3 votes

Bridge Camp Bridge



Photo From WISAARD

BH Photo #202423


Pratt pony truss bridge over White River on Pedestrian Walkway
King County, Washington, and Pierce County, Washington
Open to traffic
Built 1902
- American Bridge Co. of New York
- George S. Morison of New Bedford, Massachusetts
- Ralph Modjeski of Bochnia, Poland
- Northern Pacific Railway (NP)
Pin connected Pratt pony truss bridge
Length of largest span: 152.0 ft.
Total length: 217.0 ft.
Deck width: 12.0 ft.
Approximate latitude, longitude
+47.17234, -121.79720   (decimal degrees)
47°10'20" N, 121°47'50" W   (degrees°minutes'seconds")
Approximate UTM coordinates
10/591148/5225018 (zone/easting/northing)
Quadrangle map:
Cyclone Creek
Inventory number
BH 48976 (Bridgehunter.com ID)

Update Log 

  • July 29, 2014: Updated by Luke: Added categories "Northern Pacific Railroad", "Rail-to-road", "Relocated", "George S. Morison", "Ralph Modjeski"
  • August 12, 2012: Updated by Luke Harden: Corrected status
  • June 23, 2011: New photos from K. A. Erickson
  • June 23, 2011: Added by Nathan Holth



Bridge Camp Bridge
Posted July 29, 2014, by Luke

Thank you for that very informative PDF Matt!

Bridge Camp Bridge
Posted July 29, 2014, by Matt Sneddon (mtsneddon [at] yahoo [dot] com)

The history and description of this bridge has been updated in the Washington Department of Archaeology and Historic Preservation's database. Unfortunately the WISAARD system has a poor formatting interface which makes the document harder to read.

Attachment #1 (application/pdf; 570,004 bytes)

Bridge Camp Bridge
Posted August 12, 2012, by K. A. Erickson

Contrary to what some may believe this bridge still carries logging traffic as evidenced by the picture below. It goes by the moniker "6000 Logging Road".

Bridge Camp Bridge
Posted June 23, 2011, by Nathan Holth (form3 [at] historicbridges [dot] org)

Your photo of the end post clearly shows empty holes at the top, which appears to prove that this was indeed once a through truss. It also shows the outriggers are bolted, since they were added at a later date than when the bridge was first built.

Bridge Camp Bridge
Posted June 23, 2011, by Nathan Holth (form3 [at] historicbridges [dot] org)

Your theory about someone not wanting to worry about height restrictions makes sense. A 152 foot pony truss is not normal, especially one from 1902 and pin connected. Someone must have had a desire to eliminate overhead bracing.

They certainly could have been removed when the bridge was relocated and/or reconstructed for the logging use.

Bridge Camp Bridge
Posted June 23, 2011, by K. A. Erickson

Remember when I said that Weyerhaeuser built their own rail and road system so they would not have to use county or state infrastructure? The idea was that they could stack their cars or trucks as tall, wide, or heavy as they wanted to something restricted on the others. Is it possible that instead of being cut out they were removed when the bridge was moved and assembled this location? I ran into someone who raised that question.

Bridge Camp Bridge
Posted June 23, 2011, by Nathan Holth (form3 [at] historicbridges [dot] org)

At first glance this appears to be a through truss with its struts removed and outriggers added. But I couldn't find a detail photo to show where the struts were cut, or any evidence that the outriggers are not original. Attached is the DAHP survey form with some history about the bridge. I disagree with their assessment however, they fail to discuss whether the truss outriggers are original or not, and condemn the bridge's non-original deck and abutments, which are generally not a consideration in truss evaluation. If this bridge really was designed as a pony truss like this it would be extremely rare.

Attachment #1 (application/pdf; 553,074 bytes)