In the early 1990s, the 142s got more powerful Cummins engines, which gave a total power output of per two-car set. Several units were then changed for use on the Merseyside PTE City Line on Merseyrail in the Liverpool region, giving them dot-matrix route signs, better seating and Merseyrail PTE paintwork.
When privatisation happened, the class 142s were taken over by Arriva Trains Northern and First North Western, and then by Northern Rail, Arriva Rail North, Northern Trains, Arriva Trains Wales and Transport for Wales. Eight Northern Rail units were withdrawn from service for a while and replaced by a series of British Rail Class 158s. First Great Western received 12 units on loan from Northern Rail from December 2007 to November 2011 (five units were returned to Northern in December 2008). This allowed most of its Class 158 fleet to be rebuilt as three-car sets.
Around the same time that the Class 142 was developed, another class of Pacer railbus was designed by Kilmarnock-based Hunslet-Barclay. These used a Walter Alexander bus body. They were given the number Class 143 and started being used in 1985. Its two 205 bhp engines gave a total output of and a top speed of . This class of Pacer originally had a capacity of 122 passengers. They were used in the North East before being transferred to Wales and the South West, and were moved over to Valley Lines and Wales & West control during privatisation. They then passed on to Arriva Trains Wales, Wessex Trains, First Great Western and Transport for Wales. The interiors were completely changed in 2000, when the Valley Lines service was introduced, with full back, coach-type seating installed throughout, along with improved fittings. This reduced seating capacity to 106 seats per set.
Then came a similar Class 144 unit, a Walter Alexander body on BREL underframe, which was introduced in 1987. A unit was formed of either a two-car set with 122 seats or a three-car set with a total capacity of 195 passengers and , but its top speed was still . The units were used in the North East, passing to Northern Spirit at privatisation, then to Arriva Trains Northern, Northern Rail, Arriva Rail North and now Northern Trains.
It has often been said that the Pacers are of poor quality. Instead of the usual bogies, Pacers use a basic four-wheel two-axle underframe. This often makes for a ride that is noisier and less comfortable than other trains, especially over points, and a loud squealing noise is heard around tight curves. Not having bogies also makes for a worse suspension and a bumpier ride; Pacers have been nicknamed "nodding donkeys" because of the trains' up-and-down motion on uneven track. The basic bench seating can also be uncomfortable. The early units, especially the s, were also very unreliable.
Pacers have only been used in certain areas of the north and south west of England and the south of Wales, but not in the richer London or south east England areas. This has also created bad feelings.
Safety worries were raised after the 1999 Winsford crash. A Virgin Trains Class 87 express train ran into an empty First North Western Class 142 Pacer, after the Pacer had fouled the main line at Winsford, Cheshire on the West Coast Main Line. The wire straps that held the body of the Pacer to its frame broke, separating the body from the frame and causing severe damage. The unit was written off. Twenty-seven passengers and crew were wounded, four badly. But all passenger injuries were on the other train, as the Class 142 was running empty at the time.
On the other hand, the Pacers were seen as a practical solution at a time when there was not a lot of money. They probably saved services on some rural lines that might not have been serviced by any trains at all if only more expensive trains had been available. They have also proved cheap to run, achieving a fuel economy of 10 miles to the gallon.
As of 2020, the oldest Pacers on the national network were nearly 35 years old. All were planned to be withdrawn and scrapped by December 2019 as they do not comply with Rail Vehicle Accessibility Regulations.
In July 2019, rollout of Northern's Class 195 CAF "Civity" units had begun on some routes. Because of this, refurbished Sprinters that no longer needed on those routes can be used to replace Pacers instead.
These units are built out of upcycled London Underground D78 Stock, built between 1978 and 1981, which were in service on the District line until 2017. To convert the old stock for mainline railway use, it will be necessary to re-use the aluminium bodyshells, traction motors and bogies from the D78 units and fit them out with new diesel engines and interiors. The D-Train units underwent acceptance testing in 2015 and Vivarail pitched them to train operating companies (TOCs), especially those bidding for the Northern franchise. While no orders were received from Northern, Transport for Wales will replace its Pacers with a combination of five D-Trains and trains taken over from other train operators, and other TOCs have ordered D-trains to replace other outdated trains: South Western Railway for the Isle of Wight's Island Line, and West Midlands Trains for the Marston Vale line
Porterbrook, which owns the Class 143 and Class 144 fleets, refurbished 144012 in 2014 to comply with the new legislation, dubbed the "144e Evolution" unit. However, no other units have been refurbished to this standard.
Several "Pacers" have been preserved for further use on heritage railways. The National Railway Museum has preserved 142001.
In May 2019, the government asked the public how to re-use the trains after withdrawal from service. One of the suggestions was re-using them as public spaces, such as village halls or cafes.
Sprinter (train)
The Sprinter is a family of diesel multiple unit trains in use on the UK railway system. They were built in the 1980s and early 1990s by BREL, Metro Cammell and Leyland. All are based around a Cummins engine with Voith hydraulic transmission. Sprinters can be seen operating in almost every part of the UK, from rural branch lines to commuter expresses into major cities.
Turbostar
Turbostar is the name given to a series of diesel multiple units (DMU) built by Bombardier Transportation (previously ADtranz) at their Litchurch Lane Works in Derby, England. The Turbostar was the first new train type to be introduced after the privatisation of British Rail, and is the most common type of diesel multiple unit (its electrical variant, the Electrostar, is the most common electric multiple unit). The first units were ordered by Chiltern Railways in 1996 and were designated Class 168 (also known as "Clubman"). Since then the family has grown with the addition of the Class 170, Class 171, and (in development) the Class 172.
Coradia (train)
Coradia is the name given to the range of multiple-unit inter-city and regional trains manufactured by Alstom. There are a number of variants of this series, used in several countries.
Bombardier Voyager family
The Voyager series is a group of high speed diesel electric multiple unit trains built by Bombardier Transportation in service on the UK railway network. The trains are among the most modern currently in operation, and are in service on many intercity routes around Great Britain. There are currently three types in service with 4 TOCs (First Hull Trains, East Midlands Trains, Virgin Trains and CrossCountry).
Diesel multiple unit
A diesel multiple unit or DMU is a multiple unit train consisting of multiple carriages powered by one or more on-board diesel engines. They may also be referred to as a railcar or railmotor, depending on country.
The diesel engine drives the train through a transmission system. The transmission system may be:
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