GRNW - Clearwater River Bridge
BG&CM - Clearwater Bridge
Photo taken by Douglas Butler
BH Photo #286254
This now inoperative swing bridge consists of two Whipple-Pratt side spans joined together by a center tower, with overhead tension ties to support the side spans when the bridge was swung.
Per the below referenced NP bridge book, the swing span is a 238' through Pin Connected Truss(TPCT) installed in 1916. It is flanked by a pair of 75' through Plate Girders(TPG), with a 6-panel pile trestle(PT) on the north side and an 11 panel pile trestle on the south side, all installed in 1951. Total length was 726'. Since other bridge book examples imply a 15' standard trestle panel, at least 6 panels were double length. Photographs suggest 2 on the north side and 4 on the south, all in the deep water adjacent to the TPGs.
The swing span is a circa 1880 product of the Phoenix Bridge Works, with their characteristic Phoenix patent wrought iron tubular posts used for most compression members. The source of this recycled span is not currently known, but one possibility is the NP's original bridge over the mouth of the Snake river at Ainsworth, opened in 1884. The UP also had a swing bridge over the Snake at Riperia, opened in 1888, but that span had distinctly different trussing. See Thomas Winpenny's "Without Fitting, Filing or Chipping"(1996) for a history of the bridge works, and Hal Riegger's "The Camas Prairie"(1981) for local railroad history.
- Whipple-Pratt through truss swing bridge over Clearwater River on Great Northwest Railroad
- Kamiah, Lewis County, Idaho, and Idaho County, Idaho
- Open to traffic
- Est. 1880's construction, original location unknown, installed 1916
- - Phoenix Bridge Co. of Phoenixville, Pennsylvania
- - Bountiful Grain & Craig Mountain Railroad (BGCM)
- Camas Prairie Railroad (CSP)
- Northern Pacific Railroad (NP)
- Pin connected Whipple-Pratt through truss swing bridge.
Length of largest span: 238.0 ft.
Total length: 726.0 ft.
- Also called
- BG&CM - Clearwater River Bridge
Kamiah Swing Bridge
- Approximate latitude, longitude
- +46.24102, -116.03770 (decimal degrees)
46°14'28" N, 116°02'16" W (degrees°minutes'seconds")
- Approximate UTM coordinates
- 11/574188/5121276 (zone/easting/northing)
- Quadrangle map:
- 1140 ft. above sea level
- Inventory number
- BH 56584 (Bridgehunter.com ID)
- January 20, 2020: New photo from Geoff Hubbs
- June 20, 2019: New photo from Adam
- January 15, 2019: Updated by John C Stutz: Expanded description, in anticipation of loading detail photos.
- September 9, 2018: Updated by Fmiser: added length and description
- June 23, 2014: New photo from Douglas Butler
- June 12, 2013: Added by Luke Harden
- Hayden Bridge (Same design) - A simple pin connected Whipple-Pratt through truss, of similar date and design, by the same builder. Very extensivly documented, with a link to an HAER report.