TWA operated these new planes from STL to Hawaii and I seem to recall that they frequently had pitstops in LAX on the way out to the islands, and the gas tanks were pretty near empty on the return from Hawaii to STL. With ATL being quite a bit further from STL (I think it's about 400 miles ATL-STL, so probably about 300 extra flight miles since STL is northwest of ATL) these planes would need to be making pitstops in LAX to get out to Hawaii and returning they might be needing those stops as well.