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NP - Duwamish River Bridge

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Photos 

A 1911 Strauss heel trunnion early design

Photo taken by Douglas Butler

Map 

Street View 

Description 

The bridge was reconstructed in later years of the 1920's with the operating machinery built into the bridge tower and the struts transferred or translated from the bridge tower to the bascule span for a better suited operation.

NP - Duwamish River Bridge 

Written by Douglas Butler

In 1911 the Northern Pacific railroad constructed a Strauss heel trunnion of the Strauss bascule bridge company with the 2 dc motors of 25 horsepower the machinery was installed on the end of the bascule span, the struts attached to the counterweight bridge tower for a season until the late 1928 then Joseph B Strauss reversed or translate the arrangement.

Facts 

Overview
Bridge over Duwamish River on Northern Pacific Railroad
Location
Seattle, King County, Washington
Status
Open to traffic Repaired in the late 1920's by taking the operating struts from the counterweight bridge tower and placed on the bascule truss the operating machinery was removed from the span,and built into the counterweight bridge tower
History
Built 1911; Repaired and energy translated from the span to the counterweight in late 1920's
Builder
- Strauss Bascule Bridge Co. of Chicago, Illinois
Railroad
- Northern Pacific Railroad (NP)
Design
Warren through truss bascule
Dimensions
Total length: 160.0 ft.
Approximate latitude, longitude
+47.57002, -122.35228   (decimal degrees)
47°34'12" N, 122°21'08" W   (degrees°minutes'seconds")
Approximate UTM coordinates
10/548717/5268715 (zone/easting/northing)
Quadrangle map:
Seattle South
Inventory number
BH 57617 (Bridgehunter.com ID)

Update Log 

  • March 30, 2017: New photo from Douglas Butler
  • February 9, 2017: New photos from Douglas Butler
  • January 26, 2016: New photo from Douglas Butler
  • January 13, 2016: New photo from Douglas Butler
  • August 5, 2015: New photos from Douglas Butler
  • February 5, 2015: Essay added by Douglas Butler
  • August 20, 2013: New Street View added by Douglas Butler
  • August 16, 2013: New photos from Douglas Butler
  • August 15, 2013: Added by Douglas Butler

Related Bridges 

  • BNSF - Duwamish River Bridge (Successor) - The bridge was repaired and the energy was transferred or translated from the bascule span to the counterweight in the late 1920's for a better suited operation

Sources 

Comments 

NP - Duwamish River Bridge
Posted February 6, 2015, by Patrick Feller (nakrnsm [at] aol [dot] com)

Good luck, Robert. You aren't being picky.

NP - Duwamish River Bridge
Posted February 6, 2015, by Douglas Butler

Robert I understand what you are coming from however I'm not an engineer but a student with a prolific study of movable drawbridges in the past 14 years as well drawing them. I also read details of all bridge types I know that you aren't trying to be mean but even engineers makes flawed mistakes, I can admit I make mistakes sometimes, but here I had mention about the early design heel trunnion type that was constructed in 1911 with the struts attached to the counterweight bridge tower with the drive machinery installed on the bascule span, the span is heavy in the raised position and in the lowered position the counterweight is heavy, I assume that you viewed my work. However in the late 1920's the bridge had reversed as the strut attached to the bascule truss to support the counterweight while the machinery was installed inside the counterweight bridge tower. As the bridge is raised the counterweight is heavy then the span is heavy in the lowered position check out movable bridge engineering book by Terry L Koglin thanks.

NP - Duwamish River Bridge
Posted February 5, 2015, by Robert Thompson (rkt (dot) engineering (at) gmail (dot) com)

I hope I'm not being too picky here, but:

"Bridge closed with the counterweight heavy with the drive machinery installed on the bascule span."

"The energy in the late 1920's transferred from the span to the counterweight and the drive machinery installed in the counterweight bridge tower, in the closed position the span is heavy for a better suited operation."

"Bridge raised the struts fixed to the bascule span returns back to the counterweight support system in most heel trunnion bascule bridge the struts supports the counterweight making the counterweight heavy"

I am an engineer who deals with technical language every day. What I snipped out and posted above makes no sense at all. Could this be translated to actual, technically correct English?

NP - Duwamish River Bridge
Posted September 23, 2014, by Anonymous

Constrution of the bridge and the completion of the bridge in 1911