No votes cast

RI - Sylvan Slough Lattice Truss


Rock Island Lumber Co. Sawmill Fire 1908

Courtesy of Retro Quad Cities


View this photo at facebook.com

BH Photo #485275


Lost Lattice through truss bridge over Sylvan Slough on Railroad
Rock Island, Rock Island County, Illinois
Replaced by new bridge
Built 1893; Replaced 1923
- Chicago, Rock Island & Pacific Railroad (CRIP (1866-1920); RI (1920-1975) ROCK (1975-1980))
Lattice through truss
Approximate latitude, longitude
+41.51165, -90.56183   (decimal degrees)
41°30'42" N, 90°33'43" W   (degrees°minutes'seconds")
Approximate UTM coordinates
15/703467/4598428 (zone/easting/northing)
Quadrangle map:
Davenport East
Inventory number
BH 52440 (Bridgehunter.com ID)

Update Log 

  • January 5, 2022: New photo from Luke
  • November 21, 2020: New photo from Luke
  • November 7, 2020: New photo from Luke
  • December 28, 2012: Updated by John Marvig: Added information
  • August 10, 2012: Updated by Luke Harden: Added categories "Relocated", "Railroad"
  • May 12, 2012: Added by Luke Harden

Related Bridges 



RI - Sylvan Slough Lattice Truss
Posted January 6, 2022, by John Marvig (marvigj27 [at] gmail [dot] com)

Unfortunately, most of any records that would publicly available for the Rock Island probably ended up in the trash, or hopefully are still in a basement somewhere. The measurements on the two Rock River bridges certainly do not suggest any relation to this bridge at all.

The northern bridge has a single 150' span, followed by two 155' spans. I saw no alterations to these spans to suggest that they were heavily modified. The piers did not have a date stamp, nor did the abutments. The north abutment appears to be newer than the other substructures, while the remaining substructures may to be older stone with a concrete encasement. The sizes strongly indicate these spans are not related to Sylvan Slough.

The southern bridge has two 135' spans, with a 150' span on the end. All piers are stamped with a 1930 date, and appear to have been constructed then. The two shorter spans do show signs of alterations, mainly limited to the portals. The portals of the shorter spans are also different than the southern span. The date stamps strongly indicate these spans are not related to Sylvan Slough.

RI - Sylvan Slough Bridge
Posted January 5, 2022, by Luke

For posterity's sake and to give credit where credit is due, I want to note that the "The spans were reused on the Rock River" thing has been debunked by John Marvig.

Specifically, the span lengths don't match up and there are no signs of modification suggesting their lengths were altered.

This persistent myth was even printed in a bulletin published as part of the 2011 Quad Cities Train Festival. Said bulletin was the basis for some of my earliest entries on the site.

The Rock Island DID reuse bridges, but the lattice trusses that spanned here previously were not relocated down-line to the Rock River. Where did they end up? John will probably find that out too.