I found the pressurised cement trailers from Herpa and decided that the cement silos, needed a smaller silo to load the trailers. The loading silo is a combination of the frame from the Walthers - Grain Surge Bin kit & bottom tapered chute, Plumbing Pressure Pipe Socket & Domed Cap, Evergreen "H" Beams and 0.5mm Styrene Sheet.
The pressure pipe fittings (socket & cap) were a little rough, so I added the 0.5mm styrene sheet to provide a smooth surface. It also allowed the "H" beams to line up with the frame below.
Overall it's been a great little addition and will add to scene, it was relatively easy to make and I would use it again to make loading silos or vessels. Next step will be to attach the silo to the frame, add the access ladders, and piping from the main silos.