|20150820,21 4195 12:24:18
The tow we initially saw under the bridge seems to have stopped for now. I didn't think Lock and Dam #52 was still being used. It seems they are doing construction there. Maybe I-24 is not the only congestion because of construction. (Update: I was wrong. Lock and Dam #52 has evidently not been retired and they were using the lock during this visit.)
Under the bridge is a medium sized tow heading downstream. So tows in both directions are using the north channel.
And the construction barge is making good progress towards the bridge.
Later when we crossed the Blue Hummer Bridge, my wife took some downstream pictures. She caught a 15-barge tow heading under the bridge. I analyzed the first tow I saw, and I think this is a different upstream tow.