Since the frictional resistance between the load and two-thirds of the floor is larger than that of one-third of the floor the load is not moved in stages 1 to 3 inclusive, and remains in place.

The principle is valid in both directions, providing for both the loading and unloading of the trailer.

The principle of the Cargo Floor® sliding floor
The entire floor slides in one direction, transporting the load.
1st third of the floor is retracted, two-thirds is stationary
2nd third of the floor is retracted, two-thirds is stationary
3rd third of the floor is retracted, two-thirds is stationary
the entire floor is slid in the same direction, transporting the load.