The Cantilever gate shown in figure 2 has two gate roller posts and one latch post. The gate slides between the two rollers on top and bottom and is also held up by these rollers. As it slides to close, the counterbalance which is the extra length of the gate, is held between the two rollers.
Cantilever gates require enough space for full length of the opening plus the counter balance or back frame section on the opening side. These gates are always welded and the horizontal rails on top and bottom are always 2 1/2 inch OD. or 2" X 2" square tube.