Section 9: Signal Post Signs and Signals for Degraded Working

(Page 2 of 3)

In 1933, the LNER installed colour light signals between York and Northallerton. All the main signals, apart from junction signals, were provided with some form of auxiliary light to locate the signal in the event of the main signal light failing. In the case of automatic signals, the illuminated "A" sign (see [9.8]) acted as the auxiliary light. Controlled signals were fitted with a plain white auxiliary light that would be illuminated only if the main aspect failed [9.24]. Semi-automatic signals had both an illuminated "A" sign and a plain white auxiliary light, the latter being provided for use when the signal was not working automatically. The junction signals had multiple signal heads (see [6.22]) and so did not require to be fitted with auxiliary lights.

[9.24] Auxiliary Light (LNER).

Following accidents in 1933 and 1934 resulting from the 'stop and proceed' rule, the MoT recommended the use of "P" ('proceed') signs on signals [9.25]. These signs were in use on the Southern Railway from 1936. When illuminated, the "P" sign gave authority to pass the signal concerned at 'danger', during failure.

[9.25] "P" Sign.

Signs of a new design were introduced for the identification of automatic [9.26] and semi-automatic signals [9.27]. These signs may incorporate the signal's identification number [9.28 & 9.29].

[9.26] Automatic Signal Plate.	[9.27] Semi-Automatic Signal Plate.


[9.28] Automatic Signal Plate with Signal Identification.	[9.29] Semi-Automatic Signal Plate with Signal Identification.

An additional sign for the identification of Intermediate Block Home signals was introduced in c.1961 [9.30]. The signal number may be incorporated onto the sign [9.31].

[9.30] Intermediate Block Home Signal Plate.	[9.31] Intermediate Block Home Signal Plate with Signal Identification.

From 1962 the practice of fitting a "T" sign (see [9.15]) or a diamond sign with the letter "T" (see [9.17]) to a signal to denote the provision of a telephone was discontinued. The signal post telephone would continue to be identified by the black and white diagonally striped sign (see [9.14]). Concurrent with that change, a new sign with a St. Andrew's cross was introduced [9.32]. This would be used to distinguish lineside telephones not at signals or telephones at signals where Rule 55 did not apply (e.g. signals not on running lines or loops).

[9.32] Telephone Sign.

When a driver was detained at a signal bearing a black and white diagonally striped sign (see [9.14]), the rules normally required that he contact the signalman after waiting two minutes (this was varied to three minutes on the Southern Region). In 1987, signal post telephone signs incorporating a numeral [9.33] were introduced at certain signals. The numeral indicates the number of minutes that the driver should wait before contacting the signalman when detained at the signal, when at variance with the standard time.

If the striped sign bears a numeral "0" [9.34], the driver must immediately contact the signalman when the train is detained at the signal. Such signs may be exhibited at signals temporarily during times of severe disruption. Some are permanently fitted to the signal post but are folded shut when not in use. A driver may be instructed by the signalman to open the sign.

[9.33] Signal Post Telephone Sign (e.g. initial contact to be made after a five minute delay).	[9.34] 'Zero Minutes' Plate.

Concerns over the safety of staff using signal post telephones at locations where there is limited clearance from an adjacent line prompted the introduction of new procedures for using such telephones. 1987 saw the introduction of diamond signs coloured yellow and bearing either the letter "T" or "L", with an associated white flashing light [9.35 & 9.36]. Where either sign is provided, the driver need not remind the signalman of the presence of the train when detained, but must communicate with the signalman when the white flashing light is exhibited. The associated telephones have a call back facility. Where the signal has a diamond sign bearing the letter "L", this indicates that a loudspeaking telephone is provided. Use of this type of telephone does not normally require the driver to leave the driving cab. By 1993, loudspeaking telephones were no longer being installed.

[9.35] Yellow Diamond Sign with "T".	[9.36] Yellow Diamond Sign with "L".

From 1993, yellow diamond signs bearing the letter "X" [9.37] were provided at certain signals. This sign indicates that the signal post telephone must not be used (except in an emergency) because it is located in an area of limited clearance. Communication with the signalman must normally be by radio equipment unless the driver has been informed that it is safe to use the telephone. The telephone cabinet was given a special sign bearing a yellow roundel superimposed on a black cross [9.38] instead of the usual black and white diagonally striped sign (see [9.14]).

[9.37] Yellow Diamond Sign with "X".	[9.38] Signal Post Telephone Sign - Limited Clearance.

A potentially unsafe situation was revealed when a colour light signal fitted with a yellow diamond sign and displaying a single yellow aspect (see [2.93]) was mistaken by a driver as a double yellow aspect (see [2.95]). To avoid a recurrence, it was decided that in future (from 1995), the background colour of all diamond signs should be white [9.39 - 9.41].

[9.39] White Diamond Sign with "T".	[9.40] White Diamond Sign with "L".	[9.41] White Diamond Sign with "X".

Also in 1995, the sign fitted to telephone cabinets located in areas of restricted clearance (see [9.38]) was altered. The yellow roundel was retained but the St. Andrew's cross was replaced by diagonal stripes [9.42], this being more appropriate for a signal post telephone.

[9.42] Signal Post Telephone Sign - Limited Clearance.

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