in accordance with the present invention a combination hatch cover design is provided in a railway hopper car roof wherein a smaller hatch cover is entirely mounted upon a larger , preferably elongated or continuous hatch cover and wherein the smaller hatch cover can be operated independently of the locking arrangement of the larger cover . the combination hatch covers of the present invention may be made of metallic or non - metallic material , preferably of metal alloy or reinforced plastic . if desired , the small cover can be mounted with its axis along the longitudinal axis of the large cover whereby in open position the small hatch cover will not obstruct the walkway on the car .