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The various signs that are installed to give instructions to drivers of electric trains passing through the traction current changeover zones were of the same design as the signs used on the French railway system (SNCF) [18.22 - 18.26]. These signs were installed at Dollands Moor in 1993 in readiness for the opening of the Channel Tunnel, and also between Kensington and North Pole on the West London Line.
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The sign provided at the start of the traction current changeover zone [18.22] instructs the driver to open the main circuit breakers to shut off the power, and to lower the pantograph(s) or raise the conductor rail shoes in preparation for the changeover. |
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For a changeover from AC to DC traction power, another sign marks the position by which the pantograph(s) must be lowered. This sign depicts a pair of solid white shapes, each resembling the cross section of a plano-concave lens, set horizontally against a square black background with a white border [18.23]. The driver may lower the retractable shoegear, and the train may take DC traction power. A subsidiary plate may be fitted showing the voltage type to be selected [18.24] (these are not fitted between Kensington and North Pole).
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[18.23] Execute Sign for Lower Pantograph(s).
Area: Various Usage: Medium Status: Current |
[18.24] Execute Sign for Lower Pantograph(s), with subsidiary plate.
Area: Various Usage: Medium Status: Current |
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For a changeover from DC to AC traction power, a sign marks the position by which the shoegear must be raised. This sign has a similar appearance to the 'lower pantograph' sign described above, but rotated through 90° [18.25]. The driver may raise the pantograph(s), and the train may take AC traction power. A subsidiary plate may be fitted showing the voltage type to be selected [18.26] (these are not fitted between Kensington and North Pole).
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[18.25] Execute Sign for Raise Pantograph(s).
Area: Various Usage: Medium Status: Current |
[18.26] Execute Sign for Raise Pantograph(s), with subsidiary plate.
Area: Various Usage: Medium Status: Current |
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At some locations, an 'abort' board bearing a letter "A" [18.27] may be placed ahead of a traction current changeover zone. This sign applies only to Eurostar drivers. If the changeover has not been successfully completed by the time the front of the train reaches this sign, the train must be brought to a stand and the driver must examine the train. Alternatively, a 'degraded' board bearing a letter "D" [18.28] may be placed ahead of a changeover zone. If the changeover has not been successfully completed by the time the front of the train reaches this sign, the driver must advise the Route Control Centre of the exact status of the train and stop at a location where assistance may be rendered.
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[18.27] Power Changeover Abort Board.
Area: NR/CTRL Interfaces Usage: Low Status: Current |
[18.28] 'Degraded' Board.
Area: NR/CTRL Interfaces Usage: Low Status: Current |
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The electrification of the line between Dalston and North Woolwich in 1985 left the North London Line with 750 V DC third rail electrification from end to end, between Richmond and North Woolwich. In addition, 25 kV AC overhead wire electrification was installed between Camden Road and Stratford in 1986/1987, primarily for use by freight trains. Passenger services on the North London Line were operated from 1986 by dual-voltage Class 313 electric multiple units capable of drawing power from either system, and signs were installed at each location where their pantographs had to be raised or lowered (Acton Central, Camden Road, Dalston Kingsland and Hackney Wick). The signs were square in shape, with the legend "313 units" in red above the instruction "pan up" [18.29] or "pan down" [18.30] in blue ("pan" being short for "pantograph").
Between Camden Road East Junction and Dalston Junction, the No. 1 lines were electrified with 25 kV AC overhead wire in 1987, while the No. 2 lines retained their 750 V DC third rail electrification. Signs erected on both approaches to this section advised drivers of Class 313 units to lower the pantograph if routed onto the No. 2 lines [18.31]. In 1996, the electrification system between Acton Central and Camden Road was altered from 750 V DC third rail to 25 kV AC overhead wire.
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[18.29] "Pan Up" Sign.
Area: North London Line Usage: Low Status: Current |
[18.30] "Pan Down" Sign.
Area: North London Line Usage: Low Status: Current |
[18.31] "Pan Down" Sign applicable only to trains routed to No. 2 line.
Area: Camden Road / Dalston Kingsland Usage: Low Status: Historical |
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Where services formed of Class 313 units joined or left the North London Line by an adjoining route on which a change of electrification system occurred, the "pan up" and "pan down" signs at these locations had a similar appearance to those on the North London Line but were circular in shape [18.32 & 18.33].
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[18.32] "Pan Up" Sign.
Area: North Pole Junction / Willesden / Primrose Hill Usage: Low Status: Current |
[18.33] "Pan Down" Sign.
Area: North Pole Junction / Willesden / Primrose Hill Usage: Low Status: Current |
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The later introduction of newer dual-voltage electric multiple units on the North London and West London lines (which began with the replacement of the Class 313s by Class 378s in 2009) led to the "pan up" and "pan down" signs on those routes being altered. The "313 units" legends at the top of the square signs (see [18.29 & 18.30]) were altered to refer to the new rolling stock (e.g. "378 units" or "313/378 units"), while those on the circular signs (see [18.32 & 18.33]) were replaced by the generic legend "AC units".
In February 2002, the one remaining flood alarm signal at the east end of Silvertown Tunnel (see [18.14 & 18.15]) was replaced. The new indicator normally displayed a solid white rectangle [18.34]. In the event of flooding, the indication changed to display the words "tunnel flooded" in red letters [18.35]. This indicator lasted until closure of the North Woolwich line in May 2007.
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[18.34] Flood Alarm Signal (normal aspect).
Area: Silvertown Tunnel Usage: Low Status: Historical |
[18.35] Flood Alarm Signal ('stop' aspect).
Area: Silvertown Tunnel Usage: Low Status: Historical |
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The Parcel Sidings South at Preston station are partly electrified, the limit of electrification on each siding being marked by a notice board reading "electric trains stop". In addition, a sign bearing an exclamation mark and the words "electric trains stop ahead" on a white circular background with a red border [18.36] is installed at the entrance of each siding. |
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On the Channel Tunnel Rail Link (CTRL), which opened from 2003, signage associated with a neutral section mirrors French practice. The first sign encountered by drivers is a warning board stating the distance to the neutral section, in metres [18.37]. A sign positioned on the approach to, and close to the neutral section marks the point by which the main circuit breaker on the traction unit should have been opened [18.38]. If this has not occurred automatically, the driver should open the circuit breaker manually. Beyond the neutral section is a sign to indicate the point where the driver can reclose the main circuit breaker, if it has not occurred automatically [18.39]. If the train has more than one locomotive or power car in operation, the rearmost vehicle should have passed the sign before the circuit breaker is closed. An 'end of restriction' marker (see [25.44 & 25.45]) may be provided for this purpose.
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[18.37] Warning Sign for Neutral Section (e.g. 400 metres ahead).
Area: CTRL Usage: Medium Status: Obsolescent |
[18.38] Open Circuit Breaker Sign.
Area: CTRL Usage: Medium Status: Current |
[18.39] Close Circuit Breaker Sign.
Area: CTRL Usage: Medium Status: Current |
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