The first coal-hauling freight cars were gondolas. Hoppers came into service later in the Nineteenth Century and ruled the coal business for a century. There were other experimental and even a few production high-capacity coal gondola designs in the first half of the Twentieth Century, most notably the “battleship” gondolas of the Virginian and Norfolk and Western. Beginning in the 1960s, the Southern began experimenting with coal gons again, followed by several utility companies and railroads in the 1970s.
In the early 1990s, the high-capacity coal gondola made a roaring comeback. While eastern railroads Conrail, CSX and Norfolk Southern began rebuilding thousands of hoppers, carbuilder Johnstown America produced aluminum “bathtub” gondolas for utility companies and western roads tapping into the booming Powder River Basin coal fields. Called “Coal Porters” by the builder, the cars took their nickname from the two tubs mounted longitudinally alongside the center sill at the bottom of the car.
The new gondolas had capacities of 100 tons or greater. The tubs that gave the cars their bathtub name helped add capacity, and also lower the center of gravity. The gondolas are cheaper to build and operate than hoppers of the same size because of the lack of mechanical doors and hardware to maintain. Like the cars that preceded them, the only practical means of unloading a car this size is to put it in a rotary dumper and empty the car by turning it upside down. To speed the process, cars are equipped with a rotary coupler on one end. A car at one end of the train has these couplers on both ends so that it too can remained coupled to the train and locomotives if needed.
With more and more customers consuming coal by the trainload as opposed to the carload, and many investing in their own dumping equipment, the gondola was poised for a renaissance. Today, the trend continues with more and more coal being transported in gondolas. Many of the earlier gondolas from the 1970s and 1980s are now seeing service hauling trash and scrap. Hoppers will continue to see service for a long time however for companies who lack rotary dumpers or choose the option. (Some companies have purchased hoppers to unload in the event that a rotary dumper fails.) Coal is still the number one commodity hauled by rail, so a trainload of tubs is a perfect addition to almost any contemporary layout.