Rating:
No votes cast

U.S. 23 Au Sable Bridge (Old)

Photo 

US 23 Au Sable Bridge

Did this pony truss replace the through truss?

Photo from old postcard

Enlarge

BH Photo #485542

Map 

Facts 

Overview
Lost Pratt through truss bridge over Au Sable River on U.S. 23
Location
Au Sable, Iosco County, Michigan
Status
Replaced by a new bridge
Design
Pratt through truss
Approximate latitude, longitude
+44.40730, -83.32476   (decimal degrees)
44°24'26" N, 83°19'29" W   (degrees°minutes'seconds")
Approximate UTM coordinates
17/314893/4919740 (zone/easting/northing)
Inventory number
BH 86796 (Bridgehunter.com ID)

Update Log 

  • November 16, 2020: New photo from Geoff Hubbs
  • September 30, 2019: Added by Mike Kerkau

Related Bridges 

Sources 

Comments 

U.S. 23 Au Sable Bridge (Old)
Posted November 16, 2020, by Mike Daffron (daffmikron [at] gmail [dot] com)

For what it's worth, the car looks to be a late 30's model.

U.S. 23 Au Sable Bridge (Old)
Posted November 16, 2020, by Geoff Hubbs (geoffrey [dot] hubbs [at] att [dot] net)

Mike,

No date on the postcard. The image was on Pinterest for a postcard on Ebay.

Hope you find more.

Geoff

U.S. 23 Au Sable Bridge (Old)
Posted November 16, 2020, by Mike Kerkau (mjkerkau [at] gmail [dot] com)

Geoff:

The page in Hyde's book that has a photo of the through truss dates it to around 1920. Any date for that postcard? (Other than with the R4 panels on the approach, it can't be any earlier than the 1930s.)

For that matter, any other information with regards to that postcard? (Where did it come from?)

In any case, there is only one pre-1972 aerial available - from 1958 - and the image is not clear enough to be able to distinguish a type.

U.S. 23 Au Sable Bridge (Old)
Posted November 1, 2019, by Anonymous

I looked them both over Mike, and while the portal bracing does appear to be very similar the sway bracing is quite different. And while that doesn't necessarily rule out Joliet as a possible fabricator, I have seen a few different firms use the large Lattice or X style portal bracing.

I'm wondering with this being a ca. 1920 bridge on a US road if it might be an early state designed structure. Nathan is far more versed in Michigan bridges than I, so he might have some input on it.

U.S. 23 Au Sable Bridge (Old)
Posted November 1, 2019, by Mike Kerkau (mjkerkau [at] gmail [dot] com)

Question, probably for Tony.

Those top panels at either entrance to this bridge - are those distinctive enough that they're identifiable of only one builder? Or would this have been a standard enough design that it could have been anyone?

Reason I ask is - it just clicked in my head. The Currie Parkway bridge in Midland County has these same distinctive top panels at the entrances, and that one is identified as a Joliet (original) build. Is that enough to say that this one was, too?