That cable in the pic is not taunt and looks to be a safety stop during construction.
The loop at the top is not supporting weight.
“What lifts the gates?”
Guys go out before the monsoon season starts, and winch them up. They go out months later, and lock them down through the rest of the year.
During the Summer, when the gates are open, Border Patrol runs back and forth all shift, playing whack-a-mole.
It is better than the whole border being open (the gates can be monitored with cameras and sensors/alarms), but we could really use a better design to manage flood debris, without as much open vulnerability.
“The loop at the top is not supporting weight.”
Looks like the gate sits on some brackets on the side posts, once it’s hauled up.
Not a high tech solution.