1915 12th Street Trafficway Viaduct in Kansas City, MO

(Bridge Hunter; Historic Bridges; 3D Satellite)

This viaduct crosses a lot of railroad tracks and climbs up to the top of the river bluff on the Missouri side. The trafficway has two roadways. The top deck is 2,300' long and as a grade of 5.5%. In the 1900s, engineers still had to worry about what a horse&wagon team could do. So the lower deck goes to a road on the side of the bluff so that it has only a 2.5% grade. Remember that reinforced concrete was still rather novel at the beginning of the 20th Century. Because of its two decks and 134' bowstring arch, it pushed the state-of-art for reinforced concrete construction. The form work was significant because 150 of the 200 workers were carpenters. But the work was organized so well that the viaduct was built in just 15 months. [ASCE, ahr-kc] It has been rehabilitated in 1965 and 2006. [BridgeHunter]

I've seen 200' and 150' for the height of the bluff. Since 5.5%*2300 = 126.5, it seems the 150' is more correct. And as I researched, the height went down. "The upper deck measures 2,278 feet and the lower deck is roughly 1,884 feet in length. At its highest point, the bridge measures 118 feet above the valley floor and measures roughly 30 feet wide." And some sources put the completion date as 1914. But it was opened to traffic on March 18, 1915. [NortheastNews]

This bridge was designed by J. A. L. Waddell. I recognize him as the pioneer of the lift bridge design starting with the 1894 Halsted Bridge in Chicago, IL. I was not aware that he also made significant contributions to reinforced concrete designs. And he added a 591' nickel-steel arch to his design repertoire for the 1917 Detroit-Superior Bridge in Cleveland, OH. [ahr-kc]

Street View

Street View

Street View

Street View

Street View

Real Photo Postcard via NortheastNews

ahr-kc

Doug Hitchcock posted
[Doug identifies the roundhouse as B&O/Chicago & Alton.]

Melanie Rowley posted
William W. Dobson shared
William W. DobsonAuthor Alvin Phipps, looks like round house next to bridge.
Alvin Phipps William W. Dobson I think it is the Illinois Central round house it was on that side of bridge and was made like that it was still standing till late 1990 or early 2000. The old Frisco shop was on the other side of the bridge later BN merged with Frisco it is still there now is a lumber yard shop still there. That yard is known as the 19th street yard BNSF is now got they switch down there. We had to go work on the Locos down there.

Doug Hitchcock commented on his post
[This shows the streetcar incline that was replaced by the trafficway. I think those are cable cars so their grade restrictions are not determined by the friction of wheels on rails.]