An overhead guide track system for automated material handling and storage facilities wherein at least one transfer unit is suspended from carriages that travel along the track system, the track system including a plurality of first and second support beams being assembled in an X-Y manner such that the first and second support beams intersect with one another in perpendicular relationship and wherein each of the first and second support beams includes a horizontal flange connected to a central vertical web, each of the vertical webs of the first and second beams having opposite ends connected to vertically oriented pedestals at a plurality of intersections of the first and second support beams and which pedestals support transfer plates over which the carriages are supported as the carriages pass over open gaps between the horizontal flanges at the intersections of the first and second support beams.