Barge in Lock Video

Video of a barge going through the lock at Trempealeau, WI

The barge & tug were too big to be lowered at the same time, so the tug pushed the barges (6 total) in and then backed out of the lock.  Once the water level inside the lock was low enough to equal the south end of the lock the south gate was opened and the barges were pushed out with only the current of the river.  Then the water level in the lock was raised to equal the north end of the lock, the north gate was opened and the tug entered.  Once again the water level was lowered (only about 1 foot), the south gate was opened and the tug was hooked up with the barges (huge cables) and the whole thing went on down the river.

The whole process took about 2 hours.  This goes on every time it goes through a lock.  It could easily go through all 27 locks along the trip.  The tugs have housing accommedations for the crew and have a cook or two and full kitchen.  They work around the clock 24/7 so there must be enough guys to cover all shifts.

The locks & dams were created because there were sections of the Mississippi River that were too shallow for most barges/vessels.  So the water was dammed up, sometimes as far upstream as the next dam and the locks were created to get the vessels from one side of the dam to the other.  Okay, that is a very simple explanation for a very complex system, but you can get more info at http://www.mvp.usace.army.mil/navigation/default.asp?pageid=145