Introduction

This is an introduction page on the subject of Single-Line Block Sections on railways of the UK West Country. There are links to associated pages in RailWest which will list (as far as possible) all the known single-line block sections in the West Country, with details (where available) of the method of single-line control, the configuration of staff, tablet or token and the dates of usage etc. For quick access to details of any individual line please click on the appropriate link in the Index below.

It is not intended to describe here the actual method of operation of the different forms of single-line control, as this subject will be covered elsewhere. Some information on single-line control instruments can be found in The Signal Box website and it is hoped to include more details in RailWest in due course. However some background information is necessary in order to understand the details set out in the other RailWest pages, so please read the rest of this Introduction page first.

Types of Equipment

Until about 1890 most (but by no means all) single-line block sections in the West Country were controlled by the "Train Staff and Ticket" (TS&T) method. After the invention of the Electric Train Tablet (ETT) system by Edward Tyer in 1878 the London & South Western Railway (L&SWR) eventually adopted ETT as their standard for new works, as well as fitting it retrospectively in due course to all their existing sections. Under their influence ETT was applied gradually also to the Somerset & Dorset Joint Railway (S&DJR) from 1885 onwards, although one S&DJR section did remain as TS&T until British Railways (BR) days.

By contrast the Great Western Railway (GWR) adopted the Electric Train Staff (ETS) system patented by Webb & Thompson in 1889 and they deployed this extensively throughout their system. [This equipment is sometimes called the 'large' ETS to distinguish it from an alternative smaller 'miniature' ETS system.] About 1908 the GWR adopted Tyer's No 7 pattern of ETT as their standard instrument instead, but in the event only a few sections were fitted with this equipment before there was a further change of policy. In 1912 GWR engineers Blackall and Jacobs invented the Electric Key Token (EKT) system and thereafter the GWR used EKT for new work and the replacement of old equipment.

The GWR also licensed their EKT system to Tyer, who then manufactured EKT equipment for other railways. In later years the Southern Railway, and then BR Southern Region (BR(SR)), used Tyer's EKT as a replacement on several ETT sections, although their design of EKT equipment varied from the pattern used by the GWR and BR Western Region (BR(WR)). However in the West Country most (but not all) examples of EKT equipment on former Southern Railway lines were fitted in fact after 1948 by BR(WR) using the ex-GWR pattern.

Some other varieties of single-line control also existed in the West Country, such as a few "One Engine in Steam" (OES) sections, some "No Signalman Key Token" working, and a solitary example of the Railway Signal Company's "Miniature ETS". There were also a few examples of 'long section' working, where an intermediate signal-box might be closed at certain times and the 'short' sections on either side of it worked as a single 'long' section, and sometimes different control systems were for the 'long' and 'short' sections.

Configurations

Wherever there were two or more adjacent sections of single-line worked by some form of staff, tablet or token then it was vital to ensure that the driver of a train entering one section was not given the wrong staff/tablet/token by mistake - with potentially disastrous results. Apart from the driver being required to satisfy himself that he had the correct item before entering the section, a further safeguard was provided by what is known usually as the 'configuration' of the staff/tablet/token. [The term 'configuration' probably really only applies to the various 'electric' systems - ie ETT, ETS and EKT - but a similar principle applied to the 'manual' OES and TS&T systems.] Configuration information (where known) is given in the RailWest lists of sections.

For the 'manual' OES and TS&T systems the 'configuration' was achieved usually by one or both of two methods - the colour of the train staff and the shape of its cross-section. Colour was used for visual identification in daylight, whilst the cross-section shape enabled the staff to be identified by touch at night. Typical examples of staff configuration might be "round, red" or "square, blue" etc. In all cases the staff would bear the name of the section to which it applied - usually the names of the signal-boxes at each end of the section. In the case of TS&T the tickets themselves might also be of the same colour and/or shape as the relevant staff, although on some sections different colours were used for the tickets for 'Up' and 'Down' directions.

For the 'electric' ETT, ETS and EKT systems the 'configuration' was achieved by some aspect of the mechanical form of the staff/tablet/token, usually the position and/or shape of a notch or ring. The purpose of this aspect of the configuration was to prevent the staff/tablet/token being replaced into the wrong instrument after use. Sometimes there was also a variation in shape and/or the use of different colours and this provided visual identification of the correct item. In all cases again the staff/tablet/token would bear the name of the section to which it applied - usually the names of the signal-boxes at each end of the section. In general the configurations for the different types of ETS, ETT and EKT equipments were standardised and identified by letter - 'A', 'B', 'C' and 'D'. In some cases this letter was engraved on the item itself and/or the instrument in which it was kept, although this appears to have been a practice mostly confined to ETS (both 'large' and 'miniature' versions).

Examples of Electric Train Tablet Configurations
Configuration 'A'	Configuration 'B'	Configuration 'C'
Round centre hole Round notch in edge	Square centre hole Rectangular notch	Triangular centre hole Combined rectangular + long round notch
NOTE: In the 'C' configuration tablet the left-hand rectangular notch is NOT part of the normal configuration

Register of Single-Line Sections

The RailWest register of single-line block sections in the West Country has been divided into separate pages for the Great Western Railway, the London & South Western Railway and Southern Railway, the Somerset & Dorset Joint Railway and other minor railways. These pages provide historical details - there is a separate page for all current day sections. For quick access to details of any individual line please click on the appropriate link in the Index below.

The RailWest register will not be a comprehensive record for all single-line sections which ever existed in the West Country, as it would be virtually impossible to collate or present all that information. Many main lines were built originally as single-track and then were doubled piecemeal over the years, a process which lasted for example on the Great Western Railway in Cornwall until the early part of the 20th Century. The register therefore, with a few exceptions, will concentrate on those branch and secondary lines which remained as single-track for most of their existence.

In general the register will provide details for the period from about 1900 onwards, but details for earlier periods will be included where known. It is important to remember that the method of working and the type of equipment in use may have changed over the years. Much of the information has been taken from records of the British Railways period after 1948, so in many cases the method of working may have been changed at least once beforehand - for example, many of the sections listed as being worked by EKT would have been ETT or ETS before that and perhaps even TS&T originally. Furthermore, from about the late 1960s onwards it became the practice to use the term 'token' as a generic description for a staff, tablet or token regardless of the actual type, but as far as possible the entries in this register will make the necessary distinction.

The actual block sections themselves sometimes changed as signal-boxes were closed or new ones were opened. This situation became more common from the 1950s onward, as lines were rationalised prior to closure and the numbers of signal boxes (and hence block sections) declined rapidly. Conversely several new sections appeared as parts of some double-track lines were reduced to single track in order to save on maintenance costs. However many of those new sections now fall completely within the control of one signal box and therefore are not worked by any of the 'traditional' methods. A separate table is provided to list current-day sections.

© Chris Osment 2002