After knowing that halfpiper fixtures were popular for the North American market during the 1940s and early 1950s and that F100T17 and F90T17 fluorescent tubes were popular around that time, I have mostly known that halfpiper fixtures mostly used F20T12 and F40T12 fluorescent tubes using preheat ballasts. After knowing this information, I am beginning to wonder if any North American halfpiper preheat fluorescent tube fixtures designed for F100T17 and F90T17 fluorescent tubes actually existed. If they did, I would be interested in knowing which manufacturers made such fixtures.