D&RGW Green River Bridge
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This page was last updated on October 14, 2024.
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Overview
The five Rio Grande bridges over the Green River at Green River, Utah, and their year of completions.
-- 1883, narrow-gauge, timber pile trestle, destroyed by floods in Spring 1883.
-- 1883, narrow-gauge, second timber pile trestle with Howe trusses, replacing first timber pile trestle
-- 1885, narrow-gauge, wrought iron four-span Pratt truss (three 165-foot spans, one 115-foot span), pin connected; standard-gauge track laid in 1890
-- 1900, standard-gauge, steel three-span Parker truss, one one-span Pratt truss, pin connected
-- 1931, standard-gauge, steel three-span Warren truss with verticals, riveted connections
First Bridge
(1882-1883)
The first bridge over the Green River was a timber pile trestle erected in the winter of 1882-1883 and destroyed by spring floods in March 1883.
March 27, 1883
"The Denver & Rio Grande telegraph lines were connected at Grand Junction on Monday, 215 miles from Salt Lake. It is expected the line will be working through to Denver to-day. The Green River bridge will be so near completion on Thursday [March 29th] as to allow the passage of trains." (Salt Lake Daily Herald, March 27, 1883)
March 29, 1883
"The First Through Train. -- On Monday next the first through train will leave Denver for Salt Lake over the Denver and Rio Grande Railroad. It is expected that the bridge over Green River will be finished to-day, when the line will practically be completed for the whole distance, and the new connecting link between Utah and the east will have been established. It was promised six months ago that the road would be completed by the first week in April, and it is not a little pleasing to note that promise will be kept." (Salt Lake Daily Herald, March 29, 1883)
"The Denver & Rio Grande Western Railway completed construction of its narrow gauge line across the Utah desert to a connection with the Denver & Rio Grande. The joining of the rails actually occurred at Desert Switch, 14 miles west of Green River, at 1:30 p.m. Friday afternoon, March 30, 1883." (Dreams, Visions and Visionaries, CRRM Annual No. 20, 1993, page 64)
(Research suggests that this first bridge was a temporary bridge, constructed to allow construction materials to be moved west of Green River, and to allow operations to begin as soon as the final track connection was completed on March 30th. The first bridge may have been temporary pending the completion of the final Howe truss version being built in Canon City, and delivered to the site very soon after the first operations. The first passenger train eastward from Salt Lake City to Denver did not operate until April 8th, which may indicate that for public safety reasons, the Howe truss bridge wasn't installed and ready for service until that date.)
Second Bridge
(1883)
The second bridge was a timber pile trestle and with framed Howe trusses, completed in 1883.
The following comes from the April 14, 1883 issue of the Ogden Standard newspaper.
There are two bridges of note west of Gunnison; these are at Grand Junction, crossing the Grand River in Colorado, and at Green River in Utah. That at Grand River is 700 feet long, has five Howe trusses, longest span 150 feet, landed on stone piers built on bed rock foundation.
The bridge at Green River has six Howe spans, is built of Colorado timber, shipped from Durango, and framed at Canon City. The iron work was prepared at Pueblo. This bridge is 400 feet long. Al the ties used on the road are of spruce pine.
(Read the Wikipedia article about Howe Truss bridges)
(Read about the history and design of Howe Truss bridges)
Third Bridge
(1884-1885)
The third Rio Grande bridge over the Green River was a pin-connected wrought iron Pratt truss of three 165-foot main spans plus a 115-foot-long fourth approach span on the west bank.
(The 115-foot fourth span on the west bank was eliminated in 1931 when the fifth bridge replaced the fourth bridge.)
The third bridge was erected in the winter of 1884-1885 by the bankruptcy trustee of the narrow gauge Denver & Rio Grande Western Railway Company prior to the company's reorganization as the Rio Grande Western Railway Company.
A photo taken in 1890 by William Henry Jackson, held at the Denver Public Library, shows the third Green River bridge. It also shows the newly completed standard gauge tracks.
(View the W. H. Jackson photo at Denver Public Library)
The bridge in the photos taken by George Edward Anderson in 1900 show the third Rio Grande bridge over the Green River being replaced by the fourth bridge.
The stone piers, according to one source constructed with Chinese labor, were commenced in 1883 just after the railway was completed, then suspended while the D&RGW's lease to the D&RG (the Colorado lines) collapsed, and not completed until 1884.
(View the George Edward Anderson photos at Brigham Young University)
The G. E. Anderson photos show the dismantling of the 1885 iron trusses of the third bridge in preparation for replacement by much heavier steel Parker trusses of the fourth bridge. As the existing bridge was dismantled, the track was supported by the pile trestle.
The following is an abstract of Pratt truss design taken from Wikipedia.
A Pratt truss includes vertical members and diagonals that slope down towards the center, the opposite of the Howe truss. The interior diagonals are under tension under balanced loading and vertical elements under compression. The Pratt truss was invented in 1844 by Thomas and Caleb Pratt. This truss is practical for use with spans up to 250 feet and was a common configuration for railroad bridges as truss bridges moved from wood to metal. They lend themselves well to long spans. They were common in the United States between 1844 and the early 20th century.
(Read about the history and design of Pratt Truss bridges)
Fourth Bridge
(1900)
The fourth bridge was a steel bridge of Parker trusses, completed in 1900.
A Parker truss bridge is a Pratt truss design with a polygonal upper chord.
Fifth Bridge
(1931)
The current Green River bridge is the fifth bridge at Green River. The superstructure is a 495-foot long riveted-connection Warren truss with verticals, of three equal spans of 165 feet each.
The bridge was designed to the 1923 AREA specification with an E-70 loading, and was fabricated by the American Bridge Co. in 1931, and installed in 1931.
The fifth bridge included extending the west bank embankment to eliminate the 115-foot fourth span at the west end of the bridge. The ashlar stone pediments on each abutment of the third bridge were also cut down in 1931.
Mark Hemphill comments about Warren truss bridge design.
The name "Warren Truss" is irritating. It should be named a Whipple Truss, for Squire Whipple (1804-1888), rightly regarded as the father of the iron and steel truss bridge. Whipple designed bridges for the New York & Erie, Baltimore & Ohio, and other railroads. Whipple developed most of the truss patterns used by railroads in the U.S., patterns then copied by railroads worldwide. Whipple worked out the first theoretical method of calculating stresses and sizing members of a truss, in place of the rule-of-thumb methods that then abounded, often to the sorrow of the users and owners of the bridge.
The origin of the Warren Truss's namesake was James Warren, an engineer in England who with Willoughby Monzani in 1848 patented a design they had not even developed, but borrowed from others. Bridge historian Dr. Frank Griggs, Jr., observed, "Warren, when he developed his truss, did not know how to size his members nor could he distinguish between tension and compression in his web members. He never designed or built a truss with an inclined end post nor a truss with verticals. A truss as he patented it was never built." Whipple had already designed and built what became known as the Warren truss, but the wrong name stuck regardless.
More Information
(Download the National Park Service's two-page PDF describing all types of truss bridges)
(Read the Wikipedia article about truss bridges)
Sources
Research completed by Mark Hemphill.
Available online digital newspapers.
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