girders in 1921 with the help of derrick cranes above the new superstructure

With the growing rail traffic at the beginning of the 20th century and the steady increase in the weight of the steam locomotives and the freight transported, the bridge from the 1870s reached its load limit. In addition, marshalling yards were built at the approaches to the bridge in Cincinnati and in Ludlow , which were connected by the bridge. The Southern Railway decided with the city of Cincinnati to build a new double-track superstructure and hired the steel bridge specialist Ralph Modjeski , who built the world's largest cantilever bridge with the construction of the Québec Bridge in 1919 . Modjeski designed a steel truss bridge that was built between 1921 and 1922 by the American Bridge Company around the old superstructure with ongoing operations. The bridge piers had to be reinforced for this purpose, for which additional steel girders were attached in the upper area, which were encased with concrete. In order to be able to dispense with additional scaffolding in the river bed in the center during construction, Modjeski decided to use a continuous girder over the river instead of the three individual trusses , which could largely be erected using cantilever structures. For this purpose, derrick cranes were used , which were installed on the top chords of the new girders. The old swing bridge was replaced by a lift bridge of the same length , which only had a lifting height of 4 m and was operated by a combination of counterweights and hydraulic cylinders . It was rarely used and is no longer functional today. The pillar of the old swing bridge was not removed at the time and is still under the lift bridge.

Expansion and reconstruction of the adjacent railway systems

Construction of the Cincinnati Union Terminal just behind the bridge in 1932
The Cincinnati Southern Railway (blue) is now part of the Norfolk Southern Railway (red) route network

By 1933, Cincinnati's largest passenger station was built in the north immediately behind the bridge. The Cincinnati Union Terminal was designed for a daily capacity of 216 trains, most of which reached the station from the south via the Cincinnati Southern Bridge . The sharp decline in passenger traffic led to the closure of the station in the early 1970s, the terminal hall was placed under monument protection in 1977 and has served as a museum since 1990. In 1982 the Southern Railway merged with the Norfolk and Western Railway to form the Norfolk Southern Corporation , which in 1990 became the Norfolk Southern Railway (NS). The NS thereby became the owner of the Cincinnati, New Orleans and Texas Pacific Railway and contract partner of the city of Cincinnati in the lease of the Cincinnati Southern Railway running until 2026. In 1987 the city negotiated new terms of the contract with Norfolk Southern, which improved the city's revenue. This amounted in 2017 to around 21.8 million  US dollars and amounted in 1987 to a total of about $ 500 million. To date, the Cincinnati Southern Railway is the only municipal railroad company of this size in the United States.

Marshalling yards behind the bridge in Cincinnati 2013 (Gest Street Yard in front, Queensgate Yard to the left and behind )

The bridge, together with the upstream C&O Railroad Bridge, has served since the 1980s as the southern access to the NS (Gest Street Yard) and CSX ( Queensgate Yard ) marshalling yards , which today extend over the area of ​​the former railway tracks of the passenger station and each with it are equipped with a container terminal . On the Kentucky side, another smaller NS marshalling yard joins the truss bridge in Ludlow, the origins of which go back to the 1870s and which was expanded into a depot with a locomotive shed at the turn of the century . With the end of the era of steam locomotives in the early 1950s, the facilities were largely shut down. Traffic over the Cincinnati Southern Bridge was about 30 trains a day in 2002.

description

Main bridge

The altogether 988 m long structure has a central truss bridge over the Ohio, which is divided into three single parallel girders . Starting at the abutment on the Kentucky side, these are a smaller 33 m long girder with overhead tracks, the 133 m long girder of the former lift bridge and a 340 m long continuous girder that extends over four river piers and spans of about 157 m and two times 90 m forms. The two large girders lead the track level on their lower chords and are designed as stud frameworks. In order to achieve a higher load-bearing capacity, additional posts and additional longitudinal and transverse struts were integrated in the lower area, which means that the framework fields are further subdivided and reinforced (Baltimore truss) . The lattice girders are 10 m wide with a construction height of 21 m (dimensions between the central axes of the belts), the continuous girder weighs 3550 t and the single-span girder of the former lifting bridge 1135 t; including the access roads, the total amount of steel used was over 7400 t.

The superstructure had a cantilevered walkway on the west side until well into the 21st century, but this was closed in the 1970s and finally removed in the early 2010s.

  • The continuous girder over three bridge fields in 1987, the footpath on the west side still exists

  • Schematic drawing of the bridge from 1922 with the new and the old superstructure from 1877, information in the Anglo-American units feet (′) and inches (″), Cincinnati on the left

  • The Cincinnati Southern Bridge over the Ohio 2005, Cincinnati on the right

Driveways

On the Kentucky side, the small NS marshalling yard in Ludlow is directly connected to the truss bridge. On the Ohio side in Cincinnati, the main bridge is followed over a length of over 500 m by a multitude of girder bridges made of solid wall girders , which here form a slight S-curve, cross several streets and tracks and branch off at the end. The configuration has been changed several times over the years with the expansion and renovation of the crossing and subsequent infrastructure. Since the two-track expansion in 1922, the tracks have mainly been guided on separate beam girders, some of which still rest on the pillars from 1877, which were widened in the 1920s; recognizable by their division into two parts made of bricked sandstone and concrete. Behind Eighth Street West are the abutments, where two tracks each lead into the Gest Street Yard of the NS and the larger Queensgate Yard of the CSX .

Bridge piers

Piers Cincinnati Southern Bridge 1922.jpg
Piers Cincinnati Southern Bridge Details.png
Piers Cincinnati Southern Bridge 1987.jpg


Conversion of the river pillars for the double-track superstructure in 1922 (reinforcement by horizontal and vertical steel girders, the pillars on the right in 1987)

The main bridge rests on six brick sandstone pillars from 1877. The river piers were built directly on the bedrock of the river bed and have a footprint of around 8 m × 16 m, the longest reaching a height of 36 m (Pier # 4). The smaller pillars of the main bridge and the access roads following the bank were anchored in the ground using pile foundations . Since the original pillars tapered over the last ten meters, their contact area was reduced to around 4 m × 9 m. For the over 10 m wide double-track superstructure, the pillars in the upper area had to be widened and reinforced in the 1920s. For this purpose, 9 m long steel girders were attached to the outside, the pillars were then shortened by about 2 m and the vertical ones were connected with additional horizontal steel girders. The construction was then encased with concrete, creating contact areas of around 4 m × 13 m that support the bearings of the superstructure. The clear height under the truss bridge is 31 m at low tide and 12 m at high tide.

Web links

Commons : Cincinnati Southern Bridge  - collection of pictures, videos, and audio files

literature

Individual evidence

  1. ^ Charles Gilbert Hall: The Cincinnati Southern Railway: A History. The McDonald Press, Cincinnati 1902, pp. 53 f.
  2. ↑ a b c John E. Kleber (Ed.): The Kentucky Encyclopedia. 3rd edition, University Press of Kentucky, Lexington 2015, ISBN 0-8131-1772-0 , p. 191.
  3. ↑ a b c d Double-Track Spans Placed on Single-Track Piers. In: Railway Age. Vol. 72, No. 21, 1922, pp. 1215-1220.
  4. ^ FW Henrici: The New Ohio River Bridge of the Southern Railway at Cincinnati, Ohio. In: Proc. Thirty-second Annual Convention, American Railway Bridge and Building Association. Vol. 32, 1923, pp. 49-60.
  5. ^ About Union Terminal. Cincinnati Museum Center, accessed May 25, 2019.
  6. ↑ Carolyn Pitts: Cincinnati Union Terminal. National Register of Historic Places Inventory Nomination Form, United State Department of the Interior, National Park Service, 1977.
  7. ^ Board of Trustees, Cincinnati Southern Railway: Financial Statements and Additional Financial Information 2017. Clark, Schaefer, Hackett & Co., Cincinnati, Ohio 2018. Retrieved March 17, 2019.
  8. ^ Cincinnati Southern Railway. Transportation & Engineering, City of Cincinnati. Retrieved March 17, 2019.
  9. ↑ Paul A. Tenkotte, James C. Claypool: The Encyclopedia of Northern Kentucky. University Press of Kentucky, Lexington 2009, ISBN 978-0-8131-2565-7 , p. 182.
  10. ^ A b c Jacob R. Mecklenborg: Cincinnati Southern Bridge. at cincinnati-transit.net, accessed May 25, 2019.
  11. ^ Glenn A. Knoblock: Historic Iron and Steel Bridges in Maine, New Hampshire and Vermont. McFarland, Jefferson 2012, ISBN 978-0-7864-4843-2 , pp. 36 f.
  12. ^ A b The Cincinnati Bridge of the Southern Ry. In: Railway Review. Vol. 71, No. 17, 1922, pp. 555-557.
  13. ↑ Silas L. Schumo: The St. Louis Bridge and the Cincinnati Southern Railway. In: Railroad Gazette. Vol. 10, September 27, 1878, p. 467 f.
  14. ^ Test of the Cincinnati Southern Railway Bridge over the Ohio River. In: Railroad Gazette. Vol. 9, November 16, 1877, pp. 511 f.
This article was added to the list of articles worth reading on June 6, 2019 in this version .