MudChicken teaches me new words all the time.[:)]
Think of it as the thread of the stream basically…
The KCS bridge at Vicksburg has had problems with piers settling since it opened in 1930. The bridge is actually a combination highway and rail bridge (US Highway 80). The roadway is 18’ wide and I believe is actually closed now. Rail traffic only uses the bridge other than crews using the roadway for access to work on the bridge itself. It is owned by the Vicksburg Bridge Commission and is/was a toll bridge.
In one of my more interesting books, Mary Costello’s “Climbing the Mississippi River Bridge by Bridge”, she has a note about this problem. Shortly after the bridge was completed a large slide of the entire riverbank occurred causing the settling of the two east piers and the first tower. The bridge has been maintained in proper level in spite of the settlement.
The I-20 bridge just to the south here also has problems with its piers due to settlement.
That’s correct, the roadway is closed to the public (and has been for a long time). The bridge was built as a private initiative and was later sold to the commission, and it is used by the railway on a toll basis.
The alignment shift is at the east end. The last time I rode over it a few years ago, we got out on the platform of the business car to look at it. The alignment shift is noticeable visually but not in ride quality as the speed limit is low.
RWM
PAUL DN: Wasn’t the now KCS bridge over the Mississippi at Vicksburg closed for a while because of scoring of one pier? Seem to recall if it hadn’t been found when it was the bridge could have been lost?
The Harahan Bridge at Memphis (formerly FRISCO RR-MO PAC RR, et. al.) Apparently, for years, has had what was described as a “floating” pier, no support from river bottom or into bed rock;(The Western one in the river.) I was told this many years ago, by a railroad watchman and a track foreman. Still is used daily by UP.