View source for Engineering:Glossary of rail transport terms

{{Short description|Words used in the rail transport industry}}

'''Rail transport terms''' are a form of technical terminology applied to railways. Although many terms are uniform across different nations and companies, they are by no means universal, with differences often originating from parallel development of rail transport systems in different parts of the world, and in the national origins of the engineers and managers who built the inaugural rail [[Physics:Infrastructure|infrastructure]]. An example is the term ''railroad'', used (but not exclusively) in [[Earth:North America|North America]], and ''railway'', generally used in English-speaking countries outside North America and by the [[Organization:International Union of Railways|International Union of Railways]]. In English-speaking countries outside the United Kingdom, a mixture of US and UK terms may exist.<ref>{{cite conference|title=The Snowtown to Port Pirie Line |last=McAuliffe |first=Des |date=1999 |book-title=Proceedings of the 1999 Convention |location=Adelaide |conference=Modelling the Railways of South Australia |page={{Nowrap|1–129}}}}</ref>

The abbreviation "UIC" refers to terminology adopted by the [[Organization:International Union of Railways|International Union of Railways]] in its official publications and thesaurus.<ref name="UIC">{{cite web|url=http://www.uic.org/spip.php?article1593|archive-url=https://web.archive.org/web/20150606032638/http://www.uic.org/spip.php?article1593|work=UIC.org|title=Transport Thesaurus|date=1995|archive-date=6 June 2015|access-date=20 May 2009|url-status=dead}}</ref>


== 0–9 ==

== A ==
{{glossary}}
{{term|Acorn.}}
{{defn|A general term used to finish the ends of rods of various forms.<ref name=":1">{{Cite book|url=https://books.google.com/books?id=jCJMAAAAMAAJ|title=Locomotive Dictionary|publisher=N.K. Gregg|year=1906|isbn=9780912318202|location=New York|page=1|agency=American Railway Master Mechanics' Association}}</ref>}}

{{term|Adhesion railway}}
{{defn|The most common type of {{gli|railway}}, where power is applied by driving some or all of the {{gli|wheel|wheels}} of the {{gli|locomotive}}.<ref>{{cite journal| journal=The Railway News and Joint Stock Journal| title=Combined Adhesion ad Cog-Wheel Railways| date=19 January 1889| pages=100–101| location=London| volume=51| issue=1307}}</ref>}}

{{term|Adhesive weight}}
{{defn|The weight on the driving {{gli|wheel|wheels}} of a {{gli|locomotive}}, which determines the frictional grip between wheels and {{gli|rail}}, and hence the drawbar pull a locomotive can exert<ref>{{cite book|last=McClellan|first=George B.|title=Reports of Explorations and Surveys to Ascertain the Most Practicable and Economical Route for a Railroad from the Mississippi River to the Pacific Ocean|date=21 November 1854|volume=1|page=116|chapter=Memoranda on Railways|url=https://books.google.com/books?id=LshOAAAAcAAJ}}</ref>}}

{{term|Adjusting spring}}
{{defn|A heavy spiral spring or nest of springs used for controlling the side motion of a two-wheel radial trailing truck.<ref name=":1"/>}}

{{term|Adjusting spring case}}
{{defn|{{ghat|Also '''Centering spring cylinder'''.}}
A cylindrical cast-iron holder in which an adjusting string is placed.<ref name=":1"/>}}

{{term|Adjusting spring seat}}
{{defn|A casting, or a part of the bolster of a two-wheel trailing truck, forming a bearing for the end of the adjusting spring.<ref name=":1"/>}}

{{term|Admission}}
{{defn|The opening of steam port to admit steam to one end of a cylinder. If the valve has no lead, admission takes place at the moment the piston of its stroke and just as it is to begin the return stroke.<ref name=":1"/>}}

{{term|Air brake}} 
{{ghat|Also '''[[Engineering:Railway air brake|Railway air brake]]. '''}}
{{defn|Any brake operated by air pressure, but usually restricted to systems of continuous brakes operated by compressed air, in distinction from Vacuum Brakes, which are operated by creating a vacuum. The air is compressed by some form of steam pump on the locomotive, or a motor-compressor on electric locomotives, and is conveyed by pipes and flexible hose between the engine, tender and cars to cylinders and pistons under the tender and each car, by which the pressure is transmitted to the brake levers, and thence to the brake shoes. This system is what is now termed the straight-air brake. This brake is now obsolete in steam road practice, having been replaced by the Automatic Air Brake.<ref name=":1"/>}}

{{term|Air brake hose}}
{{defn|Flexible tubes made of alternate layers of rubber and canvas by which the brake pipes under engines, tenders, and cars are connected together, and compressed air, which operates the brakes, conducted through the train. The hose is made with a coupling at each end of the engine and tender so that it can readily be connected or disconnected. Also called air hose and brake hose.<ref name=":1"/>}}

{{term|Air cylinder (air pump)}}
{{defn|A cylinder forming part of the air brake pump and having its piston fastened to the same rod to which the piston of the steam cylinder is fastened. It is furnished with air inlet and discharge valves at each end, communicating respectively with the air inlet and the discharge pipe.<ref name=":1"/>}}

{{term|Air cylinder bracket}}
{{defn|A projecting piece of metal bolted to the frame of a locomotive or tender, to which the brake cylinder is attached. See '''Truck Brake,''' '''Tender Brake.'''<ref name=":1"/>}}

{{term|Air cylinder gasket}}
{{defn|See Gasket.<ref name=":1"/>}}

{{term|Air cylinder oil cup (air pump)}}
{{defn|A small brass receptacle with a stopcock or faucet, screwed to the air cylinder of an air pump, to hold a supply of lubricant for the air cylinder. See '''Automatic Air Cylinder Oil Cup.'''<ref name=":1"/>}}

{{term|Air drum}}
{{Ghat|Also '''Main Reservoir''' and '''Reservoir'''.}}
{{defn|A cylindrical reservoir, made of sheet steel, into which air is pumped and stored for use in the air brake system and train air signal line. Sometimes placed under the cab deck or between the frames in front of the guide yoke; but now two are commonly used, placed under the running board near the cab, one on each side of the engine.<ref name=":1"/>}}

{{term|Air drum hanger}}
{{defn|An iron strap riveted to the lower side of the running board, or to the boiler, to support the air drum.<ref name=":1"/>}}

{{term|Air drum head}}
{{defn|The end of the air drum, to which the cylindrical body is riveted or welded.<ref name=":1"/>}}

{{term|Air drum saddle}}
{{defn|A strip of iron fastened to the locomotive frame for supporting the air drum or drums when the drums are placed between the cylinder saddles and the guide yoke.<ref name=":1"/>}}

{{term|Air gage (air brake)}}
{{defn|A gage to register the pressure of air in the reservoirs, brake pipe, or brake cylinders, similar to an ordinary steam pressure gage. They are made either with a single pointer or with two pointers, to indicate on one dial both the reservoir pressure and the brake pipe pressure. The latter type is called a duplex gage.<ref name=":1"/>}}

{{term|Air gage fitting}}
{{defn|A pipe connection by means of whichan air gage is connected to an engineer's brake valve in a locomotive cab.<ref name=":1"/>}}

{{term|Air gage stand}}
{{defn|A bracket or support to hold an air gage.<ref name=":1"/>}}

{{term|Alerter or watchdog}}
{{defn|Similar to the [[Engineering:Dead man's switch|dead man's switch]] other than it does not require the operator's constant interaction. Instead, an alarm is sounded at a preset interval in which the operator must respond by pressing a button to reset the alarm and timer if no other controls are operated. If the operator does not respond within a preset time, the prime mover is automatically throttled back to idle and the brakes are automatically applied.<ref>{{cite book|title=The Code of Federal Regulations of the United States of America – 49: Transportation|publisher=Office of the Federal Register, National Archives and Records Administration|location=Washington, DC|date=1 October 2006|page=691|chapter=§ 238.237: Automated monitoring|url=https://books.google.com/books?id=Bp48AAAAIAAJ}}</ref>}}

{{term|Adhesion railway#All-weather adhesion}}
{{defn|The adhesion available during traction mode with 99% reliability in all weather conditions<ref>{{cite web|url=http://www.asa.transport.nsw.gov.au/sites/default/files/asa/railcorp-legacy/disciplines/rollingstock/epr-012.pdf|title=EPR 012: Testing of locomotive all weather adhesion|date=October 2011|publisher=RailCorp|access-date=25 October 2014|archive-url=https://web.archive.org/web/20140621230312/http://www.asa.transport.nsw.gov.au/sites/default/files/asa/railcorp-legacy/disciplines/rollingstock/epr-012.pdf|archive-date=21 June 2014|url-status=dead}}</ref>}}

{{term|Alternator}}
{{defn|An electrical generator that converts mechanical energy to electrical energy in the form of [[Physics:Alternating current|alternating current]]<ref>{{cite book|last=Aylmer-Small|first=Sidney|title=Electrical railroading; or, Electricity as applied to railroad transportation|publisher=Frederick J. Drake & Co.|location=Chicago|date=1908|pages=[https://archive.org/details/electricalrailr02aylmgoog/page/n460 456]–463|chapter=Lesson 28: Alternators|url=https://archive.org/details/electricalrailr02aylmgoog}}</ref>}}

{{term|[[Company:American Locomotive Company|American Locomotive Company]] (Alco)}}
{{defn|The second largest builder of steam locomotives in the United States<ref name="Trains Glossary A">{{cite web| url=http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=A| archive-url=https://web.archive.org/web/20140831175630/http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=A| title=Railroading Glossary: A| publisher=Kalmbach Publishing| website=TRN.Trains.com| access-date=20 February 2013| archive-date=31 August 2014}}</ref><ref>{{cite book|last=Solomon|first=Brian|title=Alco Locomotives|publisher=MBI Publishing Company|date=2009|page=8|isbn=9781616731366|url=https://books.google.com/books?id=8A4I4eOtkGwC}}</ref>}}

{{term|American type}}
{{defn|A steam locomotive with a 4-4-0 wheel arrangement.<ref>White (1968), p. 46.</ref>}}
[[File:WheelArrangement 4-4-0.svg|thumb|upright=0.5|The ''American'' wheel arrangement]]

{{term|Angle cock}}
{{defn|A valve affixed to each end of a piece of rolling stock that, when opened, admits compressed air to the brake pipe (or vents it to the atmosphere if air hose is detached)<ref>{{Cite patent | country = US | number = 1031835 | title = Angle-cock hanger for air-brake pipes of railway-cars | pubdate = 1912-07-09| inventor1-last=Burnett|inventor1-first = Richard Webb}}</ref>}}

{{term|Annett's key}}

{{term|Articulated locomotive}}
{{defn|A steam locomotive with one or more engine units that can move relative to the main frame<ref name="Trains Glossary A" /><ref>{{cite book|title=Locomotive Cyclopedia of American Practice|editor1=Roy V. Wright |editor2=Charles N. Winter |publisher=Simmons-Boardman Publishing Co.|location=New York|date=1922|edition=sixth|page=102|url=https://books.google.com/books?id=oMY1AQAAMAAJ}}</ref>}}

{{term|Articulated vehicles (articulation)}}
{{defn|The sharing of one truck by adjacent ends of two rail vehicles.}}

{{term|Ashpan}}
{{defn|A feature of a locomotive with the same form and purpose as the domestic variety (i.e. to collect the ashes that fall through the bars of the grate). The only significant difference is the size, measured in feet rather than inches.}}

{{term|Asynchronous motor}}
{{defn|An alternating current electric motor whose speed varies with load and has no fixed relation to the frequency of the supply.}}

{{term|Atlantic type}}
[[File:WheelArrangement 4-4-2.svg|thumb|upright=0.5|The ''Atlantic'' wheel arrangement]]
{{defn|A steam locomotive with a 4-4-2 wheel arrangement.<ref>{{cite web| url=http://www.steamlocomotive.com/atlantic/| title=4-4-2 "Atlantic" Type Locomotives| website=SteamLocomotive.com| access-date=13 October 2014| archive-url=https://web.archive.org/web/20130817205905/http://www.steamlocomotive.com/atlantic/| archive-date=17 August 2013| url-status=dead}}</ref><ref>{{cite book| url=https://books.google.com/books?id=K4YMAwAAQBAJ| title=Locomotive Cyclopedia of American Practice| year=1947| page=103| publisher=American Railway Master Mechanics' Association| isbn=9785874485672}}</ref><ref>{{cite book| url=https://books.google.com/books?id=AzJCeF3oUnUC| title=Perfecting the American Steam Locomotive| chapter=4: The Second Generation| page=47| first=J. Parker| last=Lamb| publisher=Indiana University Press| location=Bloomington, IN| date=2003| isbn=0-253-34219-8}}</ref>}}

{{term|Automatic block signaling (ABS)}}
{{defn|A system that consists of a series of signals that divide a railway line into a series of blocks and then functions to control the movement of trains between them through automatic signals.}}

{{term|Automatic train control (ATC)}}
{{defn|A system that applies an emergency brake if the driver does not react to certain signals or speed restrictions<ref>{{Cite book|title=IEC 60050-821:1998 – International Electrotechnical Vocabulary – Part 821: Signalling and security apparatus for railways|publisher=[[Organization:International Electrotechnical Commission|International Electrotechnical Commission]]|year=1998}}</ref>}}

{{term|[[Engineering:Automatic train operation|Automatic train operation]] (ATO)}} 
{{defn|A technology for automation of trains.}}

{{term|Automatic train protection (ATP)}}
{{defn|A system that enforces obedience to signals and speed restrictions by speed supervision, including automatic stop at signals<ref name="ERA Glossary">{{cite web|url=http://www.era.europa.eu/document-register/documents/glossary%20of%20railway%20terminology-selection-%20en-fr-de.pdf.pdf|title=ERA Glossary|website=ERA.Europa.eu|access-date=23 March 2017}}</ref>}}

{{term|GWR Autotrain}}
{{defn|A branch-line train consisting of a steam locomotive and passenger carriages that can be driven from either end by means of rodding to the regulator and an additional [[Engineering:Vacuum brake|vacuum brake]] valve. The fireman remains with the locomotive and, when the driver is at the other end, the fireman controls the [[Engineering:Cutoff (steam engine)|cut off]] and vacuum ejectors in addition to his usual duties. See also: Push-pull train.}}

[[File:Achslager-Nordbahn-Wagen.JPG|thumb|upright=0.5|A Swiss ''axle box'']]
{{term|Axlebox}}
{{defn|The housing that holds the axle bearings on a rail vehicle<ref>{{Cite magazine|title=The Evolution of Railway Axlebox Technology|url=http://evolution.skf.com/the-evolution-of-railway-axlebox-technology/|magazine=Evolution|publisher=SKF|date=7 December 2010|access-date=18 September 2014}}</ref> The housing that attaches to the end of the axle to the bogie and contains the bearing on which the axle rotates<ref>{{Cite web|title=Glossary: A|url=http://www.railway-technical.com/newglos.shtml#A|website=Railway-Technical.com|publisher=Railway Technical Web Pages|date=2014|access-date=19 November 2014|url-status=dead|archive-url=https://web.archive.org/web/20141007220720/http://www.railway-technical.com/newglos.shtml#A|archive-date=7 October 2014}}</ref> See also ''journal box'' below.}}
{{glossary end}}

== B ==
{{glossary}}
[[File:4017 Backhead 20040426.jpg|thumb|upright=0.5|The ''backhead'' of UP 4017, a locomotive at the National Railroad Museum in Green Bay, Wisconsin]]
{{term|Backhead}}
{{defn|The cab-side rear panel of a steam locomotive boiler through which the firebox is accessed.<ref>{{cite book| title=Locomotive Cyclopedia of American Practice| url=https://books.google.com/books?id=oMY1AQAAMAAJ&q=backhead&pg=PA379| via=Google Books| page=16| edition=sixth| year=1922| editor-first=Roy V.| editor-last=Wright| publisher=Simons-Boardman Publishing Company| location=New York, NY}}</ref>}}

[[File:BNSF-badorder.jpg|thumb|upright=0.5|An example of a BNSF Railway ''bad order'' repair tag]]
{{term|Bad order}}
{{defn|A tag or note applied to a defective piece of equipment. Generally, equipment tagged as bad order must not be used until repaired, inspected, and approved for use.<ref name="Trains Glossary B">{{cite web| url=http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=B| archive-url=https://web.archive.org/web/20140821181829/http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=B| title=Railroading Glossary: B| publisher=Kalmbach Publishing| website=TRN.Trains.com| access-date=20 February 2013| archive-date=21 August 2014}}</ref><ref>{{cite book|title=The Code of Federal Regulations of the United States of America – 49: Transportation|publisher=Office of the Federal Register, National Archives and Records Administration|location=Washington, DC|date=1 October 2006|pages=177–178|chapter=§ 215.9 Movement of defective cars for repair|url=https://books.google.com/books?id=Bp48AAAAIAAJ}}</ref>}}

{{term|Bail off}}
{{defn|To release the locomotive brakes while the train brakes are applied, to permit smoother handling and prevent excessive slack, [[Engineering:Wheel slide protection#Wheel slide and braking|wheel slide]] and flat wheels.<ref>{{cite web|title=Air Brake/Train Handling Rulebook – Procedure 3.2.2|url=http://www.midcontinent.org/1385/dload/brakes1.pdf|website=Mid Continent railway museum|access-date=19 September 2014|archive-url=https://web.archive.org/web/20141020083616/http://www.midcontinent.org/1385/dload/brakes1.pdf|archive-date=20 October 2014|url-status=dead}}</ref>}}

{{term|[[Engineering:Engine balance|Balancing]]}}
{{defn|The reciprocation and revolving masses of any steam, diesel or electric locomotive need balancing, if it is to work smoothly. Revolving masses can easily be balanced by counterweights, but the balancing of reciprocating parts is a matter of compromise and judgement.}}

{{term|Balise}}
{{defn|A transponder that is used as an intermittent data point in an automatic train protection (ATP) system or as reference point for train location in radio-based train control<ref name="ERA Glossary" />}}

{{term|Ballast}}
{{defn|Aggregate stone, gravel, or cinders forming the track bed on which sleepers (ties) and track are laid to ensure stability and proper drainage<ref name="Trains Glossary B" /><ref>{{cite book|last=Bianculli|first=Anthony J. |title=Trains and Technology: The American Railroad in the Nineteenth Century|publisher=Rosemont Publishing & Printing Corp.|date=2003|volume=3: Track and Structures|page=40|isbn=0-87413-802-7|url=https://books.google.com/books?id=7T3qECx0CLUC}}</ref>}}

{{term|Ballast tamper}}
{{defn|See ''Tamping machine''.}}

{{term|Balloon}}

{{term|[[Engineering:Bay platform|Bay platform]]}}
{{defn|A [[Engineering:Railway platform|platform]] and track arrangement where the train pulls into a siding, or dead-end, when serving the platform.}}

{{term|Bellmouth}}
{{defn|A widening of an underground rail tunnel, in preparation for future connection or expansion of service. Used particularly in subway nomenclature.<ref>{{cite web|title=Glossary|url=http://web.mta.info/capital/sas_docs/sdeis/glossary.pdf|page=2|website=MTA.info|publisher=MTA|access-date=12 October 2014}}</ref><ref>{{cite news|last=Martin|first=Douglas|title=Subway Planners' Lofty Ambitions Are Buried as Dead-End Curiosities|url=https://www.nytimes.com/1996/11/17/nyregion/subway-planners-lofty-ambitions-are-buried-as-dead-end-curiosities.html|newspaper={{wipe|The New York Times}}|access-date=27 June 2015|date=17 November 1996}}</ref>}}

[[File:WheelArrangement 2-8-4.svg|thumb|upright=0.5|The ''Berkshire'' wheel arrangement]]
{{term|Berkshire type}}
{{defn|A steam locomotive with a 2-8-4 wheel arrangement.<ref>{{cite book| url=https://books.google.com/books?id=AzJCeF3oUnUC| title=Perfecting the American Steam Locomotive| first=J. Parker| last=Lamb| publisher=Indiana University Press| location=Bloomington, IN| date=2003| isbn=0-253-34219-8| pages=85–88}}</ref><ref>{{cite book| url=https://books.google.com/books?id=6EE9Q8PQ_y8C| title=Northwestern Pennsylvania Railroads| first=Kenneth C.| last=Springirth| series=Images of Rail| publisher=Arcadia Publishing| date=2010| isbn=978-0-7385-7347-2| page=68}}</ref><ref name="Solomon 2009 52">{{cite book| url=https://books.google.com/books?id=8A4I4eOtkGwC| title=Alco Locomotives| first=Brian| last=Solomon| page=52| publisher=MBI Publishing Company| date=2009| isbn=9781616731366}}</ref>}}

{{term|Bilevel rail car}}
{{defn|A type of rail car that has two levels of passenger accommodation, as opposed to one, increasing passenger capacity.}}

{{term|Blastpipe}}
{{defn|A part of a steam locomotive that discharges exhaust steam from the cylinders into the smokebox beneath the chimney to increase draught through the fire.}}

{{term|Block section}}
{{defn|A section of track in a fixed block system that a train may only enter when it is not occupied by other vehicles.<ref name=":2"/>}}

{{term|Bo-Bo (Europe)}}
{{defn|A locomotive with a four-wheel, two wheels per truck configuration, each individually powered, as opposed to a six-wheel "Co-Co" configuration.}}

{{term|[[Engineering:Bogie|Bogie]]}}
{{defn|A swivel-mounted wheel assembly; known as a Truck in North America.}}

{{term|[[Engineering:Boiler|Boiler]]}}
{{defn|A cylindrical container adjacent to the ''firebox'' in which steam is produced to drive a steam locomotive.<ref>White (1968).</ref>}}

{{term|[[Engineering:List of railroad truck parts#Truck bolster|Bolster]]}}
{{defn|A transverse floating beam member of a truck suspension system supporting the weight of a vehicle body.<ref>{{Cite web|title=Railroad Dictionary: B|url=http://www.csx.com/index.cfm/about-csx/company-overview/railroad-dictionary/?i=B|publisher=CSX Transportation|website=CSX.com|date=2012|access-date=15 November 2014|url-status=dead|archive-url=https://web.archive.org/web/20140729222810/http://www.csx.com/index.cfm/about-csx/company-overview/railroad-dictionary/?i=B|archive-date=29 July 2014}}</ref>}}

{{term|[[Engineering:Boom barrier|Boom barrier]]}}
[[File:Level crossing P1210798.jpg|thumb|upright=0.5|''Boom barriers'' at a railway crossing in France]]
{{defn|A pivoted road barrier at a [[Engineering:Level crossing|level crossing]]}}

{{term|Booster engine}}
{{defn|An extra set of cylinders that can be engaged on a steam locomotive to drive a trailing truck or tender truck to give additional tractive effort at starting and low speeds<ref name="Trains Glossary B" /><ref>{{cite book|title=Official Proceedings of the New York Railroad Club|date=1920|volume=30|pages=6072–6074|chapter=Trailer Booster| url=https://books.google.com/books?id=tv9KAAAAYAAJ}}</ref>}}

{{term|[[Engineering:Brakeman's cabin|Brakeman's cabin]] or brakeman's cab}}
{{defn|A small hut at one end of a railway wagon to protect the brakeman from the elements.}}

{{term|Brake pipe}}
{{defn|The main air pipe of a train's air brake system<ref>{{cite web|title=Air Brakes – Basics|url=http://www.railway-technical.com/air-brakes.shtml#Basics|website=Railway Technical Web Pages|access-date=19 September 2014|archive-url=https://web.archive.org/web/20141007081345/http://www.railway-technical.com/air-brakes.shtml#Basics|archive-date=7 October 2014|url-status=dead}}</ref>}}

{{term|Branch line}}
{{defn|A secondary railway line that splits off from a main line<ref name="Trains Glossary B" />}}

{{term|Brick arch}}
{{defn|A brick or concrete baffle provided at the front of a locomotive firebox below the tubes to extend the flame path. Early locomotives burned coke; provision of a brick arch was necessary before coal could be used without producing excessive smoke.}}

{{term|British Rail Universal Trolley Equipment (BRUTE)}}
{{defn|A type of platform trolley found on stations all over the UK rail network from the late 1960s to the early 1980s.}}

{{term|Broad gauge}}
{{defn|Track where the rails are spaced farther apart than standard gauge, or {{Track gauge|sg}}<ref name="Trains Glossary B" />}}

{{term|Bubble car}}
{{defn|A nickname for a British Rail Class 121 railcar<ref>{{cite web|title=50 years of the Bubble car |url=http://www.chilternrailways.co.uk/news/50-years-bubble-car |website=Chiltern Railways |access-date=19 September 2014 |archive-url=https://web.archive.org/web/20140714134952/http://www.chilternrailways.co.uk/news/50-years-bubble-car |archive-date=14 July 2014 |url-status=dead }}</ref>}}

{{term|Buckeye coupler}}
{{defn|A side-operated version of the top- or bottom-operated [[Engineering:Janney coupler|Janney coupler]]<ref>{{cite book| url=https://books.google.com/books?id=cpxMAAAAYAAJ| title=Proceedings: Seventh Session, Washington, May 1905| volume=II| edition=English| location=Brussels| publisher=P. Weissenbruch, Printer to the King| date=1906| chapter=Question VII| pages=3–20}}</ref>}}

{{term|Buffer}}
{{defn|A device that cushions the ends of rail vehicles against each other.}}

{{term|Buffer stop or bumper post}}
{{defn|The barrier installed at the end of a dead-end track to prevent rail vehicles from proceeding further.}}

{{term|[[Builder's plate]]}}
{{defn|The [[Nameplate|nameplate]] fitted by their manufacturer to locomotives and items of rolling stock.}}

{{term|[[Engineering:Flatcar#Bulkhead flatcars|Bulkhead flatcar]]}}
{{defn|An open-top [[Engineering:Flatcar|flatcar]] with a wall at each end.}}

{{term|Bungalow}}
{{defn|The housing for signals and communications computers that control switches, crossings, and other such controls, relaying information to and from the rail traffic control (RTC)<ref>{{cite book|first=Ed|last=Sobey|title=A Field Guide to Roadside Technology|date=2006|publisher=Chicago Review Press|isbn=9781613741795|page=[https://archive.org/details/fieldguidetoroad00sobe/page/20 20]|url=https://archive.org/details/fieldguidetoroad00sobe |url-access=registration}}</ref>}}

{{term|Bustitution}}
{{defn|A blend of the words "bus" and "substitution", the practice of replacing a train service with one provided by buses, whether as a temporary or a permanent measure.}}
{{glossary end}}

== C ==
{{glossary}}
{{term|Cab}}
{{defn|The control room of a locomotive housing the engine crew and the controls<ref>{{cite book| url=https://archive.org/details/locomotivedicti00assogoog| title=Locomotive Dictionary; compiled for American Railway Master Mechanics' Association| edition=first| first=George L.| last=Fowler| work=The Railroad Gazette and The Railway Gazette| location=New York, Chicago and London| date=1906| page=[https://archive.org/details/locomotivedicti00assogoog/page/n27 15]}}</ref><ref>{{cite book| url=https://books.google.com/books?id=afTuqHUAAIwC| title=Modern Diesel Locomotives| first=Hans| last=Halberstadt| pages=61–63| date=1996| publisher=MBI Publishing Co.| location=Osceola, WI| isbn=0-7603-0199-9}}</ref>}}

{{term|[[Engineering:Cab forward|Cab forward]]}}
{{defn|A steam locomotive with its cab at the leading end of the boiler, rather than the usual trailing end adjacent to the tender. The best known example is the Southern Pacific Railroad's AC type, built to handle drag freights through the SP's many tunnels and snow sheds without the danger of the exhaust asphyxiating the engine crew.}}

{{term|Cabless}}
{{defn|A locomotive without a cab. Commonly referred to as a ''B unit'' or a ''Slug'', although not all ''Slugs'' are cabless.}}

{{term|[[Engineering:Caboose|Caboose]]}}
[[File:ConRail Bay Cab Caboose.jpg|thumb|upright=0.5|A ''[[Engineering:Caboose|caboose]]'' on display at the National New York Central Railroad Museum]]
{{defn|In North America, a railroad car attached usually to the end of a train, in which railroad workers could ride and monitor track and rolling stock conditions. Largely obsolete, having been replaced by the electronic [[Engineering:End-of-train device|end-of-train device]] (ETD), or flashing rear-end device (FRED).<ref name="Trains Glossary C">{{cite web| url=http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=C| archive-url=https://web.archive.org/web/20140913071106/http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=C| title=Railroading Glossary: C| publisher=Kalmbach Publishing| website=TRN.Trains.com| access-date=20 February 2013| archive-date=13 September 2014}}</ref>}}

{{term|Cant}}
{{defn|The angle of an individual rail relative to vertical (e.g. around curves).}}

{{term|Carbody unit}}
{{defn|A locomotive that derives structural strength from a bridge-truss design framework in the sides and roof, which cover the full width of the locomotive.}}

{{term|[[Engineering:Overhead line|Catenary]]}}
[[File:Amtrak Regional viewed from NJ Transit train.jpg|thumb|upright=0.5|A ''catenary'' is visible above this electric Amtrak train.]]
{{defn|The overhead wire system used to send electricity to an [[Engineering:Electric locomotive|electric locomotive]] or [[Engineering:Electric multiple unit|multiple unit]], tram or light rail vehicle<ref name="Trains Glossary C" />}}

{{term|[[Engineering:Flatcar#Centerbeam flatcars/Lumber racks|Centerbeam]]}}
{{defn|A bulkhead flatcar with a braced beam bisecting its length, used to transport lumber products}}

{{term|Challenger type}}
[[File:WheelArrangement 4-6-6-4.svg|thumb|upright=0.5|The ''Challenger'' wheel arrangement]]
{{defn|A steam locomotive with a 4-6-6-4 wheel arrangement.<ref>{{cite book| url=https://books.google.com/books?id=8A4I4eOtkGwC| title=Alco Locomotives| first=Brian| last=Solomon| page=70| publisher=MBI Publishing Company| date=2009| isbn=9781616731366}}</ref><ref>{{cite book| url=https://books.google.com/books?id=AzJCeF3oUnUC| title=Perfecting the American Steam Locomotive| first=J. Parker| last=Lamb| page=107| publisher=Indiana University Press| location=Bloomington, IN| date=2003| isbn=0-253-34219-8}}</ref><ref>{{cite magazine| url=https://books.google.com/books?id=qMsi_tVhJXUC| magazine=Boys' Life| date=June 1952| title=Name That Locomotive| first=John| last=Taylor| page=40| publisher=Boy Scouts of America}}</ref><ref>{{cite book| url=https://books.google.com/books?id=chjWRJbaa_QC| title=American Passenger Trains and Locomotives Illustrated| chapter=34: The City Streamliners| page=144| first=Mark| last=Wegman| date=2008| publisher=Voyageur Press, an imprint of MBI Publishing Company| location=Minneapolis, Minnesota| isbn=978-0-7603-3475-1}}</ref>}}

{{term|Chord}}
{{defn|A section of subsidiary track that interconnects two primary tracks that cross at separated grades, to permit traffic to flow between them.}}

{{term|Co-Co locomotives (EU)}}
{{defn|A heavier duty locomotive with six wheels, three wheels per truck (all axles being separately driven) configuration as opposed to a four-wheel "Bo-Bo" configuration. The correct classification is Co'Co', but Co-Co is used more often.}}

{{term|Coal pusher}}
{{defn|A steam-operated device in the tender intended to push coal forward to a point where it can be shovelled directly into the fire.<ref>{{Cite web|title=Locomotive Stoker and Coal Pusher|url=http://www.railarchive.net/firing/p028.htm|website=RailArchive.net|access-date=2 October 2014}}</ref>}}

{{term|Colour light signal}}
{{defn|A signal in which the colour of the light determines the signal meaning.}}

{{term|Colour position signal}}
{{defn|A signal that uses both colour and light position to indicate meaning.}}

{{term|Combined power handle}}
{{defn|A handle or [[Engineering:Lever|lever]] that controls both the [[Engineering:Throttle|throttle]] and [[Engineering:Dynamic braking|dynamic braking]] on the locomotive: on a desktop-type control stand, forward (away from operator) past center operates the dynamic brake, backward (toward operator) past center, is throttle up.<ref>{{cite web| url=http://www.tsb.gc.ca/eng/rapports-reports/rail/2002/r02v0057/r02v0057.asp| title=Railway Investigation Report R02V0057| publisher=Transportation Safety Board of Canada| date=28 April 2002| access-date=19 October 2014}}</ref><ref>{{cite AV media| last=Velazquez| first=Matthew| title=How to Operate a Diesel Locomotive| type=slide presentation| date=15 October 2014| url=http://prezi.com/hscd1pph9cb_/how-to-operate-a-diesel-locomotive/| access-date=19 October 2014}}</ref><ref>{{cite web| url=http://quizlet.com/18196785/2013-el.ecp32bwh-p40-p42-study-guide-flash-cards/| title=2013 Elec.P32BWH-P40-P42 Study Guide| website=Quizlet.com| access-date=19 October 2014}}</ref>}}

{{term|Compound locomotive}}
{{defn|A steam locomotive passing steam through two sets of cylinders. One set uses high pressure steam, then passes the low pressure exhausted steam to the second.<ref>White (1968), p 209-210.</ref>}}

{{term|Configurable System}}
{{defn|Capability of the system to allow users to select, from pre-programmed functions (modular software units), those functions necessary to accomplish a control strategy or other complex function, without the use of computer language.<ref>{{cite web| url=https://www.saiglobal.com/pdftemp/previews/osh/iso/iso_12345_10-01/t008875e.pdf| title=Industrial process measurement control functions and instrumentation – Symbolic representation – Part 4: Basic symbols for process computer, interface, and shared display/control functions| date=15 August 1985| page=1}}</ref>}}

{{term|Consist}}
{{defn|Single vehicle or a group of vehicles that are not separated during normal operation.<ref>{{cite web|url=https://www.din.de/en/services/din-term|title=IEC 61375-2-3:2017-02: Electronic railway equipment – Train communication network (TCN) – Part 2-3: TCN communication profile|website=DIN.de|access-date=28 June 2017}} {{Registration required}}</ref>}}

{{term|Consolidation type}}
[[File:WheelArrangement 2-8-0.svg|thumb|upright=0.5|The ''Consolidation'' wheel arrangement]]
{{defn|A steam locomotive with a 2-8-0 wheel arrangement.<ref>{{cite magazine|magazine=The Locomotive Magazine| page=98| date=15 June 1906| title=New Locomotives, Swiss State Railways| volume=XII| issue=166| url=https://books.google.com/books?id=l-bNAAAAMAAJ}}</ref><ref>{{cite book| url=https://books.google.com/books?id=K4YMAwAAQBAJ| title=Locomotive Cyclopedia of American Practice| chapter=Consolidation Type Locomotives| author=American Railway Master Mechanics' Association| year=1947|pages=31, 125–127| publisher=Рипол Классик| isbn=9785874485672}}</ref>}}

{{term|Container on flat car (COFC)}}
{{defn|The loading of a shipping container onto a simple flat car.<ref name="Trains Glossary C" />}}

{{term|Continuous welded rail (CWR)}}
{{defn|A form of track made from rails welded together by with a [[Chemistry:Thermite|thermite]] reaction or flash butt welding to form one continuous rail that may be several kilometres long.<ref name="Trains Glossary C" />}}

{{term|Control car}}
{{defn|A passenger coach with a full set of train controls at one end, allowing for the use of push-pull train operation.<ref>{{Cite book|first1=P.|last1=Mallaband|first2=L. J.|last2=Bowles|title=Coaching Stock of British Railways 1978|publisher=RCTS Railway Correspondence and Travel Society|date=1982|isbn=0-901115-44-4|page=91}}</ref>}}

{{term|Control System }}
{{defn|The microprocessor based control and fault diagnostic system has been developed for conventional electric locomotives including locos provided with static converter. It performs logical control of the locomotive by continuously monitoring various digital/ analog inputs and checks for any abnormality in the operation.<ref>{{Cite web|url=http://www.rdso.indianrailways.gov.in/works/uploads/File/Introductory%20handbook%20on%20Microprocessor%20controlled%20electric%20locomotives.pdf|title=Introductory Handbook on Microprocessor Controlled Electric Locomotives}}</ref>}}

{{term|[[Engineering:Headstock (rolling stock)#Length over headstocks|Coupler pulling faces, length over]]}}
{{defn|Effective length of piece of rolling stock}}

{{term|Coupling rods}}
{{defn|Rods between crank pins on the wheels, transferring power from a driving axle to a driven axle of a locomotive.<ref name="White 465-6">White (1968), p 465-466.</ref>}}

{{term|[[Engineering:Covered goods wagon|Covered goods wagon]] (UIC)}}
{{defn|A type of rolling stock with a flat bottom enclosed on all sides and top, which is loaded and unloaded from sliding doors on each side.<ref name="Trains Glossary B" /><ref>{{cite book|last=Welsh|first=Joe|title=The American Railroad: Working for the Nation|publisher=MBI Publishing Company|location=St. Paul, MN|date=2006|page=58|isbn=978-0-7603-1631-3|url=https://books.google.com/books?id=TPqntdv9w7kC|orig-year=first published 1999 by Andover Junction Publications}}</ref>}}

{{term|Cow-calf or cow and calf}}
{{defn|A diesel locomotive with a crew cab permanently coupled to and acting as a controller for a similar slave diesel locomotive without a crew cab, primarily used for switching or shunting duties for large groups of rolling stock. Also known as ''master and slave''.}}

{{term|Crank pin}}
{{defn|A pin protruding from a wheel into a main or coupling rod.}}

{{term|[[Engineering:Crosshead|Crosshead]]}}
{{defn|In a steam locomotive, the moving member of a sliding guide that absorbs upward and downward forces from the connecting (main) rod, which otherwise would tend to bend the piston rod.<ref>White (1968), p 186-187.</ref>}}

{{term|Cut}}
{{defn|To uncouple one or more cars from a train (i.e. to "make a cut").<ref name="CSXC">{{Cite web|title=Railroad Dictionary: C|url=https://www.csx.com/index.cfm/about-us/company-overview/railroad-dictionary/?i=C|publisher=CSX Transportation|website=CSX.com|date=2012|access-date=31 December 2016}}</ref>}}
{{defn|Same as "cutting"<ref name="CSXC" />}}

{{term|Cut lever}}
{{defn|A manual lever that releases the pin of an [[Engineering:Janney coupler|automatic coupler]] when pulled to separate cars or locomotives.<ref>{{cite book| url=https://books.google.com/books?id=QJoKAAAAYAAJ| title=Reports of Cases Determined in the Appellate Courts of Illinois| volume=171| page=182| author=Illinois. Appellate Court| chapter=Jorte v. Chicago & Alton R. Co., 171 Ill. App. 179| date=1913| location=Chicago| publisher=Callaghan & Co.}}</ref><ref>{{cite book| url=https://books.google.com/books?id=ikcL2SVDSxMC| title=Supreme Court Appellate Division – Third Department: John L. Nolan v. A. Vedder Magee, Blakeslee Lumber Company, Veeder & Brown, Knapp & Hotchkiss Lumber Company and The Crane & Veeder Company| publisher=The Reporter Co.| location=New York| date=1913| isbn=9780224618175}}</ref>}}

{{term|[[Engineering:Cutoff (steam engine)|Cut off]]}}
{{ghat| Also see '''{{gli|Reverser handle}}.'''}}
{{defn|A variable device on steam locomotives that closes the steam valve to the [[Physics:Cylinder (engine)|steam cylinder]] before the end of the piston stroke, thus conserving steam while letting steam in the cylinder expand under its own energy.}}

{{term|[[Engineering:Cut (earthmoving)|Cutting]]}}
{{defn|A channel dug through a hillside to enable rail track to maintain a shallow gradient. See also ''embankment''.}}

{{term|Cycle braking}}
{{defn|Making repeated service brake reductions in short succession to maintain a constant speed on short but steep grades. Each reduction must be at least 5 PSI lower than the previous one to keep the brakes applying regularly, but excessive cycle braking can deplete the air supply and require an emergency application.<ref>{{cite web|title=Railroad Related Terms|url=http://www.alaskarails.org/terminology/related-terms.html#nameC|website=AlaskaRails.org|access-date=2 October 2014}}</ref>}}

{{term|[[Physics:Cylinder (engine)|Cylinder]]}}
{{defn|A cavity in a reciprocating engine in which a piston travels.}}

{{term|Cylinder cock}}
{{defn|On steam locomotives, crews use this appurtenance to drain water from the steam cylinders when the throttle is open, thus preventing damage to the pistons, running gear, and cylinder heads.<ref>{{cite web|title=Steam Locomotive Glossary|url=http://www.railway-technical.com/st-glos.shtml#C|website=Railway-Technical.com|url-status=dead|archive-url=https://web.archive.org/web/20080128230325/http://www.railway-technical.com/st-glos.shtml#C|archive-date=28 January 2008}}</ref>}}
{{glossary end}}

== D ==
{{glossary}}
{{term|Dark signal}}
{{defn|A block signal that is displaying no discernible aspect, often due to burned out lamps or local power failure. Most railroads require that a dark signal be treated as displaying its most restrictive aspect (e.g. stop and stay for an absolute signal).<ref>{{cite book| url=https://books.google.com/books?id=G_cnAQAAMAAJ| title=Annual Report, Part 1| page=918| location=Albany, New York| publisher=The Argus Company |date=1903}}</ref>}}

{{term|Dark territory}}
{{defn|A section of track without block signals.<ref>{{cite news|url=https://www.ntsb.gov/pressrel/2006/060613.htm|title=Failure to adhere to track warrant control rules caused collision|last=Holloway|first=Keith|date=13 June 2006|work=NTSB press release|publisher=National Transportation Safety Board|quote=Non-signaled (dark) territory presents a unique problem for rail safety|access-date=29 May 2009}}</ref>}}

{{term|Dead-end rail}}
{{defn|A railway ending in a locality (''terminus'') with no other rail services. Typically includes '''buffer stops''' at the end of the tracks. The opposite of '''rail crossing'''}}

{{term|Dead man's handle}}
{{defn|A safety mechanism on a train controller that automatically applies the brake if the driver releases the handle. It is intended to stop a train if the driver is incapacitated. In some forms, this device may be pedal-actuated. See also [[Engineering:Dead-man's vigilance device|Dead-man's vigilance device]].}}

{{term|Decapod type}}
[[File:WheelArrangement 2-10-0.svg|thumb|upright=0.5|The ''Decapod'' wheel arrangement]]
{{defn|A steam locomotive with a 2-10-0 wheel arrangement.<ref>{{cite book| url=https://books.google.com/books?id=MM2ph3S2V2cC| title=Seaboard Air Line Railway: Steam Boats, Locomotives, and History| first=Richard E.| last=Prince| page=163| orig-year=first published 1966| date=2000| publisher=Indiana University Press| location=Bloomington, IN| isbn=0-253-33695-3}}</ref><ref>{{cite magazine|magazine=Locomotive Firemen and Enginemen's Magazine| page=777| date=December 1907| volume=43| issue=6| url=https://books.google.com/books?id=F3MWAAAAYAAJ| location=Indianapolis, IN| publisher=Brotherhood of Locomotive Firemen and Enginemen| title=Development of American Steam Locomotives}}</ref><ref name=":3"/>}}

{{term|Defect detector}}
{{defn|A track side device used to detect various defects such as [[Engineering:Hot box|hotboxes]] (overheated axle bearings), dragging equipment, leaning cars, overloaded cars, overheight cars, seized (locked) wheels, etc.<ref name="Trains Glossary D" />}}

{{term|Degraded Operation}}
{{defn|Operation resulting from an unplanned event that prevents the normal delivery of train services.<ref name=":2">{{cite web| url=http://www.era.europa.eu/Document-Register/Pages/Glossary-of-railway-terms.aspx|archive-url=https://web.archive.org/web/20180807032709/http://www.era.europa.eu/Document-Register/Pages/Glossary-of-railway-terms.aspx| url-status=dead| archive-date=7 August 2018| title=ERA Glossary of Railway Terms| date= 8 November 2010| access-date=7 August 2018}}</ref>}}

{{term|[[Social:Demurrage#Railway transport|Demurrage]]}}
{{defn|A monetary charge levied by a railroad to a customer for excessive delay in loading or unloading cars.}}

{{term|Derail or derailer}}
{{defn|A safety device that derails vehicles that pass it, typically to prevent rolling stock from accidentally entering the mainline from a siding.<ref name="Trains Glossary D">{{cite web| url=http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=D| archive-url=https://web.archive.org/web/20140830031106/http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=D| title=Railroading Glossary: D| publisher=Kalmbach Publishing| website=TRN.Trains.com| access-date=20 February 2013| archive-date=30 August 2014}}</ref>}}

{{term|Detonator}}
[[File:Track Detonator.JPG|thumb|upright=0.5|A ''detonator'' on a rail]]
{{defn|A small explosive charge placed on the running rail, which detonates loudly when run over to warn drivers in following trains of an incident ahead. Known as a torpedo in the United States.}}

{{term|Diamond}}
[[File:MulberryXing.jpg|thumb|upright=0.5|A railroad crossing at grade, also known as a ''diamond'']]
{{defn|Track that lets a rail line cross another at grade<ref name="Trains Glossary D" />}}

{{term|Diesel multiple unit (DMU)}}
[[File:Szynobus Wlkp..JPG|thumb|upright=0.5|A ''diesel multiple unit'' in Poland]]
{{defn|A set of diesel-powered self-propelling passenger rail vehicles able to operate in multiple with other such sets. Such units, especially those consisting of a single vehicle, are sometimes termed railcars.}}

{{term|[[Direct traffic control]] (DTC)}}
{{defn|A system in which train dispatchers communicate directly with train crews via radio to authorize track occupancy in predefined blocks.<ref name="Trains Glossary D" />}}

{{term|[[Engineering:Distributed power|Distributed power]]}}
{{defn|A practice originally used to move large trains through the mountains. Now commonly used to facilitate longer, heavier trains in all types of terrain. Consists of the locomotives on the head end, a "swing" (mid-train) helper or two, and pusher locomotive(s) on the rear; today, all units are remotely controlled by the engineer in the lead unit. The remote locomotives are referred to as '''Distributed Power Units (DPUs)'''. The power distribution alleviates stress on the couplers and relieves the lead units of the full weight of the train, making it easier to move on grades.}}

{{term|Ditch lights}}
[[File:Canadian National diesels southbound on the Norfolk Southern near Polaris Mall in Columbus, Ohio (2092116881).jpg|thumb|upright=0.5|A [[Company:Canadian National Railway|Canadian National Railway]] train showing the placement of ''ditch lights'' on the locomotive]]
{{defn|A pair of lights, usually found on modern locomotives, located some distance below and outboard of the main headlight. They may also flash alternately when a locomotive sounds its [[Train horn|horn]].<ref>{{cite web|title=Ditch Lights|url=http://www.american-rails.com/ditch-lights.html|website=American Rails|access-date=2 October 2014}}</ref>}}

{{term|Division}}
{{defn|In North America, the trackage area under the jurisdiction of a railway superintendent.<ref>{{Cite web|title=Railroad Dictionary: D|url=http://www.csx.com/index.cfm/about-csx/company-overview/railroad-dictionary/?i=D|publisher=CSX Transportation|website=CSX.com|date=2012|access-date=24 July 2015|archive-url=https://web.archive.org/web/20150725070047/http://www.csx.com/index.cfm/about-csx/company-overview/railroad-dictionary/?i=D|archive-date=25 July 2015|url-status=dead}}</ref>}}

{{term|Dog or dogspike (India)}}
{{defn|A spike with a slightly altered head shape for easier extraction when the spike has become too loose in the sleeper.<ref>{{cite book| url=https://books.google.com/books?id=5QYmBAAAQBAJ| title=Railway Track Engineering| edition=fourth|page=122| publisher=Tata McGraw Hill Education Private Ltd.| location=New Delhi, India| date=2010| orig-year=first edition published 2000| isbn=978-0-07-068012-8}}</ref><ref>{{cite book| url=https://books.google.com/books?id=LPeKxIjmDtYC| title=Australian Railwayman: From Cadet Engineer to Railways Commissioner| first=Ron J.| last=Fitch| date=2006| publisher=Rosenberg Publishing Pty Ltd| isbn=1-877058-48-3}}</ref>}}

{{term|Doodlebug}}
{{defn|A self-powered gasoline-electric passenger car used for small capacity rural commuter service.<ref name="Trains Glossary D" /> Also a British Rail Class 153 DMU.}}

{{term|Double}}
{{defn|If a train has insufficient power to climb a grade and no helpers are available, the crew splits the train into two sections and runs them separately to the top.<ref>{{cite web | url = http://www.trains.com/trn/default.aspx?c=a&id=211 | work = Trains | title = Grades and Curves}}</ref>}}

{{term|Double heading}}
{{defn|A configuration in which two locomotives are coupled head-to-tail so they can haul a heavy train up a long or steep hill. Currently, double heading (and occasionally triple heading) are used primarily by large passenger trains or as a show for railfans.}}

{{term|[[Engineering:Drag freight|Drag]]}}
{{defn|A long, heavy freight train moving at low speed.}}

{{term|Dragging equipment detector}}
{{defn|See Defect detector.<ref name="Trains Glossary D" />}}

{{term|[[Engineering:Drawbar (haulage)#Rail|Drawbar]]}}
{{defn|The part of a coupler that attaches to the frame of the car or locomotive; may be equipped with a pneumatic cushion depending on a freight car's design cargo (e.g. an [[Engineering:Autorack|autorack]]). Alternately, the pinned double bars coupling a steam locomotive to its tender.}}

{{term|Driver or engine driver}}
{{defn|The operator of a locomotive.<ref name="Trains Glossary E">{{cite web| url=http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=E| archive-url=https://web.archive.org/web/20140822154846/http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=E| title=Railroading Glossary: E| publisher=Kalmbach Publishing| website=TRN.Trains.com| access-date=20 February 2013| archive-date=22 August 2014}}</ref>}}

{{term|Driver only operation (DO or DOO)}}
{{defn|Operation of a train by the engineer or driver only.<ref>{{cite book|last=Ellis|first=Iain|title=Ellis' British Railway Engineering Encyclopaedia|publisher=Lulu.com|date=2006|page=105|isbn=978-1-84728-643-7|url=https://books.google.com/books?id=zkDYawSkRpAC}}</ref>{{self-published inline|date=February 2020}} Also known as one person train operation (OPTO)}}

{{term|Driver}}
{{defn|A wheel in contact with the rail that also propels a locomotive}}

{{term|Dual control stand}}
{{defn|the practice of having two control stands (a "control stand" is a diesel locomotive subsystem which integrates all engine and brake functional controls within the operational radius of the locomotive engineer's left forearm from his/her customary seating position, facing forward at all times) in the cab of a hood unit locomotive, one on either side facing opposite directions to allow operation either [[Engineering:Long hood|long hood]] or [[Engineering:Short hood|short hood]] forward at all times. }}

{{term|Dwarf signal}}
{{defn|A signal light that is considerably smaller and closer to the ground than a high-mast signal; often absolute, and placed within interlocking limits, its aspects tend to differ from those conveyed by a taller signal for certain indications. Also called 'pot' or 'jack'.}}

{{term|Dwell time}}
{{defn|The time a train spends at a scheduled stop without moving. Typically, this time is spent boarding or deboarding passengers, but it may also be spent waiting for traffic ahead to clear, or idling time in order to get back on schedule.<ref>{{Cite web|url=http://trt.trb.org/trt.asp?NN=Bbjs|title=TRT Home – Transportation Research Thesaurus (TRT)|website=trt.trb.org|access-date=2017-08-30}}</ref>}}

{{term|[[Engineering:Dynamic braking|Dynamic braking]]}}
{{defn|The use of a traction motors' output, working as generators, to retard train speed without relying solely on the air brakes.}}
{{glossary end}}

== E ==
{{glossary}}
{{term|[[Organization:Aspirator (pump)|Ejector]]}}
{{defn|A component of [[Engineering:Vacuum brake|vacuum brake]] system usually fitted in pairs. Steam passing through a cone sucks air from the train pipe to create the vacuum.}}
{{defn|A small ejector running continuously to overcome leaks and to restore the vacuum after light braking and a large ejector operated when needed to release the brakes quickly after a heavy application or to create the initial vacuum after coupling}}

{{term|[[Engineering:Electric multiple unit|Electric multiple unit]] (EMU)}}
{{defn|A set of electrically powered self-propelling passenger rail vehicles able to operate in multiple with other such sets.}}

{{term|Electro-Motive Diesel (EMD)}}
{{defn|The world's second largest builder of railroad locomotives. EMD was previously Electro-Motive Division of [[Company:General Motors|General Motors]] before being sold.}}

{{term|Elevated railway, el, or L}}
{{defn|A railway built on supports over city streets.}}

{{term|[[Earth:Embankment (transportation)|Embankment]]}}
{{defn|A bank, usually of earth but sometimes of stone, constructed to form a level or minimally graded trackbed for a line of railway needing to pass over a depression in the terrain or other pre-existing surface feature. See also ''cutting''.}}

{{term|Empty coaching stock (ECS)}}
{{defn|A train used to bring carriages into (or out of) service. They usually run between sidings and main stations, with the carriages then forming a service train to another destination. They are often worked under freight train rules (e.g. without needing a guard in the UK).<ref>{{cite web|title=Train Technical Specification|url=https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/82840/tts-redacted.pdf|access-date=2 October 2014}}</ref>}}

{{term|Emergency release}}
{{defn|A device accessible under certain conditions that permits the operation of an apparatus in case of failure.<ref>{{cite web| url=https://webstore.iec.ch/publication/265| title=International Electrotechnical Vocabulary – Part 821: Signalling and security apparatus for railways| date=29 April 1998| access-date=15 December 2017}}</ref>}}

{{term|End-cab switcher}}
{{defn|A switching locomotive with no short hood, thus having its cab forming one end of its car body.}}

{{term|Engineer}}
{{defn|In North America, the operator of a locomotive.}}

{{term|Equalizing reservoir}}
{{defn|A small air reservoir in a locomotive control stand. When the automatic brake valve is operated, this reservoir responds by reducing or increasing the air pressure in the ''brake pipe''.<ref>{{cite web|title=Air brakes|url=http://railroad.net/articles/railfanning/airbrakes/|website=Railroad.net|access-date=2 October 2014}}</ref>}}

{{term|Event recorder}}
{{defn|A device that continuously captures analog and digital train systems information and stores that data for a minimum of 48 hours. This data is used to evaluate incidents and accidents. Typical stored data includes speed, brake pressure, dynamic brake, horn activation, track signal, etc. In the U.S., event recorders are mandated by the Federal Railroad Administration (FRA) for freight, passenger and commuter rail. Regulations for railroads outside the U.S. vary by country. Transit operations are not generally required to have event recorders, but have begun to add them voluntarily.}}

{{term|[[Engineering:Express train|Express train]]}}

{{term|Extra }}
{{defn|A train not included in the normal schedule of a railroad.<ref>{{cite web| url=http://www.globalsecurity.org/military/library/policy/army/fm/55-20/ch2.htm| title=FM 55-20, Chapter 2, Railway Train Operations| website=GlobalSecurity.org| access-date=13 October 2014}}</ref><ref>{{cite book| title=Railroad Operation and Railway Signalling| first=Edmund John| last=Phillips| publisher=Simmons-Boardman Publishing Co.| location=Chicago| date=1942| page=40| url=https://books.google.com/books?id=TYXl3x5ZrooC| access-date=13 October 2014}}</ref><ref>{{cite book| title=Train Rules and Train Dispatching: A Practical Guide for Train Dispatchers, Enginemen, Trainmen and All who Have to Do with the Movement of Trains| page=129| url=https://books.google.com/books?id=X2sEAAAAMAAJ| access-date=13 October 2014| first=Harry Andrews| last=Dalby| edition=first| date=1904| location=New York and London| publisher=The Locomotive Publishing Co.}}</ref> They often run during busy holiday travel periods in order to handle larger crowds and reduce the number of passengers waiting or stranded at a station. In train order territory, extras are required to clear the main line for scheduled trains to pass.<ref>{{cite web| url=http://www.globalsecurity.org/military/library/policy/army/fm/55-20/ch4.htm| title=FM 55-20, Chapter 4, Rail Dispatching Operations and Procedures| website=GlobalSecurity.org| access-date=13 October 2014}}</ref>}}
{{glossary end}}

== F ==
{{glossary}}
{{term|Facing}}
{{defn|A turnout that can select which way to diverge a train—the opposite of trailing.}}

{{term|[[Engineering:Fairlie locomotive|Fairlie]]}}
{{defn|A type of [[Engineering:Articulated locomotive|articulated locomotive]], typically (but not exclusively) with two [[Engineering:Boiler|boiler]]s and connected fireboxes in a central cab.}}

{{term|Fall plate}}
{{defn|A heavy, hinged steel plate attached in a horizontal position to the rear of the locomotive footplate or front of a locomotive tender. When the tender is attached to its locomotive the plate is allowed to fall to cover the gap in the "floor" between the two units. The sliding edge is not fixed and has a smooth [[Engineering:Chamfer|chamfer]] so as to avoid a trip hazard.<ref>{{cite web|title=What Are Fall Plates?|url=http://www.wisegeek.com/what-are-fall-plates.htm|website=WiseGEEK|access-date=2 October 2014}}</ref>}}

{{term|Fallen flag}}
{{defn|An abandoned or bankrupt railroad or one absorbed by another company that loses its historic name.<ref>{{Cite book|title=Indianapolis Union and Belt Railroads|last=Darbee, Jeffrey T.|isbn=9780253029508|location=Bloomington, Indiana|pages=207–208|chapter=page 207|oclc=987437589|chapter-url=https://books.google.com/books?id=oQAvDwAAQBAJ&pg=PA207|date = 7 September 2017}}</ref>}}

{{term|[[Chemistry:Feedwater heater|Feedwater heater]]}}
{{defn|A device to preheat the water for a steam locomotive to improve efficiency.}}

{{term|Feed valve or regulating valve}}
{{defn|A valve that controls the amount of air pressure channelled from the locomotive's main reservoir to the brake pipe, in accordance with the set pressure in the equalizing reservoir.<ref>{{cite web|title=An Introduction to Train Brakes|url=http://www.tarorigin.com/art/Jbentley/|website=The Traffic Accident Reconstruction Origin|access-date=2 October 2014}}</ref>}}

{{term|Fiddle yard}}
{{defn|In railway modelling, a concealed group of sidings used to provide more realistic operation in a limited space.}}

{{term|Firebox}}
{{defn|In steam locomotives, a chamber in which a fire produces sufficient heat to create steam once the hot gases created there are carried into the adjacent boiler via tubes or flues.<ref>White (1968), p102-108.</ref>}}

{{term|Fireman, stoker, or boilerman}}
{{defn|A worker whose primary job is to shovel coal into the firebox and ensure that the boiler maintains sufficient steam pressure.}}

{{term|Flat}}
{{defn|A wheel defect where the tread of a wheel has a flat spot and is no longer round; flats can be heard as regular clicking or banging noises when the wheel passes by. This is caused either by a locked bearing, or a brake that was not fully released before the car was moved, dragging the wheel without turning.<ref name="Trains Glossary F">{{cite web | url=http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=F | title=Railroading Glossary: F | publisher=Kalmbach Publishing | work=Trains | access-date=20 February 2013}}</ref>}}

{{term|Flying junction or flyover}}
{{defn|A railway junction that has a track configuration in which merging or crossing railroad lines provide track connections with each other without requiring trains to cross in front of opposing traffic on the same level<ref name="Trains Glossary F" />}}

{{term|Fouling point}}
{{defn|A point of a switch turnout where a car or locomotive on one track obstructs movements on the adjacent track.<ref>{{cite book|first=Iain|last=Ellis|title=Ellis' British Railway Engineering Encyclopaedia|date=2006|publisher=Lulu.com|isbn=9781847286437|page=141|url=https://books.google.com/books?id=zkDYawSkRpAC&pg=PA68 |access-date=2 October 2014}}</ref>{{self-published inline|date=February 2020}}}}

{{term|[[Engineering:Four-quadrant gate|Four-quadrant gate]]}}
[[File:Level crossing - Chertsey - England - 270404.jpg|thumb|upright=0.5|''Four-quadrant gates'' rising]]
{{defn|A type of [[Engineering:Boom barrier|boom barrier]]}}

{{term|Free-mo}}
{{defn|A type of modular layout in model railroading.}}

{{term|Freight wagon (UIC)}}
{{defn|A rail vehicle designed for the carriage of freight.}}

{{term|Full service reduction}}
{{defn|[[File:Demonstrating fusee use.jpg|thumb|upright=0.5|A brakeman uses a ''fusee'' to demonstrate a hand signal indicating "stop"]]The maximum air pressure that can be exerted against brake pistons in a normal brake application. To increase pressure beyond this point, the brakes must be placed in emergency.<ref>{{cite web|title=North American Freight Train Brakes|url=http://www.railway-technical.com/brake2.shtml|website=Railway technical web pages|access-date=2 October 2014}}</ref>}}

{{term|[[Earth:Flare#Roadside & Rail|Fusee]]}}
{{defn|A pyrotechnic device similar to an automotive flare that is used in signalling.<ref name="Trains Glossary F" />}}

{{term|[[Engineering:Fusible plug|Fusible plug]]}}
{{defn|A threaded plug, with a soft metal core, that is screwed into the crown plate of a firebox. If the water level gets too low the core melts and the noise of the escaping steam warns the enginemen.}}
{{glossary end}}

== G ==
{{glossary}}
{{term|[[Engineering:Garratt locomotive|Garratt locomotive]]}}
[[File:Garratt articulated steam locomotive -- concept diagram.png|thumb|upright=0.5|Concept of the ''Garratt locomotive'']]
{{defn|A type of [[Engineering:Steam locomotive|steam locomotive]] that is [[Engineering:Articulated locomotive|articulated]] into three parts<ref>{{Cite book|last=Durrant|first=A. E.|title=The Garratt Locomotive|page=13|publisher=David & Charles Locomotive Studies|location=London|date=1969|isbn=7153435646}}</ref>}}

{{term|Gauge}}
{{defn|The width between the inner faces of the rails.}}

{{term|Geep}}
[[File:3801 EMD GP38-2 diesel locomotive.jpg|thumb|upright=0.5|An EMD GP38-2, "General Purpose" (GP) locomotives are often called a "''Geep''"]]
{{defn|Any of the GP ("general-purpose") series of Electro-Motive four-axle diesel locomotives; originally applied only to EMD GP7, GP9, and GP18 models<ref name="Trains Glossary G">{{cite web| url=http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=G| archive-url=https://web.archive.org/web/20140821181620/http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=G| title=Railroading Glossary: G| publisher=Kalmbach Publishing| website=TRN.Trains.com| access-date=20 February 2013| archive-date=21 August 2014}}</ref>}}

{{term|Generator field}}
{{defn|The control switch of a diesel-electric locomotive that opens or closes the circuit between the main generator and the traction motors.<ref>{{cite book| url=https://books.google.com/books?id=8ns-AAAAYAAJ| title=Operation and Maintenance of Diesel-electric Locomotives| page=107| date=October 1965}}</ref>}}

{{term|Get a knuckle}}
{{defn|To break a train in two, usually by shearing the knuckle pin in a [[Engineering:Railway coupling#AAR coupler|coupler]], often caused by the application of excessive head end power at startup.<ref>{{cite book| url=https://books.google.com/books?id=8bewAAAAIAAJ| title=The Hoghead: An Industrial Ethnology of the Locomotive Engineer| first=Frederick C.| last=Gamst| publisher=Holt, Rinehart and Winston| date=1980| page=96| isbn=9780030526367}}</ref><ref>{{cite book| url=https://books.google.com/books?id=QgkqAQAAIAAJ| title=Proceedings| publisher=Railway Fuel and Operating Officers Association| date=1966|pages=72, 92}}</ref>}}

{{term|GEVO}}
{{defn|A nickname for [[Company:General Electric|General Electric]]'s Evolution series of modern diesel locomotives.<ref>{{cite book| url=https://books.google.com/books?id=Gt8OtslzijYC| title=The Model Railroader's Guide to Diesel Locomotives| first=Jeff| last=Wilson| location=Waukesha, WI| publisher=Kalmbach Publishing| date=2009| isbn=978-0-89024-761-7}}</ref><ref>{{cite press release| url=http://www.getransportation.com/news/ge-and-kazakhstan-temir-zholy-ktz-announce-ge-evolution-series-passenger-locomotive-be| title=GE and Kazakhstan Temir Zholy (KTZ) Announce GE Evolution Series Passenger Locomotive to be Manufactured in Astana| date=19 September 2012| access-date=14 October 2014| archive-date=11 March 2017| archive-url=https://web.archive.org/web/20170311111618/http://getransportation.com/news/ge-and-kazakhstan-temir-zholy-ktz-announce-ge-evolution-series-passenger-locomotive-be| url-status=dead}}</ref>}}

{{term|[[Engineering:Gladhand connector|Gladhand connector]]}}
{{defn|A quick coupling and uncoupling connector at the end of a trainline air hose that resembles a pair of shaking hands when hoses are connected.}}

{{term|Go-devil}}
{{defn|A hand-powered railroad car (see [[Engineering:Handcar|Handcar]] and Draisine), or a small gasoline powered railroad car.<ref>{{cite web| url=http://www.merriam-webster.com/dictionary/go-devil| title=Go-devil| website=Merriam-Webster Dictionary| access-date=14 October 2014}}</ref><ref>{{cite book| url=https://books.google.com/books?id=wbImAQAAIAAJ| title=Dialect Notes| page=25| volume=5| date=1918}}</ref>}}

{{term|Grab bar or Grab iron}}
{{defn|A handle on the side of a car to allow switching personnel to hold on.<ref>{{cite journal| journal=The Railroad Trainman| url=https://books.google.com/books?id=VH0fAAAAYAAJ| pages=581–584| volume=27| title=Safety Appliances| issue=7| publisher=Brotherhood of Railroad Trainmen| location=Cleveland, OH| date=July 1910}}</ref>}}
{{glossary end}}

== H ==
<!-- This section is linked from [[Engineering:Steam locomotive|Steam locomotive]]. -->
; Harmonic rock or harmonic rock and roll
: The condition of locomotives and cars swaying in opposite directions when traversing depressions on the roadbed. A potentially dangerous condition that can cause coupler damage, lading damage, or derailments at slower speeds.<ref>{{cite book| url=https://books.google.com/books?id=DuCF2u_-n6AC| title=Computer-Aided Simulation in Railway Dynamics| first1=Rao V.| last1=Dukkipati| first2=Joseph R.| last2=Amyot| page=31| isbn=0-8247-7787-5| date=1988| publisher=Marcel Dekker, Inc.| location=New York}}</ref><ref>{{cite book| url=https://books.google.com/books?id=ygKio-Ks0doC| title=Railroad Engineering| date=1982| publisher=John Wiley & Sons, Inc.| isbn=0-471-36400-2| pages=664–666}}</ref>
; Head-End Power
: A scheme whereby the locomotive engine or a separate generator provides hotel power to carriages<ref name="Trains Glossary H">{{cite web| url=http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=H| archive-url=https://web.archive.org/web/20140821182340/http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=H| title=Railroading Glossary: H| publisher=Kalmbach Publishing| website=TRN.Trains.com| access-date=20 February 2013| archive-date=21 August 2014}}</ref>
; [[Engineering:Headboard (train)|Headboard]]
: A sign attached to a locomotive to identify a named train or charter, or for other special occasions<ref name="Webb, Deltic">{{cite book |title=The Deltic Locomotives of British Rail |page=40 |first=Brian |last=Webb |publisher=David & Charles |location=Newton Abbot |isbn=0-7153-8110-5 |date=1982}}</ref>
; [[Engineering:Headstock (rolling stock)|Headstock]]
: A transverse structural member located at the extreme end of a rail vehicle's underframe. The headstock supports the [[Engineering:Railway coupling|coupling]] at that end of the vehicle, and may also support buffers, in which case it may also be known as a "buffer beam".<ref name="rtwp">{{cite web|title=Glossary|url=http://www.railway-technical.com/newglos.shtml#H|work=Railway Technical Web Pages|access-date=29 August 2012|url-status=dead|archive-url=https://web.archive.org/web/20141007220720/http://www.railway-technical.com/newglos.shtml#H|archive-date=7 October 2014}}</ref>
; Heavy haul
: Heavy freight operations<ref>{{cite web| url=http://www.ihha.net/about-ihha| title=About IHHA| website=International Heavy Haul Association| access-date=14 October 2014}}</ref><ref>{{cite book| url=https://books.google.com/books?id=C9kXj4ZvDAYC| title=ICLEM 2010: Logistics for Sustained Economic Development – Infrastructure, Information, Integration| chapter=Dangerous Condition Monitoring Technology of Heavy-haul Train| first1=Jianxin| last1=Liu| first2=Kaiyun| last2=Wang| first3=Bin| last3=Zhang| first4=Hanbiao| last4=Nong| first5=Jun| last5=Wang| date=October 2010| publisher=American Society of Civil Engineers| isbn=9780784476116}}</ref><ref>{{cite book| url=https://books.google.com/books?id=T5ihq6By_vkC| chapter=Selection of Rail Types for High-speed Railway and Heavy-haul Railway| first1=Wang Jianxi| last1=Wang| first2=Xiangguo| last2=Li| first3=Shougang| last3=Huang| title=ICCTP 2010: Integrated Transportation Systems Green, Intelligent, Reliable| date=2 July 2010| publisher=American Society of Civil Engineers| isbn=9780784476055}}</ref>
; High rail
: The upper rail in a curve or superelevation, which typically experiences higher lateral loads and greater wear
; Hole
: A passing siding. Inferior trains "lay over in the hole" to let superior ones pass.<ref>{{cite book| url=https://books.google.com/books?id=-zEdAQAAMAAJ| title=Railroad dispatcher communications training materials| page=24| first1=Judith B.| last1=Gertler| first2=Sarah| last2=Acton| publisher=United States Federal Railroad Administration, Office of Research and Development| year=2003}}</ref>
; Home signal
: See absolute signal.
; {{anchor|Horn block}}Horn blocks
: Plates lining the axlebox cut-outs in a locomotive frame to allow smooth vertical movement under control of the springs<ref>{{cite journal| url=https://books.google.com/books?id=TiswAQAAMAAJ| journal=New England Railroad Club| date=10 February 1903| location=Boston, MA| pages=34–65| first=John Hector| last=Graham| title=Paper by John Hector Graham}}</ref><ref>{{cite journal| journal=The Railway Engineer| date=October 1908| pages=320–321| title=Locomotive Journals and Bearings| volume=XXIX| issue=345| url=https://books.google.com/books?id=h05BAQAAMAAJ}}</ref>
; Hostling
: The action of shuttling a locomotive from the yard to the engine house or vice versa<ref>{{Cite encyclopedia |dictionary=Merriam-Webster |entry=hostling |url=http://www.merriam-webster.com/dictionary/hostling |edition=2014 |year=2014 |access-date=11 October 2014|title=Definition of HOSTLING }}</ref>
; [[Engineering:Hot box|Hotbox]]
: An axle bearing that has become excessively hot due to [[Physics:Friction|friction]]<ref name="Trains Glossary H" /><ref>{{cite journal| url=http://info.detnews.com/hotbox/index.cfm| journal=The Hotbox| publisher=North Central Region National Model Railroad Association| access-date=24 January 2008| title=Hotbox |archive-url = https://archive.today/20080107111410/http://info.detnews.com/hotbox/index.cfm |archive-date = 7 January 2008}}</ref><ref>{{cite patent|country=US|number=4659043|pubdate=1987-04-21|title=Railroad hot box detector|assign1=Servo Corporation of America|inventor1-last=Gallagher|inventor1-first=Cornelius A.}}</ref>
; Hotbox detector
: A device attached to the track that monitors passing trains for hot axles, and reports results via radio transmission (typical in the US) or a circuit to the signal box (typical in the UK). See ''defect detector''.<ref name="Trains Glossary H" />
; Hudson type
: [[File:WheelArrangement 4-6-4.svg|thumb|upright=0.5|The ''Hudson'' wheel arrangement]]A steam locomotive with a 4-6-4 wheel arrangement<ref name="Solomon 2009 52" /><ref>{{cite book| url=https://books.google.com/books?id=tEr0AwAAQBAJ| title=North American Locomotives: A Railroad-by-Railroad Photohistory| first=Brian| last=Solomon| page=6| publisher=MBI Publishing Company| year=2012| isbn=9781610586856}}</ref>
; Hump
: A raised section in a rail sorting yard that allows operators to use gravity to move freight railcars into the proper position within the yard when making up trains of cars. This is faster and requires less effort than moving cars with a switching engine.<ref name="Trains Glossary H" />
; [[Hunting oscillation|Hunting]]
: Swaying motion of a railway vehicle or bogie caused by the coning action on which the directional stability of an adhesion railway depends. The truck or bogie wanders from side to side between the rails, "hunting" for the optimum location based on the forces at play.<ref name="Trains Glossary H" />

== I ==
; Independent brake or locomotive brake
: The braking system that applies or releases the brakes of a locomotive independently from its train<ref>{{cite book| url=https://books.google.com/books?id=tSAxAQAAMAAJ| title=1000 Practical Air Brake Questions and Answers for Railroad Men| year=1913| publisher=Walter's Print| location=Lasrobe, Pennsylvania}}</ref><ref>{{cite book| url=https://books.google.com/books?id=cLUkqc18yFcC| title=The American Freight Train| first=Jim| last=Boyd| page=27| publisher=MBI Publishing Company| year=2001| isbn=9780760308332}}</ref>
; Infill station or in-fill station
: A train station built on an existing passenger line to address demand in a location between existing stations
; [[Physics:Injector|Injector]]
: A device to force water into a steam locomotive's boiler by steam pressure<ref name="Trains Glossary I">{{cite web| url=http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=I| archive-url=https://web.archive.org/web/20140913071112/http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=I| title=Railroading Glossary: I| publisher=Kalmbach Publishing| website=TRN.Trains.com| access-date=20 February 2013| archive-date=13 September 2014}}</ref>
; Insulated rail joint (IRJ) or insulated block joint (IBJ)
: Rail joints incorporating insulation to isolate individual track circuits<ref>{{cite book| url=https://books.google.com/books?id=8y3_xqbY0gYC| title=Train Accident Reconstruction and FELA and Railroad Litigation| first1=James R.| last1=Loumiet| first2=William G.| last2=Jungbauer| first3=Bernard S.| last3=Abrams| page=62| publisher=Lawyers & Judges Publishing Company| location=Tucson, Arizona| edition=fourth| year=2005| isbn=978-1-930056-93-0}}</ref><ref>{{cite book| url=https://books.google.com/books?id=5QYmBAAAQBAJ| title=Railway Track Engineering| chapter=3.16: Insulated Rail Joints| page=86| edition=fourth| publisher=Tata McGraw Hill Education Private Ltd.| location=New Delhi, India| year=2010| orig-year=first edition published 2000| isbn=978-0-07-068012-8}}</ref>
; Interchange
: Any track or yard where rail cars are transferred from one carrier to another<ref>{{cite book| url=https://books.google.com/books?id=t0tkZwRg1ssC| title=Realistic Model Railroad Design| first=Tony| last=Koester| page=73| year=2004| publisher=Kalmbach Publishing| location=Waukesha, Wisconsin| isbn=0-89024-581-9}}</ref><ref>{{cite book| url=https://books.google.com/books?id=J3xDGltyvlEC| title=Critical Infrastructure Protection III: Third IFIP WG 11.10 International Conference| location=Hanover, New Hampshire| date=23 March 2009| chapter=14: Secure Cross-Domain Train Scheduling| pages=199–211| first1=Mark| last1=Hartong| first2=Rajni| last2=Goel| first3=Duminda| last3=Wijesekera| publisher=Springer Science & Business Media| isbn=9783642047978}}</ref>
; Interlocking
: An arrangement of switches and signals interconnected in a way that each movement follows the other in a proper and safe sequence<ref>{{cite web|url=http://www.era.europa.eu/Document-Register/Documents/Glossary%20of%20railway%20terminology-selection-%20EN-FR-DE.pdf.pdf|title=ERA Glossary of Railway Terms|date=February 2009|website=ERA.Europa.eu|access-date=2017-03-30}}</ref>
; [[Engineering:Intermodal freight transport|Intermodal freight transport]]
: Moving goods by more than one type of vehicle, often achieved using shipping containers that are transferred among railroad ''flatcars'', ships, airplanes, and tractor-trailer trucks<ref name="Trains Glossary I" />
; Intermodal passenger transport
: Moving people by more than one type of vehicle<ref name="Trains Glossary I" />
; Interoperability
: Ability of a transport network to operate trains and infrastructures to provide, accept and use services so exchanged without any substantial change in functionality or performance<ref>{{cite book|title=IEC 62290-1:2014: Railway applications – Urban guided transport management and command/control systems, Part 1: System principles and fundamental concepts.|publisher=IEC Publications|date=2014|location=[[Place:Geneva|Geneva]]}}</ref>
; [[Engineering:Island platform|Island platform]]
: A [[Engineering:Railway platform|railway platform]] that has tracks along the full lengths of both sides

== J ==
[[File:Journal box.png|thumb|upright=0.5|A ''journal box'' complete with bearing and journal]]
; Jacobs Bogie
: A [[Engineering:Bogie|Bogie]], or truck (American), shared between two pieces of rolling stock.  Cars joined with Jacobs bogies are semi-permanently joined in an articulated configuration.  A weight-saving feature used on lightweight passenger trains.
; Joint bar or rail joiner
: A metal plate that joins the ends of rails in jointed track<ref>{{cite web| publisher=[[Company:Union Pacific Railroad|Union Pacific Railroad]]| url=http://www.uprr.com/aboutup/funfacts/rrtalk/engine.shtml| title=Fun Facts| access-date=5 March 2007}}</ref>
; Jointed track
: Track in which the rails are laid in lengths of around 20&nbsp;m and bolted to each other end-to-end by means of fishplates or joint bars<ref name="Trains Glossary J">{{cite web| url=http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=J| archive-url=https://web.archive.org/web/20140913071116/http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=J| title=Railroading Glossary: J| publisher=Kalmbach Publishing| website=TRN.Trains.com| access-date=20 February 2013| archive-date=13 September 2014}}</ref>
; Journal bearing
: A bearing without [[Physics:Rolling-element bearing|rolling elements]]; a plain bearing<ref name="CSXJ">{{Cite web|title=Railroad Dictionary: J |url=http://www.csx.com/index.cfm/about-csx/company-overview/railroad-dictionary/?i=J |publisher=CSX Corporation |website=CSX.com |year=2012 |access-date=15 November 2014 |archive-url=https://web.archive.org/web/20140729221255/http://www.csx.com/index.cfm/about-csx/company-overview/railroad-dictionary/?i=J |archive-date=29 July 2014 }}</ref>
; Journal box
: The housing of a journal bearing.<ref name="CSXJ" /><ref>{{Cite encyclopedia|title=Dictionary of Car and Locomotive Terms|year=1970|encyclopedia=Car and Locomotive Encyclopedia|publisher=Simmons-Boardman Publishing}}</ref> See also Axlebox above.
; Jubilee type
: [[File:WheelArrangement 4-4-4.svg|thumb|upright=0.5|The ''Jubilee'' wheel arrangement]]A steam locomotive with a 4-4-4 wheel arrangement<ref>{{cite book| url=https://books.google.com/books?id=e5eiAgAAQBAJ| title=Cleveland Mainline Railroads| first=Craig| last=Sanders| page=12| series=Images of Rail| year=2014| isbn=978-1-4671-1137-9| publisher=Arcadia Publishing| location=Charleston, SC}}</ref>
; Junction
: A point at which two lines or separate routes diverge from each other<ref name="Trains Glossary J" />

== K ==
; Keeper
: A padlock or hook securing the lever of a hand-operated switch, thereby preventing the switch points from moving as rolling stock passes over them<ref>{{cite book| url=https://books.google.com/books?id=X6YXAAAAYAAJ| title=Technical Manual TM 5-370: Railroad Construction| publisher=United States Department of the Army| date=September 1970| page=Glossary 6}}</ref><ref>{{cite book |title=The Code of Federal Regulations of the United States of America – 49: Transportation |publisher=Office of the Federal Register, National Archives and Records Administration |date=October 2006 |page=115 |url=https://books.google.com/books?id=Bp48AAAAIAAJ}}</ref>
; Kick
: To shove a car a short distance and uncouple it in motion, allowing it to roll free under gravity and/or its own inertia onto a track. Commonly practiced in bowl or hump yards to make up or break down trains or classify large numbers of cars in an expedient fashion. Differs from a flying switch in that the locomotive is pushing the car rather than pulling it when the cut is made.<ref>{{cite journal|date=September 1905|title=Taking Chances|journal=Railroad Men|volume=XVIII|issue=12|page=460|url=https://books.google.com/books?id=xWDXAAAAMAAJ}}</ref>
; Kicker
: A freight car with a defect in its brake valve that causes the entire train's brake system to go into emergency when any application is made<ref>{{cite book|last=Bibel|first=George |title=Train Wreck: The Forensics of Rail Disasters|publisher=Johns Hopkins University Press|location=Baltimore, MD|date=2012|pages=145–146|isbn=978-1-4214-0590-2|url=https://books.google.com/books?id=5mKefpEufkgC}}</ref>
; Kinematic envelope (KE)
: The outline of the space beside and above the track that must be kept [[Engineering:Engineering tolerance|clear]] of obstructions for the train to pass. This can be larger than the static clearance around an unmoving engine or car.<ref>{{cite book|title=Handbook of Railway Vehicle Dynamics|editor=Simon Iwnicki|publisher=CRC Press|location=Boca Raton, Florida|date=2006|page=184|isbn=0-8493-3321-0|url=https://books.google.com/books?id=Im0ZjhI3a-cC}}</ref> See also: [[Engineering:Loading gauge|loading gauge]] and structure gauge
; Knuckle
: The articulating part of a coupler that locks automatically in its closed position to join rail cars; so named because its movement resembles that of the human finger<ref>{{cite patent |country=US |number=936046 |status=patent |title=Car-coupling |pubdate=1909-10-05|inventor1-last=Schroeder|inventor1-first=William S.|assign1=National Malleable Castings Company}}</ref>

== L ==
; {{anchor|Lead track}}Lead track
: A non-main track from which several others branch within a short distance, such as within a rail yard or engine terminal<ref>{{cite book|title=Railroad Reports: A collection of all cases affecting railroads of every kind, decided by the courts of last resort in the United States|editor=Thomas J. Michie|publisher=The Michie Company|location=Charlottesville, VA|date=1913|volume=67|pages=315–316|chapter=MacKenzie v. New York Cent. & H. R. R. Co.|url=https://books.google.com/books?id=yc49AAAAIAAJ}}</ref>
; [[Engineering:Level crossing|Level crossing]] (LC), railroad crossing, railway crossing, train crossing, or grade crossing
: A crossing on one level ("at-grade intersection")—without recourse to a bridge or tunnel—generally of a railway line by a road or path. Not to be confused with non-dead-end railways (see '''Rail crossing''')
; Light engine
: A locomotive travelling on its own, or perhaps with just a caboose ([[Engineering:Brake van|brake van]]) attached<ref name="Trains Glossary L">{{cite web| url=http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=L| archive-url=https://web.archive.org/web/20140826045205/http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=L| title=Railroading Glossary: L| publisher=Kalmbach Publishing| website=TRN.Trains.com| access-date=20 February 2013| archive-date=26 August 2014}}</ref>
; [[Engineering:Light rail|Light rail]]
: A city-based rail system based on [[Engineering:Tram|tram]] design standards that operates mostly in private rights-of-way separated from other traffic but sometimes, if necessary, mixed with other traffic in city streets.<ref>{{Cite web |url=http://www.lrta.org/explain.html |publisher=Light Rail Transit Association |website=LRTA.org |title=What is Light Rail? |access-date=6 July 2009 |archive-url=https://web.archive.org/web/20160605081140/http://www.lrta.org/explain.html |archive-date=5 June 2016 |url-status=dead }}</ref> Light rail vehicles (LRVs) generally have a top speed of around {{convert|55|mph|km/h|abbr=on}} though mostly operating at much lower speeds, more akin to road vehicles. Light rail vehicles usually run on trackage that weighs less per foot (due to a smaller track profile) than the tracks used for main-line freight trains; thus they are "light rail" due to the smaller rails usually used.<ref name="Trains Glossary L" />
; Link and pin
: An obsolete method of coupling rail cars, consisting of manually dropping the coupling pin into the drawbar as the cars joined. Extremely hazardous to the brakemen of its day, it was outlawed in the United States by the Railroad Safety Appliance Act of 1893.
; Local train
: A train that stops at most, if not all, stations along its route<ref>{{cite book|last=Grutzik|first=Joe|title=Adventure Lessons: Teachings of an Existential Vagabond|publisher=Good & Brown Publishers|location=Los Angeles, California|date=2005|page=34|isbn=0-9768915-1-4|url=https://books.google.com/books?id=7aSGR3q8sW4C}}</ref>
; {{anchor|Lunar}}Lunar
: An off-white color of railway signal light, like the [[Astronomy:Moon|Moon]], achieved by the use of a clear lens of very light blue, to make it distinct from a light that has a broken lens.<ref>{{cite journal|last=Elliott|first=W. H.|date=January 1906|title=Signaling|journal=Railroad Men| volume=XIX| issue=4| pages=128–137| url=https://books.google.com/books?id=QGHXAAAAMAAJ}}</ref><ref>{{cite book|last=Solomon|first=Brian|title=Railroad Signaling|publisher=MBI Publishing Company|date=2003|page=48}}</ref>

== M ==
; [[Physics:Maglev|Maglev]]
: A system of high speed train transportation that uses two sets of magnets: one set to repel and push the train up off the track, and another set to move the elevated train ahead, taking advantage of the lack of friction.
; Main generator
: The [[Engineering:Electric generator|electric generator]] in a diesel-electric locomotive that is coupled directly to the prime mover and feeds electrical energy to the traction motors<ref>{{cite book|title=Operation and Maintenance of Diesel-Electric Locomotives|publisher=United States Departments of the Army and the Air Force|date=October 1965|page=77|url=https://books.google.com/books?id=8ns-AAAAYAAJ}}</ref>
; Main reservoir
: The compressed-air tank of a locomotive containing source air for the brakes and other pneumatic appliances<ref>{{cite book|last=Fowler|first=George L.|title=Locomotive Dictionary|publisher=Lulu.com|date=2008|volume=1|pages=55, 65|isbn=9781935327615}}</ref>{{self-published inline|date=February 2020}}
; Mallet
: A type of compound [[Engineering:Articulated locomotive|articulated locomotive]] designed by the Swiss mechanical engineer Anatole Mallet (pronounced "mallay").<ref name="Trains Glossary M">{{cite web| url=http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=M| archive-url=https://web.archive.org/web/20140821182116/http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=M| title=Railroading Glossary: M| publisher=Kalmbach Publishing| website=TRN.Trains.com| access-date=20 February 2013| archive-date=21 August 2014}}</ref><ref>{{cite book|title=Locomotive Cyclopedia of American Practice|publisher=Simmons-Boardman Publishing Co.|location=New York|date=1922|edition=sixth|pages=102–103|url=https://books.google.com/books?id=oMY1AQAAMAAJ}}</ref> See Compound engine.
; Manifest
: An express freight train carrying a variety of general merchandise<ref>{{cite book|last=Bedwell|first=Harry|title=The Boomer: A Story of the Rails|publisher=First University of Minnesota Press|location=Minneapolis, MN|date=2006|orig-year=first published 1936|page=322|url=https://books.google.com/books?id=dR482FDKz38C|isbn=9781452909080}}</ref><ref>{{cite book|last=Green|first=Jonathon|title=Cassell's Dictionary of Slang|publisher=Weidenfeld & Nicolson|location=London|date=2005| orig-year=first edition published 1998|edition=second|page=923|isbn=0-304-366366|url=https://books.google.com/books?id=5GpLcC4a5fAC}}</ref>
; Mars Light
: A nose-mounted mechanically oscillated light used to warn traffic of an approaching locomotive.  Functionally replaced by ditch lights on modern locomotives.
; Mechanical semaphore signal
: A signal in which the aspect is conveyed by moving an arm<ref>{{cite book|last=Bianculli|first=Anthony J. |title=Trains and Technology: The American Railroad in the Nineteenth Century|publisher=Rosemont Publishing & Printing Corp., Associated University Presses|date=2003|volume=4: Bridges and Tunnels, Signals|page=172|isbn=0-87413-803-5|url=https://books.google.com/books?id=tbtdcXXnq5kC}}</ref><ref>{{cite book|title=The Railroad Signal Dictionary|editor1=Braman B. Adams |editor2=Rodney Hitt |work=Railroad Age Gazette|location=Chicago|date=1908|edition=first|url=https://archive.org/details/railroadsignald01assogoog}}</ref>
; Meet
: In rail transport operations, a meet occurs when two trains arrive at a location and pass each other on parallel tracks, such as on a siding, usually in opposing directions.<ref>{{cite web| url=https://www.american-rails.com/glossary.html| title=Railroad Glossary: Definitions And Terms| website=American-Rails.com| access-date=26 October 2020}}</ref><ref>{{cite book| url=https://www.apta.com/wp-content/uploads/APTA-Compendium-of-Definitions-Acronyms-for-Rail-Systems.pdf| page=180| quote=Siding (passing track, side track): A track adjacent to a main or a secondary track, for meeting, passing, or storing cars or trains| title=Compendium of Definitions and Acronyms for Rail Systems| date=20 June 2019| publisher=American Public Transportation Association| location=Washington, D.C.| access-date=26 October 2020}}</ref> This is also sometimes referred to as a crossing of two trains.<ref>{{cite web| url=https://www.tasrail.com.au/glossary-of-train-speak| quote=crossing loop: ... a facility that permits trains to both cross and pass each other.| title=Glossary of Train Speak| website=TasRail| access-date=26 October 2020}}</ref>
; Mikado type
: [[File:WheelArrangement 2-8-2.svg|thumb|upright=0.5|The ''Mikado'' wheel arrangement]]A steam locomotive with a 2-8-2 wheel arrangement<ref>{{cite book|last=James|first=W. P.|title=Locomotive Engineman's Manual|publisher=Periscope Film|date=2008|edition=fifteenth|pages=24–27|chapter=Mikado Type Locomotives|url=https://books.google.com/books?id=pGVg8K91PlEC|orig-year=first edition published 1916|isbn=9780981652689}}</ref>
; {{Visible anchor|Milk train}}
:In the U.S., milk trains ran from the countryside to cities making numerous stops at minor depots to pick up cans of fresh milk, making them a colloquial expression for a very slow train.
: In the U. K., an aggregator for transporting milk from farms to dairies, such as British Railways Milk Trains; as these trains invariably ran very early in the morning, "milk train" became a colloquialism for a particularly early train.<ref>{{cite book|last=Glazier|first=Stephen|title=Random House Webster's word menu|publisher=Random House|date=1998|page=212|isbn=9780375700835}}</ref><ref>{{cite book|title=The New Partridge Dictionary of Slang and Unconventional English|editor1=Tom Dalzell |editor2=Terry Victor |publisher=Routledge|location=New York|date=2006|volume=II: J-Z|page=1295|isbn=0-415-25938-X|url=https://books.google.com/books?id=mAdUqLrKw4YC}}</ref><ref>{{cite book|title=World Book Dictionary|publisher=World Book, Inc.| location=Chicago| date=2003| page=1318| isbn=0-7166-0299-7| url=https://books.google.com/books?id=oPW_pTjpeCQC}}</ref>
; [[Engineering:Modalohr|Modalohr]]
: An inter-modal car
; Mogul type
: [[File:WheelArrangement 2-6-0.svg|thumb|upright=0.5|The ''Mogul'' wheel arrangement]]A steam locomotive with a 2-6-0 wheel arrangement<ref>White (1968), p 62-65.</ref>
; Mothballed
: A track that is still serviceable but no trains are running on them.<ref>{{Cite web|url=https://www.greaterauckland.org.nz/2018/02/23/re-opening-mothballed-lines/|title = Re-Opening Mothballed Lines|date = 22 February 2018}}</ref><ref>{{Cite web|url=https://www.stuff.co.nz/travel/destinations/nz/107344321/travelling-new-zealandss-railways-is-all-about-terminated-lines|title=Travelling New Zealand's railways is all about terminated lines|date=29 September 2018}}</ref>
; Mountain type
: [[File:WheelArrangement 4-8-2.svg|thumb|upright=0.5|The ''Mountain'' wheel arrangement]]A steam locomotive with a 4-8-2 wheel arrangement<ref>{{cite book|title=Locomotive Cyclopedia of American Practice|publisher=American Railway Master Mechanics' Association|pages=192–206|chapter=4-8-2 Locomotives|year=1947 |isbn=9785874485672|url=https://books.google.com/books?id=K4YMAwAAQBAJ}}</ref>
; Mud ring
: The bottom of the water space surrounding a steam locomotive's firebox that collects solids precipitating from the water supply during the boiling process<ref>{{cite book|title=Locomotive Cyclopedia of American Practice|editor=Roy V. Wright |editor2=Charles N. Winter|publisher=Simmons-Boardman Publishing Co.|location=New York|date=1922|edition=sixth|pages=46, 62|url=https://books.google.com/books?id=oMY1AQAAMAAJ}}</ref>
; Multiple aspect signalling
: A system of colour-light signalling in which signals may show three or four aspects<ref>{{cite book|last=Duffy|first=Michael C. |title=Electric Railways 1880–1990|publisher=The Institution of Engineering and Technology|location=Stevenage, UK|date=2008|series=History of Technology|pages=191–193|isbn=978-0-85296-805-5|url=https://books.google.com/books?id=cpFEm3aqz_MC|orig-year=first edition published 2003}}</ref>
; [[Engineering:Multiple unit|Multiple unit]] (MU)
: A self-propelled rail vehicle that can be joined with compatible others and controlled from a single driving station. The sub-classes of this type of vehicle; Diesel Multiple Unit (DMU), Diesel-Electric Multiple Unit (DEMU) and [[Engineering:Electric multiple unit|Electric Multiple Unit]] (EMU) are more common terms. These may also be termed railcars.
; [[Engineering:Multiple-unit train control|Multiple-unit train control]]
:The control of multiple locomotives or MUs from a single set of controls.

== N ==
[[File:CombinedTrack.svg|thumb|upright=0.5|Comparison between standard gauge (blue) and one common ''narrow gauge'' (red) rail spacing]]
; Narrow gauge
: Railroad track where the rails are spaced less than {{Track gauge|sg}} apart,<ref name="Trains Glossary N">{{cite web| url=http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=N| archive-url=https://web.archive.org/web/20140822151806/http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=N| title=Railroading Glossary: N| publisher=Kalmbach Publishing| website=TRN.Trains.com| access-date=23 March 2017| archive-date=22 August 2014}}</ref>
; Northern type
: [[File:WheelArrangement 4-8-4.svg|thumb|upright=0.5|The ''Northern'' wheel arrangement]]A steam locomotive with a 4-8-4 wheel arrangement, also known in North America as "Pocono", "Niagara", "Confederation", "Greenbrier", and "Potomac"<ref>{{cite book|last=Solomon|first=Brian|title=North American Locomotives: A Railroad-by-Railroad Photohistory|publisher=MBI Publishing Company|date=2012|page=6|isbn=9781610586856|url=https://books.google.com/books?id=tEr0AwAAQBAJ}}</ref><ref>{{cite book|last=Glischinski|first=Steve |title=Santa Fe Railway|publisher=Andover Junction Publishing|date=1997|series=Railroad Color History|page=104|isbn=0-7603-0380-0|url=https://books.google.com/books?id=lBKFXZC-_ZYC}}</ref>
; {{Visible anchor|Notch 8}} or run 8
: The eighth notch of a locomotive throttle control, indicating full power on the standard American diesel locomotive control scheme<ref>{{cite book|last=Wilson|first=Jeff|title=The Model Railroader's Guide to Diesel Locomotives|publisher=Kalmbach Publishing|location=Waukesha, WI|date=2009|page=15|isbn=978-0-89024-761-7|url=https://books.google.com/books?id=Gt8OtslzijYC}}</ref><ref>{{cite book|last1=Loumiet|first1=James R.| last2=jungbauer| first2=William G.| edition=fourth| title=Train Accident Reconstruction and FELA and Railroad Litigation|publisher=Lawyers & Judges Publishing Co.|location=Tucson, Arizona|date=2005|page=226|isbn=978-1-930056-93-0|url=https://books.google.com/books?id=8y3_xqbY0gYC}}</ref>

== O ==
; [[Engineering:Open wagon|Open wagon]] (UIC)
: A form of freight hauling car for bulk goods<ref name="Trains Glossary O">{{cite web| url=http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=O| archive-url=https://web.archive.org/web/20140913071124/http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=O| title=Railroading Glossary: O| publisher=Kalmbach Publishing| website=TRN.Trains.com| access-date=20 February 2013| archive-date=13 September 2014}}</ref>
; Out to foul
: When equipment is placed ahead of the fouling point of a switch turnout

== P ==
[[File:WheelArrangement 4-6-2.svg|thumb|upright=0.5|The ''Pacific'' wheel arrangement]] [[File:Schynige Platte diamond pantograph.jpg|thumb|upright=0.5|A ''pantograph'']]
; Pacific type
: A steam locomotive with a 4-6-2 wheel arrangement<ref>{{cite book|title=The Engineering Index|editor1=Henry Harrison Suplee, B.Sc. |editor2=J.H. Cuntz, C.E. M.E. |editor3=Charles Buxton Going, Ph.B. |publisher=The Engineering Magazine|location=New York and London|date=1906|volume=IV: 1901–1905|page=714|url=https://books.google.com/books?id=X1E0AAAAMAAJ}}</ref>
; Pannier tank
: A [[Engineering:Tank locomotive|tank locomotive]] where the water tanks are mounted on the boiler in [[Engineering:Pannier|pannier]]-like fashion
; Pantograph
: An apparatus mounted on the roof of a rail vehicle to allow the collection of electric current from overhead lines<ref name="Trains Glossary P">{{cite web| url=http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=P| archive-url=https://web.archive.org/web/20140913071128/http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=P| title=Railroading Glossary: P| publisher=Kalmbach Publishing| website=TRN.Trains.com| access-date=20 February 2013| archive-date=13 September 2014}}</ref><ref>{{cite book|last=Hay|first=William Walter|title=Railroad Engineering|publisher=John Wiley & Sons, Inc.|date=1982|pages=134–135|isbn=0-471-36400-2|url=https://books.google.com/books?id=ygKio-Ks0doC}}</ref>
; Paperwork
: As a reason for delays, written instructions conveyed to a train's engineer in which the train must proceed slower than its normal speed. These instructions are either handed to the crew or recited and read back over radio.<ref>{{Cite web|url=http://web.mta.info/lirr/MyLIRR/2018/07-2018.htm|archive-url = https://web.archive.org/web/20190202152544/http://web.mta.info/lirr/MyLIRR/2018/07-2018.htm|archive-date = 2 February 2019|title = MyLIRR – July 2018}}</ref>
; Pennsy
: Abbreviation for the former Pennsylvania Railroad<ref>{{cite book|last=Treese|first=Lorett|title=Railroads of Pennsylvania: Fragments of the Past in the Keystone Landscape|publisher=Stackpole Books|location=Mechanicsburg, Pennsylvania|date=2003|page=5|isbn=0-8117-2622-3|url=https://books.google.com/books?id=WU83s_xdIF4C}}</ref>
; Per diem (pronounced by some U.S. railroaders ''per die-um,'' not ''per dee-um'')
: A fee paid by a rail company to the owner of a car (or ''wagon'') for the time it spends on the company's property<ref name="Trains Glossary P" /><ref>{{cite book|title=Arbitration Cases No. 1 – No. 61; Decided by the Per Diem Rules Arbitration Committee|publisher=The American Railway Association|location=New York|date=June 1913|url=https://books.google.com/books?id=jiE9AAAAYAAJ}}</ref>
: An authorized living expense payment for some workers forced away from their home terminal<ref name="Trains Glossary P" /><ref>{{cite book|title=Publication 1194-B: A Selection of ... Internal Revenue Service Tax Information Publications|publisher=United States Internal Revenue Service|date=2000|volume=2|page=247|url=https://books.google.com/books?id=8dCRAAAAMAAJ}}</ref>
; Permissive signal
: A block signal whose most restrictive indication is stop and proceed. A permissive signal is identified by the presence of a number plate affixed to the mast or supporting structure. Proceeding beyond a permissive signal at stop is allowed at restricted speed if operating conditions enable a train operator to stop before reaching any train or obstruction.<ref>{{cite journal|date=February 1922|title=Locomotive Engineers Journal|publisher=Brotherhood of Locomotive Engineers|location=Des Moines, Iowa|volume=56|issue=2|page=197|url=https://books.google.com/books?id=Y6KZAAAAIAAJ}}</ref><ref>{{cite book|last=Weiser|first=Eugene |title=The Pennsylvania Railroad: A Brief Look in Time|publisher=Dragonwick Publishing|location=Seaford, DE|date=2013|series=The History of the American Railroads|pages=30–31|isbn=978-1300640783|url=https://books.google.com/books?id=hrAXBAAAQBAJ}}</ref><ref>{{cite book|last=Solomon|first=Brian|title=Railroad Signaling|publisher=MBI Publishing Company|date=2003|page=103|isbn=9781616738976|url=https://books.google.com/books?id=rIf4y6otfu0C}}</ref>
; Pilot
: A deflective shield affixed to the front of a locomotive to protect its wheels from on-track debris; archaically called a "cowcatcher"<ref>{{cite book|first=Anthony|last=Hyman|title=Charles Babbage: Pioneer of the Computer|publisher=[[Organization:Oxford University Press|Oxford University Press]]|year=1982|isbn=978-0-198-58170-3|pages = 142–143 | quote = Babbage suggested to Hodgson of the railway company what was later called a 'cow-catcher' for sweeping obstacles off the line. }}</ref> See also: Pilot (locomotive)
: An employee qualified on the operating rules and physical characteristics of a certain section of the railroad, assisting a crew member who is not so qualified<ref>{{cite book|title=1980 Census of Population: Classified Index of Industries and Occupations|publisher=United States Department of Commerce, Bureau of the Census|date=November 1982|page=O-143|url=https://books.google.com/books?id=tLLhHHKEhE4C}}</ref><ref>{{cite book|author=United States National Railroad Adjustment Board|title=Awards ... First Division, National Railroad Adjustment Board|publisher=U.S. Government Printing Office|location=Washington, DC|page=83|url=https://books.google.com/books?id=juxAAAAAIAAJ}}</ref> See also: Railroad engineer
; Pilot engine
: The leading locomotive during a double-heading operation<ref name="Hawkins-pilotengine">{{cite book|last=Hawkins|first=Nehemiah |title=Hawkins' mechanical dictionary|publisher=Theodore Audel & Co. Publishers|location=New York and London|date=1909|page=400|url=https://books.google.com/books?id=HLlXAAAAYAAJ}}</ref>
: An unattached locomotive driven a specified distance in front of a special train<ref name="Hawkins-pilotengine" /><ref>{{cite book|title=The Encyclopaedic Dictionary|publisher=Cassell & Co., Ltd.|location=London, Paris, New York & Melbourne|date=1886|volume=5, part 2|page=519|url=https://books.google.com/books?id=uJxiAAAAMAAJ}}</ref><ref>{{cite book|last=Ogilvie, LL.D.|first=John|title=The Imperial Dictionary of the English Language|editor=Charles Annandale, M.A.|publisher=Blackie & Son|location=London|date=1883|volume=III: L-Screak|page=445|url=https://books.google.com/books?id=oHwCAAAAQAAJ}}</ref>
; Pilot man
: Where it is necessary to temporarily work a section of line as single track (for instance if the other track of a double-track line is out of use), a person (the pilot man) acts as the single track token.
; [[Engineering:Piston|Piston]]
: The moving component in the [[Physics:Cylinder (engine)|cylinder]] of a [[Physics:Steam engine|steam engine]] or [[Earth:Internal combustion engine|internal combustion engine]] that translates into motion the force exerted by pressurised steam or quickly-burning fuel<ref>White (1968), p 207-208.</ref>
; Piston travel
: A specified distance that a brake piston may move from its cylinder to the brake rigging. If the travel exceeds or falls short of this distance, the equipment must be set out for repair.<ref>{{cite book|last=Shade|first=Howard Milton|title=What Railroad Men Should Know|date=25 January 1917|pages=96–97|chapter=Piston Travel|url=https://books.google.com/books?id=-pzVAAAAMAAJ}}</ref>
; [[Biology:Platform screen doors|Platform screen doors]]
: Infrastructure used to separate the platform from train tracks.
; Pony truck
: A two-wheel truck or bogie at the front of a locomotive<ref>White (1968), p 174.</ref>
; Porch
: The extended walkway at either end of a U.S. locomotive<ref>{{cite book|last=Wilson|first=Jeff|title=The Model Railroader's Guide to Diesel Locomotives|publisher=Kalmbach Publishing|location=Waukesha, WI|date=2009|page=48|isbn=978-0-89024-761-7|url=https://books.google.com/books?id=Gt8OtslzijYC}}</ref>
; Porter
: An employee who performs or performed (the role has now largely become obsolete) various physical duties, chiefly but not exclusively involving lifting. Various types of porter include:
:* A ''baggage porter'' assisting with luggage
:* An ''operating porter'' assisting with safeworking duties
:* A ''station porter'' assisting with general station duties
:* A ''lad porter'' being a junior station porter
; [[Engineering:Portion working|Portion working]]
: The practice of coupling two or more passenger trains together over common sections of their respective routes, but otherwise operating the trains separately<ref name="rentrains">{{cite web|title=The Potential for Increased On-Rail Competition|url=http://www.rail-reg.gov.uk/pr13/PDF/on-rail_competition_renaissance_trains.pdf|publisher=Renaissance Trains/Office of Rail Regulation UK|access-date=15 February 2013}}</ref><ref name="PTN">{{cite web|title=Further written evidence from Jonathan Tyler, Passenger Transport Networks (HSR 138A)|url=https://publications.parliament.uk/pa/cm201012/cmselect/cmtran/1185/1185vw124.htm|publisher=House of Commons|access-date=15 February 2013}}</ref>
; Position light signal
: [[File:OVERBROOK 18R-Approach-Medium.jpg|thumb|upright=0.5|A ''position light signal'']]A block signal in which the relative position of the lights determines the meaning
; Positive train control (PTC)
: An American system of functional requirements for monitoring and controlling train movements with the aim of increasing operational safety
; Possession
: In Britain, a period of time when one or more tracks are closed for maintenance. For the duration of the work, a person in charge of possession (PICOP) has control of the line. When work is complete the possession is relinquished and control of the line handed back to the signaller.<ref>{{cite book| url=https://books.google.com/books?id=zkDYawSkRpAC| title=Ellis' British Railway Engineering Encyclopaedia| page=269| year=2006| isbn=978-1-84728-643-7|oclc=683418325| publisher=Lulu.com| first=Iain| last=Ellis}}</ref>{{self-published inline|date=February 2020}}
; Pound
: The weight (and thus the cross section) of a length of rail. A heavier rail can carry heavier loads with less distortion and less damage to the rails themselves and the roadbed.
; Power
: A locomotive or group of connected (MU'd) locomotives serving as the motive power for a train<ref name="Trains Glossary P" />
; Power braking
: Pulling against the train brakes at the higher end of the locomotive's power output (e.g. notches five through eight on a conventional throttle). This is considered wasteful of fuel and brake shoes, and is therefore discouraged by most operating departments.<ref>{{cite book|title=Train Accident Reconstruction and FELA and Railroad Litigation|publisher=Lawyers & Judges Publishing Co.|location=Tucson, Arizona|date=2005|page=42|isbn=978-1-930056-93-0| last1=Loumiet| first1=James R.| last2=Jungbauer| first2=William G.| edition=fourth}}</ref><ref>{{cite book|title=Handbook of Railway Vehicle Dynamics|editor=Simon Iwnicki|publisher=CRC Press|location=Boca Raton, Florida|date=2006|pages=240–241|isbn=0-8493-3321-0|url=https://books.google.com/books?id=Im0ZjhI3a-cC}}</ref>
; Prairie type
: [[File:WheelArrangement 2-6-2.svg|thumb|upright=0.5|The ''Prairie'' wheel arrangement]]A steam locomotive with a 2-6-2 wheel arrangement<ref name=":3">{{cite book|title=Locomotive Cyclopedia of American Practice|date=23 August 2023 |publisher=American Railway Master Mechanics' Association|page=102|isbn=9785874485672|url=https://books.google.com/books?id=K4YMAwAAQBAJ}}</ref>
; Prime mover
: The internal combustion engine of a diesel locomotive
; Pull apart
: A rail broken from cold-related contraction<ref>{{cite journal|date=1996|title=Railway Track and Structures|publisher=Simmons-Boardman Publishing|volume=92|page=27|url=https://books.google.com/books?id=aGg9AQAAIAAJ}}</ref><ref>{{cite book|last1=McCulloch|first1=David S.| last2=Bonilla| first2=Manuel G.| title=The Alaska Earthquake, March 27, 1964: Effects on Transportation and Utilities|publisher=United States Government Printing Office|location=Washington, DC|date=1970|series=Geological Survey Professional Paper|page=D135}}</ref>
; Push pole
: [[File:PushPoleSRM.jpg|thumb|upright=0.5|A ''push pole'']]A pole about {{convert|12|ft|cm|0}} long and having a diameter of {{convert|5|in|mm|0}} and used in the United States between 1870 and the mid-1960s to push a freight car onto or off a siding or onto another track by being placed between a locomotive (on an adjacent track) and the freight car. The two ends of the poles were placed in receptacles called push pole pockets.<ref>{{cite web | title = 1 Killed, 20 Hurt in Jersey Wreck; Freight Car Jumps Rails and Rips Sides of Passenger Cars at Stevens. Fire Follows Collision Edward Lawrence of Bordentown, Brakeman, Crushed Between Freight Car and Coach. | date = 26 June 1920 | url = https://timesmachine.nytimes.com/timesmachine/1920/06/26/97759707.pdf | access-date = 5 October 2008 }}</ref> The practice of using a push pole for switching was called "poling".<ref>{{cite book| page=89| title=The Age of Steam| first1=Lucius| last1=Beebe|  first2=Charles| last2=Clegg|  publisher=Promontory Press| location=New York| year=1994| lccn=72-86410| isbn=0-88394-079-5}}</ref>
; Push–pull train
: A configuration for&nbsp;[[Engineering:Locomotive|locomotive]]-hauled&nbsp;[[Engineering:Train|train]]s,&nbsp;allowing them to be driven from either end of the train, whether having a locomotive at each end or not. See also: Auto train. See Top and tail for train with locomotives at both front and back.<ref name="Trains Glossary P" />

== R ==
; [[Engineering:Rack railway|Rack railway]], rack-and-pinion railway, or cog railway
: A steep-grade railway with a toothed rack rail (usually between the running rails), used when adhesion is insufficient
; [[Engineering:Railbus|Railbus]]
: A passenger rail vehicle (typically non-articulated or rigid frame) that derived from bus propulsion and construction technology, but may evolve into larger dimensions, performance, and characteristics similar in appearance to a light DMU railcar
; Railcar
: A powered single unit or articulated passenger car, usually "railroad-derived" light DMU or [[Engineering:Electric multiple unit|EMU]], with a driver's cab at one or both ends
; Rail crossing
: The opposite of a '''dead-end rail''', i.e. a line connecting locations accessed by other railways, often associated with the overcoming of natural obstacles, such as mountain ranges.<ref>[https://books.google.com/books?id=d_VCiFfiObEC ''1,000 Places to See Before You Die''], p. 272 ["Completed in 1910, the Bernina line is the highest railway crossing in the Alps."]</ref> Not to be confused with a railway crossing a road (see '''Level crossing''')
; Railfan
: A hobbyist or enthusiast of trains
; Rail grinder
: A machine used to remove irregularities in the surface of the rails that may be self-powered or part of a consist
; Rail profile
: [[File:Rail profile.svg|thumb|upright=0.5|''Rail profiles'' for flat-bottom and bullhead rails]]The cross section shape of rail. There are many rail profiles, often specific to individual railroads. Rails must be periodically scanned electronically, the data inspected and analysed, then re-profiled with rail grinding machines to maintain the safe and proper ''rail profile''. Rails that cannot be brought back to the proper rail profile are condemned and replaced.
; Rail squeal
: A screeching train-track friction sound, most commonly occurring on [[Engineering:Minimum railway curve radius|sharp curves]] or heavy braking<ref>{{cite book|last=Thompson|first=David|title=Railway Noise and Vibration: Mechanisms, Modelling and Means of Control|publisher=Linacre House|location=Oxford|date=2009|edition=first|page=8|isbn=978-0-08-045147-3|url=https://books.google.com/books?id=zciPgBeYafsC}}</ref>
; [[Engineering:Switcher|Rail tractor]]
: A small petrol (gas) or diesel [[Engineering:Switcher|shunting]] (switcher) locomotive
; [[Engineering:Railroad car|Railroad car]]
: Any railroad vehicle other than a locomotive
; Railroadiana
: Artifacts of railways around the world
; {{Visible anchor|Railway line}}, railroad line, rail line, or train line
: A railway route connecting two or more places or other railway routes<ref name="FreeDict-RyLine">{{cite web| url=http://www.thefreedictionary.com/railway+line| title=railway line| work=The Free Dictionary| access-date=19 October 2014}}</ref>
: A railway route constructed by an organization, usually one formed for that purpose<ref name="FreeDict-RyLine" /><ref>{{cite news| url=https://news.yahoo.com/china-russia-said-mull-high-speed-moscow-beijing-070811667.html| title=China, Russia mull high-speed Moscow-Beijing rail line: report| date=17 October 2014| work=Yahoo News| access-date=19 October 2014}}</ref><ref>{{cite news| url=https://www.bbc.com/news/world-africa-27368877| title=China to build new East Africa railway line| publisher=BBC News| date=12 May 2014| access-date=19 October 2014}}</ref>
: A railway route that has an official name (notably bestowed by engineers line references in the UK)<ref>{{cite web| url=http://www.nationalrail.co.uk/times_fares/46418.aspx| title=Named Railway Lines| work=National Rail Enquiries| access-date=19 October 2014}}</ref>
: A set of railway routes that are bundled for publicity purposes (e.g. a UK train operating company)<ref>{{cite web| url=http://data.worldbank.org/indicator/IS.RRS.TOTL.KM| title=Rail Lines (total route-km)| work=The World Bank| access-date=19 October 2014}}</ref><ref>{{cite web| url=http://www.jreast.co.jp/e/info/map_a4ol.pdf| title=Railway Lines Network| publisher=JR East Group| date=16 March 2013| access-date=19 October 2014}}</ref>
; Railway station
: [[File:Union Station from Columbus Circle, Washington, D.C. 2011.jpg|thumb|upright=0.5|Washington, D.C.'s Union Station is an example of a ''railway station'']]A train station, a stopping point for trains, usually with passenger access
; Railway terminal
: A building for passengers at the end of a railway line
; [[Red]]
: A colour generally associated with stop, when shown by signals or flags
; Red zone
: The area between, under, or within a few feet of cars and locomotives. To enter the zone, a ground employee must obtain protection from the locomotive engineer (if a locomotive is coupled) or a blue signal (if no locomotive is coupled).<ref>{{cite web| url=http://www.safety.networkrail.co.uk/Services/Jargon-Buster/R/RA-RE/Red-Zone-Working| title=Red Zone Working| website=Safety.NetworkRail.co.uk| access-date=19 October 2014| archive-url=http://webarchive.nationalarchives.gov.uk/20150506213822/https%3A//www.safety.networkrail.co.uk/Services/Jargon%2DBuster/R/RA%2DRE/Red%2DZone%2DWorking| archive-date=6 May 2015| url-status=dead}}</ref><ref>{{cite web| url=http://www.csx.com/index.cfm/customers/non-freight-services/propertyreal-estate/permitting-utility-installations-and-rights-of-entry/safety-requirements/| title=CSX Safety Requirements for Corridor Activity| publisher=CSX Transportation| access-date=19 October 2014| archive-url=https://web.archive.org/web/20140823223410/http://csx.com/index.cfm/customers/non-freight-services/propertyreal-estate/permitting-utility-installations-and-rights-of-entry/safety-requirements/| archive-date=23 August 2014| url-status=dead}}</ref><ref>{{cite book| url=https://books.google.com/books?id=zkDYawSkRpAC| title=Ellis' British Railway Engineering Encyclopaedia| first=Iain| last=Ellis| publisher=Lulu.com| page=292| year=2006| isbn=978-1-84728-643-7}}</ref>{{self-published inline|date=February 2020}}
; [[Physics:Refrigerator car|Reefer]]
: A refrigerated railcar, used to transport perishable goods<ref>{{cite book|last=Barry|first=Steve|title=Railroad Rolling Stock|publisher=Voyageur Press, an imprint of MBI Publishing Company|location=Minneapolis, MN|date=2008|page=71|isbn=978-0-7603-3260-3|url=https://books.google.com/books?id=woJyATGsf6kC}}</ref>
; {{Visible anchor|Refuge siding}}
: A siding used as a passing place on a main line, where slow trains may be held whilst an express passes—a simpler, but less convenient, form of the passing loop
; [[Reporting mark]]
: A two- to four-letter code, assigned by the Association of American Railroads, that is applied to equipment operating on North American railroads to identify the owner<ref name="Trains Glossary R">{{cite web| url=http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=R| archive-url=https://web.archive.org/web/20140913071133/http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=R| title=Railroading Glossary: R| publisher=Kalmbach Publishing| website=TRN.Trains.com| access-date=20 February 2013| archive-date=13 September 2014}}</ref><ref>{{cite web| url=https://www.railinc.com/rportal/documents/18/260641/GuideforRailroads.pdf| title=Guide for Railroads| publisher=Association of American Railroads| date=30 May 2013| access-date=19 October 2014}}</ref><ref>{{cite web| url=http://trn.trains.com/railroads/abcs-of-railroading/2006/05/understanding-railroad-reporting-marks| title=Understanding railroad reporting marks| date=1 May 2006| work=Trains Magazine| publisher=Kalmbach Publishing| location=Waukesha, WI| access-date=19 October 2014}}</ref>
; Rerail frog or rerailer
: [[File:RerailFrog-SRM.jpg|thumb|upright=0.5|A ''rerail frog'' or ''rerailer'' stored (on its side) on a locomotive. The slot is placed over the rail and the derailed wheel is pushed or pulled until it runs up the rerailer and back on to the track.]]
A metal casting incorporating a slot that allows the casting to fit over the rail near the wheel of a derailed car. The locomotive then pushes or pulls the car so that the derailed wheel runs up the rerailer and back on to the track.<ref>{{cite book|last=Skrabec|first=Quentin R. Jr.|title=George Westinghouse: Gentle Genius|publisher=Algora Publishing|date=2007|page=34|isbn=978-0-87586-507-2|url=https://books.google.com/books?id=GSFLhlsILOAC}}</ref>
; Retarder
: A device installed in a classification yard used to reduce the speed of freight cars as they are sorted into consists<ref>{{cite magazine |date=October 1925 |title=Safety at the Switches |magazine=Popular Science Monthly |volume=107 |issue=4 |page=38 |location=New York |publisher=Popular Science Publishing Co. |url=https://books.google.com/books?id=0CcDAAAAMBAJ&q=railroad+retarder&pg=PA38 }}</ref>
; [[Engineering:Cutoff (steam engine)|Reverser]] or reverser handle
: The handle that controls the directional control on a locomotive. See also Cut off.
; Ribbon rail
: Continuously welded rail<ref name="Trains Glossary R" />
; Right-side failure
: A failure in a signalling or other safety critical system that leaves the system in a safe condition<ref>{{cite book|last=Ellis|first=Iain|title=Ellis' British Railway Engineering Encyclopaedia|publisher=Lulu.com|date=2006|page=300|isbn=978-1-84728-643-7|url=https://books.google.com/books?id=zkDYawSkRpAC}}</ref>{{self-published inline|date=February 2020}}
; [[Engineering:Roadrailer|Roadrailer]]
: A highway trailer, or semi-trailer, that is specially equipped for direct use on a railroad
; [[Engineering:Rolling stock|Rolling stock]]
: In UK parlance, any railway vehicle that is not capable of moving under its own power<ref>{{cite book| url=https://books.google.com/books?id=zkDYawSkRpAC| title=Ellis' British Railway Engineering Encyclopaedia| first=Iain| last=Ellis| publisher=Lulu.com| page=302| year=2006| isbn=978-1-84728-643-7}}</ref>{{self-published inline|date=February 2020}}
: In US parlance, any railroad car or locomotive<ref name="Trains Glossary R" /><ref>{{cite book|title=Internal Revenue Code: §§1-860G|publisher=United States Internal Revenue Service|date=1 July 2007|volume=1|page=1067|isbn=978-0-8080-1684-7|url=https://books.google.com/books?id=mxcdg30XbAkC}}</ref><ref>{{cite book|title=The Code of Federal Regulations of the United States of America – 49: Transportation|publisher=Office of the Federal Register, National Archives and Records Administration|location=Washington, DC|date=1 April 2003|pages=321–330|chapter=§1.48-1 Definition of section 38 property|url=https://books.google.com/books?id=Osg6AAAAIAAJ}}</ref>
; Rookie
: See Trainee.
; Rotary
: Short for [[Engineering:Rotary snowplow|rotary snowplow]], an extreme-duty railroad snowplow used mainly in the mountain ranges of the American West<ref>{{cite book|last=Scribbins|first=Jim|title=Milwaukee Road Remembered|publisher=Kalmbach Publishing|date=2008|edition=University of Minnesota Press|series=Fesler-Lempert Minnesota Heritage Book Series|page=115|isbn=978-0-8166-5625-7|url=https://books.google.com/books?id=b8SyLZIIMLMC|orig-year=first published 1990}}</ref>
; [[File:John Street Roundhouse.jpg|thumb|upright=0.5|A ''roundhouse'' and turntable, viewed from above]] Roundhouse
: [[File:Toyooka station (Hyogo prefecture) Miyazu line engine running track.jpg|thumb|upright=0.5|Platform track and a ''run-round'' loop at Toyooka Station, Hyogo, Japan, the terminus of the line from Miyazu]]A circular or semi-circular structure used for storage and running maintenance of locomotives
; {{visible anchor|Route selector panel}}, punch box, or train-identification pushbuttons (New York City Subway)
: A box or panel adjacent to a rail line at an interlocking, with several buttons for train operators to select a desired route, which is then either communicated to a signal tower where an operator fulfills the request, or switched automatically<ref>{{cite web|title=Subway Signals: Interlocking|url=http://www.nycsubway.org/wiki/Subway_Signals:_Interlocking|website=NYCSubway.org|access-date=25 November 2015}}</ref><ref>{{cite web|title=Utah Transit Authority Light Rail Design Criteria: Chapter 1 General Requirements|url=http://rideuta.com/files/LRTDesignCriteriaManualCh1-18Rev4FINALNov07.pdf|publisher=Utah Transit Authority|access-date=25 November 2015|date=November 2007|archive-url=https://web.archive.org/web/20151126095254/http://rideuta.com/files/LRTDesignCriteriaManualCh1-18Rev4FINALNov07.pdf|archive-date=26 November 2015|url-status=dead}}</ref>
; [[Engineering:Ruling gradient|Ruling gradient]]
: The longest or steepest grade on a division, thus setting the standard for track speeds, locomotive tonnage ratings, and train handling instructions<ref>{{cite journal|last1=Jameson|first1=C. D.|last2=Forney| first2=M. N.|date=July 1888|title=The Principles of Railroad Location|journal=The Railroad and Engineering Journal|location=New York|volume=LXII|issue=7|pages=297–301|url=https://books.google.com/books?id=_dFLAAAAYAAJ}}</ref>
; Run
: The action verb for the train's movement.  The train ''runs'' across the track.
; Runaway
: A heavy train that has lost speed control while descending a steep grade, due to either brake failure or poor preparation by the crew<ref>{{cite journal|date=January 1904|title=Catching a Runaway Engine|journal=Railroad Men|volume=XVII|issue=4|pages=141–142|url=https://books.google.com/books?id=QGDXAAAAMAAJ}}</ref>
; Running track
: An other-than-main track, typically providing access to a yard or industry and governed by the requirements of restricted speed<ref>{{cite book|title=Railroad Design and Construction at Army and Air Force Installations|publisher=United States Departments of the Army and the Air Force|location=Washington, DC|date=July 1980|page=2|url=https://books.google.com/books?id=GKoXAAAAYAAJ}}</ref>
; Run-round
: The practice of detaching a locomotive from its train, driving it to the other end of the train and re-attaching it, to allow the train to proceed in the direction it has just come from (e.g. when it reaches its destination and forms a service in the other direction).<ref name="Trains Glossary R" /><ref>{{cite book|last=Niemann|first=Linda G. |title=Railroad Noir: The American West at the End of the Twentieth Century|publisher=Indiana University Press|location=Bloomington, IN|date=2010|page=151|isbn=978-0-253-35446-4|url=https://books.google.com/books?id=Cr8P5AteoagC}}</ref>
; Run-through power
: Locomotives that remain attached to a manifest or unit train from their home rails over the tracks of a receiving railroad until the train reaches its final destination<ref>{{cite book|author=R.L. Banks & Associates| title=Study of merger alternatives: run-through trains: a report to the Rail Services Planning Office, Interstate Commerce Commission|publisher=Interstate Commerce Commission, Rail Services Planning Office|date=1977|url=https://books.google.com/books?id=7ug6AAAAMAAJ}}</ref>

== S ==
; Saddle tank
: A [[Engineering:Tank locomotive|tank locomotive]] with the water tank mounted on top of the boiler like a saddle<ref name="Trains Glossary S">{{cite web| url=http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=S| archive-url=https://web.archive.org/web/20140821182619/http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=S| title=Railroading Glossary: S| publisher=Kalmbach Publishing| website=TRN.Trains.com| access-date=20 February 2013| archive-date=21 August 2014}}</ref>
; Safe place
: An area within the network of an operator where evacuation of passengers can be performed, depending on current operational conditions, with a minimum of risk to the passengers (e.g. stations, refuges on the line)<ref>{{Cite book|title=Railway Applications – Urban Guided Transport Management and Command/Control Systems|chapter=Part 1: System Principles and Fundamental Concepts|date=10 July 2014}}</ref>{{Page needed|date=March 2018}}
; Safeworking
: In Australia, the system of rules and equipment designed to ensure the safe operation of trains<ref>{{cite book|last=Macfarlane|first=Ian|title=Railway Safety: Block Safeworking|publisher=Engineers Australia|date=2002|isbn=9780858258266|url=https://books.google.com/books?id=uaF7AAAACAAJ}}</ref>
; Sandbox
: A container on locomotives and self-propelled multiple units, or trams, that run on tramways and adhesion railways. The container holds sand, which a crew can drop onto the rail to improve rail adhesion under wet, steep, or slippery rail conditions. The sandbox and operating mechanism are collectively known as ''sanding gear''.
; Sandite
: Consists of a mixture of sand, [[Chemistry:Aluminium|aluminium]], and a unique type of adhesive, used instead of plain sand for extreme slippery rail conditions
; Santa Fe type
: [[File:WheelArrangement 2-10-2.svg|thumb|upright=0.5|The ''Santa Fe'' wheel arrangement]]A steam locomotive with a 2-10-2 wheel arrangement, named for the Atchison, Topeka and Santa Fe Railway—the first railroad to use such a configuration<ref>{{cite magazine|date=January 1923|title=Baldwin Locomotives and the Santa Fe "Power" Supremacy|magazine=The Santa Fe Magazine|publisher=Atchison, Topeka and Santa Fe Railroad|location=Chicago|volume=XVII|issue=2|pages=131–133|url=https://books.google.com/books?id=aDcwAQAAMAAJ}}</ref><ref>{{cite book|title=Locomotive Cyclopedia of American Practice|editor1=Roy V. Wright |editor2=Charles N. Winter |publisher=Simmons-Boardman Publishing Co.|location=New York|date=1922|edition=sixth|pages=137–148|url=https://books.google.com/books?id=oMY1AQAAMAAJ}}</ref>
; Saturated locomotive
: A steam locomotive not equipped with a superheater; the steam thus remains at the same temperature as the water in the boiler<ref>{{cite journal| url=https://books.google.com/books?id=2HAWAAAAYAAJ&q=saturated+locomotive&pg=PA408| via=Google Books| pages=406–409| journal=Brotherhood of Locomotive Firemen and Enginemen's Magazine| date=October 1914| volume=57| issue=4| location=Columbus, Ohio| publisher=Brotherhood of Locomotive Firemen and Enginemen| title=Sustained Tractive Power With Superheater Locomotives}}</ref>
; Scale
: Solid debris distilled from boiling water in a steam locomotive. To prevent corrosion damage from scale build-up, the locomotive must undergo a boiler wash once each operating month.<ref>{{cite book|title=The Code of Federal Regulations of the United States of America – 49: Transportation|publisher=Office of the Federal Register, National Archives and Records Administration|location=Washington, DC|date=1 October 2012|page=543|url=https://books.google.com/books?id=xcWakAXYB48C|isbn=9780160914874}}</ref>
; [[Engineering:Schnabel car|Schnabel car]]
: A specialized type of freight car for extra heavy and oversized loads where the car is loaded in such a way that the load forms part of the car superstructure<ref>{{cite web| url=http://www.railwayage.com/index.php/mechanical/freight-cars/kasgro-builds-worlds-largest-railroad-car%E2%80%9D.html| title=Kasgro builds "World's Largest Railroad Car"| website=Railway Age| first=William C.| last=Vantuono| date=14 June 2012| access-date=28 December 2016}}</ref>
; Searchlight
: A signal with a single light source usually capable of displaying three different colors. An internal mechanism governs the color displayed.<ref name="Trains Glossary S" />
; [[Engineering:Section (rail transport)|Section]]
: A portion of a [[Engineering:Train|train]] that may be operated independently or combined with other sections to operate as a single unit<ref>{{cite book| url=https://books.google.com/books?id=orbWT5ZnLOcC&q=sections&pg=PA95| via=Google Books| title=Realistic Model Railroad Operation: How to Run Your Trains Like the Real Thing| first=Tony| last=Koester| publisher=Kalmbach Books| location=Waukesha, Wisconsin| page=64| year=2003| isbn=0-89024-418-9}}</ref><ref>{{Pinkepank diesel spotters guide 2|page=EMD-123}}</ref>
: A portion of railway line designated for signalling or maintenance<ref>{{cite book| url=https://books.google.com/books?id=7GUhAAAAMAAJ&q=train+section&pg=PA137| via=Google Books| page=137| title=Returns of Accidents and Casualties as Reported to the Board of Trade by the Several Railway Companies in the United Kingdom| location=London| publisher=Darling & Son| year=1898}}</ref><ref>{{cite book| url=https://books.google.com/books?id=MZspAAAAYAAJ&q=section| via=Google Books| chapter=Section-Foremen| page=40| title=Eastern Railroad Co. General Rules and Regulations| date=June 1882| location=Boston| publisher=Franklin Press; Rand, Avery & Co.}}</ref>
: An interior portion of a sleeping car made up of two double seats during daytime that convert to two double berths during night-time<ref>{{cite book| url=https://books.google.com/books?id=w8pAAQAAMAAJ&q=sleeping+car+section&pg=PA153| via=Google Books| page=153| title=Car Builders' Cyclopedia of American Practice| volume=6| year=1909| publisher=Railway Gazette| location={{wipe|New York City}} and {{wipe|Chicago}}}}</ref>
; [[Engineering:Railway semaphore signal|Semaphore signal]]
: [[File:Rail-semaphore-signal-Dave-F.jpg|thumb|upright=0.5|A British lower-quadrant ''semaphore signal'' with subsidiary arm below]]A type of signal that has a moving arm to change the indication
; [[Engineering:Shay locomotive|Shay locomotive]]
: A type of geared steam locomotive built to the patents of Ephraim Shay<ref name="Trains Glossary S" />
; Shunt
: In UK and Australian parlance, to make up and divide trains in sidings, to move trains to or from sidings, or to move trains between platforms in a station<ref>{{cite book|last=Ellis|first=Iain|title=Ellis' British Railway Engineering Encyclopaedia|publisher=Lulu.com|date=2006|page=322|isbn=978-1-84728-643-7|url=https://books.google.com/books?id=zkDYawSkRpAC}}</ref>{{self-published inline|date=February 2020}}
; Shoofly
:Temporary track used to avoid an obstacle that blocks movement on the normal track section
; [[Engineering:Shuttle train|Shuttle train]]
: A train, usually a passenger service, that runs back and forth, usually over a relatively short distance, such as between a junction station and a branch-line terminus.
; Side tank
: A [[Engineering:Tank locomotive|tank locomotive]] with water tanks mounted each side of the boiler
; Siding
: A section of track off the main line. Sidings are often used for storing rolling stock or freight. A siding is also used as a form of rail access for warehouses and other businesses, where the siding often meets up with loading docks at rail car height. In the U.S. the term also covers the British term ''loop''. Also, a passing track in the U.S.
; Signal
: [[File:CSX Cum-Sub 145-MAGNOLIA-CPL-brackets-winter.jpg|thumb|upright=0.5|A two-head color position ''signal'' on a CSXT mainline where the left head displays "Stop" and the right, "Clear"]]A device that indicates the condition of the line ahead to the driver of a train
; Signal box
: A building or room that houses signal levers (usually in a frame), a control panel or a VDU-based control system
; Signal passed at danger
: The British term for the event in which a train passes a signal to stop without authorization to do so<ref>{{cite web | title = Signals Passed at Danger | url = http://orr.gov.uk/rail/health-and-safety/infrastructure-safety/signals-passed-at-danger | website = ORR.gov.uk | publisher = Office of Rail and Road | access-date = 2018-05-12 }}</ref>
; Signaller or signalman
: A person in charge of the signalling at a station or junction, often in a signal box
; Slippery rail
: The condition of fallen leaves or other debris lying on and clinging to a railroad track that could cause train wheel slippage, resulting in premature wheel wear and train delays
; Slow order
: A local speed restriction below the track's normal speed limit often designated by yellow and green flags. Slow orders can be imposed on a temporary basis to protect, for example, maintenance of way employees while sections of track are under repair. Widely used in areas where track is substandard and in need of repair.
; Slug
: A locomotive that contains traction motors yet lacks the diesel engine to create its own power, which is instead supplied by a connected mother locomotive<ref name="Trains Glossary S" />
; Smokebox
: An enclosed (normally cylindrical) space attached to the end of the boiler opposite the firebox on a steam locomotive (normally the front). Supports the stack; steam pipes to and from the cylinders pass through here; contains the blastpipe where the exhaust steam is used to provide draft for the fire. In [[Engineering:Superheater|superheated]] locomotives, also contains the superheater header and (optionally) a front-end throttle.
; Snowplow, snow plow, snowplough, or snow plough
: [[File:CNR-Snow-Plough-SRM.jpg|thumb|upright=0.5|A [[Company:Canadian National Railway|Canadian National Railway]] prairie rail ''snowplow'']]A rail service vehicle used for snow removal from train tracks<ref>{{cite web | publisher = Canadian Railway Hall of Fame | title = Rotary Snow Plow | date = 2006 | url = http://www.railfame.ca/sec_ind/technology/en_2002_RotarySnowPlow.asp | website = RailFame.ca | access-date = 3 October 2008 | archive-url = https://archive.today/20121206001220/http://www.railfame.ca/sec_ind/technology/en_2002_RotarySnowPlow.asp | archive-date = 6 December 2012 | url-status = dead }}</ref>
; Snow shed
: A long shelter erected over a railroad track on the side of a mountain to protect the line from avalanches and drifting<ref name="Ellis 2006 341">{{cite book|last=Ellis|first=Iain|title=Ellis' British Railway Engineering Encyclopaedia|publisher=Lulu.com|date=2006|page=341|isbn=978-1-84728-643-7|url=https://books.google.com/books?id=zkDYawSkRpAC}}</ref>{{self-published inline|date=February 2020}}
; Span bolster
: The beam between two bogies
; Spike
: [[File:Railroad spikes.JPG|thumb|upright=0.5|Two unused and one heavily corroded ''spikes'', with an [[Inch|inch]] ruler shown for scale]]A bolt, pin, or nail used to hold rails, or plates connected to the rails (known as tie plates), to sleepers (ties)
; Spiral easement
: See [[Track transition curve]]. Also known as tangent lead-in.<ref name="Trains Glossary S" />
; [[Engineering:Spreader (railroad)|Spreader]]
: [[File:Jordan-Spreader-SRM.jpg|thumb|upright=0.5|A Jordan ''[[Engineering:Spreader (railroad)|spreader]]'']]Maintenance of way equipment designed to spread or shape ballast profiles, remove snow, clean and dig ditches as well as trim embankments
; Spur line
: A very short branch line may be called a spur line.
; Self-propelled ultrasonic rail testing (SPURT) (India)
: A self-propelled rail-defect detector car<ref>{{cite news | url = http://www.thehindubusinessline.com/2005/10/02/stories/2005100201710300.htm | title = ICF Rolls Out Prototype Cars to Test Rails | access-date = 30 January 2008 | date = 2 October 2005 | website = TheHinduBusinessLine.com }}</ref>
; Staff and ticket
: The Australian term for a method of safeworking involving a token{{Definition|date=October 2014}}<ref name="Trains Glossary S" />
; Standard gauge
: A gauge where the rails are spaced {{Track gauge|sg}} apart—by far the most common gauge worldwide<ref name="Trains Glossary S" />
; [[Social:Station master|Station master]]
: The person in charge of a station
; [[Engineering:Steam generator (railroad)|Steam generator]]
: A device generally used in passenger trains to create steam for heating. The steam generator is usually in the locomotive but may also be located in other cars.<ref name="Trains Glossary S" />
; Steam reverser
: A reversing gear worked by a steam cylinder controlled from the cab
; Stop signal overrun
: The American term for the event in which a train passes a signal to stop without authorization to do so
; Subdivision
: In North America, the trackage area within a division covered by a single timetable<ref>{{Cite web|title=Railroad Dictionary: S|url=http://www.csx.com/index.cfm/about-csx/company-overview/railroad-dictionary/?i=S|publisher=CSX Transportation|website=CSX.com|date=2012|access-date=24 July 2015|archive-url=https://web.archive.org/web/20150725070158/http://www.csx.com/index.cfm/about-csx/company-overview/railroad-dictionary/?i=S|archive-date=25 July 2015|url-status=dead}}</ref>
; [[Engineering:Supercharger|Supercharger]]
: A mechanical device that boosts the pressure of engine intake air to above atmospheric level, causing an increase in power. Not to be confused with the blower used to scavenge the cylinders of a naturally aspirated two-stroke Diesel engine.
; Superelevation
: Areas on curves where the outside rail is elevated higher than the inside rail, creating a banked curve, generally allowing higher speeds and more comfort for passengers (on passenger trains).
; [[Engineering:Superheater|Superheater]]
: A device in a steam locomotive that raises the temperature of saturated steam substantially beyond the boiling point of water, increasing power and efficiency<ref name="Trains Glossary S" />
; [[Engineering:Surveying|Survey]]
: To determine the position of constructed objects, including rail infrastructure, in relation to the earth's surface. This is accomplished by measuring angles and distances based on the principles of triangulation.
; [[Engineering:Surveying|Surveyor]]
: A person assigned to perform survey work
; Switchback or zig zag
: A method of climbing and descending steep gradients, where shallow-gradient track reverses direction for a while, and then reverses again to continue in the original direction
; Switchman
: A railroad worker responsible for assembling trains and switching railroad cars in a yard

== T ==
; [[Engineering:Tamping machine|Tamping machine]]
: [[File:Rail track tamper - DR73238 - Jarvis Fastline livery - Chester railway station - 2005-10-09.jpg|thumb|upright=0.5|A track ''tamping machine'']]Generally, a locomotive used in track maintenance and equipped with track lifting facilities, and paddles that push ballast beneath a rail track to assure its level and cant
; [[Engineering:Tank car|Tank car]]
:  A type of rolling stock designed to transport liquid and gaseous commodities
; [[Engineering:Tank locomotive|Tank locomotive]] or Tank engine
: A steam locomotive that carries its water in one or more on-board water tanks rather than in a separate [[Engineering:Tender (rail)|tender]]. 
; Team track
: In North America, A spur or siding for loading freight, often used by firms not having their own direct rail access<ref name="Trains Glossary T">{{cite web| url=http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=T| archive-url=https://web.archive.org/web/20140822084725/http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=T| title=Railroading Glossary: T| publisher=Kalmbach Publishing| website=TRN.Trains.com| access-date=20 February 2013| archive-date=22 August 2014}}</ref>
; [[Engineering:Tender (rail)|Tender]]
: A specialized rail car attached to a steam locomotive to carry its fuel and water supplies, sometimes along with tools and flagging equipment
; Terminal railroad (or terminal railway)
: A company in the United States that owns no cars of its own and transports only the [[Engineering:Railroad car|railroad car]]s of other companies around a specific terminal station<ref>{{cite book|url=https://archive.org/details/judicialandstat03paulgoog|page=[https://archive.org/details/judicialandstat03paulgoog/page/n329 802]|quote=Terminal Railroad definition.|title=Judicial and Statutory Definitions of Words and Phrases|date=22 December 2017|publisher=West Publishing Company|via=Internet Archive}}</ref>
; Texas type
: [[File:WheelArrangement 2-10-4.svg|thumb|upright=0.5|The ''Texas'' wheel arrangement]]A steam locomotive with a 2-10-4 wheel arrangement{{Citation needed|date=October 2014}}
; [[Engineering:Third rail|Third rail]]
: An electrified rail that runs along the tracks, giving power to trains. Used mostly in subways and rapid transit systems.<ref name="Trains Glossary T" />
; Through coach
: A passenger coach that is disconnected from one train and attached to another before continuing on with its journey, thus avoiding the need for passengers themselves to switch trains<ref name="irfca.org">{{Cite web |title=Railway Operations – I |url=http://www.irfca.org/faq/faq-ops.html |publisher=Indian Railways Fan Club |website=IRFCA.org |date=2010 |access-date=15 October 2014}}</ref>
; Through platform
: The standard [[Engineering:Railway platform|platform]] and track arrangement at a station. The train pulls alongside the platform, arriving from one end of the station, and may pass out the other end of the station by continuing along the same track<ref>{{cite book|last=Ellis|first=Iain|title=Ellis' British Railway Engineering Encyclopaedia|publisher=Lulu.com|date=2006|page=377|isbn=978-1-84728-643-7|url=https://books.google.com/books?id=zkDYawSkRpAC}}</ref>{{self-published inline|date=February 2020}}
; Tie plate
: A plate bolted to sleepers to hold the rails in place
; Trailer on flat car (TOFC)
: [[Engineering:Intermodal freight transport|Intermodal freight transport]]<ref name="Trains Glossary T" />
; Token
: A physical object given to a locomotive driver to authorize use of a particular stretch of single track
; Track bed or trackbed
: The foundation of rail tracks
; Track bulletin
: In North America, a form used by railroad employees that shows the locations of slow orders, maintenance of way work locations, and other conditions affecting the track and movement of trains{{Citation needed|date=October 2014}}
; Track circuit
: An electrical circuit that detects the presence of locomotives or cars (as their wheelsets electrically bond the rails) in a block of track, and provides real-time input to signaling logic
; [[Track transition curve]]
: The gradual application of superelevation and tighter curve radius, calculated with reference to the anticipated line speed and the final curve radius, on the approach to a bend. Also known as the ''transition spiral'' and ''spiral easement''.
; [[Track Warrant Control]]
: Control of train movements by "track warrants" which are sets of instructions issued to a train crew authorizing specific train movements. 
; Trackside objects
: See Wayobjects.
; [[Engineering:Traction current pylon|Traction current pylon]]
; [[Engineering:Traction motor|Traction motor]]
: A large electric motor that powers the driving wheels of an [[Engineering:Electric locomotive|electric]] or diesel-electric locomotive<ref name="Trains Glossary T" />
; [[Physics:Tractive effort|Tractive effort]]
: The pulling or pushing [[Physics:Force|force]] exerted by a locomotive or other vehicle
; Trailing
: A turnout where both legs merge in the direction of travel—the opposite of facing
; Train bell
: In North American practice, the warning bell on a locomotive or any autonomous railway vehicle <!-- To be continued -->
; [[Engineering:Railway coupling|Train coupler]] 
: The mechanical interface that links vehicles so a driver can operate them together. The coupler can be a purely mechanical device such as a screw coupler or bar coupler. Alternatively the coupler can also incorporate electrical or pneumatic connections.<ref>{{Cite book|title=PD IEC/TS 62580-2:2016: Electronic railway equipment. On-board multimedia and telematic subsystems for ailways. Video surveillance/CCTV services|date=7 June 2016|page=17}}</ref>
; [[Train horn]]
: The warning horn in a locomotive or in a control car
; Trainman
: In North America, an employee assigned to train service, such as a conductor, brakeman, or switchman
; Train inauguration
: The automated process of train bus configuration that includes detecting all bus nodes and their orientation, assigning the numbers to particular bus nodes and collecting their properties.<ref>{{Cite book|title=UIC code 556 4th edition|date=11 August 2005}}</ref>{{Page needed|date=February 2018}}
; Train operation and management
: In Europe, the procedures and related equipment enabling a coherent operation of the different structural subsystem, both during normal and degraded operation, including in particular train driving, traffic planning and management<ref>{{Cite book|title=Directive 2007/59/ECof the European Parliament and of the Council|date=23 October 2007}}</ref>{{Page needed|date=February 2018}}
; {{Visible anchor|Trainmaster}}, terminal manager, or road manager
: In North America, an employee who supervises operations over a given territory<ref>{{cite book | last1=McDavid | first1=Richard A. | last2=Echaore-McDavid | first2=Susan | title=Career Opportunities in Transportation | url=https://books.google.com/books?id=ZjhzVdBbCrAC&pg=PT154 | publisher=Ferguson | location=New York | date=2009 | isbn=978-0-8160-7401-3 | page=134}}</ref>
; Train order
: The process whereby signallers or dispatchers can change the order or timing of trains to maximise overall train service performance in real time{{Citation needed|date=August 2017}}
; Train set
: A toy train with its tracks, buildings, etc.<ref>{{Cite book|title=Merriam-Webster|url=https://www.merriam-webster.com/dictionary/train%20set}}</ref>
; Trainset
: A group of [[Engineering:Rolling stock|rolling stock]] that is permanently or semi-permanently coupled together to form a unified set of equipment. Trainsets are most often used in [[Engineering:Passenger train|passenger train]] configurations.{{Citation needed|date=October 2014}}
; [[Engineering:Tram|Tram]]
: A city-based rail system that typically shares its operational space with other vehicles and often runs on, across, or down the center of city streets
; Tram-train
: [[Engineering:Tram|Tram]]s that are designed to run both on the tracks of a city-based rail system and on the existing railway networks. Tram-trains' dual-voltage capability makes it possible to operate at lower speeds on city streets and at over {{Convert|60|mph|km/h}} on main line tracks allowing travel in an extended geographical area without changing the method of transport.
; Treadle [[File:Rail turntable viewed from the CN Tower.jpg|thumb|upright=0.5|A ''turntable'' in Toronto, Canada]]
: A mechanical or electrical device for detecting the presence of a rail vehicle with pin-point accuracy, unlike a track circuit, which provides detection over an arbitrary distances
; Turnout or points
: A [[Engineering:Railroad switch|switch]]{{Citation needed|date=October 2014}}
; Turntable
: A section of track that rotates to let locomotives and rolling stock turn around or access several engine maintenance sidings in a small area

== U ==
; [[Engineering:Unit train|Unit train]]
: A train in which all [[Engineering:Railroad car|cars]] (wagons) carry the same commodity and are shipped from the same origin to the same destination, without being split up or stored en route<ref>{{cite encyclopedia |title=Unit train |url=https://www.britannica.com/EBchecked/topic/615316/unit-train |encyclopedia=[[Encyclopædia Britannica]] |year=2014 }}</ref>
; Underbridge
: In the parlance of rail transport in the United Kingdom, an 'underbridge' is a bridge that allows a roadway to cross {{em|under}} the course of a railway line, in contrast to an overbridge, or [[Engineering:Overpass|overpass]], that crosses {{em|over}} the railway.

== V ==
; [[Engineering:Vactrain|Vactrain]]
: A proposed design for very-high-speed rail transportation.
; [[Engineering:Vacuum brake|Vacuum brake]]
: A continuous train brake that is fail-safe in operation. It is powered by a [[Physics:Vacuum|vacuum]] from the locomotive but the application is actually by [[Physics:Atmospheric pressure|atmospheric pressure]] when the vacuum is released. Primarily used historically in Britain and in countries influenced by British practice. Now largely superseded by the air brake.
; [[Engineering:Valve gear|Valve gear]]
: The linkage mechanism that operates the valve for a driving cylinder, to alternately admit steam to the cylinder and then exhaust it when the piston's stroke is nearly complete<ref>{{cite book|title=Handbook for Railway Steam Locomotive Enginemen|date=2014|publisher=Ian Allan Publishing|location=Hersham, Surrey|isbn=978-0-7110-3794-6|oclc=866583611|page=98|section=Valve Gears|orig-year=1957, British Transport Commission|edition=1st}}</ref>

== W ==
{{glossary}}

{{term|[[Engineering:Boiler (power generation)#Haycock and wagon top boilers|Wagon Top Boiler]]}}
{{ghat|Also see '''{{gli|Extended Wagon Top Boiler}}.'''}}
{{defn|A {{gli|boiler}} having the steam dome over the firebox and a sloping course from in front of the firebox to the cylindrical shell.}}

{{term|Waist (of Boiler)}}
{{ghat|Also see '''{{gli|Waist Sheet}}.'''}}
{{defn|That part of the boiler shell immediately in front of the firebox.}}

{{term|Waist Brace}}
{{ghat|Also see '''{{gli|Expansion Knee}}.'''}}
{{defn|A vertical steel plate riveted to the waist sheet crosstie and to an angle piece which is also fastened to the waist of a boiler to secure that part to the frame, and at the same time allow a small amount of expansion and contraction.}}

{{term|Waist Brace Angle}}
{{defn|A steel strip riveted to the shell of a boiler and having its edge bent to a right angle, and to which a plate or strut is fastened for the purpose of bracing the waist of a boiler to the frames.}}

{{term|Waist Sheet}}
{{defn|The plate forming that portion of a boiler directly ahead of the outside firebox sheet. It is sometimes made cylindrical in shape and sometimes tapering or conical.}}

{{term|Waist Sheet Crosstie}}
{{defn|A transverse brace or casting binding the frames together in front of the firebox and usually having a plate fastened to it and to the boiler to support the waist of the boiler at this point.}}

{{term|Waist Sheet Wearing Plate}}
{{defn|A steel strip riveted to the waist sheet of a boiler and to the angle of the waist sheet brace or expansion plate, to reinforce the bearing or support of the boiler at this point.}}

{{term|Walschaerts Valve Gear}}
{{ghat|Also see '''Valve Gear.'''}}
{{defn|A valve gear socalled from its inventor, largely in use in Europe and being rapidly introduced in the United States. It has no eccentric and is entirely outside of the frames.}}

{{term|Washer}}
{{defn|A plate of metal or other material, usually annular, which is placed under a nut or bolt head to give it a better bearing. Two or more washers are sometimes combined and called washer plates, strap washers, double or twin washers, triple washers, etc. They are sometimes made beveled or triangular for a rod or bolt, which is oblique, with reference to the bearing surface. A socket washer or Hush washer is one provided with a recess for the bolt head, so as to leave it Hush with the adjoining parts. Cut or wrought washers are those stamped out of rolled iron plates. Cast washers are made from cast iron. Both kinds are used.}}

{{term|Wash-out Plug}}
{{defn|A short, solid metal cylinder with a screw thread cut on the outside and a square or hexagonal head for convenience in applying a wrench, screwed into the water leg and above the crown sheet of a locomotive boiler. Wash-out plugs are usually located near the bottom of a water leg, a little above the mud ring, or above the crown sheet, and from four to eight are provided in order to allow mud to be thoroughly washed out.}}

{{term|Waste}}
{{defn|The spoiled bobbins of cotton or woolen mills, used for wiping machinery and for Journal Packing, which sec.}}

{{term|Waste Cock or Waste Valve}}
{{defn|An arrangement attached to and forming part of the body of an injector, consisting of a valve provided with a handle or lever. If this valve is left open when the steam and water supply valves to the injector are also open, steam passes back through the injector feetf pipe and may thus be used to prevent the water in the tender tank from freezing.}}

{{term|Water}}
{{defn|A liquid composed of two gases, hydrogen and oxygen in the proportion of 8 to 1 by weight, colorless and transparent in the pure state. It is never obtained pure for locomotive use, always holding in solution a quantity of solid matter such as sulphates and carbonates of lime and magnesia that may form objectionable quantities of scale in a boiler. See Steam. Boilers fed with water that forms much scale must be washed out at frequent intervals; in some districts even at the completion of every trip. The best practice at present is to install water-treating plants at water stations, by means of which the scale forming matters in the water are chemically treated and removed before the water reaches the locomotives.}}

{{term|Water Brake}}
{{defn|An arrangement, consisting of a set of pipes and valves connected to a locomotive boiler below the water line, for admitting water to the cylinders to retard the motion of the pistons and thus act as a brake on the locomotive, which is run with the reverse lever back of the center. It is used on lines having long, steep grades.}}

{{term|Water Brake Valve}}
{{defn|A globe valve with its connecting pipe screwed in the boiler back head below the water line, for operating the water brake.}}

{{term|Water Cooler}} 
{{defn|A tank or vessel for carrying drinking water which is usually cooled with ice. The sides are generally made double, and the space between Tilled with some non-conducting substance. When used on locomotives they are commonly located on the tender tank.}}

{{term|Water column (railroad) Also Standpipe}}
{{defn|A device used for delivering a large volume of water into the tank or tender of a steam locomotive.}}

{{term|Water gauge or water glass}}
[[File:Water gauge Chatfield.jpg|thumb|upright=0.5|A ''water gauge'']]
{{defn|A device to enable an engineman or fireman to observe the height of water in a locomotive boiler. It consists of two brass fittings screwed into the back head, one above the other, and connected by a stout glass tube which communicates, through the fittings, with the water and steam in the boiler. The water level showing in the glass tube must be the same as that inside the boiler.}}

{{term|Water Gage Casing}}
{{defn|A covering or protector around a water gage glass. The casing prevents the glass from flying about in case of breakage.}}

{{term|Water Gage Cock}}
{{defn|One of two brass fittings screwed into a locomotive boiler head, having a valve or plug cock for opening or closing communication between the boiler and the water gage glass. The end of the glass tube rests in an opening in the gage cock and is held in place by a coupling nut which is screwed down on an elastic washer surrounding the tube.}}

{{term|Water Gage Cock Extension}}
{{defn|A piece of pipe leading from an opening in a boiler to one of the water gage cocks.}}

{{term|Water Gage Cock Gland}}
{{defn|A neck or extension formed on a water gage cock to receive the end of the glass tube, or the stem of the cock or plug.}}

{{term|Water Gage Nut}}
{{defn|A hexagonal brass nut surrounding a water gage glass near the end and holding an elastic washer so as to prevent leakage of water or steam around it.}}

{{term|Water Grate}} 
{{defn|See Grate and Water Pull Bar Grate.}}

{{term|Water Leg}}
{{defn|The space between the inner and outer sheets of a firebox. At the bottom, where the two sheets are riveted to the mud ring, the width of the water leg is from three to five inches, increasing more or less rapidly, according to the design and size of the firebox.}}

{{term|Water Pull Bar Grate}}
{{ghat|Also see Grate}}
{{defn|A grate designed for burning anthracite coal, consisting of tubes running longitudinally through the bottom of the firebox and communicating with the front and back water legs, usually screwed into the tube sheet and expanded into the back sheet, a copper ferrule being used to insure a tight joint. Between the water tubes, iron pull bars, enclosed in short tubes, pass completely through the back water leg and project a snort distance outside the back head. These outer ends have slots in them, into which a rod can be put, and the bars pulled out for the purpose of dumping or cleaning the fire. Midway of the length of tfye firebox is a bearer or bridge that supports both the tubes and bars that form the grate. A similar bearer is placed at the front end of the box to hold the bars.}}

{{term|Water Scoop}}
{{defn|A device for putting water in a locomotive tender, while it is in motion, from a trough laid between the rails, and sometimes called a track tank. It consists of a cast-iron or steel plate conduit of rectangular cross section, about 8 x 12 inhes, passing up through the tender tank and turned over at the top so as to discharge the water downward. The lower end, underneath the tender frame, is fitted with a scoop or dipper that can be lowered into the trough by a lever worked by hand, or by compressed air applied in a cylinder whose piston rod is connected to the mechanism for raising and lowering the scoop. Owing to its inertia, the water is forced up through the siphon pipe into the tender tank when the scoop moves through the trough at a speed of from 25 to 40 miles per hour.}}

{{term|Water Scoop Air Cylinder}}
{{defn|A small cast-iron cylinder fastened underneath a tender for operating the water scoop. Compressed air is conveyed to it from the main air reservoir through a valve, thus moving the piston. The piston rod is connected to the levers that lower the dipper into the water trough between the rails. To insure the rapid raising of the dipper, when the locomotive reaches the end of the track tank, a coil spring is fastened to the scoop mechanism.}}

{{term|Water Scoop Air Cylinder Piston}}
{{defn|A metal disk fitted inside a water scoop air cylinder and having attached to it a rod connected to the operating mechanism of the scoop.}}

{{term|Water Scoop Arm}}
{{defn|A bent lever or bell crank, to one end of which the air cylinder piston rod is attached, while to the other the links for raising and lowering the dipper are bolted.}}

{{term|Water Scoop Body}}
{{defn|That portion of a water scoop shaped like the frustum of a pyramid that is lowered into the track trough and to the lower end of which the dipper or nozzle is attached. It is usually made of cast iron.}}

{{term|Water Scoop Cylinder Connecting Rod}}
{{defn|A short rod attached to the end of the piston rod of a water scoop cylinder, and with a coil spring attached to the end. This spring raises the scoop out of the water when the end of the track tank is reached and holds it in that position.}}

{{term|Water Scoop Cylinder Piston Rod}}
{{defn|A wrought-iron or cast-steel rod attached to the piston of the air cylinder at one end, and to the bell crank for operating the water scoop at the other.}}

{{term|Water Scoop Cylinder Support}}
{{defn|A metal carrier secured underneath a tender frame for the purpose of holding the water scoop air cylinder, which is bolted to it.}}

{{term|Water Scoop Delivery Pipe}}
{{defn|The square pipe which joins the scoop with the siphon pipe in the tender tank.}}

{{term|Water Scoop Delivery Pipe Brace}}
{{defn|A rod secured to the tender frame center sills to stiffen the delivery pipe.}}

{{term|Water Scoop Delivery Pipe Bracket}}
{{defn|A cast-iron support riveted on to the end of the delivery pipe and having a hole or bearing in its outer end for one of the trunnions of the water scoop.}}

{{term|Water Scoop Dipper}}
{{defn|A hinged extension or hood at the end of a water scoop. That portion of the scoop that goes into the water.}}

{{term|Water Scoop Dipper Adjusting Bracket}}
{{defn|A support or holder fastened underneath a tender to limit the movement of the dipper arm and thus prevent the scoop from hanging too low and striking the ties or ballast.}}

{{term|Water Scoop Dipper Lifting Link}}
{{defn|A short metal bar attached to the bell crank or arm of the scoop-lifting mechanism and to the dipper, for raising it out of the water.}}

{{term|Water Scoop End Support}}
{{defn|A metal rod fastened to either side of the outer end of a water scoop, next to the dipper, a.nd to the under side of the tender frame.}}

{{term|Water Scoop Hanger}}
{{defn|The bracket or frame fastened underneath a tender frame to support a water scoop and the mechanism for raising and lowering it.}}

{{term|Water Scoop Lifter}}
{{defn|One of two links or bars attached to a water scoop at one end and to the water scoop arm at the other.}}

{{term|Water Scoop Locking Cylinder}}
{{defn|A small air cylinder whose function is to hold the water scoop in place and prevent it from dropping down on the track.}}

{{term|Water Scoop Neck}}
{{defn|The upper end of a water scoop; that portion that joins the water scoop pipe directly under the tender tank.}}

{{term|Water Scoop Operating Lever}}
{{defn|The arm or lever by which the water scoop is raised or lowered by hand. It extends up through the tender deck alongside the tank leg.}}

{{term|Water Scoop Operating Lever Connecting Rod}}
{{defn|A long piece of pipe or solid rod, attached to the water scoop operating lever at one end and the scoop lifting arm at the other.}}

{{term|Water Scoop Operating Lever Fulcrum}}
{{defn|A cast iron support fastened on a tender frame and holding a bolt or pin that passes through the water scoop operating lever.}}

{{term|Water Scoop Pipe}}
{{defn|The cast iron or steel plate conduit passing up through a tender for conveying the water forced into the scoop to the top of the tank.}}

{{term|Water Scoop Pneumatic Valve}}
{{defn|The valve for admitting compressed air to a water scoop cylinder.}}

{{term|Water Scoop Rod}}
{{defn|The rod connecting the water scoop lever with the arm or bell crank.}}

{{term|Water Scoop Shaft}}
{{defn|A pivot fastened at right angles to a water scoop arm and resting in bearings in supports or hangers attached to the tender frame by bolts or rivets.}}

{{term|Water Scoop Shaft Bracket}}
{{defn|A carrier attached to a tender frame and holding the ends of the water scoop shaft.}}

{{term|Water Scoop Side Brace}}
{{defn|A rod fastened on either side of a water scoop and to the side sill of a tender to give transverse stiffness to the scoop.}}

{{term|Water Scoop Spring}}
{{defn|The spring used to assist in lowering or raising a water scoop.}}

{{term|Water Scoop Spring Rod}}
{{defn|A shaft attached to a water scoop operating mechanism and to the coil spring which forms a part of it.}}

{{term|Water Space}}
{{defn|That part of a locomotive boiler that is filled with water, in contrast with the part normally occupied by steam. A Water Leg, which see, is also called a water space.}}

{{term|Water Table}}
{{defn|A device for improving the combustion of fuel in a locomotive firebox. The form invented by William Buchanan, of the N. Y. C. & H. R. R. R., consists of two flat, parallel plates, extending diagonally upward from the tube sheet to the back sheet of the firebox. These plates are about 4 Ms inches apart, are strengthened with staybolts in the same manner as are the inner and outer firebox sheets, and form an inclined water leg connecting the front and back legs of the firebox. A hole 18 or 20 inches in diameter is made through the center of the water table for the passage of the products of combustion to the upper part of the firebox on their way to the tubes. Not extensively used.}}

{{term|Water Tube}}
{{defn|A pipe containing water and surrounded with hot gases in contrast to a lire tube surrounded by water and having hot gases passing through it. See below.}}

{{term|Water Tube Boiler}}
{{defn|A boiler in which water circulates through tubes surrounded by hot gases, the products of combustion in the firebox. Not extensively used for locomotives although tried on the London & South Western.}}

{{term|[[Watt]]}}
{{defn|An electrical unit expressing the rate at which energy is transformed, or work done. It is used to express the product of the voltage of an electric circuit and the current or amperage. As it is a very small unit, a multiple of it, 1,000 times as large, and called a kilowatt, is commonly used. One kilowatt is about 1.34 [[Horsepower|horsepower]].}}

{{term|[[Engineering:Caboose|Way car]]}}
{{defn|An alternate term for a ''caboose'' used by the Chicago, Burlington and Quincy Railroad, Chicago and North Western Railway, and Atchison, Topeka and Santa Fe Railway.<ref name="Trains Glossary W">{{cite web| url=http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=W| archive-url=https://web.archive.org/web/20140830031157/http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=W| title=Railroading Glossary: W| publisher=Kalmbach Publishing| website=TRN.Trains.com| access-date=20 February 2013| archive-date=30 August 2014}}</ref>}}

{{term|Wayobjects or wayside objects}}
{{defn|Trackside objects or any structures at the wayside or beside the rail tracks usually within the right-of-way, such as railway signals, [[Engineering:Third rail|third rail]]s, overhead lines and their supports, [[Engineering:Traction current pylon|traction current pylon]]s, [[Engineering:Utility pole|utility pole]]s, [[Engineering:Railway electrification system|electrification systems]], [[Engineering:Railway platform|platforms]], or [[Engineering:Boom barrier|boom barrier]]s at [[Engineering:Level crossing|level crossing]]s.}}

{{term|Wedge}}
{{defn|1=A term in quite general use for a Journal Bearing Key, which see. |no=1}}
{{defn|1=A Pedestal Wedge, which see, is a tapering liner for the jaws of a pedestal to adjust the position of the driving box and take up wear. |no=2}}

{{term|Wedge Bolt}}
{{defn|A bolt passing through the pedestal cap of a driving or trailing wheel for adjusting the pedestal wedge.}}

{{term|Weigh Shaft (British)}}
{{defn|See '''Reverse Shaft.'''}}

{{term|Weigh Shaft Balance Weight (British)}}
{{defn|A large mass of cast iron used on British locomotives in place of a reverse shaft spring.}}

{{term|Weigh Shaft Lever (British)}}
{{defn|See '''Reverse Shaft Arm.'''}}

{{term|Well tank}}
{{defn|A type of [[Engineering:Tank locomotive|tank locomotive]]. The water tank is mounted between the frame plates, beneath the cab and boiler.}}

{{term|[[Engineering:Class U special wagon#Intermodal container well wagons|Well wagon]] (UIC)}}
{{defn|A [[Engineering:Flat wagon|flat wagon]] with a depressed centre used for carrying extra tall loads.}}

{{term|Wheel}}
{{defn|The rolling component typically pressed onto an axle and mounted on a rail car or locomotive truck or bogie. Wheels are cast or forged (wrought) and are heat treated to have a specific hardness. New wheels are trued to a specific profile before being pressed onto an axle. All wheel profiles must be periodically monitored to insure proper wheel to rail interface. Improperly trued wheels increase rolling resistance, reduce energy efficiency and may create unsafe operation. A railroad wheel typically consists of two main parts: the wheel itself, and the tire around the outside.  A railway tire is itself steel, and is typically heated and pressed onto the wheel, where it remains firmly as it shrinks and cools.}}

{{term|Wheel climb}}
{{ghat|Also '''Adhesion railway'''.}}

{{term|Wheel flange}}
{{ghat|Also '''Adhesion railway'''.}}

{{term|Wheel–rail interface}}
{{defn|The on-contact interaction between wheels and rails. The term is used in connection with the design and management of their interaction.}}

{{term|Wheel slip}}
{{defn|The loss of traction due to a slippery rail or wheel. Wheel slip was common with steam engines as they started to move due to the excessive torque often generated at low speed. Steam engines carried sand dispensing gear to increase traction at the start of motion.<ref name="Trains Glossary W" />}}

{{term|Wheeltapper}}
[[File:Wheel tapper.jpg|thumb|upright=0.5|A ''wheeltapper'' at work on the Bulgarian railway]]
{{defn|An historical railway occupation; people employed to tap train wheels with hammers and listen to the sound made to determine the integrity of the wheel; cracked wheels, like cracked bells, do not sound the same as their intact counterparts. The job was associated with the steam age, but they still operate in some eastern European countries. Modern planned maintenance procedures have mostly obviated the need for the wheel-tapper.}}

{{term|Wheel tread}}
{{ghat|Also '''Adhesion railway'''.}}

{{term|Westinghouse Air Brake.}}
{{defn|A system of continuous brakes invented and patented (the first patent in 1869) by Mr. George Westinghouse, which is operated by compressed air. The air is compressed, by a steam air pump on the locomotive or an electric motor compressor on the car. and is stored up in a tank called the main reservoir on the engine or tender. By the original form of brake the compressed air was conveyed from the tank by pipes connected together between the cars by flexible brake hose to brake cylinders under each car. by means of which the pressure of the air was communicated to the brake levers, and thence to the brake shoes. A later and improved form is the Westinghouse automatic air brake, commonly called simply Westinghouse brake, which is now in universal use. At the present time the Westinghouse brake, unless otherwise specified, is always understood to mean the automatic air brake. The change made from the original form of the Westinghouse air brake in order to make it automatic was to carry a full pressure of air at all times in the brake pipes and cause the brakes to be applied by a reduction of this pressure instead of by the admission of pressure, so that the breaking apart of the train or a reduction of pressure by escape of air at any point on the brake pipe would apply the brakes to the whole train at once. A further advantage was that the action of the brakes was made quicker by saving the appreciable interval of time required for the compressed air to flow from a single reservoir at one end of the train in sufficient quantities to fill all the brake cylinders. An auxiliary reservoir is placed under each car, containing air at the same pressure as in the brake pipes. An ingenious valve called the triple valve connects the brake pipe, auxiliary reservoir and brake cylinder together in such manner that any reduction of pressure in the brake pipe opens a passage for the air from the auxiliary reservoir to the brake cylinder, applying the brakes, and closes the connection between brake pipe and reservoir. To release the brakes, the pressure in the brake pipes is restored, when the triple valve closes the connection between the auxiliary reservoir and brake cylinder and opens one between the brake cylinder and the outer air and between the auxiliary reservoir and the brake pipe. In order that the train brakes may be applied from any car, each car is fitted with a valve called the conductor's valve, connected to the brake pipe so that the compressed air therein can be permitted to escape by opening the valve.}}

{{term|Westinghouse E-T Locomotive Brake Equipment (Air Brake)}}
{{defn|A new arrangement of air brake apparatus as applied to a locomotive. It differs from previous locomotive brake schedules principally in that the details are centralized and simplified so as to reduce the total number required, occupy less space, and give the engineman a mere certain and flexible control of the locomotive brakes. It has all the good features of any of the older equipment, besides a number of new ones, viz., uniform brake cylinder pressure on engine and tender, and a pressure-maintaining feature by which the brake-cylinder pressure is automatically held to that resulting from the brake application as long as such application lasts. See Distributing Valve.}}

{{term|Westinghouse Friction Draft Gear}}
{{defn|A form of draft gear in which the forces are absorbed and dissipated by friction. The friction device is encased in a malleable iron cylinder open at the front end. The front follower bears against a preliminary spring, the other end of which bears against the center wedge of the shape of the frustum of an octagonal pyramid. Surrounding the wedge are four pairs of segmental carriers having one rib each which lies in a groove in the cylinder. The other grooves in the cylinder are filled by friction strips resting on the carriers. These strips are of wrought iron and have lugs formed on them which engage in corresponding cavities in the carriers so that the friction strips must move with the carriers. The function of the preliminary spring is to absorb the light shocks without bringing into action the friction parts. The main release spring, placed back of the carriers, forces the carriers to their normal position when the pressure is removed and also adds to the capacity of the device. When the follower plates are moved toward each other, the preliminary spring is compressed until its capacity of 20,000 pounds is exceeded, when the follower bears against the release pin and forces it forward, relieving the wedge from the pressure of the auxiliary release spring, thereby allowing the compression of the preliminary and auxiliary preliminary springs to force the wedge forward and press the segmental carriers and friction strips firmly into the cylinder grooves. The follower then strikes and forces the segmental carriers in, producing friction between the friction strips and the grooves. The complete movement gives a resistance of 100,000 pounds. In releasing, the preliminary spring is gradually restored, and the auxiliary release spring then forces the wedge out, while the release spring returns the friction strips and carriers, giving a complete release. Owing to the varying width of the slots and lugs on the friction strips and carriers the strips are released four at a time through successive small distances. The operations of buffing and pulling are exactly the same, except that the load comes on the front or rear follower first, as the case may be. See Draft Gear.}}

{{term|Westinghouse SWA-SWB Locomotive Brake Equipment}}
{{defn|See ''Combined Automatic'' and ''Straight-Air Locomotive Brake.''}}

{{term|Westinghouse Traction Brake}}
{{defn|The adaptation of the Westinghouse air brake equipments to electrically propelled cars or trains. The changed conditions of motive power and method of operating such cars or trains have necessitated various changes in the details of the equipments, while the general principles of the Westinghouse straight-air and automatic brakes, which are the foundation of all known air brake equipments, remains the same. A motor-driven air compressor furnishes the compressed air; an electric pump governor controls the operation of the same; the brake and triple valves are of different design to accord with the conditions for which they are required. Otherwise the description of the Westinghouse Air Brake, which see, covers the traction brake also.}}

{{term|Westinghouse Train Air Signal Apparatus.}}
{{ghat|Also see '''Train Air Signal Apparatus.'''}}
{{defn| A device for utilizing the supply of compressed air required for operating the Westinghouse brakes to transmit signals to the engine or motorman's cab instead of using the ordinary bell cord.}}

{{term|Westinghouse Unit Switch System of Control}}
{{ghat|Also see '''Control System.'''}}
{{defn|A system of control for railway and other motors by means of low potential train line circuits taken from a storage battery under the car which operate electro-magnets controlling pneumatic valves and cylinders operating the main controller circuits under each car by air taken from the brake pipe. The main controller under each car consists of a group of electro-pneumatic switches which give the desired combinations to the motor circuits. A reverse switch and auxiliary resistance are essential parts of the apparatus'under each car. The apparatus is applicable for cither direct current or alternating current motors. Also called Westinghouse electro-pneumatic system of control.}}

{{term|Wheel}} 
{{defn|1=A circular frame or solid piece of wood or metal which revolves on an axis. |no=1}}
{{defn|2=A circular frame or disk, revolving on an axle, serving to support a moving vehicle. Engine truck wheels are sometimes made of chilled cast iron, but more commonly have a cast iron or cast steel center with a steel tire fastened on, as are also tender truck wheels. See ''Wheel Center.''' Driving wheels and trailing wheels are always made with a spoke center of cast iron or cast steel with a steel tire shrunk on. In addition to shrinkage, driving wheel tires are held on by bolts through the rim and by retaining rings also held by bolts. |no=2}}

{{term|Wheels}}
{{defn|(Specification for Cast Iron, A. R. M. M. Recommended Practice). At the convention of 1888 the following specifications and tests for castiron wheels were adopted as standard. In 1801 these were changed to Recommendations. The specifications and tests are as follows: 1. The cliills in which the wheels of any one wheelmakcr are cast shall be of equal diameters, and the same chill must not vary at different points more than one-sixteenth of an inch in diameter. 2. There shall not be a variation of more than one-half inch in the circumference of any given number of wheels of the same nominal diameter, furnished by any one maker, and the same wheel must not vary more than one-sixteenth of an inch in diameter. The body of the wheel must be smooth and free from slag or blow holes. The tread must be free from deep and irregular wrinkles, slag, chill cracks and sweat or beads in the throat which are one-eighth of an inch or over in diameter, or which occur in clusters of more than six inches in length. 3. The wheels broken must show clean, gray iron in the plates; the depth of pure white iron must not exceed seven-eighths of an inch or be less than three-eighths of an inch in the middle of the tread, and shall not be less than three-sixteenths of an inch in the throat. The depth of the white iron shall not vary more than one-fourth of an inch around the tread on the rail line in the same wheel. 4. Wheels shall not vary from the specified weight more than two per cent. 5. The flange shall not vary in the same wheel more than three thirty-seconds of an inch from its mean thickness. 6. The single plate part of a 33-inch wheel, known as the Washburn pattern, shall not be less than five-eighths of an inch in thickness in a wheel weighing from 550 to 575 pounds, and not less than three-fourths of an inch in thickness in a wheel weighing from 575 to 600 pounds.}}

{{term|Wheel Base}}
{{defn|The horizontal distance between centers ©f the first and last axles of a locomotive or tender. It is usual, in stating locomotive dimensions, to give the rigid wheel base, the truck wheel base and the total wheel base.}}

{{term|Wheel Bore}}
{{defn|The hole through the hub or central part of a wheel in which an axle is fitted. Also called axle seat.}}

{{term|Wheel Boss (British).}}
{{defn|American term hub. The center of the wheel, which is bored out to receive the axle.}}

{{term|Wheel Center}}
{{defn|The portion of a wheel inside of the tire and between it and the hub or boss. The centers of engine and tender truck wheels are sometimes in one piece and sometimes made up of two parts, the hub or boss, and the # central filling piece. Face plates, front and back, are also used. The term is seldom applied to chilled, cast or rolled steel wheels. Driving and trailing wheel centers are made of cast iron or cast steel. In Great Kritain, wheel centers are frequently made of wrought iron.}}

{{term|Wheel Cover}}
{{defn|A strip of thin steel plate, curved to a radius slightly greater than that of a wheel, to prevent mud and oil being spattered over the locomotive. Wheel covers are usually bolted to the engine truck frame for the truck wheels, and the under side of the running board for the driving wheels. British, splasher.}}

{{term|Wheel Cover Block}}
{{defn|A small piece of metal fastened to a running board or engine truck frame for the attachment of a wheel cover.}}

{{term|Wheel Cover Bracket}}
{{defn|A small cast iron post or holder, for the attachment of a wheel cover.}}

{{term|Wheel Cover Edge}}
{{defn|A heading or molding formed on the outer edge of a wheel cover.}}

{{term|Wheel Fit}}
{{defn|That part of a driving or truck wheel that is forced on an axle or crank pin.}}

{{term|Wheel Flange}}
{{defn|The projecting edge or rim on the periphery of a car wheel for keeping it on the rail.}}

{{term|Wheel Hub}}
{{ghat|Also see '''Hub.'''}}
{{defn|The center of a wheel surrounding the axle on which it is mounted. British, boss.}}

{{term|Wheel Hub Liner}}
{{defn|A brass or bronze disk secured to the inside hub of a wheel to form a wearing surface between the hub and the outside face of the box. Such liners are used on engine truck wheels, driving and trailing wheels.}}

{{term|Wheel Key}}
{{defn|A piece of steel slightly tapered, driven into a slot or keyway cut longitudinally in the wheel seat of a driving axle and a corresponding slot in the bore through a driving wheel hub to key or secure the wheel to the axle.}}

{{term|Wheel Plates}}
{{defn|That part of a cast iron engine truck or tender truck wheel which connects the rim and the hub. It occupies the place and fulfils the same purpose as the spokes in an open or spoke wheel. On steel-tired wheels the plates connecting the tire and hub, and bolted or fastened to each, are called wheel plates. Distinguished as front and back face plates.}}

{{term|Wheel Press (Hydraulic)}}
{{defn|A hydraulic press for forcing locomotive driving wheels on and off their axles. They are fitted with a pressure gage which is usually graduated for total tons pressure and for pounds per square inch on the rams. They are made with capacities up to 400 tons pressure.}}

{{term|Wheel Ribs (Cast Iron Wheels)}}
{{defn|More commonly, brackets. Projections cast usually on the inner side of plate car wheels to strengthen them. They are placed in a radial position and are often curved so as to permit the wheel to contract when it cools.}}

{{term|Wheel Rim Filling Piece}}
{{defn|A flat steel strip inserted in one of the radial spaces left to allow for shrinkage in casting in the rim of a driving wheel center.}}

{{term|Wheel Seat}}
{{defn|That portion of an axle that is forced into a driving wheel or truck wheel.}}

{{term|Wheel Tread}}
{{defn|The exterior cylindrical surface of a wheel which bears on the rails. The usual width of wheel tread is about 4 inches, measured from outside of wheel tread to the throat or inside of flange. The standard width from outside of wheel tread to inside face of flange, i. e.. including the entire thickness of flange, is 5!£ inches. For driving wheels the width varies from to 7 inches.}}

{{term|Wheel Web}}
{{defn|That portion of a cast iron truck wheel center between the huh and the rim.}}

{{term|[[Train whistle|Whistle]]}}
{{defn|Train whistles are used as a safety warning and also by the engineer to communicate to other railroad workers. See [[Train whistle|train whistle]] for a description of the whistle code used to communicate. Also a ''nickname'' for an [[Train horn|air horn]] on a diesel locomotive. Steam engine whistles were historically known as chimes in the US during the 19th century.}}

{{term|Whistle Bell}}
{{defn|A cylindrical brass chamber with flat or hemispherical top, for producing a sound by steam blown against the edge. It is screwed on a stem directly over the whistle bowl.}}

{{term|Whistle Bowl}}
{{defn|A hemispherical brass cup with a cylindrical extension below it containing a valve for admitting steam. The bowl has a disk over it that docs not come quite to the edge, thus leaving an annular opening through which the steam escapes, and in the center of which the steam passing up through the bell is secured.}}

{{term|Whistle Crank}}
{{defn|A short metal arm attached to the whistle lever in the cab for imparting motion to the lever or bar that opens the whistle valve.}}

{{term|Whistle Crank Fulcrum}}
{{defn|A cast-iron bracket fastened in the cab of a locomotive to form a bearing for the whistle shaft.}}

{{term|Whistle Extension}}
{{defn|The cylindrical pipe below the bowl of a whistle, containing the whistle valve.}}

{{term|Whistle Lever}}
{{defn|An arm or bar in the cab of a locomotive for operating the whistle valve. It is attached to a crank that moves the lever on the whistle through the medium of a link or bar.}}

{{term|Whistle Lever Fulcrum}}
{{defn|A small bracket attached to a whistle extension to hold the pin on which the whistle lever is pivoted.}}

{{term|Whistle Lever Rod}}
{{defn|A link or bar connecting the whistle lever on the whistle with the operating lever in the cab.}}

{{term|Whistle Nut}}
{{defn|A square or hexagonal brass nut screwed on the upper end of a whistle stem to secure the whistle bell in place, and usually surmounted by an acorn-shaped top called the whistle ornament.}}

{{term|Whistle post}}
{{ghat|Also see '''Whistle Stem.'''}}
[[File:Double Whistle post.jpg|thumb|upright=0.5|A double ''whistle post'']]
{{defn|An advance warning to the engineer of an upcoming grade crossing. It is the point at which the engineer should begin sounding the [[Train whistle|whistle]] or [[Train horn|horn]].}}

{{term|Whistle Reservoir (Train Air Signal.) }}
{{defn|A small steel reservoir sometimes installed for storing air to be used by an air whistle on electric locomotives.}}

{{term|Whistle Shaft}}
{{defn|A short metal rod in the cab, supported by a hanger or fulcrum at each end, and having the whistle lever and whistle crank attached to it.}}

{{term|Whistle Stem}}
{{defn|A steel or malleable iron standard, screwed in the center of a whistle bowl, and supporting the whistle bell. The bell has a hole through the top, tapped with a thread to fit that cut on the upper end of the whistle stem, which allows the height of the bell above the bowl to be adjusted.}}

{{term|Whistle Valve}}
{{defn|A disk with a shank or stem attached, fitting in an opening in the whistle extension for admitting steam to the whistle to cause it to sound. It is operated by a set of levers in the cab.}}

{{term|[[Whyte notation]]}}
{{defn|A system of describing steam locomotive wheel arrangements (e.g. 4-6-4, 2-10-2). The first number indicates the number of "pilot" wheels that help lead the engine into turns. The second is the number of coupled wheels ("drivers"). Third are the trailing idler wheels, usually to provide support to larger fireboxes. Articulated locomotives are similarly described. For example, a Union Pacific "Big Boy" would be described as a 4-8-8-4, wherein the pilot has four wheels, followed by two sets of drivers, eight wheels per set, and a four-wheel trailing bogie under the firebox. The numbers include the wheels on both sides of the engine, so a 2-8-2 engine would have one idler, four drivers, and a final idler on each side of the engine.}}

{{term|Wide Firebox Boiler}}
{{defn|A boiler with a wide, shallow firebox resting on the frames and extending out beyond them at the sides. The '''Wootten Firebox,''' which see, is a wide firebox for burning anthracite coal.}}

{{term|Wigwag}}
{{defn|A largely superseded Level or grade crossing warning signal that consists of a swinging disc facing road traffic, with a red light in the centre. The disc normally hangs straight down, but an approaching train sets it swinging from side to side, the red light illuminates or flashes, and a bell rings.}}

{{term|Window}}
{{defn|"An opening in the wall of a building or cab for the admission of light and of air when necessary. This opening has a frame on the sides, in winch are set movable sashes containing panes of glass." – Webster. Hence the window itself, especially in compound words, is often termed simply the sash.<ref>{{Cite book|url=https://books.google.com/books?id=jCJMAAAAMAAJ|title=Locomotive Dictionary|publisher=N.K. Gregg|year=1906|isbn=9780912318202|location=New York|page=96|agency=American Railway Master Mechanics' Association}}</ref>}}

{{term|Window Glass}}
{{defn|Panes of glass used for windows. They are either plate or rolled glass, made by pouring the molten glass onto a table having the height of the desired thickness of the plate, and then passing a roller over the top; or blown, or common window glass, the latter being by far the cheapest and most widely used, but of very much inferior quality. It is made by blowing the glass into a largo bulb, which is then slit open while still hot and flattened out.<ref name=":0">{{Cite book|url=https://books.google.com/books?id=jCJMAAAAMAAJ|title=Locomotive Dictionary|publisher=N.K. Gregg|year=1906|isbn=9780912318202|location=New York|page=97|agency=American Railway Master Mechanics' Association}}</ref>}}

{{term|Window Sill}}
{{defn|A horizontal piece of wood or metal under a window, on which the cab sashes rest when down.<ref name=":0"/>}}

{{term|Working water, foaming, or priming}}

{{term|Wootten Firebox}}
{{defn|A locomotive firebox, very wide and shallow and having a curved crown sheet of large radius, used for anthracite coal burning locomotives which require a large grate area.<ref name=":0"/>}}

{{term|Worn Flat (Car Wheels)}}
{{defn|Irregular wear under fair usage, due to unequal hardness of the tread of the wheel, and to be carefully distinguished from slid flat, which is a defect produced by the slipping of the wheels from excessive brake pressure.<ref name=":0"/>}}

{{term|Wrecking Chain}}
{{defn|A heavy steel chain, carried on a locomotive for use in emergencies.<ref name=":0"/>}}

{{term|Wrecking Frog}}
{{defn|See #Rerail frog or rerailer.}}

{{term|Wrench}}
{{defn|1=A contrivance for screwing and unscrewing a nut.<ref name=":0"/> |no=1}}
{{defn|1=A socket wrench is one having a cavity to receive a square or hexagonal end. The wrenches for the Westinghouse brake are packing nut and cap screw wrenches, and the discharge valve seat wrench. |no=2}}
{{defn|1=A spanner is a wrench for use on round or many sided nuts, like hose couplings, to which lugs or slots are added for engaging with the wrench. |no=3}}
{{defn|1=An alligator wrench for use on pipe or other cylindrical surfaces has immovable jaws, one serrated and the other smooth, inclined to each other at an acute angle. |no=4}}
{{defn|1=A monkey wrench has smooth, parallel jaws, one of which is fastened to the handle or stem, while the other can be moved up to or away from it by a sleeve nut working on a thread cut on the stem. |no=5}}

{{term|Wrist Pin}}
{{defn|Sec Crosshead Wrist Pin.<ref name=":0"/>}}

{{term|Wrong-side failure}}

{{term|Wrought Iron Wheel}}
{{defn|A steel tired wheel, with a wrought iron center, either with spokes or with solid plates.<ref name=":0"/>}}

{{term|Wye (rail)}}
{{glossary end}}

== Y ==
{{glossary}}

[[File:CNW yard, Chicago.jpg|thumb|upright=0.5|Railroad ''yard'' in {{wipe|Chicago}}, Illinois, as seen in December 1942]]
{{term|Rail yard|Yard}}{{defn|An arrangement of tracks where rolling stock is switched to and from trains, freight is loaded or unloaded, and consists made up.<ref name="Trains Glossary Y">{{cite web| url=http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=Y| archive-url=https://web.archive.org/web/20140822004745/http://trn.trains.com/Railroad%20Reference/Railroading%20Glossary.aspx?letter=Y| title=Railroading Glossary: Y| publisher=Kalmbach Publishing| website=TRN.Trains.com| access-date=20 February 2013| archive-date=22 August 2014}}</ref><ref name=":2"/>}}

{{term|[[Yellow]]}}
{{defn|A color associated with a warning or a need to slow down when used by flags or signals, but the exact meaning varies from railway to railway.}}

{{term|Yoke}}
{{ghat|Also '''Coupler Yoke''', '''Bell Yoke''', '''Guide Yoke''', '''Valve Yoke'''.}}
{{defn|A bar or bent piece connection two pieces of the same kind.<ref name=":0"/>}}

{{term|Yoke Knee}}
{{defn| See Guide Yoke Knee.<ref name=":0"/>}}

{{term|Yoke Sheet}}
{{defn|See Guide Yoke Sheet.<ref name=":0"/>}}
{{glossary end}}

== Z ==
{{glossary}}
{{term|Zig zag or switchback}}
[[File:Zig zag railway at Lithgow.jpg|thumb|upright=0.5|The Lithgow Zig Zag]]
{{defn|A method of climbing and descending steep gradients, where shallow-gradient track reverses direction for a while, and then reverses again to continue in the original direction.}}
{{glossary end}}

== See also ==

* Glossary of Australian railway terms
* Glossary of New Zealand railway terms
* Glossary of North American railway terms
* Glossary of United Kingdom railway terms
* Passenger rail terminology

{{Clear}}

== References ==
{{Reflist}}

== Further reading ==
* Canadian National Railways: Linguistic Services. Freight Car Inspection & Maintenance: English-French Vocabulary = Surveillance et entretien des wagons: vocabulaire anglais-français. Montréal: Canadian National Railways, 1973. Without ISBN or SBN
* {{Cite book| title=The Railroad Car Builder's Dictionary| first=Matthias N.| last=Forney| date=1879| publisher=[[Social:Dover Publications|Dover Publications]]}}

== External links ==
* [http://www.victorianweb.org/technology/railways/23.html British Railways compared to American Railroads]


[[Category:Rail transport]]

{{Sourceattribution|Glossary of rail transport terms}}