Abstract: A roof structure for covered hopper cars has roof sheets with curved sections disposed on each side of a continuous trough hatch opening. A hollow, beam-type side plate connects the outer margins of the roof sheets to the side wall unit and includes an outer transition member with a curved section forming part of the side plate and also having a lip extending inwardly of the vehicle to form a continuation of the curved roof sheet. A connection piece underlies transversely extending edges of the roof sheets to join the sheets. Intermediate bulkheads or partition sheets have a rounded top to fit snugly for attachment to the curved roof sheets and are rigidified by stiffeners which extend horizontally and transversely of the vehicle from side plate to side plate and are connected thereto to join with the roof sheets and intermediate bulkheads to form a rigid roof beam which resists twisting and deflecting during transit.