The caboose is a special car used as the last car on a train. It is designed to provide accommodations for
the train crew and carries such emergency equipment as lanterns and signal devices. Cabooses are of two basic
designs, both permitting men riding in them to observe train operations: they have either a raised glass cupola or
glass bays set into the sides of the car. Today many cabooses are equipped with microwave radios that provide
1.8. PASSENGER CAR
For a smooth and comfortable ride and for safety reasons, a passenger car is of heavier construction than a
freight car. Built for high-speed service, today's new commercial passenger cars are constructed of aluminum or
stainless steel; this makes them of much lighter weight than older ones. All cars used in a passenger train,
whether for mail or baggage, must meet the same safety regulations as those carrying people. Although the
Army has cars for transporting troops, for carrying guards when accompanying classified shipments, and for use
in ambulance service, the bulk of its rail equipment is for moving freight. For that reason, this text concentrates
almost entirely on freight cars.
Railway rolling stock is divided into seven broad categories: flatcar, enclosed car, gondola, hopper, tank
car, caboose, and passenger car. Many specialized variations in each category have been developed. The trend
in the design of rolling stock has been to modify equipment to meet changing transportation needs.
The open cars, such as flats, gondolas, and hoppers, are used primarily to transport equipment and bulk
products that do not need protection from the weather. With the development of containers and piggyback
trailers, the use of flats and gondolas has become more extensive. These containers and trailers offer their own
protection of contents from the weather. Perishable goods and cargo subject to damage from the weather are
transported in enclosed cars, such as the boxcar, the refrigerator car, and the heater car. Stock cars with slatted
sides are used to transport livestock and produce. These cars provide ventilation and some protection from the
weather. Tank cars are used for carrying liquids, petroleum products, and compressed gases; domes are found
on top of the tank, generally one for each compartment.