The Eagle Rock Bridge is an abandoned and collapsed iron and wood Pratt through truss over the James River in Eagle Rock, Virginia.
In May 1883, the Richmond & Allegheny Railroad Company agreed with the Botetourt County Board of Supervisors to build three bridges over the James River at Eagle Rock, Springwood, and Cartersville 1 as part of the construction of its mainline between Richmond and Clifton Forge. 1 2 Presumably, the bridges were to encourage the use of the railroad by citizens on the opposite side of the river. 8 The agreement called for the trusses of iron and wood to rest on masonry piers and to be built above the high water mark of 1877. 1 Specifications called for “strain in iron members to be 12,000 pounds per square inch” and wooden compression members to be proportioned according to C. Shaler Smith’s modification of Gordon’s formula with a safety factor of seven.
Each composite bridge was comprised of Pratt trusses, a slight modification of Thomas and Caleb Pratt’s original patent for a wood and iron truss. The 1844 design originally called for top and bottom chords of wood, verticals of wood, and iron diagonals, but all three were built with iron bottom chords as the bottom chord was subject to tensile forces. 1 Theodore Cooper listed the combination bridges as being cheaper than all-iron structures and more permanent than all-wood bridges as they were less liable to destruction from fire and decay where timber was “only used in compact forms and under compressive strains.”
The new Eagle Rock Bridge was completed in 1885. 1
In 1921, a group of citizens assembled and formed the Eagle Rock-Clifton Forge Highway Association in a bid to build a modern roadway between Eagle Rock and Clifton Forge. 5 Shortly after its formation, the organization’s scope grew to include the construction of a road between Eagle Rock and Fincastle which caught the attention of prominent business leaders in Roanoke. It led to the Virginia State Highway Commission (SHC) moving forward with the construction of VA Route 17 (which became VA Route 12 and later US Route 220) between Clifton Forge and Fincastle in the early 1930s, which included the construction of a new bridge over the James River at Eagle Rock. 3
In March 1932, the SHC came to an agreement with the Chesapeake & Ohio Railway (C&O), the successor to the Richmond & Allegheny Railroad, to release the railroad from the expense of maintaining the c. 1885 bridge which would be removed after the new structure is completed. By November, three piers of the new bridge had been completed 5 and the new crossing at Eagle Rock was completed in late 1933. 7 It was dedicated by members of the Blue Grass Trail Association and other dignitaries on August 4, 1934. 6
The circa 1885 Eagle Rock Bridge was heavily damaged in a severe flood on November 5, 1985, 9 and only one truss span survived. 8 The circa 1934 bridge was closed in 1997, removed in 1999, and replaced in 2001.
Gallery
Information
- State: Virginia
- Route: VA Route 12
- Type: Pratt Through Truss
- Status: Abandoned / Closed
- Navigational Clearance:
Sources
- Spero, Paula A. C. “A Survey and Photographic Inventory of Metal Truss Bridges in Virginia 1865-1932.” Virginia Highway & Transportation Research Council, Mar. 1980.
- Benson, Cathy. “250th Anniversary Celebration: Lime Kilns in Eagle Rock.” The Botetourt Bee, 10 Mar. 2020.
- “Have Come To Terms.” Daily Review [Clifton Forge], 21 Mar. 1932, p. 2.
- “Good Progress Made on Eagle Rock Bridge.” Daily Review [Clifton Forge], 2 Nov. 1932, p. 1.
- “The New Road to Roanoke.” Daily Review [Clifton Forge], 18 Sept. 1934, p. 2.
- “Large Crowd Was Present.” Daily Review [Clifton Forge], 6 Aug. 1934, p. 1.
- “The Blue Grass Trail to Meet at Eagle Rock.” Daily Review [Clifton Forge], 31 Jul. 1934, p. 4.
- Worsham, Gibson. “Botetourt County Reconnaissance Survey.” Virginia Division of Historic Landmarks, May 1988, p. 119-120.
- “From the archives: The flood of 1985 in Roanoke.” Richmond Times-Dispatch, 5 Nov. 2020.