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Railwayana Collectors' Network - Single Line Tokens

British Single Line
Electric Train Tokens

This is a brief guide to electric train staffs, tablets, and key tokens. One engine in steam (OES) staffs are not covered, and token instruments are only mentioned briefly.

The type of token (e.g. Tyer's No 6 tablet) actually refers to the instrument type, in fact the No 3, 4 and 6 tablets are identical in appearance but the instruments differ.

All tokens have one of several possible configurations, so that they can only be accepted by an instrument with that particular configuration. Configurations are denoted by letters and sometimes there is an associated colour and/or shape.

As with other aspects of railways, signalling occasionally deviates from the norm. Dimensions are approximate, due to wear and manufacturing variations of the examples measured.

More images of single line tokens can be found at the signalling section of the gallery.

Please email me with any corrections, further information etc.

Tyer's No 1 tablet

4 15/16inches (126 mm) diameter, made from cast iron with a brass disc riveted into a recess, - "brass faced". Instrument patented 1878 by Edward Tyer.
Image of Queensferry Junction to Dalmeny Junction tablet

Configuration is determined by the angular relationship between a round hole near the outer edge and a semicircular edge cutout, although this aspect is somewhat vague and clarification would be welcome. The shape of the centre hole does not always reflect the configuration, and some examples have a centre circular depression instead of a through-hole.

Webb and Thompson large electric train staffs

Image of Narberth to Templeton and Kenilworth to Gibbet Hill large staffs

Instrument patented 1888 by F.W.Webb and A.M.Thompson of the LNWR.

LNWR staffs usually have a cast brass head, while those used by the GWR, LBSCR, and some other companies have two brass nameplates or a sleeve fixed to the staff.
Length 23 inches (584 mm).

Some large electric train staffs have an Annett's key which was used for unlocking ground frames etc. The LNWR type of Annett's key has small projections on the cast brass head whereas the others have a key-like extension.

The configuration of large staffs is determined by the distance between the centre lines of the fourth and fifth rings, there was also a colour code, which was subject to local variation:

Configuration 4th-5th ring spacing Colour
A 3 1/2 inches red
B 3 inches blue
C 2 1/2 inches green
D 4 inches yellow

Thanks to Chris Osment of West Country Railway Archives,, for "D" configuration information.

Tyer's No 3/4/6 tablets

4 7/16 inches (112 mm) diameter, made of brass, aluminium alloy, fibre, brass faced cast iron or aluminium alloy. 4 7/16 inch tablets are usually described as Tyer's No 6.
Image of A, B, and C configuration tablets

Three configurations are known (1), A, B and C, determined by the shape of the cutout on the edge. The shape of the centre hole, usually A round, B square and C triangular, cannot always be relied on to reflect the configuration (2).

No 3 instrument patented 1890. Non-returnable. Tablet had to pass through section and be inserted into the instrument at the opposite end before another one could be removed from instrument.

No 6 instrument patented 1892. Returnable. A tablet could be returned to its originating instrument, after being used to unlock an intermediate siding for shunting to take place, without passing through the section.

Tyer's No 6 square tablet

3 1/2 inches (89 mm) square, aluminium.

Long section instrument, patented 1893.

Image of square No 6 tablet Girvan to Pinwherry

Configuration details would be welcome.

Tyer's No 5/7 tablets

3 15/16 inches (100 mm) diameter, made of brass, cast iron with a brass disc riveted to it - 'brass faced', or aluminium alloy. No 7 example shown is brass with steel inserts.
Image of No 7 tablet Gunnislake to Callington

No 5 instrument patented 1891, No 7A instrument patented 1896, No 7 instrument patented 1898. Configuration is the same as for No 6 tablets.

McKenzie & Holland tablet

3 15/16 square, aluminium alloy. Instrument patented 1896.

Image of McKenzie and Holland Shillingstone to Blandford tablet

Used for long section working by the Somerset & Dorset and Cambrian railways.

Configuration details would be welcome.

Railway Signal Co. miniature electric train staffs

Image of S and M types miniature staffs

The 'M' type, length 10 3/4 inches (273 mm), was introduced in 1906 and has four rings of two different thicknesses. The 'S' type, length 9 1/2 inches (241 mm) was introduced soon afterwards and has four rings of equal thickness. Steel shaft with brass and/or steel rings.

The configuration is determined by the position of collars as follows:

Image showing miniature staff configurations The colour coding is:

'A' configuration: red
'B' configuration: blue
'C' configuration: green
'D' configuration: yellow
'E' configuration: brown
'F' configuration: grey

Railway Signal Co. key tokens

Open key instrument patented 1925. Recessed key type (shown below) introduced c.1932.
Image of R.S.C. key token, Avenue Sidings to Grassmoor East

Steel shaft with two brass or steel rings and a brass or aluminium handle. Length 11 inches (279 mm). The configuration is determined by ridges on the shaft, in a similar way to a Yale key, and the letter is marked on the reverse side of the token's handle.

Tyer's No 9 key tokens

Patented by Blackall and Jacobs of the GWR 1912 and manufactured under licence by Tyer & Co.

The configuration of all varieties of Tyer's key tokens is determined by the position of a semicircular groove on the end, and two colour schemes are known - the less common alternative is given in brackets. Some types also have a shape associated with the configuration: 'A' configuration: red circular 'B' configuration: blue (green) square 'C' configuration: green (yellow) triangle 'D' configuration: yellow (blue) diamond.

This picture shows the four configuration groove positions:

Image showing Tyer's key token configurations

Left to right: 'A', 'B', 'C' and 'D' configuration.

Some No 9 key tokens were originally double-ended, one end for inserting into the block instrument and the other an Annett's key for use in ground frame etc. locks (3).

There is quite a variety of No 9 keys, the following may not include all of them. Further information would be welcome.

Tyer's No 9 key token: GWR type

Steel forging with one or two cast, engraved or stamped brass or aluminium nameplates. Length 7 1/2 inches (190 mm). The later type, which may pre-date 1935 (4), was made from a heavy duty aluminium alloy.

In the picture below, the left-hand token, Glyndyfrdwy-Corwen East, is an example that was originally double ended. The handle stub is clearly different from that of the second one, Abermule-Newtown.

Image of four G.W.R. type key tokens

There are two variations of GWR/BR-W aluminium keys; parallel shank, as the Maidenhead Middle-Cookham (third from left) and the more common tapered shank of the St Blazey Bridge Crossing-Luxulyan on the right-hand side.

Tyer's No 9 key token: LNER type

Image of L.N.E.R. key token, Jedburgh to Roxburgh Junction

The handle is smaller than that of the GWR type. Bronze/brass type material.

Tyer's No 9 key token: heavy brass type

Circular handle has a shaped hole to indicate the configuration.

Tyer's No 9 key token: steel (non-GWR) type

Chrome plated steel, length 5 3/4 inches (146 mm). The circular handle has a shaped hole which reflects the configuration: circular (A), square (B), triangle or star (C), diamond (D).

Tyer's No 9 key token: aluminium alloy (non-GWR/BR-W) type

Image of aluminium key token, Cairnryan Junction to Castle Kennedy

Handle shape indicates the configuration.

Tyer's No 12A key token

Image of type 12A key token, Gosport to Fareham West

Made of aluminium bronze (a durable brass-looking alloy).
Length 5 3/4 inches (146 mm). Introduced 1952.


(1) Although the manufacturer's catalogue shows a "D" configuration, with diamond shape centre hole and "V" edge cutout, no British example is known.
(2) One B configuration example, Moulton-Clay Lake, has a round centre hole.
(3) Photo's on p126 of "An Historical Survey of the Didcot, Newbury and Southampton Railway" by C.W.Judge, Oxford Pub. Co., and p74 of "Hidden Dangers - Railway Safety in the Age of Privatisation", by S.Hall, Ian Allan, show double ended key tokens.
(4) Photo dated 1935 on p101 "A Pictorial Record of Great Western Signalling" by A. Vaughan, Oxford Pub. Co. shows aluminium key tokens.

The following publications were also found useful in compiling this information:
Signalling Record Society Signalling Papers No 7 "Long and Short Section Working in Scotland" and No 11 "Electric Token Block Instruments", both by D. Stirling.
Railway World, August 1982 "Single Line Control" by M. Christensen.
Tyer & Co. and Railway Signal Co. product catalogues.