216:
main and subsidiary lines or sidings existed. On some company's lines, a three-aspect semaphore prevailed and these showed an intermediate 'Caution' aspect and thus bore a three-lensed spectacle. In 1911, the
Metropolitan Line was first to use an upper-quadrant semaphore, the idea being brought over from the United States. Following nationalisation in 1948, British Railways standardised on upper-quadrant semaphores and all regions gradually adopted that mode, replacing lower-quadrant signals gradually except that the Western Region stayed with their well-proven and nicely proportioned lower-quadrant semaphores with eventually, a heavy cast iron spectacle bearing circular coloured glasses, replacing the former thinly bordered cast spectacle frame with shaped coloured glasses, the main arms being 4 feet (1.2 m) long and subsidiaries 3 feet (0.91 m) with other subsidiaries 2 feet (0.61 m) long. Previous GWR 5-foot (1.5 m) arms placed if higher than 26 feet (7.9 m) above rail level, were changed to 4 feet (1.2 m). All replacements were of enamelled steel and bore the appropriate arm colours, red with white band for 'Stop' arm and chevroned yellow arm with black chevron for 'Distant' (Caution) arms. Both types are white on the reverse side with black band or chevron as appropriate. The final 'Call-on', Shunt' or 'Warning' arms on the Western Region were 2 feet (0.61 m) with red-white-red horizontal stripes and showed a reduced light during darkness with the appropriate black letter, C, S or W, back-lit in the 'proceed' state with a green light shown in that mode. The stop aspect was generally lunar-white during darkness. All are now removed but examples can be seen on UK heritage lines. As at 2020, there are only a few remaining semaphore signals on the Western Region of Network Rail, LED signals having replaced the majority of semaphores.
240:
187:
horizontally in its most restrictive aspect; other angles indicate less restrictive aspects. On double lines in Great
Britain signal posts are generally placed on the left of the track and always with the semaphore arm(s) facing left with the spectacle and lamp on the right of the post or doll (but on the left of the post or doll for upper-quadrant signals). Sighting problems may mean that the post is placed on the right of the other line on double track branches and on single lines, could be placed either side of the track. North American semaphore equivalents faced right, and as generally on the European continent, on double track branches, up and down lines are opposite to those in the UK.
729:
90:
360:
778:
98:
575:
421:
620:
638:
32:
308:
806:
769:
1890s, automatic electric motor-driven semaphores were correctly seen as the future and were continued in manufacture well into World War II. Although the U.S. invented and manufactured 2-arm lower quadrant electro-gas and 3-position upper quadrant electric semaphores were experimented with in the U.K. (such as the ECML, at London
Victoria, respectively and in isolated areas elsewhere) they never were widely adopted by any means.
231:
operation and these arms face right of the post. German semaphore distant signals consist of one yellow disk with a black and white outline and an (optional) thin yellow arrow-shaped disk with a black and white outline. Both the disk and arrow have coloured lenses to aid drivers during nighttime. Those types were to be seen in some other countries which used German signalling principles.
252:
380:
grouped together, and in station areas were commonly routed beneath platform faces just above rail level. The operation of a single signal wire would cause some of the adjacent wires to 'jangle', and this noise was one of the many characteristic sounds of railway travel until the gradual introduction of colour-light signals from the mid 20th century.
468:, is usually located past the points etc. and controls entry to the block section ahead. The distance between the home and starting signals is usually quite short (typically a few hundred yards), and allows a train to wait for the section ahead of it to clear without blocking the line all the way back to the previous section.
320:
position means "clear". Thus, three indications can be conveyed with just one arm and without the need for a distant arm on the same post. The early abandonment of the three-position semaphore signal in the UK allowed for the widespread replacement of two-position lower-quadrant signals by two-position upper-quadrant signals.
715:
In the 19th century, a distant signal on the
Victorian Railways required the train to stop when the signal was at red, not just to proceed with caution as is the case now. However, having stopped at a distant signal at red, the train could then proceed carefully to the home signal, being prepared to
291:
The first
British railway semaphore signals had arms that could be worked to three positions, in the lower quadrant. Used in conjunction with the time-interval system, the arm horizontal meant "danger", inclined downwards at 45 degrees meant "caution" and the arm vertical (arm hidden within the post)
215:
of an oil wick flame, thus providing a correct red or green aspect during darkness. Most railways in Great
Britain employed lower-quadrant semaphores, that is to say, the arm dropped from the horizontal, the 'danger' aspect to 'clear' at up to 60° below horizontal and variations in appearance between
691:
In the U.K., until the 1920s, distant signals were coloured red, with a red light at night. Given that their meanings were different, it was obviously unsatisfactory to have both home and distant signals showing the same colour, but one of the problems which delayed a change in the colour of distant
388:
so that if power is lost or a linkage is broken, the arm will move by gravity into the horizontal position. For lower quadrant semaphores this requires the spectacle case to be sufficiently heavy to ensure the arm rises rather than falls; this is one of the reasons for the widespread switch to upper
343:
A third type of arm with a pointed end extending outward is often used (though not in the UK) to indicate that the signal operates automatically (as in automatic block signalling systems) and in many cases indicates that the signal is 'permissive', and can be passed when showing its most restrictive
696:
signal lamp to clarify night aspects; this was fitted to distant signals and showed a white vee in addition to the main red or green light. The
Ministry of Transport recommended that the colour of distant signal arms and spectacles be altered from red to yellow in the early 1920s, although this was
339:
From 1872, distant signal arms (see below) were distinguished by having a "fishtail" notch cut into the end. All signal arms were still painted red at this time. In the 1920s, the
British railway companies began to colour their distant signal arms yellow to better distinguish them from the red stop
156:
The semaphore was swiftly embraced as a fixed manual signaling system across
Britain and North America, surpassing all other types in most applications by 1870. Such signals as electrically operated automatic and interlocking signals were widely adopted in the U.S. After 1908 with the advent of the
736:
Where signals are closely spaced, a stop signal and a distant signal can be mounted on the same post. The distant signal is always the lower of the two. The two signals are "slotted" so that the distant signal can only clear if the stop signal is clear. Both signals display a light at night, which
768:
Train order signals were typically located at the station building or signal tower, with a tall common post mounting signal arms facing in opposing directions. These were supplemented by
Automatic Block Signal semaphores (a U.S. invention), first pneumatically powered in the 1880s and then by the
601:
of the worst braked train to use the route. This is particularly important on high-speed routes. At one time it was practice to take sighting distance into account when positioning distant signals; the distant signal could therefore be positioned at less than braking distance to the corresponding
379:
connected to the signal by single wires (UK), pairs of wires (Continental Europe), or pipes supported on rollers (North America). The levers were grouped together in a building known as a "signal box" (UK and Australia) or "interlocking tower" (North America). In the UK multiple signal wires were
328:
Red was quickly chosen as the best colour for semaphore arms as it was clearly visible against most backgrounds. To enhance the visibility of the arm, a marking of contrasting colour, such as a stripe or spot, is usually applied. The rear of the arm is usually coloured white with a black marking.
279:
lines. The advantage of the upper-quadrant signal is that should the signal wire break, or the signal arm be weighed down by snow (for instance), gravity will tend to cause the signal to drop to the safe "danger" position. In a lower-quadrant signal, the opposite may happen, sending the signal to
347:
For most types of semaphore arm, the colour of light shown when the arm is in the "on" (most restrictive) position generally corresponds to the colour of the arm itself (i.e. red for a stop signal, yellow for a distant signal). When the arm is in the "off" position, a green light is displayed.
319:
A later development was the upper-quadrant three-position semaphore signal. These worked in the upper quadrant to distinguish them from the then standard two-position lower-quadrant semaphores. When the arm is inclined upwards at 45 degrees, the meaning is "caution" and the arm in the vertical
124:
by changing the angle of inclination of a pivoted 'arm'. Semaphore signals were patented in the early 1840s by Joseph James Stevens, and soon became the most widely used form of mechanical signal. Designs have altered over the intervening years, and colour light signals have replaced semaphore
230:
German semaphore home signals, which are totally different in appearance to the British semaphore signal, include one or two white arms with a red outline and a small circular disk at the end of it, and coloured lenses which display the position of the aspect(s) of the signal during nighttime
186:
holding coloured lenses which move in front of a lamp in order to provide indications at night. Usually these were combined into a single frame, though in some types (e.g. "somersault" signals in which the arm pivoted in the centre), the arm was separate from the spectacle. The arm projects
274:
During the 1870s, all the British railway companies standardised on the use of semaphore signals, which were then invariably all of the lower-quadrant type. From the 1920s onwards, upper-quadrant semaphores almost totally supplanted lower-quadrant signals in Great Britain, except on former
605:
The driver of a train encountering a distant signal at 'caution' must expect the stop signal to be at 'danger' and must adjust the train's speed so as to bring the train to a stand before reaching it. The driver of a train encountering a distant signal in the 'clear' position knows that
455:
A particular signal box may control one or more stop signals on each running line. In a traditional mechanically signalled area in the United Kingdom, it is most common for a signal box to have two stop signals governing each line. The first reached by a train is known as the
545:
If any of the signals beyond the first stop signal are at 'danger', the previous signals will also be held at 'danger' until the train is almost at a stand, to indicate to the driver that the next signal is at 'danger'. This can be enforced by instruction or by electrical
748:
Shunting signals and subsidiary signals also exist in semaphore form, with smaller arms and lights than are provided for main signals. These signals may also take the form of a disc with a horizontal stripe which is rotated 45 degrees to the clear position.
383:
Semaphore signals may also be operated by electric motors, hydraulically or pneumatically, allowing them to be located further from the controlling signal box. In some cases, they can be made to work automatically. The signals are designed to be
280:"off" when in fact it should be illustrating "danger". Their spectacle cases, which are on the opposite side of the spindle on which the signal arm is pivoted, are therefore required to be sufficiently heavy to prevent this happening.
557:
In North America, the foregoing terminology was not used, as the development of North American signalling practice diverged from that in the United Kingdom during the late nineteenth century. In North America, where the term
393:
returns to its normal position when the controlling lever is put back. Otherwise, again, the signal could fail to return to danger. These counterweights are used just as commonly on upper- as on lower-quadrant signals.)
1502:
210:
with the original blue lens to maintain the correct colour or from 1996 on the Western Region of British Railways, a 12-volt 5-watt bulb was fitted but fed at 10.7 volts to produce a brilliance approximating to the
716:
stop short of any obstruction between the two signals. Thus the distant signal at that time was a bit like a later "outer home" signal. That practice at a distant signal at that time may have been a factor in the
336:(usually painted white) can be placed behind the arm to provide adequate contrast which improves visibility. Alternatively, part of a bridge abutment conveniently located behind a signal may be painted white.
202:, this produced a green colour; it was important that the resultant colour was not even yellow-green in appearance, as this could have been confused for a distant signal at 'caution'. Later signals using
1047:
845:
In the UK, semaphore signals are as of 2024 still present on the national network's secondary routes, though increased spending on renewals has led to a faster rate of decline in recent years.
271:
forms. In a lower-quadrant signal, the arm pivots downwards for the less restrictive (known as "off") indication. Upper-quadrant signals, as the name implies, pivot the arm upward for "off".
712:
retained the red distant signal everywhere, adding a fixed upper green light so that an isolated distant signal displayed green over red, like a combined home and distant signal at caution.
283:
Current British practice mandates that semaphore signals, both upper- and lower-quadrant types, are inclined at an angle of 45 degrees from horizontal to display an "off" indication.
613:
This is enforced by interlocking; the distant signal is prevented from assuming the 'clear' position unless all relevant stop signals controlled by the signal box display 'clear'.
190:
Depending on the arm's position, the appropriately coloured lens is illuminated from behind by either an oil lamp, a gas lamp, or an incandescent lamp run at a low voltage (white
1700:
161:'s Styles "B" & "S" and the General Railway Signal Company's universal Model 2A mechanisms manual semaphores and earlier electric disc signals quickly began to disappear.
597:
Because of the long distance required to bring a moving train to a stand, distant signals must be located on the approach to the corresponding stop signal by at least the
623:
A typical signal box layout. The crossover and level crossing are protected by the home signal, while a starting signal guards the entrance to the next block section.
813:
Mechanical signals worldwide are being phased out in favour of colour light signals or, in some cases, signalling systems that do not require lineside signals (e.g.
538:
might be used at a location where it might be desirable to advance a train from a station platform before the section ahead becomes available. In this scenario, the
194:
clusters have also been tested for this purpose). Where a green light was required, a blue lens would usually be used. When combined with the mainly yellow-emitting
340:
signals. The red lenses in distant signals were changed to yellow at the same time. The practice of using red distant arms has survived in some countries however.
239:
526:
mile (440 yd; 400 m) clear of any points or sidings. This allows trains to approach when the station or junction is obstructed by another train.
582:
A signal that provides advance warning of a stop signal ahead (and which does not compel a stop when in its most restrictive position) is referred to as
371:
Worldwide, the first semaphore signals were controlled by levers situated at the signals. Some early signals protruded from the roof of the controlling
389:
quadrant signals. (The purpose of the balance weight often found on a lever lower down the post of a semaphore signal is actually to ensure the signal
740:
Exceptionally in New South Wales home and distant signals controlled from the same signal box would be installed, especially on outer home signals.
904:
693:
648:
42:
219:
Materials that were commonly used to make signal posts for semaphore signals included timber, lattice steel, tubular steel and concrete. The
697:
not universally adopted in the UK until the late 1920s. Since this time, the yellow caution aspect has remained a British railway standard.
1457:
1367:
1152:
1447:
1392:
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permits the train to draw forward from the station area toward the advanced starting signal, which controls entry to the section ahead.
708:
changed only isolated distant signals, leaving combined home and distant signals showing green over red at the caution position. The
820:
In North America, mechanical signals are almost gone from main lines. As of 2024, the only significant remaining installation was on
586:. The term originated in the UK and is used throughout the English-speaking world. In some regions, notably North America, the terms
616:
Unlike British signals, all German home signals have a respective distant signal and these are both operated from the same lever.
1720:
1357:
485:
aspect if the upper arm is in a 45 degree position (diagonal). Home signals may have an additional lower arm which can display a
142:
297:
304:
when a train passed a signal giving a false "clear" aspect because the signal arm had frozen into its slot during a blizzard.
1715:
1674:
761:
signals, with the purpose of indicating to engineers whether they should stop to receive either a "19 Order" or a "31 Order"
244:
1517:
1250:
692:
signals to yellow was the lack of a suitable yellow glass for the spectacle frame. Some British railway companies used the
497:
At some locations, more than one home signal might be provided on the same line. These will be identified by names such as
1512:
1462:
1432:
709:
1705:
1192:
1437:
1811:
1806:
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678:
432:
is any signal whose most restrictive indication is 'danger' (which compels a stop). Stop signals are used to protect
293:
76:
1407:
1101:
351:
Other shapes and colours of semaphore arms were used for specific purposes in different countries around the world.
1664:
1145:
220:
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1730:
1710:
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403:
1761:
1746:
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54:
1422:
1212:
149:, southeast London, about 1842 on the newly enlarged layout also accommodating the South Eastern Railway.
1862:
1816:
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1138:
728:
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1826:
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138:
1821:
1776:
1679:
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1382:
1334:
1182:
1177:
562:
is in common usage, it generally refers to the "generic" British definition of 'stop signal', namely
409:
359:
1831:
1801:
1796:
1786:
1751:
1669:
1477:
1402:
1270:
158:
89:
58:
990:
656:
50:
1836:
1634:
1619:
1377:
1349:
1169:
854:
777:
364:
1614:
1604:
1553:
1472:
1467:
1197:
789:
Railway-style semaphore signals have been used to control movements of boats or ships (e.g. at
717:
134:
300:
was the first company to introduce "somersault" signals, mounted away from the post, after an
1841:
1275:
1265:
1227:
1222:
758:
276:
97:
1397:
762:
206:
used green lenses. Some signals converted to electric lamps from oil, used a yellow-tinted
191:
150:
8:
1624:
1507:
1867:
1237:
1161:
898:
701:
212:
1659:
1563:
1339:
1025:
974:
953:
932:
121:
1725:
1654:
1629:
1609:
1427:
598:
574:
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aspect if the upper arm is in a 90 degree position (horizontal), and can display a
449:
1125:
1105:
838:
437:
433:
408:
The following section describes semaphore signals as they were and are used with
420:
292:
meant "clear". The vertical indication gradually came to be discontinued as the
1452:
1298:
1285:
869:
794:
732:
British semaphore stop and distant signals on common post (lower quadrant type)
445:
441:
203:
113:
19:"Semaphore signal" redirects here. For other signals sent using semaphore, see
1856:
1639:
1527:
1329:
1075:
1070:
1042:
1003:
825:
551:
619:
1573:
1417:
1324:
1255:
1207:
821:
790:
782:
547:
1599:
174:
The British semaphore signal arm consists of two parts: A wooden or metal
1260:
1118:
1098:
376:
315:, showing the distinctive central pivot about which the arm "somersaults"
224:
1649:
1522:
1487:
1245:
829:
372:
207:
101:
German semaphore distant (left) and home (right) signal exhibition in
93:
Upper quadrant semaphore signals at Castleton East Junction in England
1558:
1130:
705:
385:
146:
117:
102:
20:
307:
120:
system involves signals that display their different indications to
1644:
1568:
805:
256:
199:
1589:
1492:
1076:
The Dubbo Liberal and Macquarie Advocate (NSW : 1892 - 1927)
1051:. WA: National Library of Australia. 17 September 1926. p. 3
859:
332:
Where particularly poor background contrast cannot be avoided, a
251:
1079:. NSW: National Library of Australia. 4 November 1927. p. 5
1048:
The Bunbury Herald and Blackwood Express (WA : 1919 - 1929)
1594:
1442:
1412:
833:
737:
means that the 'danger' indication appears as red over yellow.
610:
controlled by the same signal box are in the 'clear' position.
1372:
814:
367:. These levers are connected to the signal by pairs of wires.
195:
125:
signals in most countries, but in a few they remain in use.
1362:
757:
In North America, the earliest semaphores were employed as
363:
Semaphore signal levers inside train dispatcher's room of
286:
247:, 1943. The vertical position indicates a "clear" aspect.
153:
claimed to have suggested the idea to Hutton Gregory.
578:
British semaphore distant signal (lower quadrant type)
566:
signal whose most restrictive indication is 'danger'.
516:
An outer home generally protects a neutral section of
889:
Dendy Marshall, C.F., revised by R.W. Kidner (1963).
723:
234:
424:
British semaphore stop signal (lower quadrant type)
743:
489:(40 km/h); however, these are not mandatory.
133:The first railway semaphore signal was erected by
993:Signals, Handsignals, Indicators and Signs, p. 26
785:Navigation, directing boats into the paired locks
1854:
1119:Section on signals from 'The Signal Box' website
627:
969:Kichenside, G. M. & Williams, Alan (1978),
991:Rail Safety and Standards Board Handbook RS521
888:
809:Abandoned German semaphore with missing lenses
1146:
824:'s Glorieta & Raton Subdivisions through
645:The examples and perspective in this section
323:
296:system superseded time-interval working. The
39:The examples and perspective in this article
1458:Interoperable Communications Based Signaling
903:: CS1 maint: multiple names: authors list (
793:) and also to control road traffic (e.g. at
472:
223:in Great Britain frequently made use of old
1393:Automatic Train Protection (United Kingdom)
1109:Railways: History, Signalling, Engineering.
1153:
1139:
971:British Railway Signalling, Fourth Edition
663:, or create a new section, as appropriate.
375:. Later, remote operation was effected by
182:) which pivots at different angles, and a
679:Learn how and when to remove this message
77:Learn how and when to remove this message
804:
776:
727:
618:
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419:
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306:
250:
238:
96:
88:
1358:Advanced Civil Speed Enforcement System
287:Two-position and three-position signals
143:London Brighton and South Coast Railway
1855:
1160:
752:
112:is one of the earliest forms of fixed
1518:Train Protection & Warning System
1134:
460:. The last stop signal, known as the
1251:Integrated Electronic Control Centre
1043:"A Third Colour for Railway Signals"
1022:An Illustrated History of Signalling
1002:
929:An Illustrated History of Signalling
631:
550:, which requires the provision of a
529:
25:
1513:Train automatic stopping controller
1433:Continuous Automatic Warning System
800:
772:
710:New South Wales Government Railways
13:
1193:Communications-based train control
918:The National Archives RAIL 386.58.
569:
14:
1879:
1010:. London: John Lane. p. 120.
891:A History of the Southern Railway
724:Combined stop and distant signals
235:Lower quadrant and upper quadrant
893:. London: Ian Allan. p. 50.
636:
30:
1675:Westinghouse Brake & Signal
1438:Contrôle de vitesse par balises
1304:North American railroad signals
1091:
1063:
744:Shunting and subsidiary signals
554:on the approach to the signal.
471:German home semaphore signals (
415:
255:Lower-quadrant stop signals at
1533:Transmission balise-locomotive
1498:Sistema Controllo Marcia Treno
1408:Automatische treinbeïnvloeding
1294:Application of railway signals
1035:
1014:
996:
984:
963:
950:Signalling in the Age of Steam
942:
921:
912:
882:
440:(North America - 'switches'),
404:Application of railway signals
1:
1483:Punktförmige Zugbeeinflussung
1203:European Train Control System
875:
865:Pass of Brander stone signals
628:Changes in colour and meaning
492:
313:Carrickfergus railway station
243:Upper-quadrant signal on the
169:
1423:Chinese Train Control System
1213:Radio Electronic Token Block
354:
16:Form of fixed railway signal
7:
1188:Centralized traffic control
848:
659:, discuss the issue on the
608:all applicable stop signals
263:British semaphores come in
53:, discuss the issue on the
10:
1884:
1388:Automatic train protection
594:are both in common usage.
401:
324:Colouring and shape of arm
139:London and Croydon Railway
128:
18:
1739:
1688:
1680:Westinghouse Rail Systems
1582:
1546:
1538:Transmission Voie-Machine
1383:Automatic train operation
1348:
1335:Track circuit interrupter
1317:
1284:
1236:
1183:Automatic block signaling
1178:Absolute block signalling
1168:
410:absolute block signalling
159:Union Switch & Signal
1478:Pulse code cab signaling
1403:Automatic Warning System
1309:Railway semaphore signal
1271:Solid State Interlocking
536:advanced starting signal
487:proceed at reduced speed
397:
344:aspect, at a low speed.
302:accident in January 1876
110:Railway semaphore signal
1378:Automatic train control
855:Signal passed at danger
412:in the United Kingdom.
365:Cianjur railway station
164:
1554:Level crossing signals
1473:Positive Train Control
1468:Linienzugbeeinflussung
1198:Direct traffic control
1099:"Train Order Signals."
1097:Calvert, J.B. (2004).
810:
786:
733:
718:Sunshine rail accident
624:
579:
473:
425:
368:
316:
311:Somersault signals at
298:Great Northern Railway
260:
248:
135:Charles Hutton Gregory
106:
94:
1276:Westlock Interlocking
1266:Rail operating centre
1228:Train order operation
1223:Track Warrant Control
1020:Vanns, M.A., (1997),
948:Vanns, M. A. (1995),
927:Vanns, M. A. (1997),
808:
780:
731:
622:
577:
423:
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310:
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242:
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92:
1398:Automatic train stop
657:improve this section
647:may not represent a
151:John Urpeth Rastrick
59:create a new article
51:improve this article
41:may not represent a
832:, which is used by
753:Train order signals
452:or block sections.
1863:Railway signalling
1238:Signalling control
1162:Railway signalling
1124:2018-08-31 at the
1104:2007-06-10 at the
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702:Victorian Railways
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227:for signal posts.
213:colour temperature
107:
95:
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1849:
1660:Smith and Yardley
689:
688:
681:
530:Advanced starting
245:Santa Fe Railroad
87:
86:
79:
61:, as appropriate.
1875:
1726:Transport Canada
1610:General Electric
1547:Crossing signals
1428:Cityflo 650 CBTC
1350:Train protection
1155:
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988:
982:
967:
961:
946:
940:
925:
919:
916:
910:
908:
902:
894:
886:
801:Decline in usage
773:Non-railway uses
684:
677:
673:
670:
664:
640:
639:
632:
599:braking distance
525:
524:
520:
477:) can display a
476:
474:Hauptformsignale
221:Southern Railway
82:
75:
71:
68:
62:
34:
33:
26:
1883:
1882:
1878:
1877:
1876:
1874:
1873:
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1853:
1852:
1851:
1846:
1735:
1684:
1578:
1542:
1344:
1318:Train detection
1313:
1280:
1232:
1164:
1159:
1126:Wayback Machine
1115:
1114:
1106:Wayback Machine
1096:
1092:
1082:
1080:
1069:
1068:
1064:
1054:
1052:
1041:
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1036:
1019:
1015:
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997:
989:
985:
968:
964:
947:
943:
926:
922:
917:
913:
896:
895:
887:
883:
878:
851:
839:Southwest Chief
803:
795:level crossings
781:Signals on the
775:
755:
746:
726:
685:
674:
668:
665:
654:
641:
637:
630:
592:approach signal
572:
570:Distant signals
540:starting signal
532:
522:
518:
517:
495:
446:movable bridges
442:level crossings
418:
406:
400:
357:
326:
289:
237:
172:
167:
131:
114:railway signals
83:
72:
66:
63:
48:
35:
31:
24:
17:
12:
11:
5:
1881:
1871:
1870:
1865:
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1842:United Kingdom
1839:
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1829:
1824:
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1799:
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1460:
1455:
1453:Integra-Signum
1450:
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1337:
1332:
1327:
1321:
1319:
1315:
1314:
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1306:
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1299:Cab signalling
1296:
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1279:
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1273:
1268:
1263:
1258:
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1234:
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1150:
1143:
1135:
1129:
1128:
1113:
1112:
1090:
1062:
1034:
1013:
1008:Red for Danger
995:
983:
962:
941:
920:
911:
880:
879:
877:
874:
873:
872:
870:Semaphore line
867:
862:
857:
850:
847:
802:
799:
774:
771:
754:
751:
745:
742:
725:
722:
687:
686:
651:of the subject
649:worldwide view
644:
642:
635:
629:
626:
588:distant signal
584:distant signal
571:
568:
531:
528:
494:
491:
466:section signal
417:
414:
402:Main article:
399:
396:
356:
353:
334:sighting board
325:
322:
294:absolute block
288:
285:
269:upper-quadrant
265:lower-quadrant
236:
233:
204:electric lamps
171:
168:
166:
163:
130:
127:
85:
84:
45:of the subject
43:worldwide view
38:
36:
29:
15:
9:
6:
4:
3:
2:
1880:
1869:
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1812:North America
1810:
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1714:
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1691:
1689:Organisations
1687:
1681:
1678:
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1668:
1666:
1663:
1661:
1658:
1656:
1653:
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1640:Progress Rail
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1583:Manufacturers
1581:
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1528:Trainguard MT
1526:
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1330:Track circuit
1328:
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1170:Block systems
1167:
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1144:
1142:
1137:
1136:
1133:
1127:
1123:
1120:
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1107:
1103:
1100:
1094:
1078:
1077:
1072:
1066:
1050:
1049:
1044:
1038:
1031:
1030:0-7110-2551-7
1027:
1024:, Ian Allan,
1023:
1017:
1009:
1005:
999:
992:
987:
980:
979:0-7110-0898-1
976:
973:, Ian Allan,
972:
966:
959:
958:0-7110-2350-6
955:
952:, Ian Allan,
951:
945:
938:
937:0-7110-2551-7
934:
931:, Ian Allan,
930:
924:
915:
906:
900:
892:
885:
881:
871:
868:
866:
863:
861:
858:
856:
853:
852:
846:
843:
841:
840:
835:
831:
827:
826:Glorieta Pass
823:
818:
816:
807:
798:
796:
792:
791:swing bridges
784:
779:
770:
766:
764:
760:
750:
741:
738:
730:
721:
719:
713:
711:
707:
703:
698:
695:
694:Coligny-Welch
683:
680:
672:
662:
658:
652:
650:
643:
634:
633:
621:
617:
614:
611:
609:
603:
602:stop signal.
600:
595:
593:
589:
585:
576:
567:
565:
561:
555:
553:
552:track circuit
549:
543:
541:
537:
527:
514:
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504:
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469:
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411:
405:
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387:
381:
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366:
361:
352:
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314:
309:
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299:
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258:
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232:
228:
226:
222:
217:
214:
209:
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197:
193:
188:
185:
181:
177:
162:
160:
154:
152:
148:
144:
140:
136:
126:
123:
122:train drivers
119:
115:
111:
104:
99:
91:
81:
78:
70:
67:February 2018
60:
56:
52:
46:
44:
37:
28:
27:
22:
1670:Union Switch
1574:Wayside horn
1418:Catch points
1325:Axle counter
1308:
1256:Interlocking
1208:Moving block
1108:
1093:
1081:. Retrieved
1074:
1065:
1053:. Retrieved
1046:
1037:
1021:
1016:
1007:
1004:Rolt, L.T.C.
998:
986:
970:
965:
949:
944:
928:
923:
914:
890:
884:
844:
837:
822:BNSF Railway
819:
812:
788:
783:River Weaver
767:
756:
747:
739:
735:
714:
699:
690:
675:
669:January 2013
666:
646:
615:
612:
607:
604:
596:
591:
587:
583:
581:
563:
559:
556:
548:interlocking
544:
539:
535:
533:
515:
511:second home
510:
506:
502:
498:
496:
486:
482:
478:
470:
465:
461:
457:
454:
429:
427:
416:Stop signals
407:
390:
382:
370:
350:
346:
342:
338:
333:
331:
327:
318:
290:
282:
273:
268:
264:
262:
229:
218:
189:
183:
179:
175:
173:
155:
132:
109:
108:
73:
64:
40:
1832:Switzerland
1807:New Zealand
1802:Netherlands
1508:Slide fence
1261:Lever frame
1071:"WONGARBON"
763:telegraphed
759:train order
560:home signal
458:home signal
430:stop signal
141:(later the
1857:Categories
1740:By country
1523:Train stop
1488:RS4 Codici
1246:Block post
1083:31 January
1055:31 January
876:References
830:New Mexico
507:first home
503:inner home
499:outer home
493:Outer home
373:signal box
170:Components
1868:Semaphore
1747:Australia
1600:AŽD Praha
1559:Crossbuck
1463:Crocodile
899:cite book
720:of 1908.
706:Australia
661:talk page
450:platforms
434:junctions
386:fail-safe
355:Operation
184:spectacle
147:New Cross
118:semaphore
105:, Germany
103:Steinfurt
55:talk page
21:Semaphore
1837:Thailand
1645:Safetran
1635:Magnetic
1620:Griswold
1569:E-signal
1122:Archived
1102:Archived
1006:(1955).
849:See also
655:You may
462:starting
257:St. Erth
200:oil lamp
49:You may
1782:Germany
1772:Finland
1757:Belgium
1752:Bavaria
1655:Siemens
1630:Hitachi
1605:Federal
1590:Adtranz
1493:SelTrac
1340:Treadle
1286:Signals
981:, p. 15
960:, p. 80
939:, p. 25
860:Rule 55
521:⁄
483:proceed
259:in 2007
180:"blade"
137:on the
129:Origins
116:. This
1827:Sweden
1822:Poland
1817:Norway
1787:Greece
1777:France
1762:Canada
1665:Thales
1595:Alstom
1564:Wigwag
1443:EBICAB
1413:Balise
1032:, p.75
1028:
977:
956:
935:
834:Amtrak
479:danger
438:points
377:levers
198:of an
1797:Japan
1792:Italy
1767:China
1701:AREMA
1650:Saxby
1503:SACEM
1448:IIATS
1373:ATACS
1218:Token
815:ERTMS
513:etc.
505:, or
398:Usage
196:flame
145:) at
57:, or
1721:IRSE
1716:HMRI
1625:Hall
1368:ASFA
1363:ALSN
1085:2013
1057:2013
1026:ISBN
975:ISBN
954:ISBN
933:ISBN
905:link
700:The
590:and
501:and
391:wire
267:and
225:rail
208:bulb
178:(or
165:Form
1731:UIC
1711:FRA
1706:ERA
1696:AAR
1615:GRS
836:'s
828:in
817:).
797:).
704:in
564:any
534:An
464:or
277:GWR
192:LED
176:arm
1859::
1073:.
1045:.
901:}}
897:{{
842:.
765:.
509:,
448:,
444:,
436:,
428:A
1154:e
1147:t
1140:v
1087:.
1059:.
909:.
907:)
682:)
676:(
671:)
667:(
653:.
523:4
519:1
80:)
74:(
69:)
65:(
47:.
23:.
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
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