Alton Bridge

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Coordinates: 38 ° 53 ′ 3 ″  N , 90 ° 11 ′ 5 ″  W.

Alton Bridge
Alton Bridge
The Alton Bridge from 1894, behind it the Clark Bridge of US Highway 67 from 1928 (photo from 1985)
use Railway bridge
Crossing of Mississippi River
place West Alton , Missouri
Alton , Illinois
construction Truss bridge with swing bridge
overall length 631 m
Longest span 110 m
opening 1894
planner George S. Morison
closure 1988
location
Alton Bridge (USA)
Alton Bridge

The Alton Bridge was a double-track railway bridge across the Mississippi between West Alton in Missouri and Alton in Illinois . It was north of St. Louis above the confluence of the Mississippi with the Missouri and was part of the railway network of the Chicago, Burlington and Quincy Railroad (CB&Q). In the 1880s, the CB&Q wanted to expand its network from the north to St. Louis and for this reason let the St. Clair, Madison and Belt Railway run the Alton Bridge (1894) over the Mississippi and from the St. Louis, Keokuk and North Western Railroad build the Bellefontaine Bridge (1893) over the Missouri. Both railway companies later became part of the CB&Q, which in turn merged with the Burlington Northern Railroad in 1970.

After the railway bridge, another bridge crossed the river at Alton with the first Clark Bridge from 1928. In addition, the United States Army Corps of Engineers built the first Mississippi Lock and Dam Number 26 in the immediate vicinity by 1938 . The Burlington Northern gave up the railway bridge, which was later only used as a single track, in 1988 and in the course of the construction of the Melvin Price Locks and Dam downstream , the bridges including the old barrage were later dismantled; the US Highway 67 runs in Alton since 1994 on the new Clark Bridge .

history

St. Louis and Environs route map (1910). The five railway bridges over the Missouri and Mississippi are marked , above the Alton Bridge (5) from 1894.

Access to St. Louis was only possible via two railway bridges until the 1890s; in the west over the Missouri through the Wabash Bridge from 1871 and in the east over the Mississippi through the Eads Bridge from 1874. The network of the Chicago, Burlington and Quincy Railroad (CB&Q) was from 1888 from the west over the St. Louis, Keokuk and North Western Railroad connected, which owned the route rights with the Wabash Railroad including over their bridge in Saint Charles . The high fees of the Wabash Railroad and a planned expansion of the railway facilities in St. Louis prompted the CB&Q to tackle their own access from the north via the St. Clair, Madison and Belt Railway and their own bridges. Due to the geographical location of St. Louis below the confluence of the Missouri and Mississippi rivers, both rivers had to be crossed and the CB&Q hired the bridge engineer George S. Morison to do this at the end of the decade . Morrison built the Bellefontaine Bridge for the St. Louis, Keokuk and North Western over the Missouri southwest of Alton until 1893 and a railway bridge over the Mississippi for the St. Clair, Madison and Belt Railway directly below the city until 1894 (see No. 4 and 5 in the left figure above). The smaller railway companies controlled by the CB&Q , including the bridges, were later merged into the CB&Q, which in turn became part of the Burlington Northern Railroad in 1970 (since 1995 BNSF Railway ).

The Alton Bridge was to be Morison's fifth bridge over the Mississippi, including the Merchants Bridge in St. Louis from 1890. He designed a 600-meter-long truss bridge made of steel , which he conditionally kept low through the flat river bank had what the integration of a swing bridge required. In this area, the river bed had to be laboriously dug in order to ensure a sufficiently deep shipping channel even at low tide. The delivery of the building material for the ten stone pillars began in spring 1892, but their construction and other hydraulic engineering measures could not begin until September when the river level fell. As with many of Morrison's other bridges, the Union Bridge Company was responsible for the manufacture and construction of the superstructure . In the summer of 1893 the first steel components of the trusses were delivered, which were assembled including the swing bridge by the end of March 1894; the first train passed the bridge on April 5th.

The first Mississippi crossing at Alton was in 1928, followed by a road bridge that was built downstream in the immediate vicinity of the railway bridge. The first Clark Bridge was also a truss bridge and led US Highway 67 until 1994 ; A movable bridge part could be dispensed with due to a sufficient clearance height and corresponding access roads. Between 1934 and 1938, the United States Army Corps of Engineers built the Mississippi Lock and Dam Number 26 upstream , with the locks directly in front of the swing bridge and the flow piers being integrated into the lock partition. The Burlington Northern Railroad , as the successor to the CB&Q, gave up the later single-track Alton Bridge in 1988 and in the course of the construction of the larger Melvin Price Locks and Dam about two kilometers downstream, the bridges and the old barrage were dismantled by 1994. A new cable-stayed bridge was built for US Highway 67 and was completed in 1994.

  • Construction of the Mississippi Lock and Dam Number 26 in front of the Alton Bridge swing bridge in 1935

  • Clark Bridge , Alton Bridge and Lock and Dam Number 26 shortly before their dismantling

  • Construction of the new Lock and Dam No. 26 in May 1988, the old systems and bridges in the background

  • The new Clark Bridge from 1994, view from Lock and Dam No. 26th

description

View upriver to the Alton Bridge , behind it the systems of the old barrage (photo from 1985)
Roller ring bearing with drum of the swing bridge (photo from 1985)

The main bridge consisted of six 64 m long trusses with parallel chords (English pratt truss , named after the engineer Thomas Willis Pratt, 1812–1875), to which a 110 m long truss with a curved upper chord in Parker construction (English parker truss , named after engineer Charles H. Parker, 1842-1897) in the direction of the Illinois bank, followed by a swing bridge in Parker design with an inclined top chord and a length of 137 m. The bridge with a total length of 631 m between the abutments was supported by ten stone pillars, which were anchored in the river bed by means of pile foundations .

Schematic plan of the Alton Bridge from the HAER NE-2 from 1986; Looking north, lengths in feet (′)

The truss girder of the swing bridge made up about a third of the total weight of the superstructure with 960 tons (3,560 tons) and was mounted on a drum with a diameter of 18.2 m, which rotated on a roller and cage bearing with 66 conical steel rollers (the average roller diameter was 46 cm). The round pillar of the swing bridge had a landing stage perpendicular to the bridge to protect against ship collisions, which was replaced with the construction of the barrage until 1938 by the partition wall between the main and auxiliary lock, which extended to the first pillar of the Clark Bridge .

See also

literature

Web links

Commons : Alton Bridge  - collection of images, videos and audio files

Individual evidence

  1. ^ On Certain New Work in and about St. Louis. In: Railroad Gazette. Vol. 25, December 15, 1893, pp. 899-901.
  2. ^ A b Clayton B. Fraser: Nebraska City Bridge. Historic American Engineering Record, HAER No. NE-2, Denver, Colorado 1986, pp. 305-314.
  3. ^ The History of BNSF. A legacy for the 21st century. BNSF Railway, p. 45. Retrieved April 21, 2018.
  4. ↑ Patrick W. O'Bannon: Upper Mississippi River 9-Foot Channel Project, Lock & Dam No. 26. Historic American Engineering Record, HAER No. IL-31, Denver, Colorado 1989.
  5. ^ Joe Sonderman: St. Louis: Bridges, Highways, and Roads (Images of America). Arcadia Publishing, 2016, ISBN 978-1-4671-2459-1 , Chapter One: The Mississippi Bridges .
  6. ^ A b Glenn A. Knoblock: Historic Iron and Steel Bridges in Maine, New Hampshire and Vermont. McFarland, Jefferson 2012, ISBN 978-0-7864-4843-2 , pp. 33-37.
  7. ↑ a b J. H. Warder: Turning and Lifting Machinery for 450-Ft. Swing Span, Alton Bridge. In: Engineering News and American Railway Journal. Vol. 31, June 14, 1894, p. 488 f and Inset Sheet .