Winona Rail Bridge

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Coordinates: 44 ° 2 ′ 41 ″  N , 91 ° 36 ′ 24 ″  W.

Winona Rail Bridge
Winona Rail Bridge
The Winona Rail Bridge 1985 (demolished 1990)
use Railway bridge
Crossing of Mississippi River
place Winona in Minnesota and
Buffalo County in Wisconsin
construction Truss bridge with swing bridge
overall length 847 m
Longest span 110 m
start of building 1890
opening 1891
planner George S. Morison
closure 1985 (demolished 1990)
location
Winona Rail Bridge (USA)
Winona Rail Bridge

The Winona Rail Bridge was a single-track railroad bridge over the Mississippi between Winona , Minnesota and Buffalo County , Wisconsin . The truss bridge designed by George S. Morison was built by the Winona Bridge Railway Company until 1891 , an operating company founded by several railway companies, behind which the Chicago, Burlington and Quincy Railroad played a key role as the driving force . It was the second railway bridge in Winona after the bridge built by the Chicago and North Western Railway in 1872 , and at the turn of the century it helped Winona become one of the largest cities in Minnesota at the time. From 1970, the main owner of the operating company was the Burlington Northern Railroad , which gave up the obsolete bridge in 1985 and had it demolished in 1990.

history

The first C&NW railway bridge in Winona 1898 (built in 1872, rebuilt several times and abandoned in 1977). The CBQ bridge was completed about a kilometer downstream in 1891.

The first bridge over the Mississippi in Winona was built in 1972 by the Chicago and North Western Railway (C&NW). The Chicago, Burlington and Quincy Railroad (CBQ) built its connection to the Twin Cities ( Minneapolis and St. Paul ) along the east bank of the Mississippi in Wisconsin by 1886 and also wanted to expand its connections westwards from Winona to Minnesota. Initially, the connection was made by rail ferries and temporary wooden bridges in winter. From January 1887 the passenger trains drove over the bridge of the C&NW for high fees and from 1888 plans were made for a permanent bridge of their own. To realize this, the CBQ joined forces with Green Bay, Winona & St Paul ( Green Bay and Western Railroad since 1896 ) from Wisconsin and Winona and Southwestern Railroad (W&S) from Minnesota, who are responsible for the construction and operation of the new bridge Winona Bridge Railway Company founded.

After initial drafts by W & S's chief engineer, DM Wheeler, and the approval of the War Department , the contract for the construction was awarded to the Union Bridge Company from New York, which in turn hired George S. Morison as a consulting engineer. Based on Wheeler's preliminary work, Morison designed a truss bridge with a swing bridge to be built about a kilometer downstream from the C&NW bridge. Although Morison had made the transition to steel as a building material for his bridge constructions, due to the moderate spans and the high steel prices he sometimes resorted to wrought iron , especially for components that were only subjected to pressure. Construction began in early August 1890 under the direction of Wheeler and could be completed a year later; the first train passed the bridge in July 1891.

Winona developed into one of the largest cities in Minnesota through the expansion of the railroad network; the population doubled from around 10,000 in 1880 to almost 20,000 at the turn of the century. Over the years, many of the smaller railroad companies disappeared or merged with others. The main owner of the Winona Bridge Railway Company became from 1970 the Burlington Northern Railroad , which gave up the obsolete bridge in 1985. After a fire in the wooden trestle bridges on the driveways in 1989, the bridge was finally torn down the following year. The upstream bridge of the C&NW was abandoned in 1977 and is only partially preserved today.

description

Wooden trestle bridge of the driveway on the Wisconsin side 1985, looking towards Winona at the first truss .

The bridge with a total length of 847 m consisted of four central lattice girders and wooden trestle bridges on both sides as accesses. The lattice girders were divided into a 134 m long swing bridge and a 110 m and two 73 m long static lattice girders, which were supported by six stone-walled river pillars with a concrete core. The subsequent trestle bridges had a length of 91 m to the west bank in the direction of Winona and 366 m to the east bank in the direction of Wisconsin.

Plan of the Winona Rail Bridge from the HAER NE-2 from 1986, lengths in feet (′) and inches (″).

The lattice girders were made up of post frameworks with crossed cross braces, which had a curved upper chord and the track led to the lower chord. It was a modified Pratt construction (English pratt truss ), named after the engineer Thomas Willis Pratt (1812-1875) and his father Caleb Pratt. The four bridge piers of the dormant girders had a length in the direction of the current of 6.7 m, with a width of 2.4 m and were inclined upstream, where they acted as ice breakers for the ice drift that occurred in winter . They were anchored by means of pile foundations , for which 65 wooden piles were driven over 20 m deep into the river bed for each pillar.

The swing bridge consisted of two 64 m long cantilever girders on a central truss tower 6.1 m long and 6.1 m wide and 15.2 m high. In the upper area these were attached with eye rods that were only subjected to tensile loads , whereby the lower chords ran through the entire length of the swing bridge and were mounted under the central tower on a 2.2 m high drum with a diameter of 8.6 m. The drum with the 1270-ton swing bridge was in turn mounted on a roller-ring bearing with 50 rollers, each 46 cm in diameter, which was attached to a round pillar. The pier had a diameter of 9.1 m and was anchored in the river bed with 100 piles. To protect against ship collisions, each had a 67 meter landing stage perpendicular to the bridge, over which the opened swing bridge rested. The river pillar at the west end of the swing bridge was also protected by a wooden structure along the bank and had roughly the same dimensions as the other rectangular bridge piers.

See also

literature

Web links

Individual evidence

  1. ^ Green Bay Route. Green Bay & Western Historical Society; accessed on April 15, 2018.
  2. ^ A b c d Clayton B. Fraser: Nebraska City Bridge. Historic American Engineering Record, HAER No. NE-2, Denver, Colorado 1986, pp. 281-294.
  3. ↑ a b c Swing Span of the Winona Bridge. In: Engineering News and American Railway Journal. Vol. 26, October 17, 1891, p. 370
  4. ^ Winona Bridge Railway, WBR Mississippi River Crossing At Winona. John A. Weeks III; accessed on April 15, 2018.
  5. ↑ CNW - Winona Swing Bridge. Bridgehunter, Historic and Notable Bridges of the US; accessed on April 15, 2018.
  6. ^ 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.