Historic Structures

Morley Bridge - Denver South Park & Pacific Railroad Truss Bridge, Romley Colorado

Date added: July 29, 2021 Categories: Colorado Bridges

In 1879, silver was discovered in the Sawatch Mountains south of Leadville. Within months, the town of Gunnison was platted as the smelting center for mining districts around St. Elmo, Tin Cup, Irwin, and Gothic. Almost immediately, two railroads- the Denver, South Park & Pacific and the Denver & Rio Grande- raced to lay track to Gunnison from their existing termini at Leadville. During the summer of 1880. the DSP&P built westward from Nathrop up Chalk Creek to St. Elmo before quitting construction for the winter. Early in 1881, track crews pushed past nearby Morley (also called Red Town because all the buildings were painted red, and later renamed Romley in 1897) to Alpine Pass, where they began construction of a tunnel. The tunnel lay in Ute Indian hunting lands, however, and the Ute Indians reportedly laid a curse on it because the presence of men and machinery ruined the place as a hunting ground. The work was difficult and dangerous. In their remote location, the building crew experienced difficulties among themselves that they resolved by hanging one crewmember. When the tunnel was finally completed the first train through it derailed. In 1882, the first DSP&P train steamed successfully into Gunnison through the Alpine Tunnel, then the highest tunnel on the continent. The railroad built numerous other timber and iron bridges on its way from Nathrop to Gunnison, including this wrought iron deck truss over Pomeroy Gulch at Morley. Built by a DSP&P construction crew in 1881. the Morley Bridge carried railroad traffic into the 20th century. As the mines in the region gradually played out, segments of the rail line were closed, this one in 1926, and converted to a county road. The Morley Bridge was redecked to carry cars and it carried vehicular traffic until 1992 when it was converted to a pedestrian bridge. The bridge now stands unaltered and adapted to a new use.

Beginning in the late 1870s, the pin-connected wrought iron truss was the roadway bridge of choice for medium- and long-span crossings in America. Made of numerous built-up metal members connected to form series of triangles in a variety of web configurations, trusses functioned as complex, long-span beams. Colorado's counties erected a typical array of truss types, but concentrated primarily on the Pratt and its subtypes in the late 19th and early 20th centuries. The earliest Pratts featured pinned connections in what was known as the "American style" of truss assembly. While the Pratt truss was a popular design for many years, the ever-changing technology of the field required constant upgrades and improvements to the earlier designs. As a result, cast-iron and wrought iron bridge members were virtually eliminated due to the availability of steel by the 1890s; extant examples are rare and significant in Colorado.

Supported by stone masonry abutments, the Morley Bridge features a Pratt configuration with six panels spaced evenly over an 80-foot span. The structure employs wrought iron members rolled in the Trenton Works of the New Jersey Iron Company. Its upper chords are comprised of two back-to-back channels with lacing. The verticals are similarly configured with back-to-back channels laced together by metal straps. The lower chords are made up of two or four rectangular bars with punched eyes.

The diagonals and inclined endposts use two punched eyebars; the counters are eyerods with slotted turnbuckles. The struts are comprised of two laced channels, and the lateral braces are iron rods. Bolted to the upper chords at each panel point are paired I-beam floor beams that carry the timber deck and iron rails.

Functioning in place for over 120 years, the Morley Bridge is Colorado's oldest dateable vehicular truss. It is one of the few trusses remaining in the state with wrought and cast iron components and the only pin-connected deck truss identified in the statewide historic bridge inventory. Historically and technologically significant, the Morley Bridge is one of Colorado's most important spans.