NS Train I24 has dropped off its rear block of autoracks at NS Voltz Yard and proceeds past the Wabash Searchlight Signals at Birmingham Interlocking on the NS Kansas City District-BNSF Brookfield Sub., en route to Randolph to pull and spot frame empties and loads. The autorack on the head end is a buffer car to protect the engine from the frames, which are considered shiftable loads.