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BNSF - Bacon Island Bridge


Bacon Island RR bridge

Looking NW

Photo taken by Craig Philpott in March 2010


BH Photo #157978

Street View 


Abt type trunnion pony plate/through truss bascule bridge


Pony/through plate girder bridge over Middle River on BNSF Railroad (single track)
San Joaquin County, California
Open to traffic
Built 1929.
- American Bridge Co. of New York
- BNSF Railway (BNSF)
Abt type trunnion pony plate truss bascule bridge
Also called
BNSF - Bridge No. A-1135
Approximate latitude, longitude
+37.93979, -121.53310   (decimal degrees)
37°56'23" N, 121°31'59" W   (degrees°minutes'seconds")
Approximate UTM coordinates
10/628898/4200149 (zone/easting/northing)
Quadrangle map:
Woodward Island
10 ft. above sea level
Inventory number
BH 44432 (Bridgehunter.com ID)


Abt Bascule Bridge (8)
American Bridge Co. (1,660)
BNSF Railway (1,589)
Bascule (1,084)
Beam (16,871)
Built 1929 (1,058)
Built during 1920s (10,256)
California (2,710)
Girder (11,163)
Have street view (28,880)
Movable (3,114)
Open (40,960)
Owned by railroad (13,486)
Plate girder (8,719)
Railroad (16,447)
San Joaquin County, California (58)
Steel stringer (6,707)
Through girder (4,185)

Update Log 

  • November 29, 2019: New photos from Douglas Butler
  • December 16, 2014: New photo from Douglas Butler
  • December 28, 2011: Updated by Nathan Holth: Added Date.
  • March 13, 2010: Added by Craig Philpott



BNSF - Bacon Island Bridge
Posted November 28, 2019, by Nathan Holth (webmaster [at] historicbridges [dot] org)

Gordon, thank you for providing these photos! I tried to visit these bridges some years ago on foot for HistoricBridges.org and only was able to get a few distant photos of low quality. With your drone you were able to get much better photos! Thanks again for sharing!

BNSF - Bacon Island Bridge
Posted November 28, 2019, by Gordon Osmundson (gordon [at] ihpworkshops [dot] com)

Was out last week, Nov 19 & 21, 2019, with my drone photographing this and other bridges in the area. Hope you enjoy the photos.

Bacon Island Railroad Bridge
Posted May 30, 2010, by Craig Philpott (cphilpott [at] puc [dot] edu)

Thank you, updated and corrected.

Bacon Island Railroad Bridge
Posted May 29, 2010, by James C. Bradley, Jr. (jbrad1974 [at] yahoo [dot] com)

This bridge does not belong to the Union Pacific Railroad. It is on the Burlington Northern Santa Fe Railroad, Stockton Subdivision, which runs between Stockton and Richmond. Both Amtrak and BNSF freights use the bridge several times a day.

Bacon Island Railroad Bridge
Posted March 16, 2010, by Nathan Holth (form3 [at] historicbridges [dot] org)

This bridge is an extremely rare example of an Abt Bascule type of bridge (as patented by Hugo A.F. Abt in 1921), although I wonder if the plate girder portion is original and if it might instead have once had a truss there. Looks like the approaches have been altered, and maybe they put the plate girder portion in too? If the plate girder is original, then it would be the first non-truss example of this type I am aware of.

Regardless, the portion of the bridge with the counterweight and the a-frame like assembly clearly displays all the key features of an Abt bascule bridge.

The Abt bascule is a fascinating design which was invented and patented for the purpose of having a bridge type that could replace a bridge on existing alignment without disruption of railroad traffic. The Abt Bascule is sometimes called the American Bridge bascule because they apparently built many of them.

My Port Huron Railroad Bridge page discusses Abt bascules with links to two more in Michigan. I also have copies of the Canadian and American patents for the bridge http://www.historicbridges.org/truss/phrailb/index.htm

Bacon Island Railroad Bridge
Posted March 14, 2010, by Craig Philpott (cphilpott [at] puc [dot] edu)

I agree with you regarding the visible A-frame structure but I am not familiar enough with this type of lift structure to know what portions are stationary and what portions move during the lift. More research.

Bacon Island Railroad Bridge
Posted March 14, 2010, by Anthony Dillon (spansaver [at] hotmail [dot] com)

The description is somewhat accurate, but I see what appears to be a Waddell type A-frame through truss here. Whatever you want to call it, a unique structure it is. I was looking at the surrounding area and there are a lot of interesting bridges in the area, including a large number of swing bridges.

Bacon Island Railroad Bridge
Posted March 13, 2010, by Craig Philpott (cphilpott [at] puc [dot] edu)

I seek assistance in describing the style of this bascule bridge. There are three of these bridges on the UP BNSF rail line between Stockton and Brentwood, CA, across the delta of the San Joaquin river. This is the closest I could get to one of them.