In some aspects, a conveyor chain includes a first link, a second link, and a coupler link coupled between the first link and the second link. The first link includes a first portion and a second portion, the second portion oriented parallel to and laterally spaced apart from the first portion. The first portion includes a first sprocket-engaging pin protruding laterally, and the second portion includes a second sprocket-engaging pin protruding laterally. The second link includes a first portion and a second portion. The first portion includes a first sprocket-engaging portion protruding laterally, and the second portion includes a second sprocket-engaging portion protruding laterally. A flight bar is positioned adjacent an end of the first sprocket-engaging portion of the first link.