Rating:
7 votes

St. Charles Air Line Bridge (1919)

Photos 

Photo taken by Steve Conro in September 2012

Enlarge

BH Photo #240482

Street Views 

Video 

St Charles Air Line Bridge

Ryan Jacobs

Play video on YouTube

Description 

The St. Charles Air Line (SCAL) Bridge was the world’s longest and heaviest single-leaf bridge when completed in 1919. Designed by the acclaimed Chicago bridge engineer Joseph B. Strauss, the SCAL Bridge was built using many of the design principles as the Chicago & Northwestern Railway Bridge (constructed in 1908). However, the SCAL Bridge is significant because it is an excellent example of a “heel trunnion” bascule bridge, a design developed by Strauss specifically for long bascule spans.

-Commission on Chicago Landmarks, Historic Chicago Railroad Bridges report

The Southern most bridge in the down position is the SCAL bridge and is still in use by the CNRR. The Northern, stored in the up position is the B&O/Chicago Terminal RR Bridge and is now abandoned.

Facts 

Overview
Baltimore through truss bascule bridge over the Chicago River on CN RR
Location
Chicago, Cook County, Illinois
Status
Open to traffic
Future prospects
Facing possible closure/demolition
History
Built in 1919, original length was 260 ft. -- later shortened to 220 ft. in 1930
Builder
- Strauss Bascule Bridge Co. of Chicago, Illinois
Railroads
- Amtrak (AMTK)
- Canadian National Railway (CN)
- Chicago & North Western Railway (CNW)
- Illinois Central Railroad (IC; ICG (1972-1988))
- St. Charles Air Line Railroad
Design
Strauss Trunnion Bascule
Dimensions
Length of largest span: 220.0 ft.
Total length: 2,000.0 ft.
Approximate latitude, longitude
+41.86110, -87.63456   (decimal degrees)
41°51'40" N, 87°38'04" W   (degrees°minutes'seconds")
Approximate UTM coordinates
16/447332/4634548 (zone/easting/northing)
Quadrangle map:
Englewood
Inventory numbers
HAER IL-67
BH 38237 (Bridgehunter.com ID)

Update Log 

  • March 7, 2022: New photos from Douglas Butler
  • March 3, 2022: New photo from Douglas Butler
  • January 3, 2022: New photo from Douglas Butler
  • December 20, 2020: New photos from Geoff Hubbs
  • October 24, 2020: New photos from Douglas Butler
  • October 3, 2020: New photo from Tyler
  • January 5, 2019: New photo from Douglas Butler
  • April 29, 2018: New photos from Drake Krohn
  • April 10, 2018: New photo from Douglas Butler
  • March 28, 2018: New photo from Douglas Butler
  • September 17, 2016: New photo from Dave King
  • August 22, 2016: New photos from Douglas Butler
  • January 27, 2016: New photos from Royce and Bobette Haley
  • January 26, 2016: New photo from Douglas Butler
  • January 19, 2016: New Street View added by Douglas Butler
  • December 14, 2015: Updated by Roger Deschner: Added category "Amtrak"
  • December 14, 2015: New photo from Douglas Butler
  • December 7, 2015: New Street View added by Douglas Butler
  • November 19, 2015: New video from Douglas Butler
  • August 6, 2015: New photo from Douglas Butler
  • October 30, 2014: New photo from Douglas Butler
  • August 26, 2013: New photo from Douglas Butler
  • August 21, 2013: New Street View added by Douglas Butler
  • October 1, 2012: Updated by Daniel Hopkins: Added category "Railroad"
  • September 30, 2012: Updated by Luke Harden: Added category "St. Charles Air Line Railroad"
  • September 29, 2012: Updated by Steve Conro: Added categories "Canadian National Railway", "Navigable waterway"

Related Bridges 

Sources 

Comments 

St. Charles Air Line Bridge
Posted June 6, 2021, by John Marvig (marvigj27 [at] gmail [dot] com)

It appears there is a development, complete with a riverwalk currently being constructed on the east side of this bridge. Hopefully this will make the bridge more accessible. In addition, with the construction of new bridges to the east (Clark, State, Michigan, etc), I doubt CN will be abandoning this bridge in the near future.

St. Charles Air Line Bridge
Posted October 11, 2018, by Nathan Holth (webmaster [at] historicbridges [dot] org)

See my photo here, you can see what appear to be concrete blocks that are stuck in some of the holes. https://historicbridges.org/illinois/sbrr/p1460456.jpg

St. Charles Air Line Bridge
Posted October 11, 2018, by Nathan Holth (webmaster [at] historicbridges [dot] org)

I assume the holes in the counterweight are/were intended for adjusting the weight of the span. Most bascule bridges have a method for adjusting span balance to accommodate changes in weight over service life, this might be changes in deck design, railing, mechanical adjustments that affect balance (new lock motors, etc).

St. Charles Air Line Bridge
Posted October 11, 2018, by Clark Vance (cvance [at] dogmail [dot] com)

The true mystery is why there are a bunch of holes in the weights....

St. Charles Air Line Bridge
Posted October 11, 2018, by Don Morrison

I'm not Bennett Brauer (Chris Farley character) either.

LOL

St. Charles Air Line Bridge
Posted October 11, 2018, by Don Morrison

Well, I'm definitely no "foamer", I'm not an "expert", I'm not the "source of previous comments on this page" and I'm not "a local resident", but HAER's photo caption may need to be explained by one of the "above".

Particularly the "In conjunction" part...

Merriam Webster says:

"in conjunction with

idiom

Definition of in conjunction with

formal

: in combination with : together with

The concert will be held in conjunction with the festival.

The medicine is typically used in conjunction with other treatments."

8. DETAIL OF CONCRETE COUNTERWEIGHT WHICH WAS OPERATED IN CONJUNCTION WITH BOTH OF BASCULE SPANS OF THE B & O AND THE ST. CHARLES AIRLINE, LOOKING SOUTHEAST - Baltimore & Ohio Railroad, Chicago Terminal Railroad, South Branch of Chicago River Bridge, Spanning South Branch of Chicago River, Chicago, Cook County, IL

http://www.loc.gov/pictures/item/il0633.photos.037176p/

(I am a bit of a smartass on occasion. Sorry about that.)

St. Charles Air Line Bridge
Posted October 10, 2018, by Jack Steen (tworiverstwo-4 [at] yahoo [dot] com)

ADMINISTRATOR needs to DELETE the silly comments on his site that claim falsehoods - i.e., that "...both bridges share a counterweight."

Scores of people look to this site for accurate information - not stupid ruminations of uneducated foamers.

St. Charles Air Line Bridge
Posted January 6, 2018, by Kenny Fairhurst (dwf0403 [at] gmail [dot] com)

To clarify some rumors forming in here...

The bridges do NOT share a counterweight. If that was the case, then both bridges would be operational instead of the CN bridge being the only one operable.

St. Charles Air Line Bridge
Posted August 24, 2016, by george oakley (georgeoakley49 [at] yahoo [dot] com)

Anonymous,that is cool being able to street view along the river.Comes in handy when searching for bridges.

St. Charles Air Line Bridge
Posted August 23, 2016, by Anonymous

You can move on the street view in the map to move along the river. If you look between the two bridges, it looks like they share a control house. The platform and ladder connect the one bridge to the adjacent bridge.

The two separate structures couldn't share a counterweight as they move separately from each other.

St. Charles Air Line Bridge
Posted April 21, 2016, by Nathan Holth (webmaster [at] historicbridges [dot] org)

I've heard others comment that these bridges share a counterweight but I am not sure that's actually what they share if they share anything. Maybe operating equipment? The Air Line Bridge has wing style counterweights and they should not need any supplemental support. In fact they should be overbuilt and may have had to be reduced in weight, since the Air Line Bridge originally was a couple panels longer and when it was moved here it was made shorter. There is no evidence that the counterweights are connected to B&O Bridge... moreover, if they were connected, wouldn't both bridges have to move at the same time? The Air Line Bridge raises and lowers while the B&O stays put. If anyone can clarify the shared counterweight rumor that would be awesome.

St. Charles Air Line Bridge
Posted April 21, 2016, by Shad Vargo (scih30 [at] gmail [dot] com)

Actually I think CSX still owns the B&O portion of the bridge since they cannot abandon that part due to the fact the bridges share a counterweight.

St. Charles Air Line Bridge
Posted January 28, 2016, by Steve Conro (sconro [at] yahoo [dot] com)

Don't get me wrong. If there's an interesting painting, drawing or art of some kind of a a particular bridge. By all means post it. THATS interesting. But 2,3,5,10 of each. If you look at the updates page anymore all you find is 1000's of one persons drawings. One or two of each is plenty.

St. Charles Air Line Bridge
Posted January 28, 2016, by Julie Bowers (jbowerz1 [at] gmail [dot] com)

Given the pen chance for any separate categories....the snapshots in time showing different stages of those bridges are interesting to me. I don't spend a lot of time on that span style, still intrigues.

Art is in the eye of the viewer, those paintings of the past are sure treasures, they say these decades will be the lost ones with no bits to find in the shops of our past. All digital?

I'd like to see those abstracts, never did that style either.

St. Charles Air Line Bridge
Posted January 28, 2016, by ArtS (asuckewer [at] knite [dot] com)

Julie, I absolutely agree! I previously uploaded an image of a painting that hangs in the Metropolitan Museum of Art of a bridge, done in the 1800's, that both conveys more than a period photo would and as there are no photos of that bridge, it represents the only image of a long lost bridge.

That said, as reference, unless they are technical drawings, art is subjective as opposed to objective, which, in my opinion, distracts from the overall bridge entry as a research tool. As an example, I plan on a series of bridge paintings as well. I plan on doing them in the style of Jackson Pollack. While each painting will represent a specific bridge, I highly doubt they would add value to the entry for the bridge as reference documents. Thus my suggestion of a separate category.

Also, my previous post was sincere, I really did break out in laughter when I flipped through all of Douglas' sketches.

St. Charles Air Line Bridge
Posted January 28, 2016, by Julie Bowers (jbowerz1 [at] gmail [dot] com)

Art (and I don't mean Art S) is as valid as any of the photographs. What truly is the problem? Don't look at them if you aren't interested. Can you draw? I do paintings of bridges too, and I've posted a few. I'll start posting some more. At one point I had intended to do a painting for every bridge we do, can't keep up, maybe this will be incentive.

St. Charles Air Line Bridge
Posted January 27, 2016, by ArtS (asuckewer [at] knite [dot] com)

Oh my god! That's awesome! Thanks for the comment, otherwise I would never have looked. I literally laughed when I saw the number of drawings! I didn't realize Douglas did more that one picture per bridge. Now, if we could just convince him to do a new picture of this bridge every day, we'd be all set.

It's too bad we can't have a separate section as a repository of the vast pencil sketch collection - we could have 'guess the bridge' contests :^)

Regards,

Art S.

St. Charles Air Line Bridge
Posted January 27, 2016, by Steve Conro (sconro [at] yahoo [dot] com)

Enough already with the frigging drawings.