NFLShop.com - NFL Jerseys and Gear

Classic Streamliners - TRAIN​CYCLOPEDIA

Two-bay hopper cars of the Reading Railroad.  Horydczak Collection, Library of Congress.

Two-bay hopper cars of the Reading Railroad.
A hopper car at the Pilgrim's Pride feed mill in Pittsburg, Texas.
A St. Louis - San Francisco covered hopper car at Dallas, Texas, in April of 1968.
Historic Rail - Shop Now!
Enter the Classic Streamliners Bookstore.

A covered hopper car at the Pilgrim's Pride feed mill in Pittsburg, Texas.

By Michael Barera, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=42012742

Enter the Classic Streamliners Bookstore.
Shop for Trains and Railroad Collectibles on eBay
Shop for Railroad and Train Collectibles on eBay
NFLShop.com - NFL Jerseys and Gear

A St. Louis - San Francisco (Frisco) covered hopper car at Dallas, Texas, in April of 1968.

By SMU Central University Libraries [No restrictions], via Wikimedia Commons

Hopper Car
A hopper car is a type of railroad freight car used to transport loose bulk commodities such as coal, ore, grain, and track ballast. Two main types of hopper car exist: covered hopper cars, which are equipped with a roof, and open hopper cars, which do not have a roof.

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.

Covered hopper cars are used for bulk cargo such as grain, sugar, and fertilizer that must be protected from exposure to the weather. Open hopper cars are used for commodities such as coal, which can suffer exposure with less detrimental effect. Hopper cars have been used by railways worldwide whenever automated cargo handling has been desired. "Ore jennies" is predominantly a term for shorter open hopper cars hauling taconite by the Duluth, Missabe and Iron Range Railway on Minnesota's Iron Range.

A rotary car dumper permits the use of simpler and more compact (because sloping ends are not required) gondola cars instead of hoppers. Covered hoppers, though, are still in widespread use.

Special hopper trains
The Coke Express, is a unit train of hopper cars loaded with coke, with the words "Coke Express" painted on the sides of the hoppers.

Typical American freight car weights and wheel loads
Common net car loads  - Gross car weights - Wheel loads
Tons                                    Pounds                     Pounds
80                                        220,000                     27,500 
100                                      263,000                     32,875 
101                                      268,000                     33,500
111                                      286,000                     35,750 
125                                      315,000                     39,375 

Increase in wheel loads has important implications for the rail infrastructure needed to accommodate future grain hopper car shipments. The weight of the car is transmitted to the rails and the underlying track structure through these wheel loads. As wheel loads increase, track maintenance expenses increase and the ability of a given rail weight, ballast depth, and tie configuration to handle prolonged rail traffic decreases. Moreover, the ability of a given bridge to handle prolonged rail traffic also decreases as wheel loads increase.

Etymology
The word "hopper", meaning a "container with a narrow opening at bottom", goes back to the thirteenth century, and is found in Chaucer's story "The Reeve's Tale" (written late fourteenth century) in reference to a machine for grinding grain into flour.

See also:

Gondola

Rolling Stock