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
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.
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
Instrument patented 1888 by F.W.Webb and A.M.Thompson of the
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
||4th-5th ring spacing
||3 1/2 inches
||2 1/2 inches
Thanks to Chris Osment of West Country Railway Archives, www.railwest.org.uk, 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.
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
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
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.
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.
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.
Used for long section working by the Somerset & Dorset and
Configuration details would be welcome.
Railway Signal Co. miniature electric train
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
'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.
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
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
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,
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
The handle is smaller than that of the GWR type. Bronze/brass
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)
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
Handle shape indicates the configuration.
Tyer's No 12A key token
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
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.
Tyer & Co. and Railway Signal Co. product catalogues.