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Section 18: Signs in Electrified Areas

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In 2004, work was under way to upgrade the traction power supply between Earlswood and Three Bridges. In the event of an electrical disruption occurring while this work was taking place, it was necessary for drivers of Class 375 and 377 'Electrostar' units to drive in Notch 2 through the substation area affected. When these circumstances applied, special temporary signs would be displayed at the beginning [18.37] and end [18.38] of the affected area. In certain locations, one sign applied to the tracks on either side, indicated by arrows pointing left and right [18.39 & 18.40].

[18.37] 'Notch 2' Commencement Sign.
Area: Southern Region   Usage: Low   Status: Historical
[18.38] 'Notch 2' Termination Sign.
Area: Southern Region   Usage: Low   Status: Historical
[18.39] 'Notch 2' Commencement Sign.
Area: Southern Region   Usage: Low   Status: Historical
[18.40] 'Notch 2' Termination Sign.
Area: Southern Region   Usage: Low   Status: Historical

Later in 2004, signs similar to [18.37 - 18.39] were provided in connection with power supply upgrade work between Herne Hill and Sydenham Hill. These signs applied to 'Electrostar' units of Classes 375 and 376 and therefore had the legend "375/6" at the top.


Later examples of neutral section warning boards on the CTRL [18.41] differ slightly from the earlier type (see [18.34]).

[18.41] Warning Sign for Neutral Section (e.g. 1000 metres ahead).
Area: CTRL   Usage: Medium   Status: Current

On the CTRL, a diamond shaped sign [18.42] denotes a location where the overhead catenary wire ends. Electric trains must not pass without the pantograph first being lowered. This sign is of similar style to those used on German Railways (Deutsche Bahn) for the same purpose.

[18.42] 'Limit of Electric Traction' Sign.
Area: CTRL   Usage: Unknown   Status: Current

As new rolling stock has replaced the Class 313 electric multiple units on the West London and North London lines (specifically the Class 378 EMUs in 2009), the "pan up" and "pan down" signs on those routes (see [18.27 - 18.31]) have been changed. The "313 units" legend at the top of the original signs has been replaced by either "378 units" or "313/378 units", or the generic legend "AC units".

From December 2009 until January 2010, while engineering work was taking place in the Southampton area, drivers of Class 444 and 450 'Desiro' units were required to drive under power reduction conditions. Special temporary signs were displayed at each entrance to [18.43] and exit from [18.44] the affected area.

[18.43] Class 444/450 Power Reduction Restriction Commencement Sign.
Area: Southampton   Usage: Low   Status: Historical
[18.44] Class 444/450 Power Reduction Restriction Termination Sign.
Area: Southampton   Usage: Low   Status: Historical

On the Wessex Route, during occasions when there is a problem with the electric traction supply, drivers of electric trains are required to engage 'Power Reduction Mode' (PRM) or drive in Notch 2 through the affected area. Temporary signs bearing the letters "PR" on a white background and surrounded by a blue border mark the beginning [18.45] and end [18.46] of the affected area.

[18.45] Power Reduction Mode Commencement Sign.
Area: Wessex Route   Usage: Medium   Status: Current
[18.46] Power Reduction Mode Termination Sign.
Area: Wessex Route   Usage: Medium   Status: Current

In 2011, new rules were introduced to permit electric trains to coast at high speed, with their pantographs lowered, through a section where the power to the overhead line equipment has been isolated because of damage, power failure or planned engineering work. Temporary 'lower pantograph' and 'raise pantograph' signs (see [18.21 & 18.23]) will be provided at the beginning and end of the affected section. In addition, an 'advance lower pantograph' sign with two flashing white lights [18.47] will be placed about 400 metres on the approach to the 'lower pantograph' sign and a 'do not raise pantograph' sign [18.48] will be placed beyond the 'raise pantograph' sign. If the pantograph has not been raised by the time the train reaches the 'do not raise pantograph' sign, the pantograph must not be raised until the speed of the train has been reduced to 20 m.p.h. Before allowing an electric train to approach an affected section, the signalman will verbally advise the driver that high speed coasting is taking place.

[18.47] 'Advance Lower Pantograph' Sign.
Area: All Areas   Usage: Medium   Status: Current
[18.48] 'Do Not Raise Pantograph' Sign.
Area: All Areas   Usage: Medium   Status: Current

Some of the Class 80X Intercity Express Trains (IETs) are electro-diesel ("bi-mode") units that can switch from electric to diesel traction and vice versa while running at speed. From 2017, signage was introduced at the trains' traction changeover sites, the first of these sites being located between Taplow and Maidenhead on the Great Western Main Line. The first sign, in either direction, warns drivers of the approach to the traction changeover zone and is of the standard design (see [18.20]). The driver should select "coast" on the train's power controller. For a changeover from electric to diesel traction, the warning sign is followed by a Class 80X specific notice board with the word "diesel" (see [26.19]) at the start of the changeover zone, beyond which is a 'lower pantograph' sign with a subsidiary plate reading "Class 80x" (see [18.22]), at the point by which the pantograph must be lowered. In the opposite direction, a 'raise pantograph' sign (see [18.24]) marks the start of the changeover from diesel to electric traction. Beyond this is a 'do not raise pantograph' sign (see [18.48]). If the driver has not commenced the traction changeover process by the time the train reaches this sign, changeover must not be attempted until speed has been reduced to under 20 m.p.h.

In 2018, new signs were introduced for use at neutral sections of the longer carrier wire type, the first of which were located between Maidenhead and Ruscombe on the Great Western Main Line. The signs denoting the approach to and start of a long neutral section are the same as the standard neutral section boards (see [18.17 & 18.18]), but carry a supplementary sign underneath with the word "long" [18.49 & 18.50]. Another sign, with a red diagonal cross [18.51], denotes the end of a long neutral section.

[18.49] Long Neutral Section Warning Board.
Area: All Areas   Usage: Low   Status: Current
[18.50] Long Neutral Section Indication Board.
Area: All Areas   Usage: Low   Status: Current
[18.51] 'End of Neutral Section' Sign.
Area: All Areas   Usage: Low   Status: Current