Harahan Bridge

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Coordinates: 35 ° 7 ′ 45 "  N , 90 ° 4 ′ 33"  W.

Harahan Bridge
Harahan Bridge
In the foreground the Harahan Bridge , behind it the Frisco Bridge and the Memphis – Arkansas Bridge
use Railway bridge and pedestrian bridge
Crossing of Mississippi River
place West Memphis , Arkansas and Memphis , Tennessee
Entertained by Union Pacific Railroad
construction Truss bridge
overall length 1497 m
Longest span 241 m
start of building 1913
opening 1916
planner Ralph Modjeski
location
Harahan Bridge (USA)
Harahan Bridge
Bigriverdtme.jpg
Panorama of the north side, which was developed as a pedestrian bridge
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The Harahan Bridge is a double-track railway bridge over the Mississippi River between West Memphis ( Arkansas ) and Memphis ( Tennessee ). It was designed as a truss bridge by Ralph Modjeski , built as a joint project of the Rock Island Line , the Iron Mountain Railway and the Cotton Belt Route , and commissioned in 1916. The bridge is now operated by the Union Pacific Railroad , in which the original railroad companies have merged. It is named after James Theodore Harahan , the first president of the company founded specifically for the construction and former president of the Illinois Central Railroad . Harahan was killed in a railroad accident in Illinois shortly before construction began on the way to Memphis .

Until the opening of the adjacent Memphis-Arkansas Bridge in 1949 which led Harahan Bridge also on their outer sides a road for motor vehicles , of which the reserved north since 2016 after a refurbishment pedestrians and cyclists, and today (2018) the longest pedestrian bridge is across the Mississippi. With the Frisco Bridge built between 1888 and 1892 , three bridges cross the river at this point.

history

planning

The single-track Frisco Bridge of the Kansas City, Fort Scott and Memphis Railroad (later St. Louis - San Francisco Railway , Frisco for short ), which went into operation in 1892 , was used by several different railway companies for connections to Memphis and provided with the increase in passenger and freight traffic at the turn of the century increasingly represented a bottleneck. To build another railway bridge over the Mississippi, the Chicago, Rock Island and Pacific Railroad (Rock Island Line) , the St. Louis, Iron Mountain and Southern Railway ( Iron Mountain Railway ) founded on January 3, 1912 , later Missouri Pacific Railroad ) and the St. Louis Southwestern Railway (Cotton Belt Route) the Arkansas & Memphis Railway Bridge and Terminal Company . In addition, there was local interest in a crossing for motor vehicles and trams . Representatives of the city and the railway companies agreed on the installation of additional brackets for carriageways on the outside of the bridge; however, the bridge construction company did not participate in the financing, construction and maintenance of the access roads and the integration of tram tracks was rejected.

Namesake

The experienced railroad manager James Theodore Harahan was elected president of the bridge construction company, who was long-time president of the Illinois Central Railroad until his retirement in 1911 . A few days after his election he was killed on January 22, 1912 with three other high-ranking representatives of the Rock Island Line on the way to Memphis in a rear-end collision between two trains in Kinmundy (Illinois) . The four passengers were asleep in their private compartment car at the end of the train in the early hours of the morning when it stopped at Kinmundy to fill up with water and was hit by a subsequent train that noticed it too late. The mostly wooden compartment car was almost completely destroyed and the stationary train was pushed 60 meters forward. In memory of James Theodore Harahan, the bridge to be built was named after him and later, Harahan (Louisiana), a suburb of New Orleans .

Drawing of the construction of the bridge

Construction of the railway bridge

The bridge construction engineer Ralph Modjeski was hired to build the bridge . He was already involved in the construction of the Frisco Bridge and designed a double - track truss bridge of a similar design, which was to be built about 60 meters upstream parallel to the existing bridge. Construction work on the bridge piers and abutments began in November 1913 by the Union Bridge and Construction Company of Kansas City, Missouri . The foundations of the bridge piers were built using caissons . On April 9, 1914, there was a serious accident on the fifth pillar of the bridge, in which nine workers lost their lives due to gas poisoning in the caisson. The first parts of the truss were in April 1915 by the Pennsylvania Steel Company of Philadelphia built. Virginia Bridge & Iron Co. from Roanoke took over the construction of the scaffolding pier viaduct on the Arkansas side . Construction work on the railway bridge was completed in June 1916, and the first train left in July. A total of 22 workers were killed during the construction of the bridge.

Road traffic and pedestrian bridge

The completion of the driveways for the outer carriageways was delayed by financing problems until September 1917. The road connection of Crittenden County in Arkansas favored the development of the region in the following years and in 1927 led to the establishment of West Memphis , whose population rose from then just under 1,000 to over 25,000 increased in 2010. The road link over the outside of the Harahan Bridge was in operation until the completion of the neighboring Memphis – Arkansas Bridge in 1949 and in the 1930s had an average traffic volume of 11,000 vehicles per day.

In 2014, the renovation of the north side of the road began, which was opened to pedestrians and cyclists in 2016 and is now part of a 15 km long cycle path between the city centers of Memphis and West Memphis. A special attraction of the expansion, known as the Big River Crossing , is a light installation with over 100,000 light-emitting diodes , with which the steel structure on the north side of the bridge can be illuminated in a variety of color sequences and patterns. In 2017, the installation was honored with the American Architecture Award , which is presented jointly by the Chicago Athenaeum Museum of Architecture and Design and the European Center for Architecture, Art, Design and Urban Studies .

description

Schematic representation from 1915 of the tannery girder of the Harahan Bridge with the two suspension girders (suspended span) , as well as the subsequent inverse truss girder (deck span) on the Arkansas side (left), the following scaffold pier viaduct is not shown (all lengths in feet )

The 1497.4 m long Harahan Bridge consists of three main parts and its construction is almost identical to the neighboring Frisco Bridge . Both steel bridges unite a Gerber beam over the river with a final at the Arkansas shore truss with overhead tracks, on to West Memphis each one frame pillars Viaduct (trestle bridge) with solid wall beams follows. More than 20,000 tons of steel were used for the bridge, of which almost 15,000 tons were used for the tannery girders , whereby a special weatherproof structural steel from Bethlehem Steel Corporation (Mayari R) was mainly used.

Lattice girders with outer brackets of the former carriageways (2012)

Main bridge

Suspension bracket between the 1st and 2nd pillar of the Frisco Bridge and the Harahan Bridge behind it (1985)

The tannery girder of the main bridge rests on the four river pillars , which are anchored in the river bed with their caisson foundations over 15 m high. At the locations of the central pillars, the river has a depth of around 20 m. There the piers have a length of 59 m up to the lower edge of the foundation. The tannery girder consists of several truss girders that are connected by joints to form movement joints . With a total length of 302.9 m, the central continuous beam is the longest connected lattice girder (fixed span) . It is located on the two middle river pillars and has a span of 189.3 m and a 56.8 m boom at each end. On the first current pillars in the east (Memphis side) rests a truss which also each have a 56.8-m-jib for abutment (anchor arm) and forms the continuous beam. The first of two 127.3 m long suspension girders (suspended span) is located between the arms of the first and second river pillar, which results in the longest span of 240.9 m. The beam is articulated with movement joints at its ends. The second suspension bracket is also mounted in an articulated manner on the boom of the third river pillar and rests fixed on the fourth river pillar, resulting in a span of 184.1 m. On the Arkansas bank, a 105.8 m long lattice girder in Warren / Camelback construction with overhead tracks (deck span) completes the main bridge.

Trestle Bridge

Trestle bridges of the Frisco Bridge and the Harahan Bridge behind , the outer lanes are covered (1985)

A 720 m long trestle bridge , consisting of 19 steel towers, on which 20 girder bridges measuring 24.4 m (between the towers) and 19 each 12.2 m (on the.) Follows over the floodplain of the Mississippi River on the Arkansas side Towers) rest. On the outside of the 10.5 m wide lattice girders of the main bridge and the towers of the Trestle Bridge, additional cantilevers are attached to accommodate a 4.3 m wide carriageway with railings on both sides, which was implemented using wooden planks on the steel structure. From the fourth pillar, the tracks run with a gradient of 1.2 percent in the direction of the abutment on the Arkansas side, but the outer carriageways have a gradient of 3 percent, for which the height of the jibs at the Trestle Bridge is steadily decreasing. An additional wooden viaduct was built for the access. A fire in September 1928 destroyed parts of the wooden structure and the decking and interrupted the motor vehicle connection for two months. This forced the construction of a new concrete viaduct, which had been planned for some time, which was inaugurated in July 1930.

literature

Web links

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

Individual evidence

  1. ^ Cotton Belt History - Memphis, TN Branch. Arkansas Railroad Museum. Retrieved August 22, 2017.
  2. ^ Martha Carver: Tennessee's Survey Report for Historic Highway Bridges. Tennessee Department of Transportation, 2008, pp. 457 f.
  3. ↑ a b c d New Mississippi River Bridge at Memphis. In: Railway Age Gazette. Vol. 61, No. 15, 1916, pp. 645-649.
  4. ^ Railway Officers Killed in Collision. In: Railway Age Gazette. Vol. 52, No. 4, 1912, pp. 142-144.
  5. ^ Martha Carver: Tennessee's Survey Report for Historic Highway Bridges. Tennessee Department of Transportation, 2008, pp. 458-460.
  6. ^ Ralph Modjeski: Harahan Bridge at Memphis, Tennessee. In: Journal of the Franklin Institute. Vol. 184, No. 5, November 1917, pp. 599-615, here pp. 599 f.
  7. ^ Martha Carver: Tennessee's Survey Report for Historic Highway Bridges. Tennessee Department of Transportation, 2008, p. 574.
  8. ^ A b Martha Carver: Tennessee's Survey Report for Historic Highway Bridges. Tennessee Department of Transportation, 2008, p. 460 f.
  9. ↑ Toby Sells: Big River Crossing opens Saturday. The Memphis Flyer, October 20, 2016. Retrieved August 18, 2017.
  10. ^ A historic bridge, transformed into a landmark. Philips Lighting Holding BV Retrieved August 20, 2017.
  11. ↑ HARAHAN BRIDGE - BIG RIVER CROSSING Memphis, Tennessee. The Chicago Athenaeum. Retrieved August 20, 2017.
  12. ↑ Big River Crossing Wins 2017 American Architecture Award. Downtown Memphis News, Downtown Memphis Commission (DMC). Retrieved August 20, 2017.
  13. ↑ MB Case: Substructure of the New “Harahan” Bridge at Memphis. In: Railway Age Gazette. Vol. 58, No. 17, 1915, pp. 877-881, here p. 877.
  14. ^ Ralph Modjeski: Harahan Bridge at Memphis, Tennessee. In: Journal of the Franklin Institute. Vol. 184, No. 5, November 1917, pp. 599-615, here pp. 601 f.
This version was added to the list of articles worth reading on October 1, 2017 .