steam and air connections. A special type of baggage car came equipped with doors on one end to facilitate transport of large pieces of equipment and scenery for Broadway shows and other productions. These "theatrical" baggage cars were assigned theatrical names (i.e. Romeo and Juliet), and were similar to the "horse cars" that were used to transport racehorses. Express car Express cars carried high-value freight in passenger consists. These cars resembled baggage cars, although in some cases specially-equipped box cars or refrigerator cars were used. Horse car Specialized stock cars were used to transport horses and other high value livestock as part of passenger consists. Similar equipment is used in circus trains to transport their animals. Prisoner car In some countries, such as Russia, convicts are transported from court to prison or from one prison to another by railway. In such transportation a specific type of coach, prisoner car, is used. It contains several cell compartments with minimal interior and commodities, and a separate guard compartment. Usually the windows are of nontransparent opaque glass to prevent prisoners from seeing outside and determine where they are, and windows usually also have bars to prevent escapes. Unlike other passenger cars, prisoner cars do not have doors at the ends of the wagon. Railway post office Like baggage cars, railway post office (RPO; US term) cars or travelling post offices (TPOs; British term) were not accessible to paying passengers. These cars' interiors were designed with sorting facilities that were often seen and used in conventional post offices around the world. The RPO is where mail was sorted while the train was en route. Because these cars carried mail, which often included valuables or quantities of cash and checks, the RPO staff (who were employed by the postal service and not the railroad) were the only train crews allowed to carry guns. The RPO cars were normally placed in a passenger train between the train's motive power and baggage cars, further inhibiting their access by passengers. Specialized types Colonist Car A colonist car or emigrant car was a special sleeping car designed to take immigrants from ocean ports to settlement areas in western North America at the cheapest possible fare. They offered simple sleeping berths and a cooking area for immigrants who were expected to bring their own food and bedding. Combine A combine is a car that combines features of a head-end and