The cars were built according to Pullman plan 4183; each contained six sections, six roomettes and four double bedrooms (colloquially "6-6-4").

On the inside, Pullman incorporated postwar improvements such as air-conditioning, fluorescent lighting, and sponge-rubber seats.

[1] A major improvement over the pre-war American series 6-6-4 sleeping car was the rearrangement of the accommodation: in the American series the premium-priced double bedrooms were at the vestibule end of the car over one of the trucks, the roomettes were in the middle, and the sections were at the blind (non-vestibule) end over the other truck; in the Pine series, the bedrooms were moved to the center of the car where the smoothest ride was.

[citation needed] The Louisville and Nashville Railroad (L&N) ordered 22 of the cars in 1951, primarily to replace the pre-World War II heavyweight cars on the Pan American, Humming Bird, and Georgian.

[2]: 123 The NC&StL's three cars became part of the L&N's fleet in August 1957 on the merger of the two railroads.