View source for Tank car

{{Short description|Train car for holding liquids and gases}}
{{Distinguish|Armored car (military)}}
{{Globalize|article|USA|2name=the United States|date=February 2018}}
[[File:Tank car.webp|thumb|Modern tank cars carry all types of liquid and gaseous commodities|300x300px]]
[[File:Tank cars in railyard.jpg|thumb|Rows of tank cars at a railyard in the Midwestern United States<ref name=":0" />]]
A '''tank car''' ([[International Union of Railways]] (UIC): '''tank wagon''') or '''tanker''' is a type of [[railroad car]] (UIC: railway car) or [[rolling stock]] designed to transport [[liquid]] and [[gaseous]] [[commodity|commodities]].
==History==

===Timeline===
[[File:Detail of tank car built in 1937 showing riveted construction, at the Southern California Railway Museum.jpg|thumb|Details of tank car riveting]]
The following major events occurred in the years noted:
*1865: [[Flatcar]]s with banded [[Plank (wood)|wooden planks]] or decking mounted on top are employed for the first time to transport [[crude oil]] from the fields of [[Pennsylvania]] during the [[Pennsylvanian oil rush]]. Laurence Myers of Philadelphia invented the ''Rotary Oil Car'', as he named it. It was an improvement on a patent from 1851 of a freight car for transporting coal. The new invention patented on July 18, 1865, was for the transportation of crude oil and petroleum. It was the first appearance of an oil tank on a railroad flatcar. Three books mention his invention.<ref>[https://archive.org/details/fueloilinindust00andrgoog/page/n82/mode/2up?q=lawrence+myers Fuel Oil in Industry]</ref><ref>[https://archive.org/details/petroleumindustr00bowl/page/82/mode/2up?q=myers The Petroleum Industry]</ref><ref>[https://books.google.com/books?id=PqdBAQAAIAAJ&q=lawrence+myers The Petroleum Handbook]</ref>
*1869: Wrought iron tanks, with an approximate capacity of {{convert|3500|usgal|m3 impgal|abbr=on|lk=on}} per car, replace wooden tanks.
*1888: Tank-car manufacturers sell units directly to the [[oil companies]], with capacities ranging from {{convert|6,000|to(-)|10000|usgal|m3 impgal|abbr=on}}.
*1903: Tank-car companies develop construction safety standards. More than 10,000 tank cars are in operation.
*1915: A classification system is developed by the tank-car industry to ensure the correct match of car type to product being shipped. Some 50,000 tank cars are in use.
*1930: 140,000 tank cars transport some 103 commodities.
*1940s: Virtually every tank car is engaged in oil transport in support of the [[World War II|war effort]].
*1945–1950: [[Welding]] replaces [[rivet]]ing in car construction (both underframes and tanks) for the major manufacturers, including [[American Car & Foundry]] and [[GATX|General American]]. 
*1950: [[Pipeline transport|Pipelines]] and [[tank truck]]s begin to compete for liquid transport business.
*1963: The [[Union Tank Car Company]] introduces the "Whale Belly" tank car.

==Usage==
=== North America ===
[[File:Gabarit AAR Plate-C.png|thumb|upright|AAR Plate-C loading gauge]]
[[File:Tank car magnetic gauge device.jpg|thumb|Inside the valve housing on top of a tank car in the United States, with a [[magnetic level gauge]] pulled out<ref name=":0" />]]
Many variants exist due to the wide variety of [[liquid]]s and gases transported. Tank cars can be [[pressurized]] or non-pressurized, [[Thermal insulation|insulated]] or non-insulated, and designed for single or multiple commodities. Non-pressurized cars have various fittings on the top and may have fittings on the bottom. Some of the top fittings are covered by a protective housing. Pressurized cars have a pressure plate, with all fittings, and a cylindrical protective housing at the top. Loading and unloading are done through the protective housing.

Tank cars are specialized pieces of equipment. As an example, the interior of the car may be lined with a material, such as [[glass]], or other specialized coatings to isolate the tank contents from the tank shell. Care is taken to ensure that tank contents are compatible with tank construction.

As a result of this specialization, tank cars have generally been "one-way" cars. Other cars, like [[boxcar]]s, can easily be reloaded with other goods for the return trip. Combinations of the two types were attempted, such as boxcars with fluid tanks slung beneath the floors. While the car could certainly carry a load in both directions, the limited tank size made this unsuccessful.

A large percentage of tank cars are owned by companies serviced by railroads instead of the railroads themselves. This can be verified by examining the [[reporting mark]]s on the cars. These marks invariably end in ''X'', meaning that the owner is not a [[common carrier]].

Within the rail industry, tank cars are grouped by their type and not by the cargo carried. Food-service tank cars may be lined with [[stainless steel]], glass, or plastic. Tank cars carrying [[dangerous goods]] are generally made of different types of steel, depending on the intended cargo and operating pressure. They may also be lined with rubber or coated with specialized coatings for tank protection or product purity purpose. The tank heads are also stronger to prevent ruptures during accidents. The whale-belly type is giving way to higher-capacity (longer), yet standard-width, [[Association of American Railroads|AAR]] [[Loading gauge#North America|Plate "C"]], cars.

All tank cars undergo periodic inspection for damage and corrosion. [[Pressure relief valve]]s are inspected at every loading. Pressurized cars are pressure-tested regularly to ensure the integrity of the tank.

All tank cars operating throughout North America today feature AAR Type E [[double shelf coupler]]s that are designed to prevent disengaging in event of an accident or derailment. This reduces the chance of couplers puncturing adjacent tank cars. However, if cars are prevented from disengaging in a derailment, the torsional forces of a derailing car can be transferred to other cars, resulting in the derailment of the adjacent cars.<ref>{{cite web|url=http://www.tsb.gc.ca/eng/rapports-reports/rail/2013/r13e0142/r13e0142.asp|title=Railway Investigation Report R13E0142|work=tsb.gc.ca|date=26 February 2015 }}</ref><ref>{{Cite web |url=https://www.aar.org/newsandevents/Upcoming-Events/Documents/AAR%20Tank%20Car%20Committee%20Meeting/October%202013%20TCC%20Sub%201%20FINAL.pdf |title=AGENDA - BACKGROUND, TANK CAR COMMITTEE, SUBCOMMITTEE 1, Colorado Springs, CO, October 16-17, 2013 |access-date=2015-04-28 |archive-date=2015-11-17 |archive-url=https://web.archive.org/web/20151117025147/https://www.aar.org/newsandevents/Upcoming-Events/Documents/AAR%20Tank%20Car%20Committee%20Meeting/October%202013%20TCC%20Sub%201%20FINAL.pdf |url-status=dead }}</ref>

Insulated cars (which may also incorporate heating or refrigeration systems) are used when the contents must be kept at a certain temperature. For example, the Linde tank car depicted below{{which|date=June 2013}} carries liquefied [[argon]]. Cars designed for multiple commodities are constructed of two or more tanks (compartments). Each compartment must have separate fittings. The lower capacity and added complexity of multicompartment cars means that they make up a small percentage of the tank car inventory.
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==Specialized applications==
[[File:Pressure tank car compressed liquified gasses.png|thumb|Pressure tank car for compressed liquified gasses]]
===DOT-111===
{{main|DOT-111 tank car}}
The DOT-111 tank car, designed to carry liquids such as [[Denatured alcohol|denatured]] [[Ethanol fuel|fuel ethanol]], is built to a US standard. The design has been criticized on safety grounds.<ref>{{cite web |publisher=NTSB Office of Railroad, Pipeline and Hazardous Materials Safety|url=https://www.ntsb.gov/news/events/2012/cherry_valley/presentations/Hazardous%20Materials%20Board%20Presentation%20508%20Completed.pdf |title=DOT-111 Tank Car Design |first=Paul L. |last=Stancil |archive-url=https://web.archive.org/web/20131110050941/http://www.ntsb.gov/news/events/2012/cherry_valley/presentations/hazardous%20materials%20board%20presentation%20508%20completed.pdf  |archive-date=Nov 10, 2013}}</ref> The train in the [[Lac-Mégantic derailment]] of 2013 was made up of 72 of these cars.<ref name=radiocanada>{{cite web |url=http://www.radio-canada.ca/regions/estrie/2013/07/08/003-lac-megantic-denis-lebel-enquete.shtml |title=Lac-Mégantic : la sécurité du type de wagons déjà mise en cause |date=July 8, 2013 |publisher=[[Canadian Broadcasting Corporation|Radio-Canada]] |access-date=July 8, 2013 | language=fr}}</ref>

===DOT-112===

[[DOT-112 tank car]]s are used in North America to carry pressurized gases. One of these tank cars exploded in [[Waverly, Tennessee]], killing 16, when a [[Louisville & Nashville]] train derailed. While the clean up efforts were under way, the tank car, UTLX 83013, ended up exploding from a [[BLEVE]].

===DOT-114===

[[DOT-114 tank car]]s are used in North America to carry pressurized gases.

===Milk cars===
{{Main|Milk car|British railway milk tank wagon}}
[[File:BFIX 520 20050716 Illinois Railway Museum.JPG|right|thumb|A historical [[Milk car#Tank cars for bulk loading|milk tank car]] for bulk loading at the [[Illinois Railway Museum]].]]A milk car is a specialized type of tank car designed to carry raw [[milk]] between farms, [[creamery|creameries]], and processing plants.

Milk is now commonly chilled, before loading, and transported in a glass-lined tank car. Such tank cars are often [[placard]]ed as "Food service use only".

===Liquid hydrogen tank car===
{{main|Liquid hydrogen tank car}}
Tank cars of this type are designed to carry [[cryogenic]] [[liquid Hydrogen]] (LH<sub>2</sub>). North American cars are classified as DOT113, AAR204W, and AAR204XT<ref>[http://chemresponsetool.noaa.gov/containers_guide/railcar.htm NOAA's Office of Response and Restoration: Chemical Response Tool] {{Webarchive|url=https://web.archive.org/web/20081220162837/http://chemresponsetool.noaa.gov/containers_guide/railcar.htm |date=2008-12-20 }}</ref>

===Pickle cars===
A pickle car was a specialized type of tank car designed to carry [[Pickled cucumber|pickles]]. This car consisted of several wooden or metal vats (typically three or four) and was often roofed. Pickles which are preserved in salt brine were loaded through hatches in the roof.

===Tank containers===<!-- This section is linked from [[Containerization]] -->
[[File:Railroad car with container loads.jpg|thumb|Type of shipping containers mounted on a [[spine car]]: ''[[Tank container]]'' (left), and an [[Intermodal container|open-top shipping container]] with [[canvas]] cover (right)]]
{{Further|Tank container|Liquid hydrogen tanktainer}}
A tank container, also known as ISO tank, is a specialized type of [[Intermodal container|container]] designed to carry bulk liquids, such as chemicals, [[liquid hydrogen]], [[Industrial gas|gases]] and food grade products. Both hazardous and non hazardous products can be shipped in tank containers. A standard tank container is {{convert|20|ft|m|2}} long, {{convert|8|ft|m|2}} high and {{convert|8|ft|m|2}} wide. The tank, which is made from stainless steel, is held within a box-shaped frame with the same shape as an [[intermodal container]]. This allows it to be carried on multiple modes of transport, such as truck, rail and ship.
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===Torpedo car===
{{main|Ladle transfer car}}
[[File:Hattingen - Henrichshütte - Bahn 19 ies.jpg|thumb|Torpedo car]]<!-- torpedo wagon redirects here-->
A '''torpedo car''' or '''bottle car''' is a type of railroad car used in [[steel mill]]s to haul [[molten]] [[pig iron]] from the [[blast furnace]] to begin the process of primary [[steelmaking]].

The [[thermal insulation|thermally-insulated]] vessel is mounted on [[trunnion]]s, and designed to endure extremely high temperatures, as well as keeping the metal in a molten state over extended periods of time. The vessel can be pivoted along its longitudinal axis to empty the pig iron into a [[Ladle (foundry)|ladle]]. The name is derived from the vessel's resemblance to a [[torpedo]].
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===Vinegar cars===
[[File:Vinegar Car (20804352870).jpg|thumbnail|right|Wooden vinegar car, at the Toronto Railway Museum in [[Roundhouse Park]].]]
A vinegar car is a specialized type of tank car designed to transport [[vinegar]]. The largest such car built was built by [[Morrison Railway Supply Corporation]] <!-- [[Morrison Knudsen Corporation]]
 --> in 1968. The car's underframe included all of the modern facets of freight car design including [[roller bearing]] [[Bogie|trucks]] and cushioning devices built by FreightMaster, while the tank that rode on it, made of [[Douglas fir]], had a capacity of {{convert|17100|usgal|m3 impgal}}. The car, in what has been called 'the largest wooden tank car ever built', took 18 months to build.

The [[Reinhart Vinegar Car]] can be seen at the [[Toronto Harbourfront Museum]].<ref>[https://www.trha.ca/trha/?s=vinegar+car Vinegar car]</ref> 

Vinegar is now moved in ordinary tank cars lined with glass, plastic, or [[alloy steel]].<ref>{{cite journal| journal=Railway Age| date=October 28, 1968| title=Week at a glance: Vinegar by rail - in giant wooden tanks| page=11| volume=165| issue=17 }}</ref>
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==="Whale belly" cars===
In the early 1960s, the [[Union Tank Car Company]] introduced a series of "whale belly" tank cars which offered increased capacity. These cars carried from {{convert|33000|usgal|m3 impgal|0}} in CSOX #31084<ref>{{Cite web|url=http://www.northeast.railfan.net/images/csox31084.jpg|title=CSOX #31084|access-date=July 23, 2019}}</ref> to as much as {{convert|63000|usgal|m3 impgal|0}} in [[General American Transportation Corporation|GATX]] #96500, which had been conceived as a 'rolling experiment'. The largest tank car ever placed into regular service, [http://www.northeast.railfan.net/images/utlx83699.jpg UTLX #83699], was rated at {{convert|50000|usgal|m3 impgal|0}}. It entered service in 1963 and was used for over 20 years. GATX 96500 is now on display at the [[National Museum of Transportation]] in [[Saint Louis, Missouri]]. This car is {{convert|98|ft|m|2}} long, weighs {{convert|175000|lb|kg|sigfig=3|abbr=on}} empty and rides on four two-[[Wheelset (rail transport)|axle]] [[Bogie|trucks]] for weight distribution. It transported diverse substances, such as [[liquefied petroleum gas]] (LPG) and anhydrous [[ammonia]].
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== Safety ==
[[File:Tank car with placard 1017 (chlorine).jpg|thumb|A tank car carrying [[chlorine]], displaying [[hazardous materials]] information including a [[Placard#United States Department of Transportation|U.S. DOT placard]] showing a [[UN number]]<ref name=":0">{{Cite web |last=Beaucham |first=Catherine C. |date=August 2023 |title=Evaluation of Potential Exposures to Railway Hazardous Material Inspectors |url=https://www.cdc.gov/niosh/hhe/reports/pdfs/2022-0049-3387.pdf |access-date=2024-05-04 |website=U.S. National Institute for Occupational Safety and Health |type=[[Health Hazard Evaluation Program|Health Hazard Evaluation Report]]}}</ref>]]
Where [[Janney coupler|AAR couplers]] are fitted, the [[Tightlock coupling#AAR Type F|AAR type "F" coupler]]<ref>{{Cite web|url=http://www.mcconway.com/rail_prod/f_coupler/f_coup_bod.htm|title=TypeF coupler|access-date=July 23, 2019}}</ref> is preferred as these are less likely to become separated in a derailment and become a puncture hazard for other tank cars. A type "E" coupler that has [[Double shelf coupler|shelves over and under]] the coupler that prevent the coupler sliding out of position after a [[derailment]] is used on some [[hazardous material]]s tank cars.<ref>{{Cite web|url=http://www.tedrail.com/products/classify/E%20TYPE%20COUPLER|title=E TYPE COUPLER, - Tedrail|access-date=July 23, 2019}}</ref><ref>{{Cite web|url=https://www.bing.com/images/search?q=Double+Shelf+Couplers+Tank+Cars&FORM=RESTAB|title=Double Shelf Couplers Tank Cars - Bing images|website=www.bing.com|access-date=July 23, 2019}}</ref>

In addition, some types of tank cars have a second end plate visible from the exterior, to further avoid end punctures.

It is also preferable if each [[tap (valve)]] is recessed within the body of the tank so as to present a reduced knock-off hazard during a derailment. {{Citation needed|date=November 2010}}

Tank cars have been involved in many rail disasters, including the [[Lac-Mégantic derailment]] in [[Quebec]] in 2013, the [[Nishapur train disaster]] in Iran in 2004, and the [[Viareggio train derailment]] in Italy in 2009.
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== Outside North America ==
{{expand section|date=November 2021}}
[[File:Altsevo peat2.JPG|right|thumb|Narrow gauge [[Kambarka Engineering Works|tank wagon]], {{RailGauge|750mm|lk=on}} gauge]][[File:Pskov asv07-2018 railway station area img11.jpg|thumb|Tankwagon on a Russian [[fire train]].]]
[[File:Tank wagon in Tampere Aug2009 001.jpg|thumb|A tank wagon (for [[phosphoric acid]]) near the wagon repair shop of [[VR Group|VR]] in the [[Viinikka]] district of the city of [[Tampere]], [[Finland]]]]
Outside of [[North America]], tank cars are also known as '''tank wagons''' or '''tanker wagons'''. In the [[United Kingdom]] tank wagons were traditionally four-wheel vehicles. Some long-wheelbase four-wheelers are still in use but [[bogie]] vehicles are now used as well.
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<gallery mode="packed" caption="British tank wagons" heights="150px">
File:Esso Tanker.JPG|An old [[Esso]] Tanker, at the [[Nene Valley Railway]], England
File:BTM-tankerwagons-04.jpg|Long-wheelbase four-wheel tank wagon in England
File:Beeston railway station MMB 34.jpg|Modern British tank wagons, photographed in 2013
File:Consett-tankwagon41.jpg|[[Consett Iron Company|Consett tank wagon #41]] in the [[Beamish Museum]]
</gallery>

== See also ==
{{div col}}
* [[BLEVE]]
* [[DOT-111 tank car]]
* [[Draft gear]]
* [[Hydrogen economy]]
* [[Procor]]
* [[Tank truck]]
* [[Tanker (ship)]]
* [[Vacuum flask]]
{{div col end}}

==Notes==
{{Reflist|30em}}

==References==
* {{cite web| title=History Of The Rail Tank Car| author=Herron, Jim|date=April 2002| work=e-Train, the online magazine of the Train Collectors Association| url=http://tcaetrain.org/articles/tickets/tankcar/index.html| access-date=January 21, 2012}}
* {{White - American railroad freight car}}

==External links==
{{Commons category|Tank railway wagons}}
*[http://www.railgoat.railfan.net/railwhales/ Rail Whales]
*[http://tankcarhomepage.railfan.net/ Modern Tank Car Homepage]
*[https://web.archive.org/web/20090416065631/http://www.ika.rwth-aachen.de/r2h/index.php/Liquid_Hydrogen_Transport_by_Rail Liquid Hydrogen Transport by Rail]
* [https://web.archive.org/web/20140512213217/http://www.americanrailcar.com/RailcarManufacturing/Car.aspx?car=tan Tank car dimensions]
* [https://web.archive.org/web/20111007195551/http://worldtraderef.com/WTR_site/Rail_Cars/Guide_to_Rail_Cars.asp Guide to Rail Cars]
* [https://www.bts.gov/surveys/annual-tank-car-facility-survey/tank-car-specifications-terms Bureau of Transportation]

{{Fuel Transport}}
{{Freight cars}}
{{Authority control}}

{{DEFAULTSORT:Tank Car}}
[[Category:Freight rolling stock]]