THE SIGNAL BOX

SIGNALS

BRITISH RAILWAY SIGNALS

GWR & BR(WR) Signals

The Great Western and British Railways (Western Region) did not switch to upper quadrant design as elsewhere, and as a result many lower quadrant arms on their former areas survive.

GWR stop signal
Photograph by John Hinson

GWR Stop signal

This splendid example of an early-pattern Great Western lower quadrant signal was conveniently located (for photographers) on the platform at Aberystwyth.

Notable features are the tapering wooden post, the swan-neck spectacle, and the finial painted to match the colour of the signal arm. The arm is of enamelled steel, ribbed along the edges for rigidity, although wooden arms were found on the earliest signals of this type.

This signal, worked by lever 100 in Aberystwyth box, protected the convergence of the Middle Siding and Platform 4, which took place mid-way along the platform, another starting signal was provided at the end of the platform.

Further information about Aberystwyth can be found in the Photo Gallery.

GWR bracket signal
Photograph by John Hinson

GWR Bracket signal with subsidiary arm

The Great Western experimented with concrete construction as an alternative to timber during the 1920s. Here the main post is so (notice the slots to reduce weight and wind resistance) although the small doll to the left was probably timber to minimise the weight strain on the bracket.

As the left arm only reads to a siding it bears a smaller arm. The spectacle casting is considerably more substantial than the swan-neck arrangement on the main arm, but this was the standard style for small arms at this period. Notice that the smaller glasses will display a miniature light to a driver by night.

These are the Talerddig Up Starting signals, on which further information can be found in the Photo Gallery.

GWR ringed-arm signal
Photograph by John Hinson

GWR ringed-arm signal

This signal has a small arm fitted with a ring to indicate that it reads from a siding or loop onto a running line.

The signal depicted was at Abbey Foregate, Shrewsbury.

GWR ringed arm signal
Photograph by John Hinson

GWR ringed arm signal

Tubular steel posts were introduced by the GWR during the 1940s, and remained their standard through to BR(W) days.

This example, at Newtown, is a miniature arm signal reading from a siding, and has therefore (in accordance with GW practice) been fitted with a white-painted ring. The reason why the arm is not mounted right at the top of the post is not known.

More information about this signal will be found in the Photo Gallery.

GWR route indicating signal
Photograph by John Hinson
GWR route-indicating signal
Photograph by John Hinson

GWR route-indicating signal

An alternative to the bracket signal, especially where there were a large number of routes, was provided by the route-indicating signal. These were only used in low-speed situations.

This example, at Worcester Shrub Hill, is the Station box Up Platform to Down Hereford or Down Birmingham Starting signal. It is of standard BR(W) design, with tubular steel post (narrowing slightly mid-way) and enamelled metal lower quadrant arm. The arm is different to the above examples, with a folded edge rather than ribbed.

This type of route indicator was colloquially known as a "clack-box" or "cash register".

GW/BR(W) centre pivot signals
Photograph by John Hinson

GWR/BR(W) centre-pivot signals

This bracket signal features "centre-pivot" signal arms, which the GW provided at locations where visibility was limited. These were the Walnut Tree Junction Up Main Starting signals - in this case the signals had to be visible below the station footbridge.

These signals were probably erected in 1952, but demonstrate an exception to the BR(W) policy on the use of steel arms. As these signals were only used in limited numbers, mass production methods could not be justified and centre-pivot signals were always provided with wooden arms.

More information about Walnut Tree Junction can be found in the Photo Gallery pages.

GW/BR(W) signals at Exeter West
Photograph by Martin Shaw

GWR/BR(W) siding signals

This picture shows some well-known signals which used to form part of a gantry at the end of Exeter station, controlled from the West box. However, the arms are quite interesting.

Prominent in the picture is a standard centre-pivot arm, applying to movements from the Down Platform to Down Main, so configured to allow the best view to drivers below the platform awning. Below this signal is a calling-on signal applicable to the same route as its parent when the line is already occupied.

The signal on the left is the key one applicable to this caption - it is a siding arm of the type used by the GWR at one time for moves from running lines into sidings. In this instance it led to the South Devon Sidings, a small yard to the left of the other lines. Normally, such signals were mounted on a very small bracket to displace them from the main post they were on, but here advantage has been taken of the gantry configuration and no special bracket is necessary.

Both of the small arms are sometimes mistakenly identified as themselves being "centre-pivot" but this is not the case and they are pivoted at the right-hand end like conventional signals. What makes them look a little different is the positioning of the lamp to the left of the pivot, and this makes it necessary for the green lens to be (unusually) above the red.

GWR backing signal
Photograph by John Hinson

GWR backing signal

The GWR identified a signal specifically applying to backing movements along a running line by a signal with two holes cut in it.

This was effectively the same kind of signal arm in timber as the metal Stevens "scissors" or "bow-tie" arm used on certain other railways - both were identifiable by two holes although visually completely different.

The example shown here, at Croes Newydd, is also provided with a route indicator. It is mounted on a tubular steel post.

GW electrically operated signals
Photograph by John Hinson

GWR electrically operated signals

The signals illustrated here are electrically operated by means of Westinghouse electric motors. The arms are fixed directly to these and, owing to the bulk of the motor and the positioning of the signal lamps, they differ from the standard GW signal.

Beneath the Stop and Distant arms is a Calling-On signal which is used when the line ahead is occupied.

The signals were at Newton Abbot.

GW large disc signal
Photograph by John Hinson

GWR large disc signal

An interesting solution was provided by the Great Western in a situation where both a centre-pivot arm and sight boards were necessary.

Here, a centre pivot signal was necessary owing to the limited clearance under the awning, and a white sight board is necessary to disguise the clutter of the girderwork etc.

The solution lay in the provision of a large disc signal, whilst mounted below it is one of more conventional size to represent a calling-on arm.

The signal exists half-way along the platform at Worcester Shrub Hill to protect the crossover from the middle siding. At one time, this was a scissors crossover leading into a through main line, and a similar pair of signals were mounted alongside the two shown here to read to the main line.

GWR double disc signal
Photograph by John Hinson

GWR double disc shunting signal

This is the Great Western's final design of disc, introduced in the 1930s, and known as "independent discs". This example has two discs, mounted one above each other, applying to different routes. This is the Down Platform to Middle Sidings or along Down Platform Shunt Signal at Worcester Shrub Hill Station box.

Since very early days of signalling, signals mounted one above the other always read to the routes ahead with the top arm for the left-most route. Hence, in this example, the signal cleared applies to the right-hand of the two available routes, which is straight along the Down Platform line.

Yellow-armed GW disc
Photograph by Chris Bellett, 2/2/03

GWR yellow-arm disc

Certain shunt signals may be passed at danger when the points ahead are set in their normal position, perhaps a shunting neck. These are provided with yellow "arms" rather than red. The use of such signals depends train crews' clear knowledge of the signalling and close co-operation with the signalman to avoid mishap, and such signals are no longer commonplace.

This example is at Lostwithiel, and is though to have been installed in 1943 when goods loops were provided here.

GWR yellow-arm disc
Photograph by John Hinson

GWR yellow-arm disc with black background

In this example, the "background" of the disc is black. The white background of discs had been provided as a replacement for miniature signal arms to make the indications clearer, which was certainly worthwhile for "red-armed" discs. However, yellow discs proved difficult to view in well-lit areas at night, and later examples were as seen here. A reversion to a miniature arm might have served the same purpose just as well!

This example is at Worcester Shrub Hill Station and is the Middle Siding to Down Platform Shunt Signal.

The Great Western also had another type of shunt signal that could be passed at danger. but these depended even more on train crew knowledge as these only differed from the standard red-armed disc by displaying a white light for "on" and were hence indistinguishable in daylight. These were allowed to be passed provided another shunt signal ahead was off for the move. They were a legacy from early double-twist interlocking which didn't cater for signals reading to more than one route.

GW electric shunting signals
Photograph by John Hinson

GW electric shunting signals

These signals were electrically operated shunting signals in a form not unlike a very large track circuit indicator! The red arm pivots centrally in front of an opaque glass through which the oil lamp shows at night. Wire mesh prevents damage from flying ballast or clumsy railwaymen.

These signals were at Newton Abbot, and controlled movements on the lines either side of them through a scissors crossing. One of the two parts of the scissors had been removed at the time of this photograph, explaining the empty signal face.

BR(W) repeater signal
Photograph by John Hinson

BR(W) repeater signal

This unique signal acted as a repeater for a miniature-arm signal ahead.

It doesn't correspond to any other known signal types at therefore must be regarded as a one-off. It is effectively a distant signal without the fish-tail notch in the end of the arm.

The signal was at City Basin Junction, Exeter.

GWR stop board
Photograph by John Hinson

GWR stop board

One of the simplest forms of signals is one that doesn't operate! This is the "stop board", known as Limit of Shunt on most other railways. It indicates just that, the limit to which a shunt move may proceed (without specific permission). These are only used on low-use lines and sidings.

The signal is lit from within, the lamp shining through the stencil to give an illuminated indication by night.

A few of these have survived in use in the former Western Region territory - some can even be found in power box areas. This example is at Worcester Shrub Hill, controlling movements on the Down Through Siding.

About the photographs


Comments about this article should be addressed to John Hinson