Diesel multiple unit: Difference between revisions

{{Short description|Self-powered diesel trains}}

{{redirect|DMU}}

[[File:JNR kiha40 136 erimo.jpg|thumb|A [[KiHa 40 series|JNR Class KiHa40]] in use for ''[[Erimo Express]]'' service, Hokkaido, Japan]]

[[File:Dublin 1.jpg|thumb|An [[IE 29000 Class]] diesel multiple unit on a [[Dublin Suburban Rail|western commuter]] service at [[Connolly station]], in Dublin, Ireland]]

[[File:Class 185 at Manchester Piccadilly.jpg|thumb|A {{brc|185}} diesel multiple unit operated by [[TransPennine Express]] at {{rws|Manchester Piccadilly}}, England]]

A '''diesel multiple unit''' ('''DMU''') is a [[multiple unit]] train powered by on-board [[diesel engine]]s. A DMU requires no separate [[locomotive]], as the engines are incorporated into one or more of the carriages. When additional carriages are coupled on, their controls are connected through and a single driver can control every engine in the train.  This also allows the driver to drive from a cab at either end, simplifying reversing.  Diesel-powered single-unit [[railcar]]s are generally regarded as DMUs for most operations, at least with smaller trains.  

 

The first diesel railcars appeared in the 1930s and DMUs became popular immediately post-war. They offered several cost-saving advantages, at a time when railway operations were short of funds:

* Reduced crew. They could be driven by a single driver, without a fireman.

* Simpler station layouts. They did not need a locomotive to 'run round' the train at a terminus station, merely for the driver to change ends. This made them quicker to operate in a busy station. It also permitted small stations to be simplified from a loop to a simple dead-end, also saving on signalling costs and the need to employ a signaller. This simplicity could be enough to keep small [[branch line]]s in viable operation, rather than being closed.

* Greater flexibility. As each carriage or pair of carriages was powered, more carriages could be added to a longer train and there was no need to swap in a more powerful locomotive.

The diesel engine may be located above the frame in an engine bay or under the floor. Driving controls can be at both ends, on one end or in a separate car.

DMUs may also be classified by the method of transmitting motive power to their wheels: diesel–mechanical ''DMMU'', diesel–hydraulic ''DHMU'', or diesel–electric ''DEMU''.

In a diesel–mechanical multiple unit (DMMU), the rotating energy of the engine is transmitted via a [[Transmission (mechanics)|gearbox]] and driveshaft directly to the wheels of the train, like a [[automobile|car]]. The transmissions can be shifted manually by the driver, as in the great majority of first-generation [[British Rail]] DMUs but, in most applications, gears are changed automatically.

[[File:Stadler Flirt DMU 2404 power car.jpg|thumb|right|The ''power Pack'' car of [[Stadler FLIRT]] DMU, with open bay of a diesel-generator. The Jacobs bogies under this car do not have their own traction motors, which are mounted on bogies under other cars.]]

In a diesel–electric multiple unit (DEMU), a diesel engine drives an [[electrical generator]] or an [[Alternator#Diesel electric locomotive alternators|alternator]], which produces [[electrical energy]]. The generated current is then fed to electric [[traction motor]]s on the [[wheel]]s or [[bogie]]s in the same way as a conventional [[diesel–electric locomotive]].<ref name="gaz-voyager" />

On some DEMUs, such as the [[Bombardier Voyager]], each car is entirely self-contained and has its own engine, generator and electric motors.<ref name="gaz-voyager">{{cite web|url=http://www.railwaygazette.com/news/single-view/view//cutting-noise-and-smoothing-the-ride.html |title=Cutting noise and smoothing the ride |work=[[Railway Gazette International]] |date=1 August 2000 |quote=In the Voyager application, every car has a Cummins underfloor engine and alternator supplying power to a pair of body-mounted traction motors. Each drives one inner axle through a cardan shaft and axle-mounted final drive gearbox. |access-date=20 January 2011 |url-status=dead |archive-url=https://web.archive.org/web/20120604022558/http://www.railwaygazette.com/news/single-view/view/cutting-noise-and-smoothing-the-ride.html |archive-date=4 June 2012}}</ref> In other designs, such as the [[British Rail Class 207#Technical details|Class 207]] or the [[Stadler GTW]] and [[Stadler Flirt|Stadler FLIRT DMU]],<ref>Stadler Flirt DMU/DEMU example: [[commons:Category:Elektriraudtee Classes 2200, 2300 and 2400|Elron Elektriraudtee Classes 2200, 2300 and 2400]], [[commons:File:TEXRail Stadler FLIRT DFW Airport Nov 2019.jpg|TEXRail Stadler FLIRT]]</ref> some cars within the [[consist]] may be entirely unpowered or only feature electric motors, obtaining electric current from other cars in the consist which have a generator and engine.

NMBS/SNCB uses its [[NMBS/SNCB Class 41]] DMUs on the few remaining unelectrified lines. As electrification progresses, the DMUs have become less utilised.

[[File:DMU 7023 at Zagreb Central Station, January 2020.jpg|thumb|DMU 7023 at Zagreb Central station (2020)]]

Diesel multiple units cover large number of passenger lines in Croatia, which are operated by the national passenger service operator [[HŽ Putnički prijevoz]]. On Croatian Railways, DMUs have important role since they cover local, regional and distant lines all across the country. The country's two largest towns, [[Zagreb]] and [[Split, Croatia|Split]], are connected with an [[inter-city rail|inter-city]] service that is provided by DMU [[Tilting train|tilting]] trains "[[RegioSwinger]]" (Croatian series 7123) since 2004. Those trains may also cover other lines in the country, depending on need and availability.

Luxury DMU series [[HŽ series 7021|7021]], built in [[France]], started to operate for [[Yugoslav Railways]] in 1972 and, after 1991, still remained in service of Croatian Railways until 2005. Units [[HŽ series 7121|7121]] and [[Y1 (railcar)|7122]] (which came as a replacement for [[HŽ series 7221|7221]] units), together with the newest series [[HŽ series 7022|7022]] and 7023 built in 2010s Croatia, cover many of the country's local and regional services on unelectrified or partly electrified lines.

[[Elron (rail transit)|Elron]] has since 2015 a Stadler FLIRT fleet, with 20 trains DEMU version.

Since 1968, [[Deutsche Bahn]] (DB) has designated DMUs with class numbers beginning in 6. While DB and regional transport authorities generally prefer electric power for commuter rail, many local and rural lines remain unelectrified and DMUs are needed for those areas. DMUs in service as of 2021 include the Adtranz [[DBAG Class 612|Class 612]] tilting train ("Regio Swinger"), the [[Alstom Coradia LINT]] (Classes 620–623, 640 and 648), the [[Siemens Desiro]] (Class 642) and the [[Bombardier Talent]] (Class 643/644). From 2001 to 2016 there was even a DMU version of DB's high-speed [[Intercity Express]], the Class 605 [[ICE TD]].

* [[Diakopto–Kalavryta railway]]

In the Republic of Ireland, the [[Córas Iompair Éireann]] (CIÉ), which controlled the republic's railways between 1945 and 1986, introduced DMUs in the mid-1950s and they were the first diesel trains on many main lines.<ref>{{cite book|url=https://books.google.com/books?id=gApAhy8QvoEC&q=ireland+diesel+multiple+unit+1950&pg=PA72|title=An A-Z of Famous Express Trains: An Illustrated Trip Down Memory Lane|isbn=9781446302958|last1=Holland|first1=Julian|date=January 2013|publisher=David & Charles }}{{Dead link|date=February 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

 

 

[[File:Szlovákia, Érsekújvár (Nové Zámky), SK-ZSSK 813 044-5 (Mária), SzG3-2.jpg|thumb|A ZSSK Class 813]]

Several types of DMUs operate in Slovakia; the most common is the Class 812 ZSSK, based on the [[ČD Class 810]]. These are used almost exclusively for hauling passenger trains on non-electrified [[Regional rail|regional lines]] and excel at low travel speeds. In the past, there were a number of [[express train]]s driven by [[Motor coach (rail)|motor coaches]], which often overcame heavier trains driven by steam locomotives at cruising speed. A typical example is the Slovenská strela motor express train, led on the Bratislava-Prague route by a motor car of the same name, or the Tatran express from Bratislava to Košice. Representatives of high-speed motor wagons were motor wagons of the M262 or M286 series, which lost their application in high-speed wagons; this was due to the gradual electrification of main lines and are used for passenger trains.

 

The first significant use of DMUs in Great Britain was by the [[Great Western Railway]], which introduced its small but successful series of diesel–mechanical [[GWR railcars]] in 1934. The [[London & North Eastern Railway]] (LNER) and [[London, Midland & Scottish Railway]] (LMS) also experimented with DMUs in the 1930s;<ref>{{cite web |url=http://www.lner.info/locos/IC/aw_railcar.php |title=LNER Encyclopedia: The LNER Armstrong-Whitworth Diesel–Electric Railcars |access-date=19 June 2016}}</ref> the LMS both on [[LMS railcars|its own system]] and on that of its [[Northern Counties Committee#Railcars|Northern Irish subsidiary]], but development was curtailed by [[World War II]].

 

After nationalisation, [[British Rail]]ways (BR) revived the concept in the early 1950s. At that time, there was an urgent need to move away from expensive steam traction which led to many experimental designs using diesel propulsion and [[multiple unit]]s. The early DMUs proved successful and, under BR's [[History of rail transport in Great Britain 1948–1994#The Modernisation Plan|1955 Modernisation Plan]], the building of a large fleet was authorised. These BR ''first generation'' DMUs were built between 1956 and 1963.

BR required that contracts for the design and manufacture of new locomotives and rolling stock be split between numerous private firms, as well as BR's own workshops, while different regions laid down different specifications. The result was a multitude of different types, one of which was:

* 'Intercity' units, which were more substantially constructed and shared many features with contemporary hauled coaching stock. They were built for express services on important secondary routes on the [[Scottish Region of British Railways|Scottish]], [[North Eastern Region of British Railways|North Eastern]] and [[Western Region of British Railways|Western]] regions.{{Citation needed|date=July 2012}}

In 1960, British Railways introduced its [[British Rail Classes 251 and 261|Blue Pullman]] high-speed DEMUs.<ref name="Heaps, BR Diary: 1968–1977" >{{cite book |title=BR Diary: 1968–1977 |chapter=End of the Blue Pullmans |last=Heaps |first=Chris |isbn=978-0-7110-1611-8 |year=1988 |publisher=[[Ian Allan Publishing|Ian Allan]] |location=London |pages=66–67 }}</ref> These were few in number and relatively short-lived,<ref name="Heaps, BR Diary: 1968–1977" /> but they paved the way for the very successful [[InterCity 125]] or High Speed Train (HST) units, which were built between 1975 and 1982 to take over most principal express services on non-electrified routes.<ref>{{cite news |url=http://news.bbc.co.uk/onthisday/hi/dates/stories/october/4/newsid_2486000/2486817.stm |title=1976: New train speeds into service |publisher=BBC News |access-date=15 February 2011 |date=4 October 1976 |location=London}}</ref><ref name=NewOps>{{cite web |url=http://www.railwaysarchive.co.uk/documents/DoT_WP001.pdf |archive-url=https://web.archive.org/web/20071023114338/http://www.railwaysarchive.co.uk/documents/DoT_WP001.pdf |archive-date=23 October 2007 |url-status=live |title=New opportunities for the railways: the privatisation of British Rail |publisher=Railway Archive |page=8 |access-date=15 February 2011}}</ref>

These {{convert|125|mph|0|abbr=on}} trains run with a streamlined power car at each end and typically seven to nine intermediate trailer cars.<ref name="blue253">{{cite web |title=Class 253 High Speed Train |url=http://www.railblue.com/Class%20Headers%20v2.0/class_253V.2.htm |access-date=15 February 2011 |publisher=Railblue.co.uk |archive-date=15 July 2011 |archive-url=https://web.archive.org/web/20110715150731/http://www.railblue.com/Class%20Headers%20v2.0/class_253V.2.htm |url-status=dead }}</ref><ref name="blue254">{{cite web |title=Class 254 High Speed Train |url=http://www.railblue.com/Class%20Headers%20v2.0/class_254V.2.htm |access-date=15 February 2011 |publisher=Railblue.co.uk |archive-date=15 July 2011 |archive-url=https://web.archive.org/web/20110715150736/http://www.railblue.com/Class%20Headers%20v2.0/class_254V.2.htm |url-status=dead}}</ref> Although originally classified as DEMUs, the trailer cars are very similar to locomotive-hauled stock and the power cars were later reclassified as locomotives under [[British Rail Class 43 (HST)|Class 43]].<ref name=blue253 /><ref name=blue254 />  

HSTs started being replaced in 2017 but, as of October 2022, some are still in use.<ref>{{Cite web |title=Great Western Railway calls time on long-distance HSTs |url=https://www.railmagazine.com/news/fleet/great-western-railway-calls-time-on-long-distance-hsts |access-date=8 October 2022 |work=[[Rail (magazine)|RAIL]]}}</ref><ref>{{Cite web |title=Final batch of refurbed Inter7City trains handed over to ScotRail |url=https://www.railadvent.co.uk/2021/03/final-batch-of-refurbed-inter7city-trains-handed-over-to-scotrail.html |access-date=8 October 2022 |website=RailAdvent |date=13 March 2021}}</ref>

By the early 1980s, many of the surviving first generation units were reaching the end of their design life, leading to spiralling maintenance costs, poor reliability and a negative public image for the railway. A stop gap solution was to convert some services back to locomotive haulage, as spare locomotives and hauled coaching stock were available, but this also increased operating costs. Commencing in the mid 1980s, British Rail embarked upon its so called "Sprinterisation" programme, to replace most of the first generation DMUs and many locomotive-hauled trains with three new types of DMU:

* [[Pacer (British Rail)|Class 140–144 ''Pacer'']] [[railbus]]es, ultra-low-cost diesel–mechanical units (later converted to hydraulic) utilising four-wheeled chassis and lightweight bus bodywork, designed for provincial branch line and stopping services.

* [[Sprinter (British Rail)|Sprinter]] a type of diesel–hydraulic DMUs. These fall into three sub-groups; [[British Rail Class 150|Class 150]] ''Sprinter'' (for branch line/commuter service), [[British Rail Class 153|Class 153]] / [[British Rail Class 155|155]] / [[British Rail Class 156|156]] ''Super Sprinter'' (for longer cross country services), and [[British Rail Class 158|Class 158]] / [[British Rail Class 159|159]] ''Express Sprinter'' units (for secondary express services).

* [[Networker (train)|''Networker'']] diesel–hydraulic units, of {{brc|165}} ''Network Turbo'' (standard commuter version) and {{brc|166}} ''Network Express'' (for longer distance commuter services). These took over the remaining non-electric commuter services into London's {{rws|London Marylebone||Marylebone}} and {{rws|London Paddington||Paddington}} stations.{{Citation needed|date=July 2012}}

Following the [[impact of the privatisation of British Rail]] in the late 1990s, several other DMU types have been introduced:{{Citation needed|date=February 2012}}

* {{brc|168}} ''Clubman'' and {{brc|170}}/{{brc|171}}/{{brc|172}} [[Bombardier Turbostar|Bombardier ''Turbostar'']], a development of the earlier ''Networkers''. These were built by [[Adtranz]] and later [[Bombardier Transportation|Bombardier]] at [[Derby Litchurch Lane Works]]; they are the most numerous and widespread of the post-privatisation designs. They were opperated by [[Anglia Railways]], [[Central Trains]], [[Chiltern Railways]], [[London Midland]], [[London Overground Rail Operations]], [[Midland Mainline (train operating company)|Midland Mainline]] and [[ScotRail (National Express)|ScotRail]]. All are diesel-hydraulic except for the Class 172, which is diesel-mechanical.

* {{brc|175}} [[Alstom Coradia|Alstom ''Coradia'']] diesel-hydraulic multiple units were designed by [[Alstom]], as a rival to the Class 170 Turbostar, but are operated only by [[First North Western]]

* {{brc|180}} ''Adelante'' diesel-hydraulic multiple units were an Alstom design for express services, built only for [[First Great Western]]

* {{brc|185}} [[Siemens Desiro|Siemens ''Desiro'']], built by [[Siemens Mobility]] and introduced in 2006 by [[First TransPennine Express]]

* {{brc|195}}/{{brc|196}}/{{brc|197}} [[CAF Civity|CAF ''Civity'']], built by [[Construcciones y Auxiliar de Ferrocarriles|CAF]] for [[Arriva Rail North]], [[West Midlands Trains]] and [[Transport for Wales Rail|Transport for Wales]]

* {{brc|220}}/{{brc|221}}/{{brc|222}} ''[[Bombardier Voyager|Voyagers/Meridian]]'' diesel-electric multiple units, built by Bombardier in [[Bruges]] for [[Virgin Trains]], [[Virgin CrossCountry]] and Midland Mainline.

* {{brc|800}} and {{brc|802}} were built by [[Hitachi]] for [[Great Western Railway (train operating company)|Great Western Railway]], Hull Trains, [[London North Eastern Railway]] and [[TransPennine Express]]<ref>[http://www.railwaygazette.com/news/traction-rolling-stock/single-view/view/gwr-unveils-hitachi-iep-trainset.html GWR unveils Hitachi iep trainset] {{Webarchive|url=https://web.archive.org/web/20180425131316/http://www.railwaygazette.com/news/traction-rolling-stock/single-view/view/gwr-unveils-hitachi-iep-trainset.html |date=25 April 2018}} ''[[Railway Gazette International]]'' 30 June 2016</ref>

* {{brc|755}} [[Stadler FLIRT|Stadler ''FLIRT'']] are operated by [[Greater Anglia]]<ref>[http://www.railwaygazette.com/news/passenger/single-view/view/stadler-and-bombardier-to-supply-trains-for-abellio-east-anglia-franchise.html Stadler and Bombardier to supply trains for Abellio East Anglia franchise] ''Railway Gazette International'' 10 August 2016</ref>

* {{brc|769}} were converted by [[Brush Traction]] from {{brc|319}} [[electric multiple units]] for Arriva Rail North, Great Western Railway and [[KeolisAmey Wales]]<ref>[http://www.railwaygazette.com/news/traction-rolling-stock/single-view/view/gwr-to-lease-class-769-flex-trimode-trainsets.html GWR to lease Class 769 Flex trimode trainsets] {{Webarchive|url=https://web.archive.org/web/20180727201324/http://www.railwaygazette.com/news/traction-rolling-stock/single-view/view/gwr-to-lease-class-769-flex-trimode-trainsets.html |date=27 July 2018}} ''Railway Gazette International'' 20 April 2018</ref>

* {{brc|230}} were converted by [[Vivarail]] from [[London Underground D78 Stock]]<ref>{{cite web|url=http://www.railtechnologymagazine.com/Interviews/they-dont-make-trains-like-this-anymore |title='They don't make trains like this anymore' |website=Railtechnologymagazine.com |access-date=18 July 2019}}</ref> for [[West Midlands Trains]]<ref>{{cite web |url=https://www.railway-technology.com/news/west-midlands-trains-puts-first-class-230-d-train-in-service/ |title=West Midlands Trains puts first Class 230 D Train in service |date=23 April 2019 |work=Railway Technology |access-date=18 July 2019}}</ref> and Transport for Wales<ref>{{cite web |url=https://www.dailypost.co.uk/business/business-news/new-north-wales-trains-slower-15116084 |title=New North Wales trains will be slower than Arriva ones BUT journey times will fall |last=Hughes |first=Owen |date=10 September 2018 |work=Daily Post |access-date=18 July 2019}}</ref> After the collapse of Vivarail in 2022, the West Midlands units were withdrawn from service.<ref>{{cite news |last1=Dobell |first1=Malcolm |title=Class 150 units back on the Marston Vale line |url=https://www.railengineer.co.uk/class-150-units-back-on-the-marston-vale-line/ |access-date=11 August 2024 |work=Rail Engineer |date=19 December 2023}}</ref>

[[File:otrain.jpg|thumb|Two [[Bombardier Transportation|Bombardier]] [[Talent (train)|Talent]] low-floor DMUs on O-Train [[Line 2 (O-Train)|Line 2]] in [[Ottawa]], Canada]]

* [[O-Train]] [[Line 2 (O-Train)|Line 2]] in [[Ottawa, Ontario]] uses European-standard [[Alstom Coradia LINT]] (previously [[Bombardier Talent]]) DMUs on conventional railway tracks under a specific safety agreement with [[Transport Canada]].<ref name=":1">{{Cite web |last=Cornett |first=John |date=4 May 2026 |title=Alstom Coradia LINT |url=https://www.trains-and-railroads.com/alstom-coradia-lint |url-status=live |archive-url=https://web.archive.org/web/20260311062015/https://www.trains-and-railroads.com/alstom-coradia-lint |archive-date=11 Mar 2026 |access-date=4 May 2026 |website=Trains and Railroads}}</ref>

[[File:Tren urbano de Costa Rica.jpg|thumb|An Apollo 2400 DMU in service in Costa Rica]]

Costa Rica has purchased several Apolo 2400 series DMU railcars from the former narrow gauge operator in Spain, which are run in commuter service.<ref>{{cite web |url=http://news.co.cr/six-commuter-trains-purchased-travel-easier-in-san-jose-costa-rica/8268/ |title=Six Commuter Trains Purchased: Travel Easier in San Jose Costa Rica – Costa Rica Star News |date=16 June 2012 |access-date=19 June 2016}}</ref>

A type of DMU is the [[Budd Rail Diesel Car]] (RDC). The RDC was a single passenger car, with two diesel engines and two sets of controls.<ref>{{cite journal |last1=Franz |first1=Justin |last2=Vondrak |first2=Otto M. |title=RDC Update |journal=Railfan & Railroad |issue=September 2020}}</ref>

DMU systems must be FRA-compliant to be permitted on freight rail corridors. The [[Federal Railway Administration]] has mandated higher [[Coupler (railway)|coupling strength]] requirements than European regulators, effectively prohibiting the use of lighter weight European-style [[inter-city rail]] DMUs on main line railways without timesharing with freight operations or special waivers from the FRA. This has greatly restricted the development of DMUs, as no other country requires the much heavier FRA compliant vehicles and no export market for them exists.<ref>{{cite web|url=https://sccrtc.org/wp-content/uploads/2010/09/Section3.pdf|title=Diesel Multiple Unit Assessment |date=September 2010 |website=Sccrtc.org |access-date=26 June 2023}}</ref>

* Since February 2009, [[TriMet]] is using FRA-compliant [[Colorado Railcar DMU]]s for its rush-hour [[WES Commuter Rail]] service, a suburb-to-suburb line between [[Beaverton, Oregon|Beaverton]] and [[Wilsonville, Oregon]]. The opening of the line was delayed from autumn 2008 to early 2009, due to delays in supplying the vehicles.<ref name="time travel">{{Cite news |last=Craghead |first=Alexander |date=March 2011 |title=Time Travel in Oregon? TriMet Turns to the Venerable Budd RDC |work=[[Railfan & Railroad]] |url=http://railfan.com/extraboard/rf_extra_mar2011.php |url-status=dead |access-date=2021-03-24 |archive-url=https://web.archive.org/web/20160314105748/http://railfan.com/extraboard/rf_extra_mar2011.php |archive-date=March 14, 2016}}</ref> TriMet also has four refurbished former [[Alaska Railroad|Alaska RR]]<ref name="time travel"/> and [[Trinity Railway Express]]<ref name="taut-2017oct">{{Cite magazine |date=October 2017 |title=Worldwide Review [regular news section] |magazine=[[Tramways & Urban Transit]] |page=394 |issn=1460-8324}}</ref> RDCs, as backup trainsets for when one or more Colorado Railcar DMUs is out of service.

* In [[Denton County]], Texas, [[Denton County Transportation Authority|DCTA]] also uses [[Stadler GTW]] cars to operate its [[A-train (Texas)|A-train]] service. DCTA has secured from the FRA the first-ever alternative vehicle technology waiver to use these cars on active freight corridors.<ref>{{cite news |last=Lewis |first=BJ |title=DCTA gets go-ahead to use Stadler cars |url=http://www.dentonrc.com/local-news/local-news-headlines/20120605-dcta-gets-go-ahead-to-use-stadler-cars.ece|access-date=6 June 2012 |newspaper=Denton Record-Chronicle |date=5 June 2012 |archive-url=https://web.archive.org/web/20120609012338/http://www.dentonrc.com/local-news/local-news-headlines/20120605-dcta-gets-go-ahead-to-use-stadler-cars.ece|archive-date=9 June 2012 |url-status=dead}}</ref>

[[File:TEXRail Stadler FLIRT DFW Airport Nov 2019.jpg|thumb|A Stadler FLIRT, owned by TEXRail]]

* [[TEXRail]] in [[Tarrant County, Texas]] is a commuter rail line operated by [[Trinity Metro]], which uses Stadler FLIRT DMUs. The vehicles are FRA Alternate Compliant.<ref>{{cite magazine |title=TEX Rail commuter line opens |access-date=1 April 2019 |newspaper=Railway Gazette |date=10 January 2019 |url=https://www.railwaygazette.com/news/passenger/single-view/view/tex-rail-commuter-line-opens.html |archive-date=2 April 2019 |archive-url=https://web.archive.org/web/20190402040531/https://www.railwaygazette.com/news/passenger/single-view/view/tex-rail-commuter-line-opens.html |url-status=dead}}</ref> The line has nine stops, with termini at [[DFW Airport/Terminal B station|DFW Airport]] and [[T&P Station]].<ref>{{cite web |title=TEXRail Map |access-date=1 April 2019 |website=Trinity Metro |url=https://ridetrinitymetro.org/texrail/maps/}}</ref>

* [[NJ Transit]] operates the [[River Line (NJ Transit)|River Line]] from [[Camden, NJ]] to [[Trenton, NJ]], every 15 minutes during peak hours and every 30 minutes at other times. It uses modified [[Stadler GTW]] trains of one or two cars. The line is classified as [[light rail]] because it utilises imported European-made DMUs that do not meet [[Federal Railway Administration|FRA]] crash guidelines. The cars may not operate with the [[freight rail]] service that shares the line, so evening operating hours are restricted to Saturday nights. This line currently carries over 7,500 passengers on a typical weekday, exceeding expectations.

* [[North County Transit District|NCTD]] operates the [[Sprinter (rail service)|Sprinter]] line using [[Siemens Desiro|Desiro Classic]] DMUs built by [[Siemens Mobility|Siemens]]. Opened March 2008, The line operates every half-hour daily, except limitations in the morning and at night on Saturday, Sunday and on holidays. The line runs from [[Oceanside, California]], where transfer is possible with [[Coaster (rail service)|Coaster]] [[commuter rail]] service to [[San Diego]], to [[Escondido, California]]. Like the NJT River Line, it is classified as light rail due to the use of European made DMUs, but does not run at a more typical light rail frequency.

* The [[eBART]] expansion of the [[Bay Area Rapid Transit]] system implements [[Stadler GTW]] DMU train service from [[Pittsburg/Bay Point station]] east along the Highway 4 corridor to the town of [[Antioch station (BART)|Antioch]]. Future expansions in this direction could also connect the [[eBART]] service to Oakley, Brentwood, Byron, and beyond to Tracy and Stockton. The DMU system was chosen as a less-expensive alternative to the existing third-rail BART design.<ref name="bart">{{cite web |url=http://www.bart.gov/news/articles/2009/news20090427.aspx |title=BART moves forward with $1 billion in extension projects |website=Bart.gov |access-date=19 June 2016}}</ref> Service began on 25 May 2018.<ref name="ebart">{{cite web |url=https://www.bart.gov/about/projects/ecc |title=BART to Antioch: East Contra Costa BART Extension |access-date=27 March 2019}}</ref>

* [[Arrow (rail service)|Arrow]] utilises Stadler FLIRT trainsets along its service route in [[Redlands, California]].

* [[Dallas Area Rapid Transit]] has rebuilt part of the [[St. Louis Southwestern Railway]] as the [[Silver Line (DART)|Silver Line]], using Stadler FLIRT units.

* The [[Los Angeles County Metropolitan Transportation Authority]] approved an allocation of $250,000 for a feasibility study of DMUs for "future transportation options for the region" on 5 July 2006 (Ara Najarian, Metro Board Member).<ref>{{cite web |url=http://ebb.metro.net/news_info/2006/metro_116.htm|title=July 2006 Metro to Fund Implementation Study on a Regional Connector Through Glendale and Burbank |website=Ebb.metro.net|access-date=2017-02-01}}{{dead link|date=April 2018 |bot=Redalert2fan |fix-attempted=yes }}</ref>

* [[Chicago]]'s commuter rail line, [[Metra]], is studying the use of DMUs on its newly proposed lines ([[Suburban Transit Access Route (Metra)|STAR line]], [[SouthEast Service (Metra)|SES)]]. They claim these DMUs will have better acceleration, be more fuel efficient, and seat more customers than the current diesel locomotive and double decker railcars that are currently in use.<ref name="metra">{{cite web |url=http://metraconnects.metrarail.com |title=Coming Soon page |access-date=19 June 2016}}</ref>

* Seattle area – The Central Puget Sound's regional transit agency [[Sound Transit]], along with the [[Puget Sound Regional Council]] evaluated the feasibility of both DMU and diesel locomotive technology for operation in the Eastside BNSF Corridor in response to a state legislative request. The Eastside BNSF corridor runs from the City of Snohomish in the north to Renton in the south of the metro area. Sound Transit has no plans to operate passenger rail service in the eastside BNSF corridor, but has committed limited funds to provide capital improvements in the event another public or private operator proposes to operate the service.<ref name="psrc">{{cite web |url=http://www.psrc.org/about/pubs/bnsf/fullreport/bnsf |title=BNSF Eastside Commuter Rail Feasibility Study |access-date=21 January 2010 |url-status=dead |archive-url=https://web.archive.org/web/20100211035302/http://www.psrc.org/about/pubs/bnsf/fullreport/bnsf/ |archive-date=11 February 2010}}</ref>

* The [[Long Island Rail Road]], the busiest commuter railroad in the United States, is exploring the possibility of operating DMUs on some of its lesser traveled routes in non-electrified territory (on the [[Montauk Branch|Montauk]], [[Greenport Branch|Greenport]], [[Port Jefferson Branch|Port Jefferson]] and [[Oyster Bay Branch|Oyster Bay]] branches), where operation of its current fleet of [[C3 (railcar)|C3]] bilevel railcars pulled by [[EMD DE30AC and DM30AC|DE30AC/DM30AC]] locomotives is uneconomical and inefficient.

* A proposal to use DMUs on Boston's [[Fairmount Line]] was initially approved, but was cancelled in 2016.<ref>{{cite news |url=https://www.baystatebanner.com/2016/02/10/fairmount-line-setback-no-dmus-says-mbta/ |title=Fairmount line setback: No DMUs says MBTA |first=Jule |last=Pattison-Gordon |date=10 February 2016 |publisher=Bay State Banner |access-date=20 November 2019}}</ref>

* [[NJ Transit]]'s [[Passaic–Bergen–Hudson Transit Project]] is studying the re-introduction passenger service on a portion of the [[New York, Susquehanna and Western Railway]] (NYSW) right-of-way in [[Passaic County, New Jersey|Passiac]], [[Bergen County, New Jersey|Bergen]] and [[Hudson County, New Jersey|Hudson]] counties using newly built, FRA-compliant diesel multiple units.<ref name=NJTPBH>{{cite web |url=https://www.njtransit.com/passaic-bergen-hudson-transit-project|title=Passaic Bergen Hudson Transit Project |website=Projects & Reports |publisher=NJ Transit |access-date=26 February 2021}}</ref>

 

===Asia and Australasia===

DMUs were first introduced in the mid-20th century for use on quiet branch lines that could not justify a locomotive-hauled service. Today, DMUs are widely used throughout Australia's southern states:

* Western Australia's [[Transwa]] operates the ''[[The Prospector (train)|Prospector]], [[AvonLink]]'' and ''[[Australind (train)|Australind]]'' on medium- and long-distance country services.

[[File:Bangladesh Railway, Komlapur Railway Station.jpg|thumb|A DEMU train (right) at [[Kamalapur railway station]], Dhaka]]

 

Chinese-manufactured (CNR Tangshan) DEMU was introduced in Bangladesh from 25 May 2013. DEMU is the country's first-ever commuter train service starting its journey on the Chittagong–Faujdarhat line. They also operate on the [[Chittagong Circular Railway]] and on the [[Bangladesh Railway]]'s service between [[Dhaka]] and [[Narayanganj]].<ref>{{cite web |url=http://bdnews24.com/bangladesh/2013/05/25/demu-trains-begin-debut-run-in-ctg |title=DEMU trains begin debut run in Ctg |website=[[Bdnews24.com]] |access-date=26 May 2013}}</ref> However, these trains faced reliability issues soon after the final delivery in 2015, with all 20 trains becoming inoperable beyond 2018.<ref name="SomoyNews">{{Cite web |author=Somoy National Desk |title=Railway to sell Tk 650cr worth of DEMU trains as scrap |url=https://en.somoynews.tv/news/2025-01-20/WZ7HMI1v |access-date=28 January 2025 |work=Somoy News}}</ref>

 

In 2020, technicians from Bangladesh Railway were able to repair one of the inoperative trains to working condition. However, the proposed project to repair the rest of the trains were deemed to be too expensive in the long run.<ref>{{Cite web |date=2022-10-20 |title=Another wasteful railway project |url=https://www.thedailystar.net/opinion/editorial/news/another-wasteful-railway-project-3147811 |access-date=28 January 2025 |work=The Daily Star}}</ref> By January 2025, after 10 years of service, Bangladesh Railway announced its intention to sell the DEMU trains for scrap.<ref name="SomoyNews" />

 

The [[China Railway NZJ]] was China's first double-decker SMUA is an ideal medium- and short-distance rail transport vehicle. It was independently developed and manufactured by [[CRRC Tangshan|Tangshan Works]] in 1998 and put into operation between [[Nanchang]] and [[Jiujiang]] in June of that year.<ref name=":0">{{Cite web |title=铁道馆_中国科普博览 |url=https://www.kepu.net.cn/gb/technology/railway/railway_engine/200402030022.html |access-date=24 June 2025 |website=Kepu.net.cn}}</ref>

 

The [[China Railway NYJ1]] was the country's first hydraulic transmission DMU class; it was developed by [[CRRC Qingdao Sifang|Qingdao Sifang]] at the end of 1998; it was placed into operation between [[Nanchang]] and [[Jiujiang]], and [[Nanchang]] and [[Ganzhou]] in February 1999.<ref name=":0" />  

The [[China Railway NZJ1]] "New Dawn" higher-speed [[Bilevel rail car|double-decker]] DMU was jointly developed by [[CRRC Qishuyan|Qishuyan Works]] and [[CRRC Nanjing Puzhen|Nanjing Puzhen Works]] in August 1999; it was placed into commercial operation on the [[Shanghai-Nanjing Railway]] in October of that year.<ref name=":0" />

The [[China Railway NDJ3]] "Great Wall", previously labelled the "Harmony Great Wall", is the only [[higher-speed rail|higher-speed]] DMU that is still operating in China. It was first designed to be used for passenger transport in the [[2008 Olympic Games]] and has become a mature technology platform, with export orders to Nigeria, despite initial flaws related to overheating of electrical cables in the power car.

[[File:CJ5-0505@BCR (20160905093550).jpg|thumb|right|[[CJ5 (DEMU)]], used by the [[Xi'an–Huyi railway]]]]

On 14 January 2014, [[CRRC Changchun Railway Vehicles]] announced that hybrid-[[electric multiple units]] were put into production. At the end of 2014, the first batch of hybrid EMUs, one train each with battery-catenary power supply (EEMU) and catenary power supply-internal combustion engine (DEMU), rolled off the assembly line in Changchun. From 2016 to 2020, the vehicles were tested in Hohhot and Beijing Academy of Railway Sciences.

 

DMUs (particularly DEMUs) are widely used in India. DEMUs in India are used in both the eight-coach format and the four-coach format. These trains replaced many (up to 10 car) trains with a [[WDM-2]] or [[WDM-3A]] locomotive in the middle. These old trains had the locomotive controls duplicated in the Driving Trailer coach and all the actuation information reaching the locomotive through thin communication lines. This was called a ''push-pull'' train. The longest running such service operated between Diva – Bhiwandi Road and Vasai Road; it was recently converted into an [[MEMU]] train service in 2018.

* First generation DMU:

** Rated power was 700 HP and had either three or six coaches.

** Transmission was Voith-hydraulic.  

** Max speed 100&nbsp;km/h.

** Made at first at ICF and then at [[Rail Coach Factory|RCF]].

** Rated power is 1400 HP and have eight coaches.  

** Max speed is 105&nbsp;km/h.  

** Transmission is DC electric.  

** Made at ICF and [[Rail Coach Factory|RCF]].

** Rated power is 1,600 HP and have ten coaches.  

** Max speed is 110&nbsp;km/h.  

** Transmission is AC electric.  

** Made at [[Integral Coach Factory|ICF]].

[[File:DC283 hokuto 001.jpg|thumb|right|A JR Hokkaido [[KiHa 283]] [[Tilting train|tilting DMU]] on [[Hakodate Main Line]]]]

In Japan, where gasoline-driven railbuses (on small private lines) and railmotors ([[Kihani 5000]] of the [[Japanese National Railways|national railways]]) had been built since the 1920s, the first two streamlined DMUs came in service in 1937, class [[Kiha 43000]] (キハ43000系).<ref>{{cite web|url=http://blogs.yahoo.co.jp/h53001126/4568133.html|title=キハ４３０００の資料 – しるねこの微妙な生活／浮気心あれば水心!?|access-date=19 June 2016 |archive-date=25 June 2016 |archive-url=https://web.archive.org/web/20160625140247/http://blogs.yahoo.co.jp/h53001126/4568133.html |url-status=dead}}</ref>

The service of several hundreds of diesel railcars and DMUs started in 1950s, following the improvement of fuel supply that was critical during [[World War II]].<ref>{{cite web |url=http://homepage3.nifty.com/EF57/r.museum/TP-flame.html |title=The Railway Museum in Saitama |access-date=19 June 2016 |url-status=dead |archive-url=https://web.archive.org/web/20160913212003/http://homepage3.nifty.com/EF57/r.museum/TP-flame.html |archive-date=13 September 2016}}</ref>

 

The [[Keretapi Tanah Melayu]] (KTM) has a total of 13 DMU [[KTM Class 61]] ordered from [[CRRC]] for the West Coast Line and are assembled locally at CRRCs Batu Gajah factory from 2016 to 2020. The service began 1 September along the Gemas-Kuala Lipis-Tumpat route, replacing old non-automotive stock.<ref>{{cite web|url=https://www.railjournal.com/passenger/commuter-rail/crrc-dmu-test-malaysia/ |title=New CRRC DMU on test in Malaysia |date=16 May 2019}}</ref>

 

Even without active inter-city rail services in the present day, DMUs are still used on the [[PNR Metro Commuter Line]] in [[Metro Manila]] and the Bicol Commuter service in the [[Bicol Region]].<ref name="pea">{{Cite journal|last1=Peadon|first1=Brad|title=April 2020|volume=3|journal=Philippine National Railways Rolling Stock Update|publisher=Philippine Railways Historical Society}}</ref> Three generations of DMUs are in use: second-hand DMUs handed over by [[East Japan Railway Company|JR East]] such as the [[KiHa 35]], [[KiHa 52|52]] and [[KiHa 59 series#Philippine National Railways|59]] series originally built in the 1960s and acquired in the early 2010s,<ref name="jr">{{Cite book |author=寺本光照 |title=国鉄・JR関西圏近郊電車発達史 大阪駅140年の歴史とアーバンネットワークの成立ち |date=2014 |page=73 |publisher=JTBパブリッシング |series=キャンブックス |language=ja |isbn=978-4-533-09794-2}}</ref><ref>{{cite web |url=https://railf.jp/news/2019/12/10/170000.html |title=フィリピン国鉄 KIHA59「KOGANE」が営業運転に復帰 |trans-title=Philippine National Railways KIHA59 "KOGANE" returns to commercial operation |date=10 December 2019 |work=Japan Railfan Magazine Online |publisher=Koyusha Co., Ltd. |location=Japan |language=ja |access-date=10 December 2019 |archive-url=https://archive.today/20191210102501/https://railf.jp/news/2019/12/10/170000.html |archive-date=10 December 2019 |url-status=live }}</ref> the [[PNR Hyundai Rotem DMU|Rotem DMU]]s of 2009 built by [[South Korea|Korean]] manufacturer [[Hyundai Rotem]],<ref>{{cite web |url=https://www.hyundai-rotem.co.kr/Eng/Business/Rail/Business_Record_View.asp?brid=228 |title=Railway Systems-Project Record View |website=hyundai-rotem.co.kr |access-date=25 December 2018 |archive-date=21 April 2021 |archive-url=https://web.archive.org/web/20210421053328/https://www.hyundai-rotem.co.kr/Eng/Business/Rail/Business_Record_View.asp?brid=228 |url-status=dead }}</ref> and the [[PNR 8000 class|8000]] and [[PNR 8100 class|8100 classes]] built by [[Indonesia]]n firm [[Industri Kereta Api|PT INKA]].<ref>{{cite web |url=https://ph.news.yahoo.com/two-more-pnr-trainsets-arrive-121543715.html |title=Two more PNR trainsets arrive in PH |website=ph.news.yahoo.com|access-date=12 February 2020}}</ref><ref>{{cite news |url=https://manilastandard.net/news/national/312315/pnr-unveils-2-brand-new-diesel-multiple-unit-trains-bought-from-indonesia.html |archive-url=https://web.archive.org/web/20231212031126/https://manilastandard.net/news/national/312315/pnr-unveils-2-brand-new-diesel-multiple-unit-trains-bought-from-indonesia.html |url-status=dead |archive-date=12 December 2023 |title=PNR unveils 2 brand new diesel multiple unit trains bought from Indonesia |website=Manila Standard|access-date=3 February 2020}}</ref>

 

[[Korail]] used to operates many DMUs. The Diesel Hydraulic Car (DHC), which made its debut for the [[1988 Seoul Olympics]], was able to reach speeds up to {{convert|150|km/h|0|abbr=on}} and operated [[Saemaul-ho]] services. These trains were retired in 2008.{{Citation needed|date=January 2013}}

DMUs were first introduced to [[Sri Lanka Railways]] in 1940. The aim of this was to connect minor railway stations and secondary stops on the main line not served by express trains.<ref>{{Cite web |url=https://apps.who.int/iris/rest/bitstreams/1081775/retrieve |title=Archived copy |access-date=24 December 2020 |archive-date=22 October 2022 |archive-url=https://web.archive.org/web/20221022142133/https://apps.who.int/iris/rest/bitstreams/1081775/retrieve |url-status=dead}}</ref>

DMUs are now usually used on the [[Taiwan Railway Administration]] [[Hualien–Taitung Line]], [[North-Link Line]], [[South-Link Line]]. DMUs in Taiwan are classified as Class DR:

* [[DR2700 series|Class DR2700]] – built by [[Tokyu Car Corporation]] in 1966; was the fastest train on the [[West Coast line (Taiwan)|West Coast line]]

* [[DR2800 series|Class DR2800]] – built by Tokyu Car Corporation in 1982 and 1984{{Citation needed|date=February 2014}}

* [[DR2900 series|Class DR2900]]

* [[DR3000 series|Class DR3000]]

* [[DR3100 series|Class DR3100]].

====Thailand====

 

The State Railway of Thailand [[State Railway of Thailand ASR class|ASR class]] is a DMU operated by the [[State Railway of Thailand]]. Built by [[British Rail Engineering Limited]] at [[Derby Litchurch Lane Works]] in England, it is based on the {{brc|158}}. Twenty carriages were built in 1990/91. All were painted in the same [[Regional Railways]] livery as the Class 158s:

* Numbers 2113 – 2120 (no cockpit) 8 Unit.

* [[Alstom]], France

* [[British Rail Engineering Limited]], Great Britain (1962–1980s)

* [[British Rail]]ways, Great Britain (1950s–1962)

* [[Colorado Railcar]], US (Rader Railcar 1988–1997, Colorado Railcar 1997–2008, US Railcar<ref>{{cite web |url=http://www.usrailcar.com/ |title=US Railcar |website=usrailcar.com |access-date=17 September 2009 |archive-date=18 October 2009 |archive-url=https://web.archive.org/web/20091018175709/http://www.usrailcar.com/ |url-status=dead }}</ref> 2009–present)

* [[Siemens Mobility]], Germany

* [[TÜVASAŞ]] of [[Adapazarı]], Turkey.