L&N Bridge Piers
The piers look like they've been added to because they have been.
The original plan called for the bridge to go across on just the lower portion of the piers. That long span in the center would be a drawbridge for letting river traffic thru.
The river men had different ideas. They pointed to the Suspension Bridge, which was built high enough to not need a drawbridge, and said they'd go along only if the bridge were raised.
And rivermen had a lot more political influence the bridge builders.
So raised it was.