B-52 Pylon Question

I know that the B-52 has a pylon between fuselage and inner engine pair, but I saw another one in a cutaway.

See:
[ATTACH]161829[/ATTACH]
This pylon is between the engine pylons.

This is an excerpt of this one:
Click Me

Does anyone know if this pylon is actually existing and if so, for what is it used?