British Railways came into being on January 1st 1948 when
all of the UKs' rail services were nationalised. The lines previously under
the Southern Railway became the Southern Region.
As far as suburban EMU construction went the early years
of BR witnessed only the completion of EMU types ordered prior to
nationalisation, such as the last batches of 4-SUB, 2-HAL and the 4-DD
prototypes. By late 1951 the first BR ordered EMUs began to be
constructed.
The EPB Units
The first unit numbered 5001 (pictured left) appeared from Eastleigh
works late in 1951 The style of construction and the unit layout and formation
was basically the same as that of the last batch of 4-SUB units but it featured
a redesigned cab end complete with roller blind route indicators along with
buckeye automatic couplers and a new style of multiple working jumpers. The
major departure from the SUB design was the units electrical system which
was completely redesigned to work on two voltages, the traction equipment
was supplied from the 750V third rail but all control and lighting was fed
by a 70V circuit produced by an on board motor-generator set. The braking
type employed gave the units their name. The Electro Pneumatic Brake featured
a system that allowed the driver to electrically inject air into the unit's
brakes at an even rate making for smoother and faster deceleration. The last
of the 213 4-EPB units inspired by the Bulleid design emerged in 1957. By
this time new suburban stock was being constructed to the British Railway
standard design. A style of unit that drew heavily on the 4-EPB units in
it's construction. A batch of 2-EPB units with the SUB style body was built
in 1959 on the underframes of the 2-NOL units.
The BR standard
version of the EPB design was also built in 2 and 4 coach variant, the 2
car units came first from 1954 with the 4 car ones appearing from 1957. The
units had the slightly longer BR standard underframe of 63' and the classic
Mk.1 Coach body profile. The 4 car sets also featured an updated motor control
circuit.
EPB stock worked on all three divisions of the Southern
Region and the last examples were not withdrawn until 1995.
The 2-HAP Units
During 1956 construction of 36 new units on the reclaimed
underframes of 2-NOL units commenced. These were the first to the 2-HAP design
that was to be introduced to semi-fast and outer suburban duties over the
next two years. The first batch featured the SUB style body outline with
a driving motor brake and driving trailer composite, the later coach also had a toilet
at its inner end.
At the same time as these units began construction
a fleet of all new BR standard 2-HAP was authorised with the same body style
as the BR 2-EPB sets but the layout of composite accommodation in the driving
trailer car separated by two toilets. 42 units made up this batch of BR HAPS
and they were supplemented by the construction of three more batches in 1958
(63 units), 1961 (41 units) and finally 1963 (27 units). The layout of all
the BR style batches was identical but changes were made to the electrical
control equipment and bogies in later batches.
HAPS worked on all three divisions of the Southern Region
on a variety of duties. The SUB style units were downgraded to second class
only for suburban duties in the 1970s and re-classified as 2-SAP units, they
were all withdrawn in the early 1980s. Pairs of HAP units were semi-permanently
coupled together as 4-CAP units in 1982 for the stopping trains on the coastal
routes from Brighton but these soon transferred to suburban duties on the
South Eastern division.
The last HAP and CAP units continued in traffic until 1995.
The 4-PEP Units
The 1960s on the Southern Region was concentrated on main
line electrification with the suburban routes left to soldier on with units
provided by the Southern Railway and BR (Southern). It was not until the
end of that decade that thoughts could turn to the much needed modernisation
of suburban rolling stock.
A concept for a standard type of EMU was drawn up that
could be adapted for use on DC and AC lines and built accordingly to local
requirements but based on that same basic standard pattern. To trial the
finalised concept three prototype trains were constructed - two four car
units and one two car. All were built at York works with the 4 cars delivered
for testing on the Southern Region (as they were equipped for third rail
operation) in 1971, the 2 car set arrived a year later. The PEP units, as
they were designated, featured practices that had been adopted as standard
on the London Underground for many years. The layout of all cars was open
saloon with generous provision for standing passengers in peak hours. Each
car had two sets of air operated sliding doors per side and interior finishing
was made of plastic and laminates. Car interiors were lt with fluorescent
tubes and provided with pressure ventilation and the units were gangwayed
within each set but had no brake van - the guard occupied one of the unused
driving cabs on the train where door control panels were provided. Brake
equipment was EP and also rheostatic for the first time on a BR EMU with disc
brakes fitted. The unit ends had no brake or electrical coupling pipes and
jumpers as all couplings of this nature were incorporated into the 'Scharfenberg'
automatic coupler.
The units were tested mainly on the South Western division
suburban routes from Waterloo to Shepperton, Hampton Court and Chessington
South. During 1974 the 2 car unit was transferred to test duties on the Eastern
Region and had a new vehicle built for it so it could run on AC overhead
lines. The two four cars continued in use until 1976 when they were transferred
to departmental stock. After long periods of store both were broken up during
the 1980s.
The Class 508 Units
Following on from the prototype PEP units BR ordered several
batches of new generation suburban units during the mid 1970s. The four car
class 508s were one such design, emerging from York works in 1979. 43 units
were built and their styling and formation was near identical to that of
the 4-PEP prototypes. The two outer driving cars were also the motor coaches
and each one had each axle powered by a 110hp GEC traction motor. The units
also had secondary air suspension.
The first passenger run was in December of 1979 with the
full compliment of units in traffic by the summer of the following year on
South Western division suburban traffic. The introduction of the 508 units
allowed the last of the 4-SUB units to be withdrawn so that their electrical
equipment could be reclaimed for use in the new class 455 units. As the 455s
were introduced so the 508s were transferred away from the Southern to Merseyside
but only as three car sets as one 508 trailer from each unit was retained
for use in a batch of 455 units. The last 508s left the south in 1983.
The Class 455 Units
These were originally classified as class 510 units but
that was changed to class 455 to fit them in with the existing TOPS numbering
of southern EMUs prior to delivery. The 455s were built in three batches.
All were formed as four car sets with driving trailer coaches marshaled either
side of a intermediate trailer and a non-driving motor coach which carried
all the traction equipment (four 250hp motors reclaimed from 4-SUB units).
The layout was the same as the 508 units but the body shell was not of the
style that derived from the PEP prototypes but a shortened version of the
Mk.3 coach body.
The first batch delivered in 1982 were the 455/8 variants
which were split between the Central and South Western divisions. The second
(class 455/7 - 43 units) and third (class 455/9 - 20 units) batches were
only used on the South Western division and were delivered in 1984/5. Both
final batches had a revised front end to that of the 455/8 type and the 455/7
featured the trailers recovered from the 508 units. The 455/9s had no pressure
ventilation and the last few built examples had a new system of traction
control know as 'Chopper Control'.