Robert Street Bridge

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Robert Street Bridge
Picture of the Robert Street Bridge taken in early spring, 2006.
Official name	Robert Street Bridge
Carries	South Robert Street
Crosses	Mississippi River
Locale	St. Paul, Minnesota
Design	Reinforced concrete multiple-arch
Longest span	264 feet (80.5 meters)
Total length	1534.4 feet (467.7 meters)
Width	78.5 feet (23.9 meters)
Clearance below	62 feet (18.9 meters)
Opening date	1926
Coordinates	44°56′38.13″N, 93°05′14.65″W
Maps and aerial photos Street map from Google Maps or Yahoo! Maps Topographic map from TopoZone Aerial image or topographic map from TerraServer-USA Satellite image from Google Maps or Microsoft Virtual Earth

The Robert Street Bridge is a reinforced concrete multiple-arch bridge that spans the Mississippi River in downtown St. Paul, Minnesota. The bridge is notable for its complex design that was required to accommodate river traffic, the St. Paul Union Pacific Vertical-lift Rail Bridge crossing underneath it at an angle, and roadways on the downtown side of St. Paul. The bridge is also notable for a monumental reinforced concrete rainbow arch. The rainbow arch not only provides 62 feet of headroom above the river, but also provides a strong aesthetical focus. It was built in 1924-1926 by Fegles Construction Company, Ltd. and designed by Toltz, King & Day, Inc. The bridge was added to the National Register of Historic Places in 1989.

Another view of the Robert Street Bridge that shows how the railroad track passes underneath.

The bridge was commissioned in the early 1920s to replace a wrought-iron span, originally built in 1884-1885, that had become obsolete due to increasing traffic. The engineers who designed the bridge had several obstacles to work around. The tracks of the Chicago, St. Paul, Minneapolis and Omaha Railway, St. Paul Union Depot, and the Chicago Great Western Railway mainline were factors. The engineers also had to provide adequate clearance above the river, as defined by the United States War Department at the time. Finally, the bridge had to clear Second Street in downtown St. Paul and work through a busy manufacturing district at the south end. The location of nearly every pier was dictated by these requirements. As a result, the bridge was designed with a combination of barrel-arch and rib-arch flanking spans and a rainbow arch for the central span.