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| Name | UP Nemadji River Bridge Chicago & North Western Railway Bridge #951 |
| Built By | Chicago, St. Paul, Minneapolis & Omaha Railway |
| Currently Owned By | Union Pacific Railroad |
| Superstructure Contractor | Chicago Bridge & Iron Works of Chicago, Illinois (Main Span) Unknown (North Approach) |
| Substructure Contractor | Unknown (Main Pier) Unknown (Approach Pedestals) |
| Erection Contractor | Strobel Steel Construction Company of Chicago, Illinois (North Approach) |
| Length | 2,420 Feet Total, 80 Foot Main Span |
| Width | 1 Track |
| Height Above Ground | 25 Feet (Estimated) |
| Superstructure Design | Deck Plate Girder, Steel Stringer and Timber Pile Trestle |
| Substructure Design | Stone Masonry, Steel Tower, Concrete and Timber Pile |
| Date Built | 1916, North Approach Reconstructed 1949-1954 |
| Traffic Count | 3 Trains/Day (Estimated) |
| Current Status | In Use |
| Chicago & North Western Railway Bridge Number | 951 |
| Significance | Moderate Significance |
| Documentation Date | 2/8/2014 |
In 1880, the Chicago, St. Paul, Minneapolis & Omaha Railway (Omaha Road) constructed a line between Spooner, Wisconsin and Trego, Wisconsin as part of a larger project to construct towards Bayfield, Wisconsin. In 1881, the Omaha Road constructed 9 miles from Trego, Wisconsin to Lakeside, Wisconsin. The same year, the Chippewa Falls and Northern Railway (CF&N) constructed 15 miles between Chippewa Falls, Wisconsin and Bloomer, Wisconsin. In 1882, the Omaha Road constructed an additional 52 miles from Lakeside to Itasca, Wisconsin; and the CF&N completed an additional 54 miles between Bloomer and Spooner. Also in 1882, the Omaha Road came under control of the Chicago & North Western Railway (C&NW), which had begun to construct and acquire a large railroad network throughout the Midwest. In 1883, the Eau Claire and Chippewa Falls Railroad (EC&CF) constructed 11 miles between the existing Omaha Road mainline at Eau Claire, Wisconsin and Chippewa Falls. By the end of 1883, the CF&N and EC&CF were both consolidated into the Omaha Road. In 1884, the Superior Short Line Railway (SSL), a subsidiary of the Omaha Road, completed an additional 6 miles to the St. Louis River at Superior, Wisconsin. By using trackage rights over the Northern Pacific Railway, the SSL completed an additional 2 miles in Duluth, Minnesota in 1886. The SSL would be formally merged into the Omaha Road in 1895. This line served as one of the northern mainlines of the Omaha Road, and would share the right-of-way with the other mainline between Spooner and Trego, Wisconsin. These two mainlines formed a large X through northwest Wisconsin. The line was critical to serving a booming logging and forestry industry in northwest Wisconsin.
The C&NW constructed and acquired a large amount of trackage through the Midwest, and the Omaha Road provided additional lines in western Wisconsin, southern Minnesota and parts of Iowa, Nebraska and South Dakota. By the early 20th Century, the Omaha Road operated a respectable network of railroad lines, serving in conjunction with the C&NW lines. The Omaha Road would be leased by the C&NW in 1959, and formally merged into the C&NW in 1972. Throughout the mid-20th Century, the line remained critical to the Omaha Road and C&NW. During the late 20th Century, the C&NW sought to sell or abandon unprofitable and excess lines. In 1992, the Cameron, Wisconsin to Itasca segment would be sold to Wisconsin Central, Ltd. (WC) as part of a larger sale of the other mainline between Cameron, Wisconsin and Superior, Wisconsin. Soon after, the Rice Lake to Gordon, Wisconsin segment would be abandoned in favor of the parallel Soo Line Route; and the Soo Line Route between Gordon and Itasca would be abandoned in favor of the C&NW route. The abandoned lines would be acquired for trail use. In 1995, the C&NW was purchased by Union Pacific Railroad (UP). In 2001, WC would be acquired by Canadian National Railway (CN), and become the American subsidiary of the railroad. Starting in 2004, the Wisconsin Northern Railroad (WN) leased the Chippewa Falls to Cameron line from UP. Today, the Wild Rivers Trail uses the former railroad between Rice Lake and Gordon. UP owns and operates two separate segments, including from Itasca to Superior and from Eau Claire to Chippewa Falls. CN continues to own and operate two segments, including from Cameron to Rice Lake, and from Gordon to Itasca. WN continues to operate over UP-owned tracks between Chippewa Falls and Cameron, serving a booming frac sand industry.
Located on the east side of Superior, this large deck girder and steel stringer bridge carries the former Chicago, St. Paul, Minneapolis & Omaha Railway over the Nemadji River. The first bridge at this location was constructed in 1884, when the Superior Short Line Railway extended this line into Superior. Originally intended to be a fixed timber bridge, it was decided to make the bridge a swing span, on account of the growing commercial river navigation on the Nemadji River. This first bridge consisted of a 225-foot, riveted lattice through truss swing span, set onto a stone pier and approached by timber pile trestle spans. It is unknown what company fabricated the bridge, although the Omaha Road and subsidiaries were heavily using Alden & Lassig Bridge & Iron Works at this time. By the early 20th Century, the original bridge had become too light for traffic, and navigation on the Nemadji River had significantly declined. It was decided to rebuild the bridge with a fixed span.
In 1916, the swing span would be replaced by a single deck plate girder span, approached by 167 timber pile trestle spans on the north end and 11 timber pile trestle spans on the south end. The bridge remained in this configuration until 1949, when the Omaha Road began a project to replace the north approach with steel spans. Between 1949 and 1954, the entire 2,200 foot approach would be replaced by a new steel stringer viaduct, giving the bridge its present configuration. Currently, the bridge consists of an 80-foot deck plate girder span, approached by 79 28-foot steel stringer spans on the north end and 11 timber pile trestle spans on the south end. The center stone pier of the bridge was notched to accommodate the girder span, which also rests on a timber pile pier. The north approach rests on steel towers, set onto concrete pedestals. An unknown contractor constructed the center pier when the first bridge was constructed. Chicago Bridge & Iron Works fabricated the main span, while the north approach was fabricated by an unknown contractor. Strobel Steel Construction Company erected the north approach, and an unknown contractor constructed the concrete substructures.
The deck plate girder span uses a standard design, with heavy girders and an open deck. The north approach uses two heavy steel stringers per track, typical of mid-20th Century spans. The towers are constructed mainly of solid members, connected by cross bracing. Unlike traditional steel towers, several individual towers are connected by cross bracing at various points throughout the bridge, giving a configuration of individual towers, as well as sections of two and three connected towers. Deck plate girder spans were commonly used by railroads, as they were durable and easy to construct. Steel stringer spans were also popular for lengthy viaducts, as they were the most cost effective and permanent solution. Since the last reconstruction, various repairs have been made to the bridge, including the addition of sheet piling around the south pier, and encasing the center pier with sheet metal. Overall, the bridge appears to be in fair to good condition, with no significant deterioration noted. The author has ranked this bridge as being moderately significant, due to the length of the structure.
Citations
| Builder and build date (main span) | Chicago Bridge & Iron Works plaque |
| Build date (north approach) | The Duluth News Tribune; August 15, 1954 |
| Erection Contractor (north approach) | Railway Age; Volume 131, Issue 21 |
| Railroad History Citation | ICC Valuation Information, Compiled by Richard S. Steele |