Steel in freight car construction

It has been the custom among designers of freight cars either with underframes of steel or of wood to depend upon the strength of the underframe alone in making computations for a specified carrying capacity, despite the fact that the superstructure in many cases can and does constitute a truss. The author presents the evolution in design of structural steel freight cars, with which he has been closely identified, where the value of the superstructure as a tress has been duly considered as an element of strength and in reducing weight.