Satank Bridge

“The Garfield County Commissioners original specifications indicated that the bridge should be built of steel, or a combination of steel and timber, and consist of one span of 100 feet. The stone abutment footings were to be placed at least two feet below the low-water mark, with the caps at least six feet above the high-water mark, and that they be constructed of stone “from the Frying Pan quarries or of a quality equally as good.”

On March 5th, 1900, the Garfield County Commissioners awarded the contract to build this wagon bridge to Fred H. Bullen of the Pueblo Bridge Company. On May 12th, 1900, the actual completed bridge was accepted into the County road system by the Board of County Commissioners for a total cost of $2,345.00.

The accepted plan used the tried-and-true Pratt “through-truss” design of wood and diagonal iron rods patented by Caleb and Thomas Pratt in 1844. By 1900 this was the standard fro moderate span train and road bridges in America because it was proven to be exceptionally strong, and the trusses could be prefabricated off site. Although by 1900, iron had replaced timber in most of these bridges.

The Satank Bridge – the last of the timber truss bridges still in use in Colorado – is a testament to the durability of the design. With an overall span of 100 feet, and 14 feet of clear distance between trusses, it is the longest-span timber truss bridge in the state.

After many years of disuse, rehabilitation of this historic bridge began in September 2010. The bridge was lifted from its base and set nearby so that it could be disassembled and thoroughly evaluated by engineers. The bridge was structurally rehabilitated using replacement parts constructed of specially fabricated timber members and steel-pin connections to maintain its historical appearance. Douglas fir from Oregon was once again used fro the trusses and decking. Work on the original hand-laid red sandstone masonry abutments was limited to repointing only the joints.

Only the pieces of the original bridge that were structurally sound were retained. The drawing below delineates original and new members in the rehabilitated structure.

The new structure was installed on its historic abutments where it once again serves the community and connects the north and south banks of the Roaring Fork River.”

“Around the turn of the century, after a series of well-publicized collapses and the replacement of iron with compar- atively inexpensive steel, the Howe truss declined in use as a vehicular bridge type. Although some were built as late as the 1930s, the Howe as a generic form was generally replaced by the inherently stronger Pratt truss. The Satank Bridge is interesting as a direct exemplification of that engineering trend. It is one of the older roadway trusses in Colorado, and with the demolition of the Virginia Dale Bridge (LR15), it is the only remaining timber Pratt through truss in public use in the state. Additionally, the Satank Bridge is the longest-span timber truss in thesurvey. As such it is a significant remnant among Colorado’s bridges.”