That's known as a "gap bed" lathe. It allows for a short, larger diameter workpiece to be spun over the ways. I'm about to modify one of my 12 inch swing Atlas/Craftsman lathes by raising the headstock, tool post, and tailstock by 3 inches so I can swing a bigger faceplate- - - -16 inches, I believe. I plan to use that one for refacing flywheels and boring the big ends of Babbit connecting rods for insert bearings.
Jerry