Section 22: Indicators associated with Train Dispatch

(Page 1 of 1)

Indicators for the guidance of staff carrying out train dispatch duties may need to be provided on station platforms, if the platform starting signal is not visible from the dispatch position. From at least 1928, the Southern Railway provided indicators for this purpose, showing either "On" or "Off". The indicator would show "On" [22.1] while the relevant signal displayed a 'stop' aspect, changing to "Off" [22.2] when the signal cleared to a 'proceed' aspect.

[22.1] "On" Indication.	[22.2] "Off" Indication.

On the Watford New Line, the LMS provided indicators at certain platform starting signals, which the guard operated to inform the driver that station duties were complete and the train may depart. When operated, and provided the signal was 'off', the indicator displayed an illuminated "S" (for 'Start') below the respective signal [22.3], accompanied by a high frequency buzzer.

[22.3] "S" Indication.

From 1942 on the Southern Railway, the "On" indication (see [22.1]) was deemed unnecessary and was removed as a wartime economy. Only an "Off" indication (see [22.2]) would be provided, the indicator being extinguished when the relative signal displays a 'stop' aspect.

"Off" indicators are often double-sided, in which case the rear-facing side may show an amber coloured indication [22.4]. This also applies to an "Off" indicator provided on the back of a colour light signal at places where a train may stand with the front of the train beyond the signal. In these circumstances, the rear "Off" indicator controls the starting of the train.

[22.4] Rear-facing "Off" Indication.

When a rear "Off" indicator refers to a signal which can display both main and subsidiary aspects, it may have associated with it an additional indication reading either "Main" [22.5] or "Sub" [22.6] as appropriate. Alternatively, the indicator may display just "Off" for a main aspect and "Sub" for a subsidiary aspect.

[22.5] "Main Off" Indication.	[22.6] "Sub" Indication.

An alphanumeric route indicator may be associated with an "Off" indicator to repeat the route indication displayed at the signal when a 'proceed' aspect is shown [22.7]. This most commonly occurs in the case of a rear of signal "Off" indicator.

[22.7] Route Indication associated with "Off" Indication (e.g. "F" = Fast Line).

On a bi-directional line, it is necessary to specify to which signal or direction of travel an "Off" indication applies. A plate may be fixed to the indicator, stating the signal number [22.8] or the direction of travel (i.e. 'Up' or 'Down') [22.9] to which it refers. Alternatively, an "Off" indication, when illuminated, may be accompanied by an illuminated legend "U" / "Up" or "D" / "Dn" [22.10 & 22.11]. On the Scottish Region, the direction of travel was not specified, but instead an indication "N", "S", "E" or "W" (i.e. north, south, east or west) showed at which end of the platform a 'proceed' signal aspect was being exhibited [22.12].

[22.8] "Off" Indication (e.g. applies to signal number D142).	[22.9] "Off" Indication (e.g. applies to Up direction signal).

[22.10] "Off" Indication (e.g. applies to Down direction signal).	[22.11] "Off" Indication (e.g. applies to Up direction signal).	[22.12] "Off" Indication (e.g. "N" = applies to signal at north end of platform) (Scottish Region).

'Right Away' indicators displaying an illuminated "R" [22.13] were used by the Scottish, North Eastern, Eastern and London Midland Regions. A 'right away' indicator is used at places where the driver may be unable to see the 'ready to start' handsignal. A rear-facing "R" indicator may show an amber coloured indication [22.14].

[22.13] "R" Indication.	[22.14] Rear-facing "R" Indication.

On the Western Region, the indication "R" was commonly used in alphanumeric route indicators (see Section 6) to refer to a 'Relief Line'. To avoid confusion, the 'Right Away' indicators provided on the Western Region (by 1967) displayed the letters "RA" [22.15]. The "RA" indication subsequently became standard on all regions.

[22.15] "RA" Indication.

Inner and outer platform starting signals exist on Platforms 2 and 3 at Brighton station for departing trains. Separate "Off" indicators are provided for each signal, displaying "Off Inner" [22.16] or "Off Outer" [22.17], as appropriate.

[22.16] "Off Inner" Indication (Brighton).	[22.17] "Off Outer" Indication (Brighton).

From c.1990, 'Close Doors' indicators have been provided at certain stations where platform staff are on duty. Where provided, these indicators are used for dispatching trains with power-operated doors. When operated by the platform staff, a "CD" indication is displayed [22.18], indicating to the guard (or driver of a 'driver only' train) that station work is complete and the train doors can be closed. A "CD" indicator is usually combined with an "RA" indicator (see [22.15]), in which case the "CD" indication will be extinguished when the "RA" indication is exhibited.

[22.18] 'Close Doors' Indication.

If a station is at or near a location where a reversal of Down and Up directions occurs, an illuminated "Down" or "Up" indication at an "Off" indicator (see [22.10 & 22.11]) cannot usefully specify the direction for which a signal is cleared at a bi-directional platform. The alternative employed in such situations is for the indicator to display the (suitably abbreviated) name of an important place in the same direction as the signal which is "off", either as an illuminated indication [22.19] or on a plate fixed to the indicator [22.20].

[22.19] "Off" Indication with Illuminated Direction Indication (e.g. "KLY" = Keighley).	[22.20] "Off" Indication with Direction Plate (e.g. "COL" = Colchester).

On platform lines that are subdivided by mid platform signals, an "Off" indicator (see [22.2]) associated with a mid platform signal would not usually be allowed to illuminate unless the signal ahead (at the end of the platform) is also 'off'. At stations where it is necessary to indicate that the mid platform signal alone is 'off', a supplementary indication is required to accompany the "Off" indication. This takes the form of an illuminated indicator that displays the number of the associated mid platform signal [22.21]. If the platform end signal subsequently clears, the signal number indicator is extinguished, leaving just the "Off" indication illuminated. These indicators were provided at Edinburgh Waverley station in 2006.

[22.21] Illuminated Signal Number displayed with "Off" Indication (e.g. applies to signal number 456).

Home Page