Wood frame cars In the period 1900 to 1920, Cincinnati Car Co made many arch window all wood interurban coaches, combines (part passenger, part freight), freight "motors," and work cars. It had many competitors such a JG Brill, Kuhlman, and Jewett.
Steel frame cars Starting in the 1920s, interurbans became constructed of steel for easier and faster assembly and also for improved passenger safety in accidents. But this made them consume more electric power when operating. When interurban lines began to face stiff competition from autos on state county newly paved highways, the need to use less power became essential, and Cincinnati Car was among the first manufacturer of interurbans to make lightweight cars. Its chief engineer Thomas Elliot designed the "curved-side" car, a lightweight model that used curved steel plates (not conventional flat steel plates) in body construction. Instead of the floor, the side plates and side sills bore the bulk of the weight load. Longitudinal floor supports were no longer needed, which made the cars lighter than conventional cars. The first cars of this type were sold in 1922 and many after. It was a successful product. For instance, the
Red Devil weighted only . Curved-sided cars were called "Balanced Lightweight Cars" in advertising.
Other interurban buyers Another customer of the Cincinnati Car Company was the
Northern Indiana Railway which was centered in South Bend, IN, and had lines radiating to Michigan City and Goshen in Indiana and to St. Joseph, Michigan. Cincinnati Car's lightweigt cars were purchased by the Northern Indiana Railway over the years for interurban and streetcar passenger application as well as trailers and flatcars for freight. Northern Indiana Railway purchased ten new streetcars from the Cincinnati Car Company in 1930 which was the next to last order for new cars built by CCCo. After the Northern Indiana Railway abandoned its last five city streetcar lines in 1930 and replaced them with buses. These cars went onto the Virginia Electric Company in Richmond where they continued in use until 1949. == Preserved cars ==