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Section 17: Signs at Bridges and Tunnels

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Signs that are associated with bridges or tunnels are mostly concerned with managing emergencies or other incidents that might occur at these features.



A restriction was imposed in March 1961 during reconstruction work on Harringay Viaduct (Eastern Region), prohibiting more than one locomotive from occupying the bridge portion of the viaduct. In the following month, boards with the letter "A" in black on a white background [17.1] were installed at each end of the bridge portion where the restriction applied.

[17.1] "A" Board.
Area: Harringay Viaduct   Usage: Low   Status: Historical

The Northern City Line in London (between Moorgate and Finsbury Park) is equipped with a tunnel emergency wire system. In the event of radio failure, drivers are issued with a tunnel wire telephone, which has to be clipped to the pair of tunnel wires to be used. On occasions when the tunnel wire system is defective, station staff will open a hinged flap on the headwall adjacent to the signal at the station before the affected section, to reveal a special sign showing a black telephone handset with a red diagonal cross superimposed [17.2]. The driver should make a radio test call to the signalman before entering the section where the tunnel wires are defective.

[17.2] 'Tunnel Emergency Wire System Inoperative' Sign.
Area: Northern City Line   Usage: Low   Status: Current

From December 1999, trackside bridge identification signs were fitted, on a trial basis, at certain underbridges (rail over road) on the London North Eastern Zone. The signs were designed to enable drivers to readily locate and identify bridges by their number should it be necessary in the event of an incident at or near the bridge. Each sign displays the bridge number and also the Engineer's Line Reference (ELR), which identifies the route. The word "bridge" appears at the top of the sign, but this can be replaced by "culvert" where appropriate. The sign is elliptical in shape and has a blue border [17.3]. The shape derives from the style of number plate originally affixed to bridges by many of the old railway companies.

Bridge identification signs were installed at a few underbridges on the Midlands Zone from March 2000. These signs are a similar shape to those on the London North Eastern Zone, but they omit the blue border and the word "bridge". The information on the sign is laid out in a different way, and it includes the mileage of the bridge [17.4].

[17.3] Bridge Identification Sign (e.g. ELR: LEN3; Bridge number: 154).
Area: LNE Zone (subsequently also Scotland Region)   Usage: High   Status: Current
[17.4] Bridge Identification Sign (e.g. Bridge number: 44; ELR: LEC1). Click Here for Photo
Area: Midlands Zone   Usage: Medium   Status: Current

Bridge identification signs were installed on the Southern Zone from 2000 to identify specific underbridges with a dispensation that allows trains to pass over them at 5 mph following a bridge strike. These signs show the ELR above the bridge number and the mileage below [17.5].

[17.5] Bridge Identification Sign (e.g. ELR: BML1; Bridge number: 105A).
Area: Southern Zone   Usage: Medium   Status: Current

Trials commenced in the Exeter area (Great Western Zone) in April 2001, involving temporary "bridge strike" signs being placed at rail bridges (underbridges or overbridges) that had been struck by road vehicles. The signs comprised a double-sided diagonal blue board with the words "bridge strike" [17.6]. They were positioned at the bridge concerned by rapid response staff attending a bridge strike incident. The aim was to assist drivers in locating the bridge concerned.

[17.6] Temporary "Bridge Strike" Sign.
Area: Great Western Zone   Usage: Low   Status: Historical

Later bridge identification signs on the London North Eastern Zone have the bridge's mileage stated on the sign [17.7]. Bridge identification signs of this type have been installed at certain overbridges (road over rail) on the London North Eastern Zone as well as at underbridges. There is also a miniature version, which omits the mileage and the word "bridge" [17.8].

[17.7] Bridge Identification Sign (e.g. ELR: ECM5; Bridge number: 193). Click Here for Photo
Area: LNE Zone   Usage: High   Status: Current
[17.8] Miniature Bridge Identification Sign (e.g. ELR: ECM5; Bridge number: 96).
Area: LNE Zone   Usage: Low   Status: Current

Bridge identification signs were installed on the Scotland Region from April 2004 to identify specific underbridges where a speed restriction applies to trains composed of HTA type coal hoppers. These signs are of a similar style to those originally provided on the London North Eastern Zone (see [17.3]).


Bridge identification signs were provided on certain parts of the London North Western Route to denote underbridges with a dispensation permitting movements at normal line speed following a bridge strike. These signs are similar to the original type provided on the London North Eastern Zone (see [17.3]) but have the ELR and bridge number both written in the same size of text [17.9].

[17.9] Bridge Identification Sign (e.g. ELR: OWW; Bridge number: 102).
Area: LNW Route   Usage: Medium   Status: Current

From May 2006, identification signs were installed at certain underbridges on the Scotland Route where Class 67 locomotives are subject to a speed restriction. These signs bear the bridge number and a name in black on a yellow background [17.10].

[17.10] Bridge Identification Sign.
Area: Scotland Route   Usage: Medium   Status: Uncertain

Section 2 of the Channel Tunnel Rail Link, which was opened in November 2007, includes three long twin-tube tunnels. Cross passages connect the two parallel tunnels at intervals of around 660 metres. The position of each cross passage is indicated by a sign with a yellow diamond on a black square background [17.11]. These signs are located about 25 metres beyond the centre line of each cross passage. Certain cross passages are specially equipped to facilitate emergency train evacuation and access for emergency services. These are marked by a sign bearing the letter "E" [17.12]. If a fire occurs on board and it is not possible for the train to continue until it is outside the tunnel, the front of the train should be stopped at one of these signs. This will ensure that the leading passenger door is alongside the evacuation cross passage. In the event of an incident, a driver may be instructed to stop the train at an "E" sign to evacuate passengers from a train in the opposite tunnel. To help drivers to stop at the correct location, the three cross passages on the approach to an evacuation cross passage have signs bearing the numbers "3", "2" and "1" [17.13].

[17.11] Cross Passage Sign.
Area: CTRL   Usage: Medium   Status: Current
[17.12] Evacuation Cross Passage Sign.
Area: CTRL   Usage: Medium   Status: Current
[17.13] Cross Passage Signs on approach to an evacuation cross passage.
Area: CTRL   Usage: Medium   Status: Current

Some bridge identification signs installed on the West Coast Main Line between London Euston and Rugby have the mileage at the top [17.14].

[17.14] Bridge Identification Sign (e.g. Bridge number: 62; ELR: LEC1).
Area: LNW Territory   Usage: Medium   Status: Current

In 2009, work was carried out at Shakespeare Tunnel, between Folkestone and Dover, in preparation for the Southeastern Highspeed services running between London and Dover via the Channel Tunnel Rail Link. Shakespeare Tunnel comprises two narrow parallel bores, each accommodating one track. Emergency passenger evacuation would normally take place through doors on the ends of trains; however, the streamlined Class 395 units that operate the new service have no such doors. Emergency evacuation can therefore only be carried out via doors on the side of the train. To allow for this, two existing passageways between the tunnel bores have been converted into evacuation passageways. Signage was installed in August 2009 to help drivers to stop their train at the correct location. In each bore, a stop sign reading "S1" has been provided adjacent to the first passageway, followed by a stop sign reading "S2" at the second passageway, 300 metres beyond [17.15]. Countdown signs with red diagonal bars [17.16] are installed inside each tunnel bore at 400 metres and 200 metres on the approach to the first stop sign.

[17.15] Stop Signs.
Area: Shakespeare Tunnel   Usage: Low   Status: Uncertain
[17.16] Countdown Signs ( (a) - Outer board; (b) - Inner board ).
Area: Shakespeare Tunnel   Usage: Low   Status: Uncertain

Most bridges on the former Western Region are identified only by their mileage and ELR. A form of bridge identification sign on the Western Route therefore only has that information, which is all presented in the same size of text [17.17].

[17.17] Bridge Identification Sign (e.g. ELR: OWW).
Area: Western Route   Usage: Low   Status: Current

Warning signs have been installed on the wrong-direction approaches to swing bridges in the Anglia Route that carry a double track railway (at Reedham and Somerleyton). These alert drivers to the presence of the swing bridge beyond, in the absence of a protecting signal for wrong-direction movements (e.g. during single line working). Each sign comprises a white triangular board with an exclamation mark and a yellow border, above a supplementary sign stating the name of the swing bridge and the distance to it [17.18].

[17.18] "Swing Bridge Ahead" Sign (e.g. Somerleyton).
Area: Anglia Route   Usage: Low   Status: Current

Opened in March 2021, the Crossrail Central Operating Section mainly comprises two parallel tunnels, which are connected by cross passages. A sign installed beyond each cross passage indicates the position where a train should be stopped in an emergency to align with the tunnel exit doors. Each sign has the words "cross passage" above an identification number, in black on a white background [17.19].

[17.19] Cross Passage Sign.
Area: Crossrail   Usage: Medium   Status: Current