| Name | BNSF Tarkio River Bridge (Stanton) Chicago, Burlington and Quincy Railroad Bridge #435.89 |
| Built By | Chicago, Burlington & Quincy Railroad |
| Currently Owned By | BNSF Railway |
| Superstructure Contractor | American Bridge Company of New York (Spans #2-#6) Unknown (Spans #1 and #7) |
| Substructure Contractor | Unknown |
| Length | 355 Feet Total, 80 Foot Largest Span |
| Width | 2 Tracks, 1 In Use |
| Height Above Ground | 75 Feet (Estimated) |
| Superstructure Design | Deck Plate Girder and Concrete Modular Girder |
| Substructure Design | Concrete, Steel Tower and Steel Pile |
| Date Fabricated | 1902 (Spans #2-#6) c. 1910 (Spans #1 and #7) |
| Date Erected | 1902 (Spans #2-#6) c. 1970 (South Track Spans #1 and #7) c. 2000 (North Track Spans #1 and #7) |
| Original Location (South Track Spans #1 and #7) | Unknown |
| Traffic Count | 25 Trains/Day (Estimated) |
| Current Status | In Use |
| Chicago, Burlington & Quincy Railroad Bridge Number | 435.89 |
| BNSF Railway Bridge Number | 435.89 |
| Significance | Local Significance |
| Documentation Date | 11/9/2016 |
In May 1854, the Burlington and Missouri River Railroad (B&MR) began constructing a new mainline across southern Iowa, with the goal of connecting the Mississippi River at Burlington, Iowa to the Missouri River near Omaha, Nebraska. In 1857, the first 34 miles between Burlington and the Skunk River near Rome, Iowa were completed. In 1859, an additional 41 miles between the Skunk River and Ottumwa, Iowa were completed. The railroad ceased progress during the Civil War, and eventually continued west in 1866. That year, an additional 24 miles were completed between Ottumwa and Albia, Iowa. Work continued in 1867, when an additional 46 miles were completed to Woodburn, Iowa. Between 1867 and 1868, the Chicago, Burlington & Quincy Railroad (CB&Q) constructed a bridge across the Mississippi River to connect this line to their lines in Chicago. In 1868, an additional 34 miles opened west to Afton, Iowa; followed by an additional 59 miles west to Red Oak, Iowa in 1869 and an additional 32 miles to the Pacific Junction, Iowa in 1870. In 1872, the B&MR was leased by the CB&Q; and was fully absorbed by the company in 1875. In the 1870s, the line would be extended into Nebraska, and in 1880, a bridge was constructed across the Missouri River at Plattsmouth.
This line formed a critical backbone for the CB&Q, connecting Chicago to territories west of the Missouri River. By the late 1870s, the need for a second track on this route had become apparent. A second track was constructed between Chillicothe, Iowa and Albia in 1879, including a new alignment around the south side of Albia. In 1880, a second track was constructed between Burlington and West Burlington, Iowa; as well as between Albia and Russell, Iowa. In 1885, a second track was constructed between Russell and Chariton, Iowa; followed by between Ottumwa and Chillicothe the following year. A large segment of second track opened between West Burlington and Mt. Pleasant, Iowa in 1889. By the turn of the 20th Century, several sections of this line required extensive upgrades in addition to a second track. In 1900, a second track was completed from Mt. Pleasant to Ottumwa and from Chariton to Creston, Iowa. A new alignment was constructed between Fairfield, Iowa and Batavia, Iowa; and between Agency, Iowa and Ottumwa in 1900. In 1901, the line was double tracked between Chariton and Creston. The 1901 work involved constructing a second single track alignment between Indianola Junction and Lucas, Iowa; between Woodburn and Osceola, Iowa and between Murray, Iowa and Creston. Between 1902 and 1905, the Creston to Pacific Junction segment was double tracked. In 1904, a realignment between Nodaway, Iowa and Emerson, Iowa opened to traffic; followed by a large realignment between Malvern, Iowa and Pacific Junction in 1905.
Throughout the 20th Century, this line remained critical to the CB&Q. The CB&Q invested significant capital into maintaining this line, replacing bridges, revising grades and changing the alignment in spots. One of the most prominent changes came in 1949, when the westbound track near Frederic, Iowa was straightened, to eliminate a segment of curvy original mainline. In 1970, CB&Q merged with Northern Pacific Railway and Great Northern Railway to form Burlington Northern Railroad (BN). Several segments of this line were single tracked in the mid to late 20th Century. In 1996, BN merged with Atchison, Topeka & Santa Fe Railway to form BNSF Railway, the current owner of this line. Today, this line remains a critical piece of railroad infrastructure. BNSF currently operates a portion of the Ottumwa Subdivision between Burlington and Creston; and a portion of the Creston Subdivision between Creston and Pacific Junction.
View an article discussing the 1902-03 realignment project (digitalized by Google)
Located near the town of Stanton, this large deck plate girder viaduct carries a former Chicago, Burlington & Quincy Railroad mainline over the Tarkio River. The first crossing of the Tarkio River was located approximately 1,700 feet upstream, and included timber bridges across both the Tarkio River and Little Tarkio Creek. In approximately 1880, the bridges were rebuilt with iron spans, set onto new stone piers. Between 1902 and 1903, the CB&Q realigned and double tracked their mainline across western Iowa. As part of the project, the railroad was realigned further south, and a new viaduct was constructed. Soon after completion, portions of the abutments failed due to settlement of the approach embankments, and 20-foot steel stringer and timber pile trestle spans were installed at each end. The bridge remained in this configuration until approximately 1970, when the approaches were replaced with secondhand 30-foot deck plate girder spans, set onto new concrete abutments and piers. The most recent alterations came in approximately 2000, when the approach spans of the north track were replaced with precast concrete modular girder spans, and helper bents installed in front of the end piers.
Currently, the bridge consists of two 80-foot and one 75-foot deck plate girder main spans with two 30-foot deck plate girder tower spans. On the south track, the approach spans consist of a single 30-foot deck plate girder span on either end, while the north track uses a 30-foot concrete modular girder span on either end. The bridge rests on steel towers, concrete abutments, piers and pedestals and is also supported by timber and steel pile helper bents at the ends of spans #2 and #6. The main portion of the bridge follows a standard design, with two heavy plate girders for the main spans and two lighter plate girders for the tower spans. The approach spans (spans #1 and #7) of the south track follow a similar design to the tower spans, and appear to have originally been fabricated in approximately 1910 for use at another location. The towers are heavily constructed, consisting of four heavily V-laced box beams, plate girder transverse bracing and additional V-laced and solid beams. The pedestals use a standard shape, while the approach piers and abutments both use a standard rectangular design. American Bridge Company fabricated the main portion of the bridge (spans #2 through #6), while an unknown contractor fabricated the approach spans. It is unclear if the concrete substructues were built by railroad company forces or by an unknown contractor. While the work for grading the new line in 1902-03 was contracted, there is no clear indication that the bridge work was included in the contract. In addition, sections of the same project east of Creston utilized railroad company forces to construct the concrete bridges. Deck girder viaducts were popular for tall and long bridges, as the design provided the most economical solution. Deck plate girder spans were also popular for railroad use, as they were durable and easy to construct. Since the 2000 alterations, the bridge has seen no significant changes. Today, only the north track is in use, while the south track is used as an access road. Overall, the bridge appears to be in fair to good condition, with no significant deterioration noted. The author has ranked this bridge as being locally significant, due to the common design. A number of similar viaducts were constructed along the CB&Q in Iowa.
Citations
| Build date (spans #2 through #6) | Chicago, Burlington & Quincy Railroad Valuation Summary at the Newberry Library |
| Builder (spans #2 through #6 superstructure) | American Bridge Company plaque |
| Railroad History Citation | ICC Valuation Information, Compiled by Richard S. Steele |