View source for Push–pull train

{{Short description|Train able to be operated by a driver at either end}}
{{Distinguish|Top and tail}}
{{more citations needed|date=November 2023}}
{{Use dmy dates|date=September 2022}}
[[File:push-pull-train.svg|thumb|300px|right|In a push–pull train, locomotives at both ends of a train can be used at the same time, controlled by one driver.]]
[[File:push-pull-dvt-train.svg|thumb|300px|right|When using a single locomotive, a [[control car]] with duplicate controls can be used when pushing.]]
[[File:Dvt-dvt-train.png|thumb|300px|right|A push–pull train with two control cars and a locomotive in the middle]]

'''Push–pull''' is a configuration for [[locomotive]]-hauled [[train]]s, allowing them to be driven from either end of the train, whether having a locomotive at each end or not.

A push–pull train has a locomotive at one end of the train, connected via some form of remote control, such as [[multiple-unit train control]], to a vehicle equipped with a control cab<!-- Please do not change this to [[control car]] (linked twice below) -- it really needs its own article or a redirect somewhere else --> at the other end of the train. This second vehicle may be another locomotive, or an unpowered [[control car]].

In the UK and some other parts of Europe, the control car is referred to as a ''driving trailer'' (or [[driving van trailer]]/DVT where there is no passenger accommodation); in the US and Canada, they are called ''cab cars'' and in Australia, they are called driving trailers.

==Train formation==

===Locomotive at one end===
{{Multiple unit}}
[[File:Austria cityshuttle 02.jpg|thumb|left|Push–pull train in Austria (2004); note locomotive at the rear of the train.]]
[[File:Chrást u Plzně, vlak do Plzně.jpg|thumb|left|Push–pull train in the Czech Republic (2016); note control car at the rear of the train.]]
[[File:Bf Rochlitz, Doppelstockgliederzug.jpg|thumb|Former Push–pull train of [[Deutsche Reichsbahn (East Germany)|Deutsche Reichsbahn]] (control car out of function) after the unification of Germany|alt=]]
[[File:Mallow IÉ-4006.jpg|thumb|A modern [[Mark 4 (Iarnród Éireann)|driving van trailer]] in [[Ireland]]]]
[[File:Lokomotiva 109 E2.jpg|thumb| Push–pull train in [[Slovakia]]]]

Historically, push–pull trains with steam power provided the driver with basic controls at the cab end along with a bell or other signalling code system to communicate with the fireman located in the engine itself in order to pass commands to adjust controls not available in the cab.

At low speeds, some push–pull trains are run entirely from the engine with the guard operating bell codes and brakes from the leading cab when the locomotive is pushing the train.

Many mountain railways also operate on similar principles in order to keep the locomotive lower down than the carriage to prevent any opportunity for a carriage to run away from a train down the gradient and also so that even if the locomotive ever ran away, it would not take the carriage with it.

Modern train control systems use sophisticated electronics to allow full remote control of locomotives. Nevertheless, push–pull operation still requires considerable design care to ensure that control system failure does not endanger passengers and also to ensure that in the event of a derailment, the pushing locomotive does not push a derailed train into an obstacle, worsening the accident. The 1984 [[Polmont rail accident]], in Scotland, occurred when a push–pull train struck a cow on the track.

When operating push–pull, the train can be driven from either the locomotive or the alternative cab. If the train is heading in the direction in which the locomotive end of the train is facing, this is considered 'pulling'. If the train is heading in the opposite direction, this is considered 'pushing' and the [[Motorman (locomotive)|motorman]] or [[engine driver]] is located in the alternative cab. This configuration means that the locomotive never needs to be uncoupled from the train and ensures fast turnaround times at a [[Train station|railway station]] [[terminal station|terminus]].

===Two locomotives===
[[File:NEC train 3967 passing through Rahway station, June 2007.jpg|thumb|left|A [[New Jersey Transit]] train with [[Bombardier ALP-46]] locomotives on both ends and 11 cars in between, in [[New Jersey]], United States]]

Alternatively, a push–pull train, especially a long one, may have a locomotive on each end so that there is always one locomotive pushing and one locomotive pulling. In this case, caution must be used to make sure that the two locomotives do not put too much stress on the [[railroad car|cars]] from uneven locomotives. It is usual to arrange matters so that the trailing locomotive supplies less power, i.e. that the locomotive at the front does more pulling than the locomotive at the rear does pushing. Having an independent locomotive, as opposed to a power car at each end, is also known in the railway world as a [[top and tail]]. When this configuration is used in the US, only one locomotive (usually the front locomotive) is allowed to provide [[head end power]] (HEP: electricity supply for [[HVAC|heating, air conditioning]] and lighting) to the train. The two-locomotive formation is used by the [[InterCity 125]]; its Australian equivalent, the [[New South Wales XPT|XPT]]; [[Brightline]]; [[Amtrak]]'s [[Acela]]; [[SNCF]]'s [[TGV]]; [[Taiwan Railways Administration]]'s [[E1000 series]]; and [[New Jersey Transit Rail Operations|New Jersey Transit]]'s longest [[Northeast Corridor Line]] [[Bilevel rail car|multilevel]] trains.

This form of operation has not necessarily been a function of train length; sometimes it was the most convenient way to set up push–pull operation in pre-HEP days without converting coaches to cab control operation. A prime example of this was the [[Reading Company]] which converted its small fleet of streamstyled heavyweight medium-distance coaches for its [[SEPTA diesel service|non-electric commuter operation]], with a pair of [[EMD FP7]] diesels bracketing a single five-car train, to supplant the Reading's fleet of [[Budd Rail Diesel Car|RDCs]]. This train normally operated a weekday peak-hour round trip between [[Reading Terminal]], [[Philadelphia]] and [[Reading, Pennsylvania]], from the late 1960s until 1981, with operation in the last five years by [[Conrail]] under contract to [[SEPTA]].<ref>{{cite book|last=Pawson|first=John R.|title=Delaware Valley Rails|year=1978|publisher=John R. Pawson|location=Willow Grove, PA|isbn=0-9602080-0-3|pages=62–63}}</ref>

===Locomotive in the middle===
[[File:20040529K243-27.jpg|thumb|Golden Pass Panoramic train in Switzerland with locomotive in the middle]]
A rare but possible configuration has a locomotive in the middle of the train with control cars at both ends, as was, for instance, used for a time on the Brussels–Amsterdam [[HSL-Zuid#Benelux train|Benelux train]] when there were control cars but no three-voltage (3&nbsp;kV&nbsp;DC, 1.5&nbsp;kV&nbsp;DC, 25&nbsp;kV 50&nbsp;Hz) locomotives supporting the [[ERTMS]] train control system in use on the Belgian [[HSL 4]] and the Dutch [[HSL-Zuid]]. The [[Belgian Railways Class 28 (Bombardier)|Class 28 TRAXX locomotives]] were later upgraded, and the service went back to "normal" push–pull operation.

===Distributed power===
{{Main article|Distributed power}}
In this configuration, locomotives hauling a train are located other than at the front or the back. It may include [[remote control locomotive]]s in the middle of a train. If operational considerations or economics require, trains can be made longer if intermediate locomotives are inserted in the train and are remotely controlled from the leading locomotive.

{{clear}}

==History==
===Great Britain===
====Steam====
[[File:GWR Autocoach.jpg|thumb|A single [[GWR Autocoach]] capable of steam push–pull operation]]
;Great Western Railway
The first company to use the system was the [[Great Western Railway]] which, in 1904, equipped carriages and [[0-6-0]] locomotives as an [[GWR Autocoach|autotrain]] to run on the [[Brentford Branch Line]] (between [[Southall railway station|Southall]] and [[Brentford railway station|Brentford]]) as an experimental substitute for steam [[Railmotor|railcars]]. Control was by rodding and the mechanism allowed the driving compartment to be either one or two carriages-distant from the engine. With the engine in the middle of a formation, up to four carriages could be used. To reduce the surprise of a locomotive at the "wrong" end of its train, some were initially fitted with panelling painted in carriage livery.<ref name=companion>Simmons, Jack; Biddle, Gordon (editors) 1997. ''Oxford Companion to British Railway History'' p 407. [[Oxford University Press]] {{ISBN|0-19-211697-5}}</ref> The experiment was successful and the company's remaining railcars were gradually converted for autotrain use and purpose-built units constructed.

;Other railways
Other companies followed the lead in 1905: the [[North Eastern Railway (United Kingdom)|North Eastern]] and [[London, Brighton & South Coast Railway]] using a compressed-air method of control and the [[Midland Railway]], using a cable-and-pulley mechanism. The [[Great Central Railway|Great Central]] deployed the trains in 1906, using cable controls similar to that of the Midland. By the 1920s, most companies had them and they remained in use until they were replaced by [[diesel multiple unit]]s (DMUs) in the 1950s.<ref name=companion/>

====Electric and diesel====
[[File:DBSO 9714 Ogston.jpg|thumb|[[Network Rail]] [[Driving Brake Standard Open]] in October 2009]]
In 1967, the [[Southern Region of British Railways|Southern Region]], already familiar with operating electric multiple units, applied the technique to its services from [[London Waterloo railway station|London Waterloo]] to [[Bournemouth railway station|Bournemouth]], which were operated by [[electro-diesel locomotive]]s.<ref name=companion/><ref>{{cite magazine |title= Pull and push to Bournemouth |magazine=[[Railway Gazette International|Railway Gazette]] |issue=7 July 1967 |page=481}}</ref>

In the early 1970s, the [[Scottish Region of British Railways|Scottish Region]] used a system with a [[British Rail Class 27|Class 27]] locomotive at each end of a rake of coaches that had been retrofitted with the necessary 'Blue Star' [[multiple working]] cables to control the remote unit; but some problems of delay in actuation were experienced. They were replaced in 1979 by a system in which a [[Driving Brake Standard Open]] (DBSO), converted from a [[British Rail Mark 2|Mark 2]], could control the [[British Rail Class 47|Class 47/7]] locomotive via computerised [[Time-division multiplexing|time-division multiplex]] (TDM) signalling through the train lighting circuits. This had the added benefit that intermediate carriages needed no special equipment, and was found more satisfactory. Such trains became widely used on the intensive passenger service between [[Edinburgh Waverley railway station|Edinburgh Waverley]] and [[Glasgow Queen Street railway station|Glasgow Queen Street]].<ref name=companion/><ref>Glover, John (1999). ''Railway Operations'' p 58. [[Ian Allan Publishing]], Shepperton, England. {{ISBN|0-7110-2689-0}}</ref> When the push–pull sets were replaced by multiple units, the DBSOs were transferred to operate on the [[Great Eastern Main Line]] between [[Liverpool Street railway station|Liverpool Street]] and [[Norwich railway station|Norwich]], where they were modified to work with [[British Rail Class 86|Class 86]] electric locomotives.

The original system of using the Blue Star multiple working was later revived after [[Privatisation of British Rail|privatisation]] as a way of allowing locomotive-hauled stock to replace multiple units on certain routes, thus increasing capacity without the complications of having to run around or drag a dead locomotive at the rear. It was used by [[First North Western]] and [[Wessex Trains]] with [[British Rail Class 31|Class 31s]], and by [[Abellio Greater Anglia]], [[Arriva Trains Northern]], [[Northern Rail]] and [[Arriva Rail North]] with [[British Rail Class 37|Class 37s]] all with [[British Rail Mark 2|Mark 2]] carriages.<ref>{{cite magazine |title= FNW starts locomotive haulage |magazine=[[Rail Magazine]] |issue=481 |date=18 February 2004 |page=63}}</ref><ref>{{cite magazine |title= Wessex Trains showcases its push-pull DMU replacement |magazine=[[Rail Magazine]] |issue=447 |date=30 October 2002 |page=12}}</ref><ref>{{cite magazine |title= Class 37/4s to be straight replacements for AGA 47s |magazine=[[Rail Magazine]] |issue=773 |date=29 April 2015 |page=28}}</ref><ref>{{cite magazine |title= Arriva Trains Northern to run loco-hauled service over S&C |magazine=[[Rail Express]] |issue=87 |date=August 2003 |page=5}}</ref> The same system was also adopted by [[Network Rail]] for its track observation trains, although on many trains one locomotive has recently been replaced by a DBSO modified to work with Blue Star.<ref>{{cite magazine |title= Network Rail buys four DBSOs |magazine=[[Today's Railways UK]] |issue=64 |date=April 2007 |page=70}}</ref>

====Driving Van Trailers (DVTs)====
[[File:GNER train steams into Alnmouth Station - 07 June 2005.jpg|thumb|A [[Great North Eastern Railway|GNER]] [[Driving Van Trailer#Mark 4 DVT|Mark 4 Driving Van Trailer]] at [[Alnmouth railway station|Alnmouth]] in June 2005]]
{{main article|Driving Van Trailer}}

In 1988, 52 [[Driving Van Trailer|Mark 3 Driving Van Trailers]] were built by [[British Rail Engineering Limited]] to allow it to replace life expired electric locomotives on the [[West Coast Main Line]]. These operated with [[British Rail Mark 2|Mark 2]] and [[British Rail Mark 3|Mark 3]] sets.<ref>{{cite magazine |title= Met-Cam scoops MkIV contract |magazine=[[Railway Gazette International]] |issue= February 1987 |page=73}}</ref>

As part of the electrification of the [[East Coast Main Line]], 31 [[Driving Van Trailer#Mark 4 DVT|Mark 4 Driving Van Trailers]] were built in the late 1980s by [[Metro-Cammell]] to operate with [[British Rail Mark 4|Mark 4s]] coaches at the south end of the [[InterCity 225]] sets. Some of these passed to [[Transport for Wales Rail]] in 2021 to work on their Holyhead to Cardiff ''Premier Service''.

In the 2000s, some Mark 3s have been modified to operate with [[British Rail Class 67|Class 67]] locomotives with [[Arriva Trains Wales]], [[Chiltern Railways]] and [[Wrexham & Shropshire]].

In 2019, new [[British Rail Mark 5A|Mark 5]] carriages, one of which has a cab, entered service with [[British Rail Class 68|Class 68]] locomotives for [[TransPennine Express]], in a push–pull configuration.

===Ireland===
[[CIÉ|Córas Iompair Éireann]]'s first push–pull trains were conversions of their [[CIÉ 2600 Class|2600 Class DMUs]] ([[Park Royal Vehicles|Park Royal]] body, [[Associated Equipment Company|AEC]] motors) running with the long withdrawn [[CIE 201 Class|201 Class]] [[Metropolitan-Vickers]] Bo-Bo diesels re-engined with EMD 567 prime movers; the cars were subsequently renumbered in the 6100 series (Driving van trailers), 6200 series (trailer with "blind" cab end) and 6300 series (double-gangway intermediate car). In push–pull formation, they operated [[Dublin Suburban Rail]] services from 1971 until the inauguration of the [[Dublin Area Rapid Transit|DART]] EMU service in July 1984.  The remaining push–pull trains operated on Dublin-Maynooth commuter services until they were supplanted by Cravens, and later by the modern [[IE 2600 Class|2600 Class DMUs]].

[[Iarnród Éireann]] employs push–pull trains of two different kinds. 
The first of these were built in 1996. These are [[Coaching stock of Ireland#De Dietrich (1997–present)|De Dietrich Ferroviaire]]–built [[Enterprise (train service)|Enterprise]] push–pull sets, jointly owned with [[Northern Ireland Railways]] for operation on the [[Dublin-Belfast railway line|Dublin to Belfast route]]. These are powered by [[IE 201 Class|201 Class]] locomotives.

The other type of push–pull train used in Ireland is the [[Mark 4 (Iarnród Éireann)|Mark 4]] type (not to be confused with the [[British Rail Mark 4]] type). These sets, delivered in 2005–2006, are used exclusively on the Dublin to Cork route, again operated by 201 Class locomotives.

Between 1980 and 2009, Iarnród Éireann operated push–pull sets based on the [[British Rail Mark 3]] design, with a non-gangwayed driving cab fitted.<ref>
{{cite journal|journal = Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit|title=Push–pull trains for Iarnród Éireann – Irish Rail|author= RP Grainger|volume=204|issue=16|publisher=Prof Eng Publishing|pages=21–30|issn=0954-4097|year=1990|doi=10.1243/PIME_PROC_1990_204_182_02 |s2cid=111243351 }}</ref>
These were operated with 201 Class locomotives, although in the past [[CIE 121 Class|121 Class]] locomotives were also used. The sets originally operated in the [[Dublin]] outer-suburban area and on the [[Limerick railway station|Limerick]] to [[Limerick Junction railway station|Limerick Junction]] shuttle, but were gradually moved to mainline InterCity routes out of [[Dublin Heuston railway station|Dublin Heuston]] after the introduction of railcar sets elsewhere. The entire Mark 3 fleet was withdrawn in September 2009 and scrapped in 2014.

===France===
In June 1958, [[SNCF]] commenced operating steam trains in push–pull formation out of [[Gare de l'Est]].<ref>{{cite magazine |title= Push-and-Pull Trains |magazine=[[Railway Gazette International|Railway Gazette]] |issue= 8 May 1959 |page=533}}</ref>

===North America===
[[File:Geneva Metra 071020.jpg|thumb|A [[Metra]] train in push mode, with a non-locomotive passenger car in the front. Note the engineer's station in the upper level of the passenger car.]]The first major application of push–pull operation using the modern single diesel configuration was on the [[Chicago & Northwestern]] Railroad, announced in 1958.<ref>{{cite magazine |title= C&NW Plans Push-Pull Commuting |magazine=[[Railway Age]] |issue= 21 April 1958 |pages=17–19}}</ref> In 1959, the C&NW received its first Control Cab equipped [[Bilevel rail car]]s for commuter use. The extreme efficiency and success of these trains is why almost all of the commuter rail services in the United States and Canada utilize 100% push–pull operation on their locomotive-hauled trains.{{citation needed|date=November 2013}} Examples include: [[Chicago]] ([[Metra]]); [[New York City]] ([[Metro-North Railroad|Metro-North]], the [[Long Island Rail Road]] and [[NJ Transit Rail Operations|New Jersey Transit]]); [[Philadelphia]] ([[SEPTA Regional Rail|SEPTA]]); the [[Washington, DC]] and [[Baltimore]] area ([[MARC Train|MARC]] and [[Virginia Railway Express|VRE]]); [[Boston]] ([[MBTA Commuter Rail|MBTA]]); [[Dallas-Fort Worth metroplex]] ([[Trinity Railway Express]]); [[Greater Miami|the Greater Miami area]] ([[Tri-Rail]]); the [[San Francisco Bay Area]] ([[Caltrain]] and [[Altamont Corridor Express|ACE]]); [[Southern California]] ([[Metrolink (California)|Metrolink]] and [[Coaster (rail service)|Coaster]]); [[Toronto]] ([[GO Transit]]); [[Montreal]] ([[Exo (public transit)|AMT]]); and the [[Wasatch Front]] in Utah ([[Utah Transit Authority|UTA]] [[FrontRunner]]). Most of these systems (except for SEPTA and Metro-North) continue to utilize some type of [[Bilevel rail car|bi-level passenger cars]] for push–pull service, either partially or exclusively.

Amtrak has a number of converted Metroliner EMUs in service as cab cars on the Keystone Corridor, where they operate in conjunction with ACS-64 electric locomotives.  In addition, many regional services, such as the Michigan Services, [[Downeaster (train)|''Downeaster'']], and ''Cascades'', are operated with [[Non-Powered Control Units]] – [[EMD F40PH]] locomotives converted to use as a cab control and baggage car, earning itself the nickname 'cabbage cars'.  Similarly, the ''[[Capitol Corridor]]'', ''[[San Joaquin (train)|San Joaquin]]'', and ''[[Pacific Surfliner]]'' services in California are operated in push–pull configuration using purpose-built cab cars and diesel locomotives.

The [[Muskingum Electric Railroad]] was a private, coal-hauling railway in central [[Ohio]] that ran for more than 20 years with two driverless [[General Electric]] [[GE E50C|E50C]] electric locomotives that ran backwards from the coal-fired powerplant they served to the mine where their trains were loaded by affixing bogie trucks, a headlight, and a horn to the last freight car on each train.

===Israel===
[[File:07.09.06 09 Train 163 Crossing Road 6 Bridge.JPG|thumb|A GEC–Alsthom push–pull of Israel Railways (IR)]]
In 1996, [[Israel Railways]] began running GEC–Alsthom push–pull coaches. Since then, it has also acquired push–pull coaches from [[Bombardier Double-deck Coach|Bombardier]] and [[Siemens Viaggio Light|Siemens]]. As of 2016, the bulk of Israel Railways' passenger operations use push–pull coaches. All of them have one locomotive at one end and a control car at the other end.

===Australia===
The [[New South Wales XPT]] long-distance passenger trains used by [[NSW TrainLink]] operate in a push–pull operation. In the past [[V/Line]] operated [[V/Line P class|P class]] push–pulls on interurban services to [[Bacchus Marsh railway station|Bacchus Marsh]] and [[Wyndham Vale railway station|Wyndham Vale]] until 2017. [[South Australian Railways']] [[2000 class]] DMUs could be found with at least one motor car and one cab car in a push–pull configuration until their withdrawal in 2016.

===New Zealand===
[[File:D_Class_steam_locomotive_NZR_no_197_at_Lower_Hutt_Railway_Station,_1906_ATLIB_307681.png|thumb|[[NZR D class (1874)|D Class]] NZR no 197 at [[Lower Hutt railway station|Lower Hutt]], 1906 with motor train]]
In the first quarter of the 20th century up to 13 [[Control car#New Zealand|motor trains]] ran on [[New Zealand Railways Department|NZR]].<ref>{{Cite web|url=https://paperspast.natlib.govt.nz/parliamentary/appendix-to-the-journals-of-the-house-of-representatives/1925/I/1873|title=Appendix to the Journals of the House of Representatives {{!}} 1925 Session I|website=paperspast.natlib.govt.nz|language=en|access-date=2018-05-10}}</ref>

Until 2015, the [[Public transport in Auckland|Auckland]] suburban network run by [[Transdev]] used rebuilt [[British Rail Mark 2]] carriages in either four, five or six car configurations. Three to five SA class carriages and an SD class driving carriage, fitted with a cab, were coupled to a [[New Zealand DC class locomotive|DC class]] (4- and 5-car) or [[New Zealand DF class locomotive (1979)|DFT/DFB class]] (6-car) locomotive, leased from [[KiwiRail]].

All SA and SD class cars were rebuilt by [[Hillside Workshops]]. Auckland also operated former [[Queensland Rail]] [[SX carriages]] in push–pull mode with two [[NZR DB class|DBR class]] locomotives.

Following electrification of most of the Auckland suburban railway network, these diesel units have been replaced by a modern electrical fleet that consist of one or two sets of 3 car units (each of which have one carriage that can service passengers with disabilities).

==See also==
{{Commons category}}
{{portal|Trains}}
{{div col|colwidth=30em}}
*[[Air brake (rail)]]
*[[Autotrain]]
*[[Cab (locomotive)]]
*[[Control car]]
*[[Double-heading]]
*[[GWR Autocoach]]
*[[Rail terminology]]
*[[Brake (railway)|Railway brakes]]
*[[Top and tail]]
{{div col end}}

==References==
{{Reflist}}

==Further reading==
*{{cite book | last =King | first =Mike | title =An Illustrated History of Southern Push–Pull Stock | publisher =[[Ian Allan Publishing]] (OPC) | year =2006 | isbn = 0-86093-596-5}}
*{{cite book | last =Lewis | first =John | title =Great Western Railway Auto Trailers: Pre-grouping Vehicles (Part 1) | publisher =Wild Swan Publications| year =1991 | isbn = 0-906867-99-1}}
*{{cite book | last =Lewis | first =John | title =Great Western Railway Auto Trailers: Post-Grouping and Absorbed Vehicles (Part 2) | publisher =Wild Swan Publications | year =1995 | isbn = 1-874103-25-9}}
*{{cite book | last =Lewis | first =John | title =Great Western Steam Railmotors: and their services | publisher =Wild Swan Publications | year =2004| isbn = 1-874103-96-8}}

==External links==
*[https://web.archive.org/web/20090201085947/http://railway-technical.com/pu-pl.shtml The Development of Push–Pull Operation (at Railway Technical Web Pages)] – history, mainly UK
*[http://chicago.railfan.net/cgi/photos.pl/?page=AMTK_Cabbage Amtrak cab-baggage (cabbage) cars]

{{DEFAULTSORT:Push-pull train}}
[[Category:Rail transport operations]]