Like her companion, Oahu Coach No. 1, Combine No. 36 is a wonderful example of a typical wooden open-platform passenger car of the 19th Century.  This design was the classic standard on American railroads throughout the latter half of the 1800s, until the invention of the “vestibule car” in the 1880s.  The vestibule idea (illustrated below) enclosed the ends of the cars so that passengers could walk safely from one car to the next while the train was running.  This new design quickly displaced the ‘open-platforms’ that we see on these two Hawaiian cars.   However, the Oahu Railway & Land Co. built most of its own passenger cars and continued to construct new wooden cars using the old style designs.  The railway operated a significant fleet of open-platform cars until the end of its passenger service in the 1950s.