A trailer car is just what its name implies – a car which is coupled and towed along, trailing behind a powered streetcar.  This was a cost-effective way to double capacity during peak rush times.  Trailer cars were popular in the 1910s and 1920s before the ridership crash of the Great Depression.  From 1936-2004, this carbody was used as the office of a local iron works in Union, NJ, a form of adaptive reuse which saved many trolley cars from destruction. The car is now being stabilized complete with reinstalled windows, a repaired roof, reinstalled trucks, and new paint job.