Hopper car

Two-bay hopper cars of the Reading Railroad.

New hopper cars outside the Trinity Industries plant where they were manufactured in Winder, Georgia.

A hopper car is a type of railroad freight car used to transport loose bulk commodities such as coal, ore, grain, track ballast, and the like. The name originated from the coke manufacturing industry which is part of the steel industry (see Etymology below).

This type of car is distinguished from a gondola car in that it has opening doors on the underside or on the sides to discharge its cargo. The development of the hopper car went along with the development of automated handling of such commodities, with automated loading and unloading facilities. There are two main types of hopper car: open and covered.

Covered hopper cars are used for bulk cargo that must be protected from the elements (chiefly rain) such as grain, sugar, and fertilizer. Open cars are used for commodities such as coal, which can get wet and dry out with less harmful effect. Hopper cars have been used by railways worldwide whenever automated cargo handling has been desired.

Recently in North America the open hopper car has been in a terminal decline due to the advent of the rotary car dumper (which simply inverts the car to unload it, and has become the preferred unloading technology). A rotary dumper permits the use of simpler, tougher, more compact (because sloping ends are not required) gondola cars instead of hoppers. Covered hoppers, though, are still in widespread use. For loads that are less dense (such as grains) or susceptible to damage in the weather (such as unmixed cement), covered hoppers are normally used.

Special hopper trains

The Coke Express, a unit train of hopper cars loaded with Coke (fuel), with the words "Coke Express" painted on the sides of the hoppers.

External links

• Union Pacific #7801 — photos and short history of an example of a typical self-clearing, open-top triple hopper.