To lock through (Old Hickory) you want to call (615) 847-3281, the operator to see if they have any barge traffic coming through anytime soon.
Barges normally take 2-21/2 hours to lock through. You don't want to be stuck behind a barge when you are ready to leave.
To lock through, look for the pull chain in a raceway in the wall. Pulling that chain let's the operator know that you are wanting to lock through.
If he has to blow the water out of the lift chamber, he will sound a siren for one minute to let boaters know and get out of the discharge area, on the outside of the slip wall, downstreamof the damage gates area.
Once he gets the chamber either empty or full, according to whethe you are coming up or going down, he will open the lock "doors". When the doors are fully opened and locked, he will sound a very loud horn, you may now drive in.
You MUST wear your PFD in the lock!
Once inside, there are a series of tie off floats located in raceways built into the wall. Tie your boat off to one of the. It's good to have boat bumpers with you.
The operator then close's the doors and proceeds to flood the chamber (or empty it).
When that process is complete, he opens the doors, blows the horn, and you can then untie and motor out.
From the time the doors close to drive out is about 15 minutes at normal summer pool. With the river being 17 ft higher than summer pool, it takes about half as long now.
Hope this answersyour questions about locking through.
This beats launching at the long steep ramp on the Rayon City side of the dam. Plus, the lot there has a lot of sketchy traffic unlike the Rockland ramp which is.patrolled by Hendersonville police.