|British Rail Class 172 Turbostar|
The interior of a West Midlands Trains Class 172
|In service||10 July 2010 - present|
|Number built||39 trainsets|
|Formation||2 or 3 cars per trainset|
West Midlands Trains
|Line(s) served||Snow Hill Lines|
Leamington Spa to Nuneaton
Chiltern Main Line
|Car body construction||Welded aluminium, with steel ends|
|Car length||23.62 m (77 ft in)|
|Width||2.69 m (8 ft in)|
|Height||3.77 m (12 ft in)|
|Maximum speed||100 mph (160 km/h)|
|Weight||41.6 tonnes (40.9 long tons; 45.9 short tons)|
|Prime mover(s)||One per car, MTU 6H1800R83 13-litre 6-cylinder turbo-Diesel|
|Power output||483 hp (360 kW) per engine|
|Transmission||ZF Ecomat-Rail 6-speed|
ZF Reversing final drive
|Safety system(s)||AWS, TPWS|
ATP (172/1 only)
|Multiple working||Class 150?Class 153?Class 165?Class 168?Class 170|
The British Rail Class 172 is a British diesel multiple-unit (DMU) passenger train built by Bombardier Transportation's Derby Litchurch Lane Works for use on inner-suburban passenger services. The large majority of the Class are operated by West Midlands Trains, with a small number operated by Chiltern Railways in the London area.
There are four sub-classes:
The 172/0s and 172/1s resemble the existing Turbostar trains in not having end gangways. These trains have a maximum speed of 100 mph (160 km/h).
The Class 172/2s and 172/3s used by West Midlands Trains resemble the Class 375, Class 377, Class 379 and Class 387 Electrostars by having end gangways to allow access between units. These trains have a maximum speed of 100 mph (160 km/h).
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 - gear changes can be distinctly heard as the trains accelerate and decelerate.
Class 172s have fewer seats than the Class 150s they replace, 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 23 m (75 ft 6 in) body length, as opposed to the 20 m (65 ft 7 in) length used on previous Class 150 Sprinter DMUs - increasing capacity.
West Midlands Trains operate a total of 35 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 West Midlands Railway, operated by West Midlands Trains, inherited the London Overground 172/0s 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 in Snow Hill Line.
Chiltern Railways has obtained four two-car trains in the same order as that of London Overground to supplement the current Class 165 Networker Turbos on its routes from London Marylebone, originally due to be delivered from late 2010. They do not have the tripcock 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) means there is no place for the brackets to be mounted. Thus, they are not able to operate on the Aylesbury via Amersham line whilst the current signalling system is in place unless running in multiple with other units on both the front and rear ends, which are fitted with a tripcock.
London Overground operated eight two-car Class 172s on the Gospel Oak to Barking line, replacing the old Class 150 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 and other operators. The units were leased by London Overground Rail Operations (LOROL), the London Overground concession operator, from a rolling-stock leasing company rather than purchased directly by Transport for London.
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.
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. All units have subsequently been delivered to Willesden Train Maintenance Depot (TMD).
All eight 172/0 units have entered service for London Overground. These were originally restricted to a top speed of 40 miles per hour (64 km/h) as opposed to their intended design speed of 100 mph (160 km/h), 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.
|Class||Operator||Number||Year built||Cars per set||Unit nos.|
|172/0||West Midlands Trains||8||2010||2||172001-008|
|172/2||West Midlands Trains||12||172211-222|
In 2008, First Great Western applied to the Department for Transport to re-equip its Cardiff to Portsmouth via Bristol 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, 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 DMU order was cancelled, with the needs of the train operating companies planned to be met by transfers of existing stock. Arriva Rail North and TransPennine Express did subsequently obtain new DMU rolling stock, although this was produced by CAF and Hitachi.