In the 1920s many railroads in the United States of America had retired 0 - 4 - 0 steam locomotives .
Railroads were too small to move freight cars in yards and were too small for switching duties .
In the 1920s many railroads in the United States of America had retired 0 - 4 - 0 steam locomotives , because they were too small to move freight cars in yards and were too small for switching duties .