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Home Page > Section 18; pages: 1, 2, 3
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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 affected substation area. When these circumstances applied, temporary signs were displayed at the beginning and end of the affected area. The commencement sign had the legend "375/7" above "Notch 2", on a blue inverted triangle [18.39]. The termination sign was similar but had a white diagonal band superimposed [18.40]. In certain locations, one sign applied to the tracks on either side, indicated by arrows pointing left and right [18.41 & 18.42].
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[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 |
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[18.41] 'Notch 2' Commencement Sign.
Area: Southern Region Usage: Low Status: Historical |
[18.42] 'Notch 2' Termination Sign.
Area: Southern Region Usage: Low Status: Historical |
Later in 2004, signs similar to [18.39 - 18.41] 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.
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Later examples of neutral section warning boards on the CTRL [18.43] differ slightly from the earlier type (see [18.36]). |
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On the CTRL, a diagonal white sign with two concentric blue squares [18.44] denotes a location where the overhead catenary wire ends. Electric trains must not pass without the pantograph first being lowered. Several railways in continental Europe use a similar sign for the same purpose. |
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The newer style of "section gap" board installed on the DC electrified lines in the Liverpool area had an upright shape [18.45] in contrast to the wide shape of the original boards (see [18.5]). |
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From December 2009 until January 2010, while engineering work was taking place in the Southampton area (Wessex Route), 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 [18.46] and exit from [18.47] the affected area.
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[18.46] Class 444/450 Power Reduction Restriction Commencement Sign.
Area: Southampton Usage: Low Status: Historical |
[18.47] Class 444/450 Power Reduction Restriction Termination Sign.
Area: Southampton Usage: Low Status: Historical |
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Drivers of electric trains may be required to engage 'Power Reduction Mode' (PRM) or drive in Notch 2 because of a problem with the electric traction supply. As part of a trial on the Wessex Route, the start and end points of affected areas may be marked by temporary signs. The commencement sign is in the form of a train class specific notice board (see [26.20]) with the legend "electric trains" at the top and the letters "PR" in the middle [18.48]. The termination sign bears a red diagonal cross in the manner of a train class specific 'no entry' sign (see [25.38]) with the letters "PR" superimposed on its centre [18.49].
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[18.48] Power Reduction Mode Commencement Sign.
Area: Wessex Route Usage: Medium Status: On Trial |
[18.49] Power Reduction Mode Termination Sign.
Area: Wessex Route Usage: Medium Status: On Trial |
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In August 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 [18.23 & 18.25]) will be provided at the beginning and end of the affected section. In addition, an 'advance lower pantograph' sign with two flashing white lights [18.50] will be placed about 400 metres on the approach to the 'lower pantograph' sign, and a 'do not raise pantograph' sign [18.51] 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 mph. Before allowing an electric train to approach an affected section, the signalman will verbally advise the driver that high-speed coasting is taking place.
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[18.50] 'Advance Lower Pantograph' Sign.
Area: All Areas Usage: Medium Status: Current |
[18.51] 'Do Not Raise Pantograph' Sign.
Area: All Areas Usage: Medium Status: Current |
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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 [18.22]). 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 [26.20]) at the start of the changeover zone, beyond which is a 'lower pantograph' sign with a subsidiary plate reading "Class 80x" (see [18.24]), at the point by which the pantograph must be lowered. In the opposite direction, a 'raise pantograph' sign (see [18.26]) marks the start of the changeover from diesel to electric traction. Beyond this is a 'do not raise pantograph' sign (see [18.51]). 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 mph.
In 2018, new signs were introduced for use at neutral sections of the longer carrier wire type on the Great Western Main Line, the first of which were located between Maidenhead and Ruscombe. The signs denoting the approach to and start of a long neutral section were the same as the standard neutral section boards (see [18.19 & 18.20]), but they also carried a supplementary sign underneath with the word "long" [18.52 & 18.53]. Another sign, with a red diagonal cross [18.54], denoted the end of a long neutral section. Most of these signs were removed in 2021/2022 and replaced by standard neutral section boards.
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[18.52] Long Neutral Section Warning Board.
Area: Great Western Main Line Usage: Medium Status: Obsolescent |
[18.53] Long Neutral Section Indication Board.
Area: Great Western Main Line Usage: Medium Status: Obsolescent |
[18.54] 'End of Neutral Section' Sign.
Area: Great Western Main Line Usage: Medium Status: Obsolescent |
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The Class 755 bi-mode multiple units entered service with Greater Anglia from 2019. Signs are installed alongside the car stop markers (see Section 21) at station platforms where these units perform a static power changeover while stationary. These signs have a blue border with the legend "Class 755" at the top. Each sign is divided into two parts, the upper part containing the words "power changeover", while the lower part contains a yellow warning triangle and further wording depending on which type of changeover it refers to. The sign indicating a changeover from electric to diesel power has the word "diesel" in red and is applicable to trains bound in the direction of any of the locations named underneath [18.55]. The sign indicating a changeover from diesel to electric power has the legend "electric 25kV" [18.56]. Similar signs applicable to Class 80x Intercity Express Trains are installed at some station platforms.
Signs are installed in depot areas to warn drivers of bi-mode units that the pantograph must be lowered before entering certain sidings [18.57].
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[18.55] Static Power Changeover Sign - Electric to Diesel (e.g. applicable to Class 755 trains).
Area: Various Usage: Medium Status: Current |
[18.56] Static Power Changeover Sign - Diesel to Electric.
Area: Various Usage: Medium Status: Current |
[18.57] Pantograph Down Sign (e.g. applicable to Class 755 trains).
Area: Various Usage: Low Status: Current |
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A sign relating to automatic power changeover and situated on the approach to a diverging junction may be fitted with a supplementary sign to indicate that it only applies to trains travelling towards the specified route. This can either take the form of a supplementary arrow sign (see Section 27) or a sign that identifies the applicable route by an abbreviated name, usually in white characters on a black background [18.58]. A supplementary sign that is similar but has a red diagonal stripe across it [18.59] indicates that the sign does not apply to trains travelling towards the specified route.
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[18.58] Applicable Route Sign (e.g. "diesel" sign, applicable to trains travelling towards Lydney).
Area: Various Usage: Medium Status: On Trial |
[18.59] "Route Other Than" Sign (e.g. 'lower pantograph' sign, not applicable to trains travelling towards the ECML route).
Area: Various Usage: Low Status: On Trial |
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In March 2020, the "section gap" boards (see [18.5]) on the DC electrified line between Camden and Watford Junction (the Watford 'New' Line) were replaced by isolation demarcation boards. Each board has the words "section gap" above a solid black diamond, below which there is a number that relates to the electrical section and sub-section isolation limits [18.60]. These boards are for the information of track workers and can be disregarded by train drivers. During 2021/2022, isolation demarcation boards replaced the "section gap" boards on the Merseyrail system (see [18.45]). |
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A variant of the "E" board used on the DC electrified lines in the Liverpool area at times of reduced power supply (see [18.18]) has the legend "E6" in yellow on a grey background [18.61]. These boards are only applicable to 6-car electric multiple units. |
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The Merseyrail Class 777/1 'independently powered electric multiple units' (IPEMUs) can be powered either from 750 V DC third rail or from their on-board batteries where no third rail is provided. In July 2023, 'self-powered mode change' signs showing two semicircular arrows in white on a square black background [18.62] were installed at Fazakerley for Down direction trains and at Kirkby for Up direction trains. These denote the point where a changeover from one power system to the other should be completed. |
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