What were trains made of in the 1930s?

Answer 1

The primary building material in steam locomotives was steel and cast iron.

In freight cars the basic frame was made of steel and cast iron, siding was mostly wood with some steel fittings.

Passenger cars were made primarily of steel with fabrics used in the seats and such. Most passenger cars made liberal use of wood for interior walls and cabinets.

The trucks were made of a combination of cast iron and steel. Side frames were usually cast while wheels and axles were usually steel