Second Generation EMUs

By John Jackson

It is now some forty years since the term ‘Second Generation EMU’ entered rail industry parlance. The British Rail (BR) Class 313 heralded a new era back in 1976/77 with BR’s first order of suburban passenger trains with both a pantograph (for 25Kv AC) and shoegear (for 750V DC ‘third rail’). These units continue to see daily service both on north of London commuter services and on Sussex’s Coastway services. Since those early days, over forty classes of EMU have entered traffic throughout what is now, of course, a privatised railway. More and more operators are able to opt for their use over DMUs as more of the country benefits from installation of an electrified railway.This book offers a look at all the classes found in the UK, as well as a look at the country’s electrified lines.

• Language: English
• Publisher: Amberley Publishing
• Release date: Nov 15, 2019
• ISBN: 9781445676036

Book preview

Introduction

This book tells the latest chapter in the story of Britain’s electric multiple units (or EMUs for short). In an earlier title for Amberley Publishing, we took a class by class look at second generation diesel multiple units (DMUs), and in this publication we take a similar look at their electric-powered counterparts, from the mid-1970s to the present day.

Electric-powered units are primarily for passenger use and operate with the carriages in a fixed formation without the requirement of a separate locomotive providing the power. I estimate that between two thirds and three quarters of all passenger carriages currently operating in the UK are formed into these EMUs.

The concept of using electricity to power trains is not new. In the days when steam power was the norm, lines that were predominantly underground, notably in London, were electrified using pick-up from a third rail in order to avoid the obvious problems of steam train emissions in tunnels.

Between the First and Second World Wars, the use of third rail direct current (DC) was extended, with the then Southern Region, in particular, favouring this power for services in London and South East England.

Following privatisation of our railways in 1948, a report into future electrification options was commissioned. The Southern Region was to pursue further use of third rail DC power, whilst the remaining regions of the UK opted for use of alternating current (AC) via overhead line supply.

With further railway electrification again seen as the way forward in the early 1970s, the need for a new generation of electric multiple units was recognised. Several years later the first such examples of units with either overhead or third rail supply were delivered. In some cases, these units were to be fitted with dual supply equipment to enable operation in either AC or DC electric mode.

That is where this story of second generation electric multiple units begins. Between the delivery of these units in the mid-1970s and the present day, around forty different classes have been introduced. These have been supplied by a number of manufacturers from both the UK and overseas. They vary in length from two to twelve cars, with four-car being the most popular formation. They also provided the flexibility to work in multiple formations, particularly during the peak periods, although some classes had no walkway facilities between each unit.

By the mid-1970s, British Rail had implemented a computerised system of numbering for its locomotives and rolling stock, with all units receiving a six-digit identification code. The first three digits identified the unit class. At the time, AC units commenced with a ‘3’, Southern Region DC units with a ‘4’ and other DC units with a ‘5’.

For the sake of convenience, the units featured here do not appear in strict chronological order of introduction. Rather, they have been placed in strict numeric order starting with the Class 313 units dating from early 1976 through to the present-day Class 769, deliveries of which are in progress.

During this forty-year period the UK railways have seen significant changes, not least with the privatisation of the network under the Railways Act 1993, which saw the newly organised structure come into effect in April 1994.

By then, the Channel Tunnel had become a reality, with Class 373 Eurostar operating services between London, Paris and Brussels using the EMU concept with fixed formation coaching stock.

The UK had also seen the Class 370 Advanced Passenger Trains (APT) come and go, with the ‘tilting’ technique eventually incorporated into the Class 390 Virgin Pendolino, introduced on the West Coast Main Line in the post privatisation era.

The strategy for railway electrification in recent years has been one of significant expansion, albeit with some considerable delays and cancellations in that implementation.