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Skunk River Bridge

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Photos 

Skunk 1

Photo taken by Luke Harden

Map 

Description 

In April 1876 the Story County Board of Supervisors directed County Clerk S.J. Shearer to advertise for three iron bridges over the Skunk River. One would span the river at Soper's Mill north of Ames, the second would be located in Grant Township, and the third would span the Skunk River just east of the small town of Cambridge, in Union Township. By far the longest of the three, this last bridge consisted of an 80-foot wrought iron truss supported by cylinder piers over the river's channel, with a 200-foot timber pile approach. The contract to fabricate and erect the three spans was awarded in June to the King Iron Bridge and Manufacturing Company of Cleveland, Ohio.

King apparently completed the three bridges later that year, but in September 1877 the Cambridge Bridge already required repairs. The truss's deck and stone substructure needed occasional repairs in subsequent years, the most serious of which was a partial reconstruction of the crumbling stone abutments in 1899. By the mid-1910s the Cambridge Bridge was no longer sufficient to carry traffic at this crossing. In 1916 the county hired the Ben Cole & Sons Construction Company of Ames to replace the bridge and to move the old truss to a new crossing of the Skunk River southeast of Ames. Here it was combined with an ISHC-standard pony truss on a new concrete substructure. Coincidentally, this reconstruction cost of $6,600 - the same amount as the original bridge had cost to build in 1876. The bridge carried extremely light traffic at this remote location until about 1990, when the road was vacated and the bridge abandoned in place.

The Skunk River Bridge employs a classic Warren truss configuration, with a web that relies on simple triangulation for its rigidity. "The term Warren truss girder was originally applied only to the particular case of the Triangle truss in which the web triangles are all equilateral; but later writers generally use the name for any triangular truss, noted bridge engineer J.A.L. Waddell wrote in his 1916 treatise Bridge Engineering. "As there is no special advantage in making the web triangles equilateral, there does not appear to be any good raison d'etre for the use of the true Warren type." In a state dominated by bowstrings and Pratt trusses in the 1870s and early 1880s, relatively few Warren trusses were built. Only a handful survives to the present, of which the Skunk River Bridge is the oldest. Built during the county's formative years by the nation's most prolific bridge fabricator, it is an important early transportation related resource [adapted from Fraser 1992].

Facts 

Overview
Warren through truss bridge over Skunk River on (Vacated) 255th Street in Ames
Location
Ames, Story County, Iowa
Status
Abandoned
History
Built 1876; moved here 1916; rehabilitated 1974; abandoned 1990
Builders
- Ben Cole & Sons Construction Co. of Ames, Iowa (Movers)
- Cambria Steel Co. of Johnstown, Pennsylvania (Iron/Steel Manufacturer)
- Iowa State Highway Commission of Ames, Iowa (Pony Truss Designer)
- King Bridge Co. of Cleveland, Ohio (Through Truss Builder)
Design
Pinned Warren through truss
Riveted Warren pony truss
Dimensions
Length of largest span: 80.1 ft.
Total length: 163.1 ft.
Deck width: 15.7 ft.
Vertical clearance above deck: 13.5 ft.
Recognition
Posted to the National Register of Historic Places on May 15, 1998
Also called
Old Cambridge Bridge
250th Street Bridge
Approximate latitude, longitude
+41.98656, -93.58749   (decimal degrees)
41°59'12" N, 93°35'15" W   (degrees°minutes'seconds")
Approximate UTM coordinates
15/451335/4648451 (zone/easting/northing)
Quadrangle map:
Huxley
Land survey
T. 83 N., R. 24 W., Sec. 24
Inventory numbers
IA 314920 (Iowa bridge number)
NRHP 98000484 (National Register of Historic Places reference number)
BH 14441 (Bridgehunter.com ID)
Inspection (as of 01/2011)
Deck condition rating: Imminent Failure (1 out of 9)
Superstructure condition rating: Serious (3 out of 9)
Substructure condition rating: Poor (4 out of 9)
Appraisal: Structurally deficient
Sufficiency rating: 20.6 (out of 100)
Average daily traffic (as of 2011)
10

Update Log 

  • September 30, 2014: New photos from Kevin Skow
  • November 20, 2013: Updated by Luke Harden: Noted that the ISHC designed the pony truss
  • November 14, 2012: Photo imported by Luke Harden
  • November 10, 2012: Updated by Luke Harden: Added Cambria Steel Co. in builder's section
  • March 7, 2012: Photo imported by Luke Harden
  • February 28, 2012: Photo imported by Luke Harden
  • January 25, 2012: Updated by Luke Harden: Added categories "Relocated", "Pin-connected", "Iowa State Highway Commission", "Wrought iron", "Riveted"
  • November 30, 2011: Photo imported by Luke Harden
  • August 31, 2011: Updated by Luke Harden: Edited description
  • August 31, 2011: New photos from Jason Smith
  • June 3, 2011: Updated by Luke Harden: Added photograph and integrated history of the bridge article
  • May 27, 2011: Updated by Tony Dillon: This is indeed a pinned Warren truss
  • March 27, 2011: Updated by Anthony Dillon: Added truss type
  • March 27, 2011: New photos from Bill Eichelberger

Sources 

Comments 

Skunk River Bridge
Posted October 3, 2014, by Luke

Hopefully Ames handles this bridge's situation better than they handled the Dinkey.

Skunk River Bridge
Posted October 3, 2014, by Kevin Skow (weatherbum [at] hotmail [dot] com)

Great writeup--hopefully a solution can be found that saves the bridge. Glad to help with the photos!

Skunk River Bridge
Posted October 3, 2014, by Jason Smith (JDSmith77 [at] gmx [dot] net)

Here's my write-up and latest on the bridge based on what I know so far. Hopefully sth can be done about it. Thanks for posting the photos Kevin and for the info, Luke.

Link: http://thebridgehunter.areavoices.com/2014/10/04/tree-falls-...

Skunk River Bridge
Posted October 2, 2014, by Luke

I informed the AHS of the situation and they are looking into it.

Skunk River Bridge
Posted September 30, 2014, by Kevin Skow (weatherbum [at] hotmail [dot] com)

This bridge has seen better days. A substantial amount of tree debris is lodged against the bridge pier and pony truss from the flooding this past summer. The flooding also caused the NW bank upstream of the bridge to collapse, sending several trees onto the pony truss. It appears like the pier may have shifted...the two decks are no longer level. The deck on the Warren truss is very soft and rotten. I posted pics of the bridge from this evening in the photo gallery.

Skunk River Bridge
Posted May 19, 2013, by Harry (Skip) Nickerson (harry,nickerson [at] keycoop [dot] com)

I grew up on Jewel drive and all the kids in the neighborhood would hang out down at the old bridge. I have recently moved back to the area and walk down there often. I was thinking about contacting the City about saving it and maybe adding a canoe access. Growing up we use to canoe through town and pull out there. Someone has put up a gate at the end of Ken Maril and the farmer puts a pad lock on it. That needs to be removed. It is a county road and should be open to the public.

Harry

Skunk River Bridge
Posted November 10, 2012, by Don Morrison

Wish I'd realized this was here when I was in Ames in the late 80s & early 90s. I had friends who lived on Jewell Drive.

Internet imagery shows why this was abandoned; Interstate 35 cut off Ken Maril road somewhere between 1972 and 1975, so there was no need to ever cross this bridge, assuming that there were no homes along Ken Maril east of the bridge then.

Skunk River Bridge
Posted August 31, 2011, by Jason Smith (JDSmith77 [at] gmx [dot] net)

Yep, I was passing through the area and got a few pics of this bridge as well as a couple others up the river. Nice looking structures. I'm planning on writing a book on Iowa's truss bridges and figure this one will definitely be included there. Wish I had a chance to see you when I did but was running a tight schedule....

Skunk River Bridge
Posted August 31, 2011, by Luke Harden (lmharden [at] iastate [dot] edu)

You were in my area Jason?

Skunk River Bridge
Posted May 28, 2011, by Luke Harden (lmharden [at] iastate [dot] edu)

The Skunk River Bridge is on the national register of historic places since 1998.

Source:http://www.nationalregisterofhistoricplaces.com/IA/Story/sta...

Skunk River Bridge
Posted May 27, 2011, by Luke Harden (lmharden [at] iastate [dot] edu)

also this should also be classified as abandoned as the road, 255th St. was vacated and the bridge susebquently abandoned,

Skunk River Bridge
Posted May 27, 2011, by Luke Harden (lmharden [at] iastate [dot] edu)

In April 1876 the Story County Board of Supervisors directed County Clerk S.J. Shearer to advertise for three iron bridges over the Skunk River. One would span the river at Soper's Mill north of Ames, the second would be located in Grant Township, and the third would span the Skunk River just eat of the small town of Cambridge, in Union Township. By far the longest of the three, this last bridge consisted of an 80-foot wrought iron truss supported by cylinder piers over the river's channel, with a 200-foot timber pile approach. The contract to fabricate and erect the three spans was awarded in June to the King Iron Bridge and Manufacturing Company of Cleveland, Ohio.

King apparently completed the three bridges later that year, but in September 1877 the Cambridge Bridge already required repairs. The truss's deck and stone substructure needed occasional repairs in subsequent years, the most serious of which was a partial reconstruction of the crumbling stone abutments in 1899. By the mid-1910s the Cambridge Bridge was no longer sufficient to carry traffic at this crossing. In 1916 the county hired the Cole Brothers Construction Company of Ames to replace the bridge and to move the old truss to a new crossing of the Skunk River southeast of Ames. Here it was combined with an ISHC-standard pony truss on a new concrete substructure. Coincidentally, this reconstruction cost of $6,600 - the same amount as the original bridge had cost to build in 1876. The bridge carried extremely light traffic at this remote location until about 1990, when the road was vacated and the bridge abandoned in place.

The Skunk River Bridge employs a classic Warren truss configuration, with a web that relies on simple triangulation for its rigidity. "The term Warren truss girder was originally applied only to the particular case of the Triangle truss in which the web triangles are all equilateral; but later writers generally use the name for any triangular truss, noted bridge engineer J.A.L. Waddell wrote in his 1916 treatise Bridge Engineering. "As there is no special advantage in making the web triangles equilateral, there does not appear to be any good raison d'etre for the use of the true Warren type." In a state dominated by bowstrings and Pratt trusses in the 1870s and early 1880s, relatively few Warren trusses were built. Only a handful survives to the present, of which the Skunk River Bridge is the oldest. Built during the county's formative years by the nation's most prolific bridge fabricator, it is an important early transportation related resource [adapted from Fraser 1992].

Source: http://www.iowadot.gov/historicbridges/detail.asp?id=175

Skunk River Bridge
Posted March 27, 2011, by Bill Eichelberger (wallyum [at] hotmail [dot] com)

Nice pics. I added them to the bridge page.