Check out these horizontal milling machine pictures:
M-70 and my helper
Image by Robbie1
This is the milling machine I employed to function on. It had three cutting heads and (if I keep in mind properly) 150 HP. It was a very good machine, but not numerically controlled. My helper is in the images. The element on the machine is the head box of a machine to make paper.
horizontal milling
Image by cnc-machining
big diameter horizontal milling at www.heartlandmachining.com