The Marx observation passenger car was a 6-inch passenger car based on the design Marx used for its 6-inch freights. The basic design underwent some changes and updates over the years, but Marx used the name from 1935 to 1942, then resumed production in 1946 and continued until 1961. Observation cars ran on the end of passenger trains and had a platform that passengers could use to admire the landscape as the train moved.
Marx 6-inch observation car










