As mentioned in my previous posting, the Old Chain of Rocks Bridge is quite unique as it has a dogleg [20-degree bend] right in the middle:
The reason for this unique feature: the planners had to allow for
- a 90-degree angle for barges passing underneath, directly into or with the flow of the Mississippi, and
- putting the foundations on solid rock.
For more information about this bridge check out „RailTrailsRoadTrip – Day 7 [ Old Chain of Rocks Bridge]“ in my blog „Pit’s Fritztown News„.