The term “1959 EMU” defines a range of four classes within the Mark I electric multiple units which shared a common design of their cab ends that was designed in view of a more aesthetically pleasing appearance. Each class was designed for a different area of operation. They shared some electric equipment with the previous EMUs and all had slam doors in each compartment. With two to four cars per set, all had one car that was powered on all four axles with traction motors of different manufacturers and power ratings.

The class 304 consisted of 45 four-car sets which were designated AM4 before the introduction of the TOPS classes. The classes 305, previously called AM5 and 308, previously called AM8, both consisted either of three or four cars each. The class 305 numbered 71, while the class 308 numbered 45. They were refurbished in the eighties and part of them even got gangways between the cars. While the 304 and 305 were withdrawn in the nineties, the 308 was only withdrawn in 2001 with one set being preserved.

While the others operated under 25 kV AC, the class 504 was built for the unique system with a 1,200 V DC side-contact third rail. This system was only used on the Bury Line between Manchester and Bury. It was also the only of the four classes that only consisted of two cars, with less powerful motors in the powered car. All 26 were withdrawn in 1991 when the Bury Line was converted to the Metrolink light rail system. Of two sets which were selected for preservation, only one still exists today.

In 1971, British Rail Engineering Limited (BREL) introduced a new family of electric multiple units for local transport with the prototypes of the Classes 445 and 446, which became known under the type code “PEP”. The prototypes included one two-car and two four-car sets, in which all four axles of all cars were powered. Closely spaced seats with low backrests and many electrically operated doors were used for local transport. Also new were automatic couplings, which were based on the American design and additionally had electrical and pneumatic connections. The trains could thus be coupled or uncoupled during operation without the driver having to get out or requiring assistance.

Between 1973 and 1977, these three trains were subjected to extensive trial operations, during which they were mostly used coupled together to form a ten-car unit. They were then used by the network operator until 1983 and were also used to test new assemblies such as bogies. From 1976, the first production trainsets based on the prototypes were built, with the similar classes 313, 314 and 315 making the start. What these three classes had in common was that they consisted of powered control cars and non-powered trailers and were designed for operation under 25,000 V AC. The pantograph was located on the center car to better distribute the equipment over the train.

The first was the class 313, which was built from February 1976 and additionally had contact shoes for operation under 750 V direct current via the third rail. It was used on the former Great Northern routes between London and Hertfordshire, partly using Underground tunnels. Although these tunnels were widened to accommodate regular trains, the 313 got a lower roofline.

This was followed by the class 314, which was built from 1979 for the Glasgow area and, like the class 313, was made up of three cars each. From 1980, the class 315 followed, which had a second trailer and thus had four cars each. In the course of their career, the trains were used in other areas. The contact shoes were removed from some examples of class 313 because they were no longer needed. After modernization in the areas of electronics, lighting and accessibility, they were retired from 2018. So the classes 313, 314 and 315 were replaced by the classes 717, 385 and 710.

From 1978 the Class 507 and 508 were developed for use on the Merseyrail network around Liverpool. There, the power supply is provided by direct current via the third rail. The difference between the classes is that the 507 class has only one trailer between the two powered control cars, while the 508 class has two trailers. Immediately after delivery, the 508 was transferred to London Waterloo for temporary use until the Class 455 was available in sufficient numbers. For use in the Merseyrail network, a trailer was removed again so that both classes were almost identical again. The Class 507, on the other hand, stayed on the Merseyrail network throughout its life. From 2019, both were replaced by Stadler's class 777 “Metro”.

Since it became apparent in the seventies that electrification of all main lines would not be possible, British Railways had a diesel-powered high-speed train built. In order to keep the axle loads low, a streamlined locomotive with a fast-running and light Paxman Valenta with 2,250 hp was used at each end of the train. The trains reached a service speed of 125 mph or 201 km/h and were initially classified as class 253 and 254 multiple units. Only later were they renumbered into class 43 locomotives.

The trains ran with a variable number of Mark 3 coaches and quickly spread across Britain. They are officially simply called “HST” (“High Speed Train”), but were also used as “Intercity 125” in reference to their top speed. They significantly shortened travel times compared to trains with conventional diesel locomotives. With a record of 148.5 mph (239 km/h), they are considered the fastest diesel locomotive in the world.

With the privatization of British Railways, the HST came to a variety of operators. The new VP185 engine was developed before privatization, but was only installed in some of the vehicles. After the turn of the millennium, more were re-engined with new MTU engines. At the same time, some of them were replaced by new multiple units, such as the families of the 220 and 800 classes. However, due to the increased number of passengers, many remained in service. Even after 2020, many HSTs were still active in passenger transport. Today some are used by Network Rail or to ferry trains. Some were even exported to Mexico and Nigeria.

In order to modernize passenger transport over short distances, British Railways approached the industry in 1954, which was to produce a large number of light diesel railcars. Since there was no standard design due to lack of time, several companies had a relatively free hand in the development and delivered different models, which, however, had many things in common.

All DMUs consisted of four-axle cars, which were usually coupled to form combinations of two to six vehicles. These combinations had only one cab at each end, there were only a few one-car vehicles with two cabs. The individual cars were either motorized with two diesel engines each, each of which drove the inner axle of a bogie, or unmotorized.

Most of the railcars were powered by British United Traction (BUT) diesel engines, each with 150 hp. This was a cooperation between AEC and Leyland, which also manufactured trolleybuses in addition to diesel engines for rail vehicles. The power was transmitted over a mechanical four-speed gearbox. Some classes had more powerful engines from BUT, Leyland or Rolls-Royce with up to 237 hp, some of which worked on a hydraulic gearbox. The maximum speed was 70 mph for all variants.

A total of more than 3,400 cars came from a total of ten manufacturers. The most successful variant was Metropolitan Cammell's Class 101, which was used in combinations of two to four cars. Combinations of two cars were made up of either a power car and a driving trailer or two railcars and were then referred to as “Power Twins”. Metro-Cammell supplied nearly 700 Class 101, 102 and 111 cars.

More than 1,100 came from the British Railways' works in Derby. The largest numbers of these were produced of the two- to four-car class 108 and the two- to three-car class 116. The class 116 was one of the variants that were designed for suburban traffic and had doors in each row of seats, which in Great Britain was also known as the “Slam Door Train”. A further 400 examples came from the BR workshops in Swindon. This also included the class 124, which consisted of six cars each, four of which had two 231 hp engines and thus achieved good acceleration.

Gloucester Railway Carriage and Wagon Company supplied just over 200 and Cravens just over 300 carriages. The Class 128 from Gloucester and the Class 129 from Cravens were parcel DMUs which had a parcel compartment without windows instead of a passenger compartment. While the 129 class had the standard 150 hp engines, the 128 class had two Leyland Albion engines, each with 231 hp. 

Another notable number of more than 400 came from the Birmingham Railway Carriage and Wagon Company. These consisted of 302 cars for the two- to four-car Class 104, Class 118 and Class 110, the latter with two Rolls-Royce engines of 180 hp. Smaller numbers came from Park Royal, Pressed Steel and D. Wickham & Co.

The large number and variety of classes ensured that the first generation diesel multiple units were used in all parts of the country. Production of the last pieces was already completed in 1963. In the 1980s, the Pacer and Sprinter railcars were developed, which were intended to completely replace the vehicles of the first generation. Since the Pacer was not quite convincing and the number of Sprinters was not quite sufficient, not all railcars of the first generation could be retired in the 1980s. Some examples of class 101 could not be retired until 2003, while the one-car vehicles of class 121 “Bubble Car” were in regular use until 2017.

Starting in the late fifties, British Railways ordered some types of electric multiple units whose body had the same structure as the Mark I coaches. What they have in common is that one or two cars of each set had four traction motors. In other aspects, they had differences depending on their area of service.

The first was the class 302 introduced in 1958 for operations in the London area. They were originally designated AM2 and consisted of four cars each with a huge number of slam doors. One of the inner cars had four traction motors with 143 kW each and was not only designed for operation under 25 kV, but also 6.25 kV for certain lines in London. The first sets of 112 were withdrawn in 1984 and the last ones in 1998.

The class 303 was similar and originally called AM3, but was built for operation in the Glasgow area and had only two doors on each side of each car. Each set consisted of three cars and had 155 kW per traction motor. After 92 sets of class 303, only 19 were built of the class 311 that was introduced in 1967. These were initially called AM11, could only operate under 25 kV, delivered 165 kW per motor and were manufactured by another company. While the small number of class 311 sets was already withdrawn by 1990, class 303 was only withdrawn by 2002.

The class 432 had greater changes compared to the others and was originally designated 4-REP by the Southern Region. Its class designation in the 400 range indicates hat it was designed for the third-rail DC network in the south and southeast of London. The concept consisted of a high powered four-car EMU that hauled additional three- or four-car trailer sets. So the class 432 had eight 300 kW traction motors in the two outer cars and enough power to haul the class 438 TC trailer set that also had driver compartments. In total, 15 powered sets and 34 trailer sets were built. These were withdrawn by 1991.

The classes 310 and 312 were electric multiple units designed for the 25.000 Volt AC network and based on the body of the Mark 2 coaches. They had a huge number of slam doors to ensure rapid entering and exiting of passengers. They originally consisted of four cars of which one of the inner ones was powered on all four axles with 270 kW each. Since the powered car also contained the pantograph, transformer and rectifier, it was more than 20 tons heavier than the other ones.

50 sets of the class 310 were built between 1965 and 1967 as part of the electrification of the West Coast Main Line. It was originally called AM10 and had a top speed of 75 mph (121 km/h). It was the first mass-produced multiple unit in Britain with disc brakes and had a glass wall behind the cab, allowing passengers to view the line. Thirteen sets were converted to three cars and called class 310/1.

Of the class 312, 49 sets were built between 1975 and 1978 for lines to the east and north east of London. These were faster at 90 mph (145 km/h) and were more modern in many details. Some were also equipped for a voltage of 6,250 used on some lines to the east and north east of London and were designated class 312/1. In the eighties they were superseded by new EMUs with a top speed of 100 mph. After being refurbished and being used for other services, most sets of the classes 310 and 312 were withdrawn between 2001 and 2004.

The oldest variant of the Networker family that was built in series was the class 165. To distinguish it from the electric variants, it was later called “Networker Turbo”. They were ordered by Network SouthEast for service in the Thames Valley and Chiltern Region and are therefore also known as “Thames Turbos” and “Chiltern Turbos”.

The sets consist of two or three cars, all of which are powered. Under the floor of each car is a six-cylinder turbo diesel from Perkins with a displacement of 12.2 liters and an output of 350 hp. The power is transmitted to both axles of a bogie via a hydraulic gearbox from Voith. The top speed is basically 75 mph. 

The basic variant 165/0 was built 28 times as two-car sets and eleven times as three-car sets. Some of the trains use part of the London Underground lines and have therefore got the tripcock system. In addition, the class 165/1 was built 18 times as two-car sets and 19 times as three-car sets. These received a modified gear ratio for 90 mph and yaw dampers on the bogies to be used on main lines.

For longer distances, the class 166 was built from 1992, which, like the 165/1, can reach 90 mph. In addition to an adapted interior, this has air conditioning and additional toilets in contrast to the 165. Here 21 sets were created, all of which have three cars.

Since the privatization of British Railways, the trains have changed operators several times. Today all are owned by the Great Western Railway and Chiltern Railway. Later, many Class 165 trains also received air conditioning and interior modernization, while the first class compartments were partially replaced with second class. Some trains were moved to the Bristol area following the electrification of the Great Western Main Line, others were replaced with class 168 or class 180 diesel multiple units and then moved to more remote areas. To date, only one class 165 set has been scrapped after an accident.

When it became clear that the first generation DMUs had reached the end of their service life and that the development of a full-fledged successor would take a long time, the Pacer was developed as a cheap temporary solution. The body of the Leyland National bus was used and placed on a two-axle underframe intended for a high-speed freight car. These two- or three-car vehicles were designed for a maximum service life of 20 years. Since the Sprinters could not replace them, almost all Pacers were still in use in 2015. From the passengers they got the nickname “Nodding Donkeys”, as they had very uncomfortable suspension characteristics and a high noise level. In 2019 and 2020, almost all were phased out, mainly due to new accessibility requirements. In June 2021, the last Transport for Wales vehicles ran for the last time.