This is based on the Ash Street Bridge (even though there are actually 4 separate bridges)
over the Sanitary & Ship Canal in Chicago, Illinois. This represents it as it appears today.
Apparently there is very little canal traffic so the bridges may be locked in the closed
position. In any case this is not interactive to open and close. At one time all 4 bridges
were in use with two tracks each and 4 tracks crossed those at a 90 degree angle on one end.
4 tracks crossing 8 tracks must have kept the gents in the crossing tower quite busy. I
don't know if the tower also controlled the operation of the bridges. For those who like
complex trackage a search should turn up photos. I have no idea why they are oriented this
way but photos clearly show this arrangement.