Rating:
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WSOR - Sauk City Bridge

Photos 

Looking south

One pier and span has been removed, leaving a gap between the pony truss in the river and the swing span in the foreground.

Photo taken by Robert Thompson in October 2010

Enlarge

BH Photo #184169

Map 

Street Views 

Description 

Local officials proceeding with plans to remove three remaining spans: http://www.wiscnews.com/saukprairieeagle/news/local/article_...

Remaining pier sunk Oct. 2016, raising questions as to viability of reuse of remaining spans: http://www.wiscnews.com/saukprairieeagle/news/local/article_...

This railroad bridge, being on the Fox-Wisconsin waterway, was required by law to allow the passage of vessels. As such, it was built as a swing bridge. It was unlikely, however, to open often.

On reviewing the photographs, I realized this is a very unusual swing bridge. There is no ring gear on the center pier, and at the shore end of the bridge, there is a ship's capstan and fairlead pulleys! It appears that to save money, this bridge was designed to be winched open and shut using chains or cables, as opposed to the conventional geared drive.

This is a non-symmetrical swing bridge; there is a counterweight on the shore end to compensate for the difference in span length.

(On edit, from the book "Movable Bridge Engineering":)

"There are some examples of bobtail or asymmetrical swing bridges, trussed type and girder type, from the early twentieth Century, but they seem to be concentrated in the upper Midwest. The Chicago, Milwaukee & St. Paul Railroad was a particularly vigorous proponent of this type of bridge... and at rural locations, such as the Wisconsin River. Most of these bridges are still in use for railway traffic, but some swing bridges in rural areas no longer open for navigation. ...but some examples, such as the one over the Wisconsin River at Sauk City, Wisconsin, is combined with several truss-type approach spans. The necessity of adding an expensive... counterweight to balance this bridge, when a symmetrical second arm could easily been added and the approach spans shortened, seems incongruous. It appears that the bridge was rope-operated from shore, so that the short shoreward span provided some advantage in the shorter length of operating rope required and a better angle of incidence of the tensioned rope at the span."

Facts 

Overview
Abandoned pony truss bridge over Wisconsin River on Wisconsin & Southern Railroad
Location
Sauk City, Sauk County, Wisconsin, and Dane County, Wisconsin
Status
Abandoned
Future prospects
Officials proceeding with bridge demolition plans: http://www.wiscnews.com/saukprairieeagle/news/local/article_...
History
Built 1911
Builder
- American Bridge Co. of New York (One or more spans from the Lassig Branch in Chicago, Illinois)
Railroads
- Chicago, Milwaukee, St. Paul & Pacific Railroad (MILW; CMStP&P; CMStP)
- Wisconsin & Calumet Railroad (WICT)
- Wisconsin & Southern Railroad (WSOR)
Design
Pratt pony truss
Bobtail swing deck plate girder
Pony plate girder
Dimensions
Length of largest span: 120.0 ft.
Total length: 455.0 ft.
Also called
WICT - Sauk City Bridge
MILW - Sauk City Bridge
Approximate latitude, longitude
+43.26489, -89.72699   (decimal degrees)
43°15'54" N, 89°43'37" W   (degrees°minutes'seconds")
Approximate UTM coordinates
16/278679/4793842 (zone/easting/northing)
Quadrangle map:
Sauk City
Inventory number
BH 46753 (Bridgehunter.com ID)

Update Log 

  • July 30, 2017: Updated by Alexander D. Mitchell IV: Local officials proceeding with plans to remove three remaining spans
  • July 3, 2017: New photo from Dana and Kay Klein
  • February 24, 2017: New photos from John Marvig
  • October 25, 2016: Updated by Alexander D. Mitchell IV: Bridge pier sank further Oct. 2016; link to article posted
  • September 23, 2016: New Street View added by Dana and Kay Klein
  • October 16, 2015: New Street View added by Brandon Cooper
  • June 17, 2014: New Street View added by Luke Harden
  • June 17, 2014: Updated by John Marvig: Added information, noted bridge is in Sauk City, not Prairie du Sac, and WSOR were the last operators and current owners of the bridge
  • March 23, 2014: Updated by John Marvig: Added Build Date
  • August 22, 2013: New photo from Douglas Butler
  • October 21, 2012: Updated by Luke Harden: Added "vintage" image
  • January 12, 2011: New photos from Eric Hanson
  • December 24, 2010: New Street View added by Daniel Hopkins
  • December 24, 2010: Updated by Robert Thompson: New information
  • October 31, 2010: Added by Robert Thompson

Related Bridges 

Sources 

Comments 

WSOR - Sauk City Bridge
Posted July 3, 2017, by Dana and Kay Klein

Got it. Thanks as always

WSOR - Sauk City Bridge
Posted July 3, 2017, by Luke

Dana, the image you posted belongs on https://bridgehunter.com/wi/sauk/bryant-street/

WSOR - Sauk City Bridge
Posted September 28, 2016, by Matt Lohry

This isn't good--it sure looks like the concrete pier supporting the truss is sinking. The entire span will be in the river before long.

WSOR - Sauk City Bridge
Posted September 28, 2016, by John Marvig (marvigj27 [at] gmail [dot] com)

The good news is the bridge is to become part of a new trail:

http://www.wiscnews.com/saukprairieeagle/news/local/article_...

This is better news for the back channel bridge, which is an older and more significant structure. I don't know if it is too late for this bridge (specifically the remaining truss) to be saved.

WSOR - Sauk City Bridge
Posted September 28, 2016, by Mike Cohen (Indyzmike [at] hotmail [dot] com)

While boating on the river, I noticed a lot of distortion in the alignment of a remaining section of the bridge. I did not get any pics from the water but stopped on my way through Sauk City to a couple from shore.

WSOR - Sauk City Bridge
Posted September 23, 2016, by Eric (eswart79 [at] gmail [dot] com)

Looks mother nature is tearing the bridge down, right now the truss piece and piece south of it are no longer in line with each other.

Prairie du Sac Abandoned Railroad Bridge
Posted May 9, 2013, by Randall Vos (r_vos1979 [at] yahoo [dot] com)

The missing span and pier was blown up several years ago, I cannot recall the exact year. The reason this was done was that the piers of the truss bridges are shifting in the riverbed, throwing the spans out of alignment.

Prairie du Sac Abandoned Railroad Bridge
Posted December 27, 2010, by Robert Thompson

>>Wow, it's hard to believe that the True Value store can leave that riding lawn mower right by the road without it getting stolen. Also, I'm surprised that the railroad track doesn't have a stop bumper there before the tracks cross the road.<<

1.Small-town Wisconsin. There's an old saying here; in a small town nobody uses their turn signals because everyone knows where you're going anyway.

2.Good observation. But since the line is partially dismantled on this side of the river, with no rolling stock or other access to outside trackage, they must have decided it wasn't a problem.

Prairie du Sac Abandoned Railroad Bridge
Posted December 25, 2010, by Anonymous

Wow, it's hard to believe that the True Value store can leave that riding lawn mower right by the road without it getting stolen. Also, I'm surprised that the railroad track doesn't have a stop bumper there before the tracks cross the road. I once saw a crew assembling a train and they lost track of the car count, and they drove the end car right through a warehouse roll-up door and drove the rail cars inside the building back through the back wall.

Prairie du Sac Abandoned Railroad Bridge
Posted December 25, 2010, by Robert Thompson

Thanks for the Street View, Daniel.