Section 1: Early Signals
(Page 2 of 4)
Simple two-position board signals continued to be installed on different railways. The boards for indicating 'danger' were a variety of shapes [1.16 - 1.18], and all were turned edge on for 'clear'. The disc signal used on the Newcastle & Carlisle Railway from 1840 [1.16] applied to trains in both directions. The triangular signals used on the Stockton & Darlington Railway [1.17] originally had no lamps. When lamps were later added, they showed a red light for the 'danger' position, but when operated to the 'clear' position, no light was shown.
 |
 |
 |
[1.16] Board Signal showing 'Danger'.
Area: N&CR
Usage: Unknown
Status: Historical
|
[1.17] Board Signal showing 'Danger'.
Area: S&DR
Usage: Unknown
Status: Historical
|
[1.18] Board Signal showing 'Danger'.
Area: NER
Usage: Unknown
Status: Historical
|
|
The 'double vane' or 'spectacle' signal was used on a few railways from 1840. This displayed two circular vanes for the 'danger' indication [1.19]. Both vanes were turned edge on for the 'clear' indication.
|
 |
[1.19] Double Vane Signal showing 'Danger'.
Area: LB&SCR / L&YR
Usage: Unknown
Status: Historical
|
|
The signal designed by Summerson & Russell was used at a few locations on the Stockton & Darlington Railway from 1840 until about 1852. The 'danger' indication was a red light above a green light [1.20]. For the 'proceed with caution' indication, the red light was obscured by a metal shutter, leaving just the green light visible [1.21]. The red board at the top of the post was fixed and so acted as a permanent marker.
 |
 |
[1.20] Summerson & Russell Light Signal showing 'Danger'.
Area: S&DR
Usage: Unknown
Status: Historical
|
[1.21] Summerson & Russell Light Signal showing 'Caution'.
Area: S&DR
Usage: Unknown
Status: Historical
|
In March 1840, a 'ball signal' was erected on the approach to Reading station (Great Western Railway). Known as 'The Reading Ball', it was only intended as a temporary measure. When the ball was lowered to the ground [1.22], it indicated 'danger', and when raised to masthead [1.23] the meaning was 'clear'. Daniel Gooch, Locomotive Superintendent, famously said of this signal "if the ball is not visible the train must not pass it". Those words demonstrated that railway engineers were beginning to consider the principle of 'fail-safe', whereas early forms of signal had typically indicated 'clear' by their absence. During darkness, the signal was given by a white light. A similar signal was erected at Slough, but the ball signals were soon replaced by 'disc and crossbar' signals.
 |
 |
[1.22] Ball Signal showing 'Danger'.
Area: GWR
Usage: Low
Status: Historical
|
[1.23] Ball Signal showing 'Clear'.
Area: GWR
Usage: Low
Status: Historical
|
I K Brunel designed the 'disc and crossbar' signal for the Great Western Railway in 1840. This signal gave a positive indication for both 'danger' and 'clear'. In the 'danger' position, a black crossbar was displayed [1.24]. When the signal was turned to the 'clear' position, a white disc was displayed [1.25].
 |
 |
[1.24] Disc and Crossbar Signal showing 'Danger'.
Area: GWR
Usage: Unknown
Status: Historical
|
[1.25] Disc and Crossbar Signal showing 'Clear'.
Area: GWR
Usage: Unknown
Status: Historical
|
The 'double disc and crossbar' signal was introduced from 1841 for signalling branch line trains at junctions. Two crossbars were exhibited for the 'danger' position [1.26] and two discs for the 'clear' position [1.27]. In either position, two lights were displayed during darkness.
 |
 |
[1.26] Double Disc and Crossbar Signal showing 'Danger'.
Area: GWR
Usage: Unknown
Status: Historical
|
[1.27] Double Disc and Crossbar Signal showing 'Clear'.
Area: GWR
Usage: Unknown
Status: Historical
|
