View source for Engineering:Hopper car

{{short description|Railroad freight car used for transporting loose bulk commodities}}
[[File:Covered hopper car.jpg|thumb|Covered hopper frac sand cars on the BNSF Railway through La Crosse]]
A '''hopper car''' (US) or '''[[Engineering:Open wagon#Hopper wagons|hopper wagon]]''' ([[Organization:International Union of Railways|UIC]]) is a type of railroad [[Engineering:Railroad car#Freight cars|freight car]] used to transport loose bulk commodities such as [[Earth:Coal|coal]], [[Earth:Ore|ore]], [[Biology:Cereal|grain]], and track ballast.<ref>{{cite web|url=http://www.gatx.com/wps/wcm/connect/GATX/GATX_SITE/Home/Rail/Rail+North+America/Products/Equipment+Types/Freight/Covered+Hopper/ |archive-url=https://web.archive.org/web/20100916213706/http://www.gatx.com/wps/wcm/connect/GATX/GATX_SITE/Home/Rail/Rail+North+America/Products/Equipment+Types/Freight/Covered+Hopper/ |url-status=dead |archive-date=16 September 2010 |title=Covered Hopper Railcars |publisher=GATX Corporation |access-date=11 September 2012 }}</ref><ref>{{cite web|url=http://www.gatx.com/wps/wcm/connect/GATX/GATX_SITE/Home/Rail/Rail+North+America/Products/Equipment+Types/Freight/Small+Cube+Open-Top+Hoppers/ |archive-url=https://web.archive.org/web/20100916213808/http://www.gatx.com/wps/wcm/connect/GATX/GATX_SITE/Home/Rail/Rail+North+America/Products/Equipment+Types/Freight/Small+Cube+Open-Top+Hoppers/ |url-status=dead |archive-date=16 September 2010 |title=Small Cube Open-Top Hoppers and Gondolas |publisher=GATX Corporation |access-date=11 September 2012 }}</ref><ref>{{cite web|url=http://www.crdx.com/coveredHop.html |title=Covered Hopper Cars |publisher=Chicago Freight Car Leasing Company |access-date=11 September 2012 |url-status=dead |archive-url=https://web.archive.org/web/20120416165540/http://www.crdx.com/coveredHop.html |archive-date=16 April 2012 }}</ref> 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 [[Engineering:Gondola (rail)|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.

[[Engineering:Covered hopper|Covered hopper]] cars are used for bulk cargo such as [[Biology:Cereal|grain]], [[Chemistry:Sugar|sugar]], and [[Chemistry:Fertilizer|fertilizer]] that must be protected from exposure to the weather. Open hopper cars are used for commodities such as [[Earth:Coal|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 [[Earth:Taconite|taconite]] by the Duluth, Missabe and Iron Range Railway on Minnesota's [[Chemistry:Iron Range|Iron Range]].

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

These are known as "Dual-purpose" hoppers, a type of the car referring to coal hopper car with rotary coupler on one end or on both ends. They can be used in both rotary or bottom-dump operations.
 
== Gallery ==
<gallery class=center caption="[[Engineering:Open wagon#Hopper wagons|Non North American hopper cars]]" heights="150px" widths="200px">
File:Iron ore hopper (SJ, 1900).JPG|Swedish [[Earth:Iron ore|iron ore]] hopper ([[Engineering:Mineral wagon|mineral wagon]]), built in 1900
File:Вагон.jpg|[[Company:Kambarka Engineering Works|Kambarka Engineering Works]] hopper car to transport track ballast, {{RailGauge|750mm|lk=on}} gauge
File:BOBRN class Hopper cars Freight rakes at Samalkot Junction 01.jpg|BOBRN class hopper cars freight rakes used by Indian Railways
</gallery>

== Special hopper trains ==
The Coke Express, a  CSX [[Engineering:Unit train|unit train]] of hopper cars loaded with [[Chemistry:Coke (fuel)|coke]], with the words "Coke Express" painted on the sides of the hoppers.

== Typical American freight car weights and wheel loads ==
{| class="wikitable"
|-
! colspan=3 | Common net car loads
! colspan=2 | Gross car weights
! colspan=2 | Wheel loads
|-
! Short tons !! Long tons !! Tonnes
! Pounds !! Kilograms
! Pounds !! Kilograms
|-
| {{convert|80|ST|LT t|1|disp=table}}  || {{convert|220000|lb|kg|disp=table}} || {{convert|27500|lb|kg|disp=table}}
|-
| {{convert|100|ST|LT t|1|disp=table}} || {{convert|263000|lb|kg|disp=table}} || {{convert|32875|lb|kg|disp=table}}
|-
| {{convert|101|ST|LT t|1|disp=table}} || {{convert|268000|lb|kg|disp=table}} || {{convert|33500|lb|kg|disp=table}}
|-
| {{convert|111|ST|LT t|1|disp=table}} || {{convert|286000|lb|kg|disp=table}} || {{convert|35750|lb|kg|disp=table}}
|-
| {{convert|125|ST|LT t|1|disp=table}} || {{convert|315000|lb|kg|disp=table}} || {{convert|39375|lb|kg|disp=table}}
|}

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.<ref name="carweights">{{cite web| url=http://www.mountain-plains.org/pubs/html/mpc-01-127-4/pg2.php| title=The Economics of Heavy Hopper Cars| last1=Bitzan| first1=John D.| first2=Denver D.| last2=Tolliver| date=October 2001| website=Mountain-Plains.org| publisher=Mountain Plains| access-date=2010-08-07| archive-url=https://web.archive.org/web/20110723174647/http://www.mountain-plains.org/pubs/html/mpc-01-127-4/pg2.php| archive-date=23 July 2011}}</ref> The [[Engineering:Axle load|axle load]] is twice the wheel load. 

=== Gallery ===
<gallery class=center caption="North American hopper cars" heights="150px" widths="200px">
File:Coke Express.jpg|The Coke Express rolls through a [[Engineering:Level crossing|level crossing]]. Cars display both the CSX logo and the words '''''COKE EXPRESS'''''
File:Hopper cars.jpg|Two-bay hopper cars of the Reading Railroad
File:Pittsburg August 2015 17 (hopper car).jpg|NOKL hopper car at Pittsburg, Texas, in 2015 
File:2009-07-05 Hopper car at N&W Durham Yard.jpg|N&W ballast hopper car. 
</gallery>

== Etymology ==
The word "hopper", meaning a "container with a narrow opening at bottom", goes back to the thirteenth century,<ref>{{cite web| website=Online Etymology dictionary| url=http://www.etymonline.com/index.php?search=hopper| title=Hopper}}</ref> and is found in Chaucer's story "The Reeve's Tale" (written late fourteenth century) in reference to a machine for grinding grain into [[Biology:Flour|flour]].

== See also ==
* [[Engineering:CDA wagon|CDA wagon]]
* [[Engineering:Gravity wagon|Gravity wagon]], also called a slant wagon
* [[Engineering:Hopper barge|Hopper barge]]
* Victorian Railways hopper wagons

== References ==
{{Reflist}}

== Further reading ==
* Bernard Ciry, "Les wagons-trémies à céréales et à bogies", '':fr:Rail Miniature Flash'', {{n°|632}}, Paris, Rigel Editions, juin 2018, pages 28-41.

== External links ==
* [https://web.archive.org/web/20060509071410/http://sdrm.org/roster/freight/hopp7801/index.html Union Pacific #7801] – Photos and short history of an example of a typical self-clearing, open-top triple hopper
* [https://web.archive.org/web/20140327040407/http://www.americanrailcar.com/RailcarManufacturing.aspx Rail car manufacturing]
* [https://web.archive.org/web/20111007195551/http://worldtraderef.com/WTR_site/Rail_Cars/Guide_to_Rail_Cars.asp Guide to Rail Cars] 

{{Freight cars}}

[[Category:Freight rolling stock]]

{{Sourceattribution|Hopper car}}