The British Rail Class 172 is a British

diesel multiple unit A diesel multiple unit or DMU is a multiple-unit train powered by on-board diesel engines. A DMU requires no separate locomotive, as the engines are incorporated into one or more of the carriages. Diesel-powered single-unit railcars are also ...

(DMU) passenger train built by

Bombardier Transportation Bombardier Transportation was a Canadian-German rolling stock and rail transport manufacturer, headquartered in Berlin, Germany. It was one of the world's largest companies in the rail vehicle and equipment manufacturing and servicing industry ...

's Derby Litchurch Lane Works for use on inner-suburban passenger services. The class is currently operated by

West Midlands Railway West Midlands Trains (WMT) is a train operating company in the United Kingdom. It operates passenger trains on the West Midlands franchise between London and the English Midlands under two trade names: West Midlands Railway (WMR) (within the ...

. The Class 172 is part of the

Turbostar The Bombardier Turbostar (sold as the ADtranz Turbostar until 2001) is a family of diesel multiple unit (DMU) passenger trains that was built by ADtranz and later Bombardier Transportation at Derby Litchurch Lane Works in the United Kingdom be ...

range, similar to the Class 168, Class 170 and Class 171.

Technical details and variants

There are four sub-classes: * Class 172/0 - two-car, non-gangway train sets with

for use on the Snow Hill Lines and

Leamington Spa Royal Leamington Spa, commonly known as Leamington Spa or simply Leamington (), is a spa town and civil parish in Warwickshire, England. Originally a small village called Leamington Priors, it grew into a spa town in the 18th century following ...

Nuneaton Nuneaton ( ) is a market town in the borough of Nuneaton and Bedworth in northern Warwickshire, England, close to the county border with Leicestershire and West Midlands County.OS Explorer Map 232 : Nuneaton & Tamworth: (1:25 000) : Nuneaton ...

, originally with London Overground. * Class 172/1 - two-car, non-gangway train sets with

for use on the Snow Hill Lines and

, originally with

Chiltern Railways Chiltern Railways, formally The Chiltern Railway Company Limited, is a British train operating company that has operated the Chiltern Railways franchise since July 1996. Since 2009, it has been a subsidiary of Arriva UK Trains. Chiltern Rail ...

. * Class 172/2 - two-car, gangway train sets with

for use on the Snow Hill Lines and

. * Class 172/3 - three-car, gangway train sets with

for use on the Snow Hill Lines and

. The 172/0s and 172/1s resemble the existing ''Turbostar'' trains in not having end gangways. These trains have a maximum speed of . The Class 172/2s and 172/3s used by West Midlands Trains resemble the , , and ''Electrostars'' by having end gangways to allow access between units. These trains have a maximum speed of . The 172/0 were built without any onboard toilets in common with other London Overground stock. Toilets were retrofitted when transferred to WMT. The Class 172s feature BSI (Bergische Stahl Industrie - Autocoupler) couplers which allow them to work in multiple with , units and most other units with the same coupler.

Differences from other Turbostars

The Class 172 trains are lighter than other Turbostars due to use of the Bombardier FLEXX-ECO bogies - a development of the B5000 bogies used on the Class 220 ''Voyager'' DEMU trains, rather than the previous 'Series 3' bogies. Another difference is that they have half-height airdams as opposed to the more standard full height airdams. They also differ from earlier Turbostars in having mechanical transmission rather than

hydraulic Hydraulics (from Greek: Υδραυλική) is a technology and applied science using engineering, chemistry, and other sciences involving the mechanical properties and use of liquids. At a very basic level, hydraulics is the liquid counte ...

- gear changes can be distinctly heard as the trains accelerate and decelerate.

Differences from Class 150

Class 172s have fewer seats than the s they replaced, but greater overall capacity due to the increased room for standing passengers as well as wider aisles intended to speed boarding and alighting and reduce waiting time in stations. The trains are air-conditioned and have no opening windows, unlike the Class 150s. The Class 172 is designed to a body length, as opposed to the length used on previous Class 150 Sprinter DMUs - increasing capacity.

Operators

West Midlands Railway

Leamington Spa - WMT 172006 Nuneaton service

West Midlands Trains operate a total of 39 two-car and three-car units, 27 of which had been ordered by predecessor London Midland, who originally planned for them to enter service by the end of 2010 on services to and from Birmingham Snow Hill, replacing Class 150s. The original West Midlands Trains sets have revised front ends with end gangways which make the trains look like the Electrostar family of units. From 1 September 2011, the units started operating on the Snow Hill Lines with some weekend work from Birmingham - Hereford. When first used in service, the units suffered a fault with engine vibration in the passenger cabin, which has since been rectified. The units were originally meant to replace all of the Class 150s, however three were retained. Between late 2018 and early 2019 the London Overground 172/0s moved to West Midlands Railway, operated by West Midlands Trains, to replace the remaining Class 150s for transfer to Arriva Rail North and Class 153s operating on the Coventry–Leamington line and the Coventry to Nuneaton line as well as providing extra capacity on the Snow Hill Lines.

Former operators

London Overground

Gospel Oak railway station MMB 01 172005

London Overground London Overground (also known simply as the Overground) is a suburban rail network serving London and its environs. Established in 2007 to take over Silverlink Metro routes, (via archive.org). it now serves a large part of Greater London as w ...

operated eight two-car Class 172s on the Gospel Oak to Barking line, replacing the old stock. The units were originally meant to be in service from February 2010, but due to production issues and then what were thought to be exhaust problems (which proved to be a false alarm), the trains entered service only in July 2010, and at reduced capacity due to staff training problems. By December 2010 the whole fleet was in service, allowing the Class 150s to be cascaded to

First Great Western Great Western Railway (GWR) is a British train operating company owned by FirstGroup FirstGroup plc is a British multi-national transport group, based in Aberdeen, Scotland.Angel Trains. The success of London Overground's operation of the Gospel Oak to Barking Line meant that the 2-car Class 172s eventually proved insufficient in terms of capacity. Initially, there were plans to replace them with 3- or 4-car DMUs. Later, the government announced plans to electrify the line, with the intention that TfL would procure a new fleet of 4-car EMUs ( Class 710) for use on both this route and the inner-suburban routes from Liverpool Street, taken over by London Overground from 2015. Electrification was completed in February 2018 (later than the original target of June 2017) and as of June 2018 the Class 172 units were set to be replaced by Class 710 EMUs from November 2018, although this did not happen as planned. They were temporarily replaced by Class 378s redeployed from other parts of the London Overground network and moved to West Midlands Trains in March 2019. By May 2019, Class 710s started to be introduced into service.

Chiltern Railways

obtained four two-car trains in the same order as that of London Overground to supplement the Class 168 on its routes from

London Marylebone Marylebone station ( ) is a Central London railway terminus and connected London Underground station in the Marylebone area of the City of Westminster. On the National Rail network it is also known as London Marylebone and is the southern ...

, originally due to be delivered from late 2010. They did not have the

tripcock Part of a railway signalling system, a train stop, trip stop or tripcock (sometimes called a tripper) is a train protection device that automatically stops a train if it attempts to pass a signal when the signal aspect and operating rules pr ...

safety system installed—unlike the rest of the Chiltern Railways fleet—as the design of the bogie being used (based on the B5005 found on Class 220 ''Voyager'' and Class 222 ''Meridian'' trains) meant there was no place for the brackets to be mounted. Thus, they were not able to operate on the Aylesbury via Amersham line whilst the current signalling system was in place unless running in multiple with other units on both the front and rear ends, which were fitted with a tripcock. In 2021, all of Chiltern Railways Class 172s were leased to West Midlands Trains for use with their existing Class 172 fleet pending the delivery of Class 196 "Civity" trains."CHILTERN ‘172s’ MOVE TO WEST MIDLANDS"
''www.modernrailways.com''. 20 May 2021. Retrieved 30 January 2022. It was later announced that the Class 172/1 fleet will not be returning to Chiltern once the Class 196s enter service with WMT.

Introduction into service

In late 2007 and early 2008, orders were placed with Bombardier by two rolling-stock leasing companies to purchase a number of Class 172 ''Turbostar'' trains. In December 2007, Porterbrook ordered 15 three-car and 12 two-car trains for London Midland for delivery in 2010. In January 2008, Angel Trains, on behalf of London Overground and Chiltern Railways, ordered 12 two-car trains for delivery, which would have been delivered during 2009. But difficulties over deliveries by Bombardier's suppliers led to delays in filling the Class 377 and 378 ''Electrostar'' orders, with subsequent knock-on delays for building the Class 172 sets. Work began at the end of 2009 after the freeing-up of one of Bombardier's production lines following completion of the Class 377 order for First Capital Connect. Eight 172/0 units were built for London Overground. Testing of the first batch of new units, the 172/0 sets for London Overground, commenced in March 2010 on the

Old Dalby Test Track The Old Dalby Test Track is a railway in the United Kingdom which is used for testing new designs of trains and railway infrastructure. It runs between Melton Mowbray, Leicestershire and Edwalton, on the course of the Midland Railway's route bet ...

. All units were subsequently delivered to Willesden Train Maintenance Depot (TMD). All eight 172/0 units entered service for London Overground. These were originally restricted to a top speed of as opposed to their intended design speed of , as it was thought there was a fault with the exhaust system requiring modifications to the original design and the already procured units. It was expected that units for London Midland and Chiltern would be delayed by a further 6–12 months. However, it transpired that the exhaust emission testing had been flawed and that there were no major problems with the units or the original design. Production therefore continued as planned with a slight delay. The four Chiltern Railways units entered service during summer 2011 and left for West Midlands Railway in spring 2021.

Further potential orders

In 2008,

First Great Western Great Western Railway (GWR) is a British train operating company owned by FirstGroup FirstGroup plc is a British multi-national transport group, based in Aberdeen, Scotland.Department for Transport The Department for Transport (DfT) is a department of His Majesty's Government responsible for the English transport network and a limited number of transport matters in Scotland, Wales and Northern Ireland that have not been devolved. The ...

to re-equip its

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via

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services with 11 new four-car DMUs which would potentially allow the existing Class 158 ''Express Sprinter'' trains to be transferred to other services. According to the West of England Partnership, these were likely to be "similar to Class 170s", suggesting that they might be Class 172 ''Turbostars''. The Government announced in December 2008 that Bombardier, with its ''Turbostar design'', was one of the pre-qualified bidders for the first 200 DMU vehicles of its planned 1300 new carriages. These new trains were intended for services operated by

First Great Western Great Western Railway (GWR) is a British train operating company owned by FirstGroup FirstGroup plc is a British multi-national transport group, based in Aberdeen, Scotland.First TransPennine Express and Northern Rail. However, with the announcement of the electrification schemes in the North West and on the

Great Western Main Line The Great Western Main Line (GWML) is a main line railway in England that runs westwards from London Paddington to . It connects to other main lines such as those from Reading to Penzance and Swindon to Swansea. Opened in 1841, it was the o ...

, the DMU order was cancelled, with the needs of the

train operating companies A train operating company (TOC) is a business operating passenger trains on the railway system of Great Britain under the collective National Rail brand. TOCs have existed since the privatisation of the network under the Railways Act 1993. T ...

planned to be met by transfers of existing stock. Arriva Rail North and TransPennine Express did subsequently obtain new DMU and bi-mode rolling stock, although this was produced by CAF and Hitachi and also in higher quantities - 58 CAF DMUs were allocated to Northern alone, whereas the 61 cancelled 172s (42x 3-car and 19x 4-car) would have been split up into allocations for three operators. Bombardier offered the Class 172 ''Turbostar'' to NI Railways for its '' "New Trains Two"'' specification, eventually losing out to CAF and a variation of NIR's existing Class 3000.

Fleet details

Named Units

172342 is named ''Rodger Summer''.

References

{{Use dmy dates, date=June 2021 Bombardier Transportation multiple units

172 Year 172 (Roman numerals, CLXXII) was a leap year starting on Tuesday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Scipio and Maximus (or, less frequently, year 925 ''A ...

London Overground Train-related introductions in 2010