The operating side-dump car has been a toy train favorite for generations. Seen in model form hauling everything from coal to candy canes, the prototypes for these useful cars can usually be found carrying stone, earth and ballast.
The largest and best-known builder of these cars was the Differential Car Company (Difco) which operated from 1915 to 1966 when it became part of Trinity Industries. Magor and Western Railcar also had lines of dump cars used by railroads. In addition, there were other manufacturers who built smaller side dumping cars for mining and industrial operations.
Unlike hoppers, side-dump cars empty their payload to the side of the track. To do this, the body of the car is raised by powerful pneumatic pistons. Most cars feature a double-hinged design with a pair of pistons on each side of the car so that they can unload to either side of the tracks. Power to the cars is supplied by the air compressor on the locomotive which also supplies air to the train brakes.
Typically, these cars are used in construction and maintenance projects such as large earth fills. They can also be used in other operations to carry larger chunks of rock and minerals too large for unloading through conventional hoppers. The cars are surprisingly durable, and many have been in service for several decades.
Most large railroads own at least a small fleet of these cars for their track maintenance, so they can be found almost anywhere. Their distinctive look makes them stand out in any train, and of course when it comes to our layouts they’re just fun!