Abstract: A method of manufacturing a railcar having an enclosing superstructure which is capable of accommodating large vehicles such as semi-trucks is disclosed. The method includes the preparation of a previously used railcar or a railcar originally manufactured for another purpose and the subsequent attachment of a preferably widened superstructure applied thereto. Usable space and dimensions within the superstructure enclosure are maximized by the use of shallow weight bearing side structures, large top chords, stabilizing door headers, an extension of the railcar deck and thin end doors. Railcar accessories are accommodated within the interior of the superstructure such that minimal useful space is used.