296:
cabinet; its front face displaying two indicators, a commutator handle, a bell and a tapper. The upper indicator shows the state of the forward block – along the line leading away from the signal box. The commutator is used by the signalman to indicate the state of his block, and the lower indicator displays this state, which is also displayed on a repeater indicator in the box for the block from which a train will come. At the bottom is a single-stroke bell and the tapper to sound the bell in the next box. The commutator and each of the two indicators has three positions: normal (or line blocked), line clear, and train on line. In the simplest case of a signal box serving a two-track section, there will be two block instruments, one for communicating with each of the neighbouring boxes.
598:(FOC), are allocated to one of ten classes, as set out below. It is a generalized guide intended to assist signalling staff in prioritizing trains according to their importance as well as ensuring that any special instructions that may apply at a specific location are carried out. Passenger trains are generally classified in accordance with their stopping pattern while the classification of freight trains depends upon maximum permitted speeds. Class 1 trains (together with Class 9 services, which are officially their equivalent in this regard) have the highest priority, followed by Class 2 and then so on down the list.
257:. Cooke's ideas were not taken up by the railway companies until the 1850s and 1860s. When they were developed into a practical system, it provided the ability for signalmen to communicate with each other and provided the basis for the absolute block system. By 1872 it was used on 44% of lines in Britain, rising to 75% by the end of the decade and was made mandatory on passenger-carrying lines in 1889. It successfully managed train control over most of the British railway system until generally superseded by more sophisticated systems from 1950.
330:
314:
361:. Each communication starts with a single strike of the bell meaning “Call attention”. The recipient signalman then shows that he has received the message by repeating it back to the sender. All subsequent bell messages are acknowledged promptly by repeating back to the sender – with the single exception of six strikes which indicate “Obstruction danger” which is not echoed back until all relevant signals have been set to “Stop”.
280:
271:
66:
300:
with box A will be used to receive on the bell a request from box A to take an up train. The other block instrument will do the same for box C for a down train. The commutator and lower display on the two instruments relate to the up line and the down line respectively. The upper display is a repeater from the signal box of the block ahead.
179:. This normally takes the place of an old absolute block section, and is commonly found where former absolute block sections and their associated signal boxes have been removed. Essentially an intermediate block section allows two block sections, and therefore two trains, to be on the same line but controlled by the same signal box.
97:, although some contemporary block working is operated wirelessly. This process is repeated for every block section a train passes through. The absolute block system does not replace the use of any other form of signalling, such as fixed signals, hand signals, or detonators – and, in fact, usually relies on fixed signals.
183:
intermediate block home section. The line from the intermediate block home signal to the home signal of the next signal box on the same line in the same direction of travel is the absolute block section. To clear the intermediate block home signal a "line clear" is required from the signal box in advance.
378:
on the block bell; for example to offer an express passenger train, he sends four beats consecutively; an ordinary passenger train is offered by sending three beats, and after a pause one more beat, usually written as 3-1. If the signalman at B can accept the train safely (if the line is clear up to B's
490:
B immediately offers the train on to C, after calling for attention, by sending the "Is Line Clear?" bell signal (repeating the same steps A had done while offering the train to B); if C accepts it, he repeats the bell signal and places his block indicator to "Line Clear", which moves the position of
288:
British
Railways standard block instrument. At the bottom is the tapper, bell and the commutator switch that is used to set the status of the block (close-up on the right). Above that is the indicator of the block's status which is also seen in an adjacent signal box. At the top is a repeater display
57:
by allowing only one train to occupy a defined section of track (block) at a time. Each block section is manually controlled by a signalman, who communicates with the other block sections via telegraph. This system was used on double or multiple lines where use of each line is assigned a direction of
494:
After an interval, the train will arrive and pass B; as it does so, B sends "Train
Entering Section" on the block bell to C. Then C acknowledges the bell signal and places the block instrument to "Train On Line". As the train passes, he restores his signals to danger, and when the whole of the train
382:
and will not need to be blocked by another train) he "accepts" the train by repeating the bell signal, and placing the commutator on his block instrument for the section from A to "Line Clear". The "Line Clear" is repeated at box A, and allows the signalman at A to clear, or "pull off", his signals.
377:
An example is the process of signalling a train in the up direction (from A to C) past a signal box B. The signal box in rear is A and the signal box in advance is C. The block indicators at B are in the Normal position. The signalman at A "offers" the train to B by sending an "Is Line Clear?" code
990:
Not preceded by "call attention" because it is used in an emergency. Signalman receiving it must immediately stop, using fixed signals and/or a red flag, any train travelling towards the signal box from which "obstruction danger" was sent; only once he is sure that this has been achieved should he
581:
bell signal describes the train, distinguishing between ordinary and express passenger trains, and various categories of goods train. In some locations, routing information is included in the bell code, such an ordinary passenger train to be routed to a branch at the signal box in advance would be
445:
At this point, B will not clear any of his signals. Firstly, he cannot clear his starting signal without a "Line Clear" from C. As a result, B will not clear his home signal – he can only clear it when he either has a clear run through (which he does not have without a "Line Clear" from C), or is
299:
In a simple double line configuration, where the signal boxes are A, B and C in succession in the up direction, the signal box at B will have two block instruments, one for communicating with box A for trains on the up line and one for box C for down trains. The block instrument for communicating
199:
at that signal box (this does not necessarily refer to a passenger station). Within station limits, the signalman controls the safe movement, and in normal circumstances he can directly see the position of trains there. Usually no communication with other signalmen is needed for movements within
295:
Block instruments are located in signal boxes. They show the state of the block sections before and after the signal box. Originally the different displays and commutator handle were in a variety of cabinets. The standard
British Railways block instrument brought them together in a single small
100:
Prior to the introduction of block systems, time intervals were used to keep trains sufficiently far apart; typically if five minutes had passed since the first train had departed then a second train was allowed to proceed; although the driver was warned that there was a train only five minutes
186:
An intermediate block section means that a train can approach the intermediate block home signal while there is a train between the intermediate block home signal and the home signal of the next signal box on the same line in the same direction of travel. Generally, all intermediate block home
449:
As the train passes the starting signal at A, the signalman there sends the "Train
Entering Section" signal (2 beats) on the block bell to B, and the signalman at B acknowledges the signal and moves the commutator to "Train On Line". His lower indicator on the block indicator to A repeats the
182:
Typically, a signal box with an intermediate block section will have a home signal (and associated distant signal), starting signal and an intermediate block home signal which has its own distant signal. The line from the starting signal to the intermediate block home signal is called the
135:. A block section is normally the section of track from the most advanced signal controlled by the signal box in rear, and the rearmost signal controlled by the signal box in advance. Because many signal boxes are at stations, the last signal controlled by the rear box is called the
495:
passes B complete with tail lamp attached, B sends the "Train Out Of
Section" bell signal (2-1) to A and when A acknowledges it, he places his block indicator to "Normal". The block section between A and B is now normal and A can offer B another train, if he has one.
565:
Bell codes are used to communicate with adjacent signal boxes. They can communicate information regarding the type of train being offered, the status of trains within sections or emergency information. A bell code is acknowledged as being understood by repetition.
1852:
446:
confident that the train will be able to stop at his starting (or section) signal (this is not done until the train is in view and visibly under control). Finally, his distant will not clear without both his home and starting signals being clear.
370:
2050:
882:
Sent in response to "Is Line Clear?", when authorised. The line is clear up to the home signal, but the line between the home signal and clearing point is blocked. The accepted train must be warned.
373:
The location of signals at signal boxes A, B and C. Up is defined as being towards C, and only signals in the Up direction are shown for clarity. Our example train will travel in the Up direction.
253:
2 to 5 miles (3.2 to 8.0 km) long that were to be connected together by telegraph, with instruments that showed the state of each stage. In 1842 he published these ideas in a book entitled
354:
design that is used to communicate from one signal box to an adjacent one. Each bell has its own distinctive sound so that the signalman knows which box is communicating with him.
785:
The attention signal is used to confirm that the called box is listening. A single bell is sent to the called box and repeated back to the calling box before each signal is sent.
2217:
557:
When the train has reached C, the signalman there sends "Train Out Of
Section" on the block bell and when B acknowledges it, C places the block indicator to "Normal".
1183:
89:
the train, and the first signalman may clear his signals to give permission for the train to enter the section. This communication traditionally takes place by
1717:
1807:
1502:
1797:
1742:
814:
Engine assisting in rear (known as 'bankers') sent after train entering section—normally to assist freight trains or long passenger trains up steep hills
649:
Freight train capable of running at more than 75 mph; parcels train; nominated (priority) empty passenger trains; autumn railhead treatment train
2212:
2070:
1707:
1309:
Telegraphic
Railways: Or The Single Way Recommended By Safety, Economy, And Efficiency, Under The Safeguard And Control Of The Electric Telegraph
255:
Telegraphic
Railways: Or the Single Way Recommended by Safety, Economy, and Efficiency, Under the Safeguard and Control of the Electric Telegraph
2065:
2024:
1471:
1452:
1414:
218:
and was developed in the 1840s and 1850s at the same time as the development of railways. The first commercial electrical telegraph was the
145:, which a train should not pass if they are in the on position, showing a red light. The first stop signal controlled by a box is called the
1600:
1867:
1862:
1812:
1782:
195:
The extent of the line from the rearmost home signal to the most advanced starting signal controlled from the same signal box is called
2055:
1787:
1542:
1316:
1055:
Performed every time a signal box is opened and every time two signal boxes are connected after an intermediate 'box is switched out.
383:
In case the line is not clear, B simply does not acknowledge A's "Is Line Clear?", and leaves the commutator in the Normal position.
2161:
2156:
2045:
1433:
1166:
1757:
2014:
1832:
1495:
139:, whether or not there is a station at which trains stop. This signal, and the rearmost signal controlled by the box ahead, are
2080:
2060:
1653:
1882:
1847:
1643:
871:
Only sent on blocking back and shunt moves on a line on which it was travelling in the opposite direction to normal traffic.
762:
These codes are supplemented by codes either side, to show the status of the train within the section or the section itself:
219:
150:
117:) is a section of railway line between one signal box and another – in the typical absolute block, lines are paired, with an
838:
Given to the signal box in rear if a shunting movement will block the line between the home signal and the clearing point.
2111:
2096:
1552:
239:
491:
the upper needle indicator in B's block instrument to repeat that indication. B may now clear his signals for the train.
1772:
1562:
379:
2166:
1537:
1488:
2176:
2141:
2131:
2121:
2116:
2106:
1737:
1567:
912:
623:
Express passenger train; nominated postal or parcels train; breakdown train or snowplough going to clear the line
93:
and status indications transmitted over a simple telegraph wire circuit between signalmen using a device called a
2171:
2126:
2029:
1887:
1732:
1684:
1532:
1067:
595:
31:
2181:
2151:
2146:
2136:
2101:
1827:
1752:
1658:
1620:
1304:
223:
141:
2019:
101:
ahead. This was insufficient to prevent a train colliding with the rear of one that had stopped unexpectedly.
2186:
1984:
1969:
1727:
1699:
1519:
591:
50:
1964:
1954:
1903:
1822:
1817:
1547:
227:
727:
Class 373 train (Eurostar); also used for any other specially authorized train and all trains on the new
2191:
1625:
1615:
1577:
1572:
1747:
350:, is used in conjunction with the block instruments if the bell is not integrated with them. It is a
242:
for signalling rope-hauling of carriages (as the locomotives could not cope with the steep incline).
209:
70:
1974:
1857:
860:
Given to the signal box in advance after a shunting movement is complete and outside the section.
1587:
1511:
90:
1275:"A History of the Telegraph Companies in Britain between 1838 and 1868: 3. Cooke and Wheatstone"
1213:
636:
Ordinary passenger train; breakdown train not going to clear the line; officers' special train
2009:
1913:
1689:
1467:
1448:
1429:
1410:
1312:
1162:
235:
187:
signals and their respective distants are colour light signals, normally showing two aspects.
2075:
2004:
1979:
1959:
1777:
1072:
728:
215:
82:
159:
aspect if all stop signals under a signal box's control are clear, and will otherwise show
127:
line in the opposite direction. The signal box towards which a train travels is said to be
119:
903:
Used in when a train has divided mid-section, and both parts are likely to pass through.
1024:
Should be followed, once acknowledged, by a telephone message explaining what is amiss.
1802:
1648:
1635:
849:
Given to the signal box in advance if a shunting movement needs to enter the section.
2206:
1989:
1877:
1679:
351:
320:
59:
1274:
369:
279:
1923:
1767:
1674:
1605:
1557:
1231:
827:
Given to the signal box in rear if a shunting movement needs to enter the section.
796:
Does not require "call attention", as the signalman knows he has accepted a train.
329:
313:
270:
1949:
569:
Nearly all bell codes are preceded by a single stroke on the bell, referred to as
1404:
1610:
231:
85:
to his counterpart at the next signal box. If the section is clear, the latter
65:
1999:
1872:
1837:
1595:
17:
1908:
1385:
1158:
155:
is also provided some distance from the home signal, which will only show a
38:
582:
offered by the bell code 1-3 instead of 3-1. These often vary by location.
714:
Freight train that can run at, or is timed to run at, 35 mph or less
1994:
1918:
1939:
1842:
1311:(Facsimile reprint of the original ed.). Kessinger Publishing Co.
1077:
54:
37:"Block section" redirects here. For rollercoaster block sections, see
1944:
1792:
1762:
1480:
249:
of between 15 and 20 miles (24 and 32 km), each subdivided into
1722:
1426:
Signalling Days: Final
Reminiscences of a Great Western Railwayman
1107:
1105:
64:
1712:
1484:
1032:
Train passed without tail lamp – sent to signal box in advance
1012:
Train proceeding without authority – electric token block only
245:
Cooke also put forward the idea of dividing a single line into
1462:
Vanns, Michael A. (2012). "The 1870s
Signalling Revolution".
938:
Cancels a 'Is Line Clear?' or 'Train entering section' code.
1042:
Train passed without tail lamp – sent to signal box in rear
1010:
Train proceeding without authority in the wrong direction
999:
Train proceeding without authority in the right direction
949:
Once acknowledged, the correct train description is sent.
62:, and is still used on lines which lack track circuiting.
163:– this gives a driver advance warning of a need to stop.
73:
instrument set to its default position of "line blocked"
967:
Closing of signal box where a block switch is provided
131:
and the signal box from which it travels is said to be
551:
Acknowledging that the train has cleared the section
214:
Electrical telegraphy was the first practical use of
123:– towards London (or in Scotland, Edinburgh) – and a
2089:
2038:
1932:
1896:
1698:
1667:
1634:
1586:
1518:
1447:(2nd Revised ed.). Oxford Publishing Company.
1466:. abc (2nd ed.). Hersham, Surrey: Ian Allan.
1367:
1355:
1260:
1248:
1200:
1135:
1111:
335:Internal view showing the coil, clapper and relay
1406:Ellis' British Railway Engineering Encyclopaedia
701:Freight train that can run at up to 45 mph
688:Freight train that can run at up to 60 mph
662:Freight train that can run at up to 75 mph
590:All trains, whether operated by a (passenger)
1496:
1443:Kichenside, Geoffrey; Williams, Alan (2008).
8:
1808:Interoperable Communications Based Signaling
1743:Automatic Train Protection (United Kingdom)
925:Token replaced – electric token block only
484:I acknowledge your train entering section.
53:designed to ensure the safe operation of a
1503:
1489:
1481:
2218:Railway signalling in the United Kingdom
1214:"Absolute Block System of train working"
1148:
1146:
1144:
1002:Sometimes known as "train running away"
764:
600:
497:
452:
385:
368:
226:installed a demonstration system on the
1708:Advanced Civil Speed Enforcement System
1089:
1343:
1188:UK Parliament: Hansard: House of Lords
540:The train has now cleared the section
1868:Train Protection & Warning System
1331:
1291:
1123:
1096:
7:
1601:Integrated Electronic Control Centre
1052:Testing bells and block instruments
289:of the status of the adjacent block.
1863:Train automatic stopping controller
1783:Continuous Automatic Warning System
1445:Two Centuries of Railway Signalling
439:Line is clear for a Class 2 train.
428:Is line clear for a Class 2 train?
1543:Communications-based train control
1007:2 - 5 - 5
974:7 - 5 - 5
964:5 - 5 - 7
954:5 - 5 - 5
887:3 - 3 - 5
876:3 - 5 - 5
865:3 - 3 - 4
843:3 - 3 - 2
824:Blocking back outside Home Signal
58:travel before the introduction of
25:
1184:"Railways—Telegraph Block System"
890:Line now clear to clearing point
835:Blocking back inside Home Signal
738:Empty Class 373 train (Eurostar)
77:A train approaching a section is
27:British railway signalling scheme
2213:Railway signalling block systems
328:
312:
278:
269:
2025:Westinghouse Brake & Signal
1788:ContrĂ´le de vitesse par balises
1654:North American railroad signals
358:
1883:Transmission balise-locomotive
1848:Sistema Controllo Marcia Treno
1758:Automatische treinbeĂŻnvloeding
1644:Application of railway signals
1464:Signalling in the Age of Steam
1368:Kichenside & Williams 2008
1356:Kichenside & Williams 2008
1261:Kichenside & Williams 2008
1249:Kichenside & Williams 2008
1201:Kichenside & Williams 2008
1182:Buckhurst, Lord (6 May 1872).
1136:Kichenside & Williams 2008
1112:Kichenside & Williams 2008
996:4 - 5 - 5
1:
1833:Punktförmige Zugbeeinflussung
1553:European Train Control System
1428:. Oxford Publishing Company.
1153:Faith, Nicholas (2000). "4".
240:London and Birmingham Railway
109:In absolute block working, a
39:Brake run § Block_brakes
1773:Chinese Train Control System
1563:Radio Electronic Token Block
1232:"Intermediate Block Section"
946:Train incorrectly described
915:– electric token block only
450:position of the commutator.
357:There are a set of standard
1538:Centralized traffic control
846:Shunt into forward section
573:— the main exception being
365:Example block-bell exchange
220:Cooke and Wheatstone system
2234:
1738:Automatic train protection
207:
173:intermediate block section
171:Some signal boxes have an
167:Intermediate block section
36:
29:
2030:Westinghouse Rail Systems
1888:Transmission Voie-Machine
1733:Automatic train operation
1685:Track circuit interrupter
1533:Automatic block signaling
1528:Absolute block signalling
1305:Cooke, William Fothergill
1068:Automatic block signaling
1001:
868:Train brought to a stand
718:
596:freight operating company
47:Absolute block signalling
32:Automatic block signaling
1828:Pulse code cab signaling
1753:Automatic Warning System
1659:Railway semaphore signal
1621:Solid State Interlocking
1155:Derail: Why Trains Crash
224:William Fothergill Cooke
30:Not to be confused with
1728:Automatic train control
1424:Gasson, Harold (1981).
1409:. Lulu.com. p. 6.
1021:Stop and examine train
793:Train entering section
592:train operating company
473:Train entering section
51:signalling block system
1904:Level crossing signals
1823:Positive Train Control
1818:Linienzugbeeinflussung
1548:Direct traffic control
977:Closing of signal box
879:Restricted acceptance
575:Train Entering Section
374:
74:
1626:Westlock Interlocking
1616:Rail operating centre
1578:Train order operation
1573:Track Warrant Control
804:Train out of section
675:Empty coaching stock
372:
208:Further information:
68:
1748:Automatic train stop
1403:Ellis, Iain (2006).
751:Light locomotive(s)
586:Train classification
210:Electrical telegraph
1370:, pp. 250–253.
987:Obstruction danger
957:Opening signal box
216:current electricity
1588:Signalling control
1512:Railway signalling
1039:4 - 5
832:2 - 4
821:3 - 3
811:2 - 2
801:2 - 1
758:Supplemental codes
518:Calling attention
406:Calling attention
375:
346:, also known as a
204:Railway telegraphy
75:
2200:
2199:
2010:Smith and Yardley
1473:978-0-7110-3536-2
1454:978-0-86093-672-5
1416:978-1-84728-643-7
1358:, pp. 75–77.
1273:Roberts, Steven.
1138:, pp. 14–15.
1126:, pp. 25–26.
1059:
1058:
755:
754:
555:
554:
488:
487:
443:
442:
261:Block instruments
236:Robert Stephenson
16:(Redirected from
2225:
2076:Transport Canada
1960:General Electric
1897:Crossing signals
1778:Cityflo 650 CBTC
1700:Train protection
1505:
1498:
1491:
1482:
1477:
1458:
1439:
1420:
1390:
1389:
1377:
1371:
1365:
1359:
1353:
1347:
1341:
1335:
1329:
1323:
1322:
1301:
1295:
1289:
1283:
1282:
1270:
1264:
1258:
1252:
1246:
1240:
1239:
1228:
1222:
1221:
1210:
1204:
1198:
1192:
1191:
1179:
1173:
1172:
1150:
1139:
1133:
1127:
1121:
1115:
1109:
1100:
1094:
1073:Heritage railway
857:Shunt withdrawn
765:
729:East London Line
601:
498:
453:
386:
332:
316:
282:
273:
200:station limits.
95:block instrument
21:
2233:
2232:
2228:
2227:
2226:
2224:
2223:
2222:
2203:
2202:
2201:
2196:
2085:
2034:
1928:
1892:
1694:
1668:Train detection
1663:
1630:
1582:
1514:
1509:
1474:
1461:
1455:
1442:
1436:
1423:
1417:
1402:
1399:
1394:
1393:
1380:Rolt, L. T. C.
1379:
1378:
1374:
1366:
1362:
1354:
1350:
1342:
1338:
1330:
1326:
1319:
1303:
1302:
1298:
1290:
1286:
1279:Distant Writing
1272:
1271:
1267:
1259:
1255:
1247:
1243:
1230:
1229:
1225:
1212:
1211:
1207:
1199:
1195:
1181:
1180:
1176:
1169:
1152:
1151:
1142:
1134:
1130:
1122:
1118:
1110:
1103:
1095:
1091:
1086:
1064:
782:Call attention
760:
588:
563:
367:
344:signalling bell
340:
339:
338:
337:
336:
333:
325:
324:
323:signalling bell
317:
306:
304:Signalling bell
293:
292:
291:
290:
285:
284:
283:
275:
274:
263:
247:grand divisions
222:. In July 1837
212:
206:
193:
169:
107:
42:
35:
28:
23:
22:
15:
12:
11:
5:
2231:
2229:
2221:
2220:
2215:
2205:
2204:
2198:
2197:
2195:
2194:
2192:United Kingdom
2189:
2184:
2179:
2174:
2169:
2164:
2159:
2154:
2149:
2144:
2139:
2134:
2129:
2124:
2119:
2114:
2109:
2104:
2099:
2093:
2091:
2087:
2086:
2084:
2083:
2078:
2073:
2068:
2063:
2058:
2053:
2048:
2042:
2040:
2036:
2035:
2033:
2032:
2027:
2022:
2017:
2012:
2007:
2002:
1997:
1992:
1987:
1982:
1977:
1972:
1967:
1962:
1957:
1952:
1947:
1942:
1936:
1934:
1930:
1929:
1927:
1926:
1921:
1916:
1911:
1906:
1900:
1898:
1894:
1893:
1891:
1890:
1885:
1880:
1875:
1870:
1865:
1860:
1855:
1850:
1845:
1840:
1835:
1830:
1825:
1820:
1815:
1810:
1805:
1803:Integra-Signum
1800:
1795:
1790:
1785:
1780:
1775:
1770:
1765:
1760:
1755:
1750:
1745:
1740:
1735:
1730:
1725:
1720:
1715:
1710:
1704:
1702:
1696:
1695:
1693:
1692:
1687:
1682:
1677:
1671:
1669:
1665:
1664:
1662:
1661:
1656:
1651:
1649:Cab signalling
1646:
1640:
1638:
1632:
1631:
1629:
1628:
1623:
1618:
1613:
1608:
1603:
1598:
1592:
1590:
1584:
1583:
1581:
1580:
1575:
1570:
1565:
1560:
1555:
1550:
1545:
1540:
1535:
1530:
1524:
1522:
1516:
1515:
1510:
1508:
1507:
1500:
1493:
1485:
1479:
1478:
1472:
1459:
1453:
1440:
1434:
1421:
1415:
1398:
1395:
1392:
1391:
1382:Red For Danger
1372:
1360:
1348:
1336:
1324:
1318:978-1437025774
1317:
1296:
1284:
1265:
1253:
1241:
1223:
1205:
1193:
1174:
1167:
1140:
1128:
1116:
1101:
1088:
1087:
1085:
1082:
1081:
1080:
1075:
1070:
1063:
1060:
1057:
1056:
1053:
1050:
1046:
1045:
1043:
1040:
1036:
1035:
1033:
1030:
1026:
1025:
1022:
1019:
1015:
1014:
1008:
1004:
1003:
1000:
997:
993:
992:
988:
985:
981:
980:
978:
975:
971:
970:
968:
965:
961:
960:
958:
955:
951:
950:
947:
944:
940:
939:
936:
933:
929:
928:
926:
923:
919:
918:
916:
909:
905:
904:
901:
900:Train divided
898:
894:
893:
891:
888:
884:
883:
880:
877:
873:
872:
869:
866:
862:
861:
858:
855:
851:
850:
847:
844:
840:
839:
836:
833:
829:
828:
825:
822:
818:
817:
815:
812:
808:
807:
805:
802:
798:
797:
794:
791:
787:
786:
783:
780:
776:
775:
772:
769:
759:
756:
753:
752:
749:
746:
740:
739:
736:
732:
731:
725:
722:
716:
715:
712:
709:
703:
702:
699:
696:
690:
689:
686:
683:
677:
676:
673:
670:
664:
663:
660:
657:
651:
650:
647:
644:
638:
637:
634:
631:
625:
624:
621:
618:
612:
611:
610:Type of train
608:
605:
587:
584:
579:Is Line Clear?
571:Call Attention
562:
559:
553:
552:
549:
546:
542:
541:
538:
535:
531:
530:
527:
524:
520:
519:
516:
513:
509:
508:
505:
502:
486:
485:
482:
479:
475:
474:
471:
468:
464:
463:
460:
457:
441:
440:
437:
434:
430:
429:
426:
423:
419:
418:
415:
412:
408:
407:
404:
401:
397:
396:
393:
390:
380:clearing point
366:
363:
334:
327:
326:
318:
311:
310:
309:
308:
307:
305:
302:
287:
286:
277:
276:
268:
267:
266:
265:
264:
262:
259:
205:
202:
197:station limits
192:
191:Station limits
189:
168:
165:
152:distant signal
137:starter signal
106:
103:
60:track circuits
26:
24:
18:Absolute block
14:
13:
10:
9:
6:
4:
3:
2:
2230:
2219:
2216:
2214:
2211:
2210:
2208:
2193:
2190:
2188:
2185:
2183:
2180:
2178:
2175:
2173:
2170:
2168:
2165:
2163:
2162:North America
2160:
2158:
2155:
2153:
2150:
2148:
2145:
2143:
2140:
2138:
2135:
2133:
2130:
2128:
2125:
2123:
2120:
2118:
2115:
2113:
2110:
2108:
2105:
2103:
2100:
2098:
2095:
2094:
2092:
2088:
2082:
2079:
2077:
2074:
2072:
2069:
2067:
2064:
2062:
2059:
2057:
2054:
2052:
2049:
2047:
2044:
2043:
2041:
2039:Organisations
2037:
2031:
2028:
2026:
2023:
2021:
2018:
2016:
2013:
2011:
2008:
2006:
2003:
2001:
1998:
1996:
1993:
1991:
1990:Progress Rail
1988:
1986:
1983:
1981:
1978:
1976:
1973:
1971:
1968:
1966:
1963:
1961:
1958:
1956:
1953:
1951:
1948:
1946:
1943:
1941:
1938:
1937:
1935:
1933:Manufacturers
1931:
1925:
1922:
1920:
1917:
1915:
1912:
1910:
1907:
1905:
1902:
1901:
1899:
1895:
1889:
1886:
1884:
1881:
1879:
1878:Trainguard MT
1876:
1874:
1871:
1869:
1866:
1864:
1861:
1859:
1856:
1854:
1851:
1849:
1846:
1844:
1841:
1839:
1836:
1834:
1831:
1829:
1826:
1824:
1821:
1819:
1816:
1814:
1811:
1809:
1806:
1804:
1801:
1799:
1796:
1794:
1791:
1789:
1786:
1784:
1781:
1779:
1776:
1774:
1771:
1769:
1766:
1764:
1761:
1759:
1756:
1754:
1751:
1749:
1746:
1744:
1741:
1739:
1736:
1734:
1731:
1729:
1726:
1724:
1721:
1719:
1716:
1714:
1711:
1709:
1706:
1705:
1703:
1701:
1697:
1691:
1688:
1686:
1683:
1681:
1680:Track circuit
1678:
1676:
1673:
1672:
1670:
1666:
1660:
1657:
1655:
1652:
1650:
1647:
1645:
1642:
1641:
1639:
1637:
1633:
1627:
1624:
1622:
1619:
1617:
1614:
1612:
1609:
1607:
1604:
1602:
1599:
1597:
1594:
1593:
1591:
1589:
1585:
1579:
1576:
1574:
1571:
1569:
1566:
1564:
1561:
1559:
1556:
1554:
1551:
1549:
1546:
1544:
1541:
1539:
1536:
1534:
1531:
1529:
1526:
1525:
1523:
1521:
1520:Block systems
1517:
1513:
1506:
1501:
1499:
1494:
1492:
1487:
1486:
1483:
1475:
1469:
1465:
1460:
1456:
1450:
1446:
1441:
1437:
1435:0-86093-118-8
1431:
1427:
1422:
1418:
1412:
1408:
1407:
1401:
1400:
1396:
1387:
1383:
1376:
1373:
1369:
1364:
1361:
1357:
1352:
1349:
1346:, p. 97.
1345:
1340:
1337:
1334:, p. 18.
1333:
1328:
1325:
1320:
1314:
1310:
1306:
1300:
1297:
1294:, p. 17.
1293:
1288:
1285:
1280:
1276:
1269:
1266:
1263:, p. 73.
1262:
1257:
1254:
1251:, p. 81.
1250:
1245:
1242:
1237:
1233:
1227:
1224:
1219:
1215:
1209:
1206:
1203:, p. 74.
1202:
1197:
1194:
1189:
1185:
1178:
1175:
1170:
1168:0-7522-7165-2
1164:
1160:
1156:
1149:
1147:
1145:
1141:
1137:
1132:
1129:
1125:
1120:
1117:
1114:, p. 75.
1113:
1108:
1106:
1102:
1098:
1093:
1090:
1083:
1079:
1076:
1074:
1071:
1069:
1066:
1065:
1061:
1054:
1051:
1048:
1047:
1044:
1041:
1038:
1037:
1034:
1031:
1028:
1027:
1023:
1020:
1017:
1016:
1013:
1009:
1006:
1005:
998:
995:
994:
989:
986:
983:
982:
979:
976:
973:
972:
969:
966:
963:
962:
959:
956:
953:
952:
948:
945:
942:
941:
937:
934:
931:
930:
927:
924:
921:
920:
917:
914:
910:
907:
906:
902:
899:
896:
895:
892:
889:
886:
885:
881:
878:
875:
874:
870:
867:
864:
863:
859:
856:
853:
852:
848:
845:
842:
841:
837:
834:
831:
830:
826:
823:
820:
819:
816:
813:
810:
809:
806:
803:
800:
799:
795:
792:
789:
788:
784:
781:
778:
777:
773:
770:
767:
766:
763:
757:
750:
747:
745:
742:
741:
737:
734:
733:
730:
726:
723:
721:
717:
713:
710:
708:
705:
704:
700:
697:
695:
692:
691:
687:
684:
682:
679:
678:
674:
671:
669:
666:
665:
661:
658:
656:
653:
652:
648:
645:
643:
640:
639:
635:
632:
630:
627:
626:
622:
619:
617:
614:
613:
609:
606:
603:
602:
599:
597:
593:
585:
583:
580:
576:
572:
567:
560:
558:
550:
547:
544:
543:
539:
536:
533:
532:
528:
525:
522:
521:
517:
514:
511:
510:
506:
503:
500:
499:
496:
492:
483:
480:
477:
476:
472:
469:
466:
465:
461:
458:
455:
454:
451:
447:
438:
435:
432:
431:
427:
424:
421:
420:
416:
413:
410:
409:
405:
402:
399:
398:
394:
391:
388:
387:
384:
381:
371:
364:
362:
360:
355:
353:
352:single stroke
349:
345:
331:
322:
321:single stroke
315:
303:
301:
297:
281:
272:
260:
258:
256:
252:
248:
243:
241:
237:
233:
229:
225:
221:
217:
211:
203:
201:
198:
190:
188:
184:
180:
178:
174:
166:
164:
162:
158:
154:
153:
148:
144:
143:
138:
134:
130:
126:
122:
121:
116:
112:
111:block section
105:Block section
104:
102:
98:
96:
92:
88:
84:
80:
72:
67:
63:
61:
56:
52:
49:is a British
48:
44:
40:
33:
19:
2020:Union Switch
1924:Wayside horn
1768:Catch points
1675:Axle counter
1606:Interlocking
1558:Moving block
1527:
1463:
1444:
1425:
1405:
1381:
1375:
1363:
1351:
1339:
1327:
1308:
1299:
1287:
1278:
1268:
1256:
1244:
1235:
1226:
1217:
1208:
1196:
1187:
1177:
1154:
1131:
1119:
1099:, p. 6.
1092:
1011:
761:
743:
719:
706:
693:
680:
667:
654:
641:
628:
615:
589:
578:
574:
570:
568:
564:
556:
493:
489:
448:
444:
376:
356:
347:
343:
341:
298:
294:
254:
250:
246:
244:
213:
196:
194:
185:
181:
176:
172:
170:
160:
156:
151:
146:
142:stop signals
140:
136:
132:
128:
124:
118:
114:
110:
108:
99:
94:
86:
78:
76:
46:
45:
43:
2182:Switzerland
2157:New Zealand
2152:Netherlands
1858:Slide fence
1611:Lever frame
1344:Gasson 1981
935:Cancelling
594:(TOC) or a
234:section of
232:Camden Town
147:home signal
113:(or simply
2207:Categories
2090:By country
1873:Train stop
1838:RS4 Codici
1596:Block post
1332:Vanns 2012
1292:Vanns 2012
1236:Trainguard
1218:Trainguard
1124:Vanns 2012
1097:Ellis 2006
1084:References
768:Bell code
607:Bell code
561:Bell codes
529:Attending
417:Attending
359:bell codes
348:block bell
129:in advance
91:bell codes
2097:Australia
1950:AŽD Praha
1909:Crossbuck
1813:Crocodile
1386:Pan Books
1307:(2008) .
1159:Channel 4
991:respond.
83:signalman
71:telegraph
2187:Thailand
1995:Safetran
1985:Magnetic
1970:Griswold
1919:E-signal
1062:See also
911:Release
771:Meaning
507:Meaning
462:Meaning
395:Meaning
69:A block
2132:Germany
2122:Finland
2107:Belgium
2102:Bavaria
2005:Siemens
1980:Hitachi
1955:Federal
1940:Adtranz
1843:SelTrac
1690:Treadle
1636:Signals
1397:Sources
1220:. 2018.
1161:Books.
1078:Rule 55
319:Tyer's
161:caution
133:in rear
115:section
87:accepts
79:offered
55:railway
2177:Sweden
2172:Poland
2167:Norway
2137:Greece
2127:France
2112:Canada
2015:Thales
1945:Alstom
1914:Wigwag
1793:EBICAB
1763:Balise
1470:
1451:
1432:
1413:
1315:
1165:
943:5 - 3
932:3 - 5
922:2 - 5
908:5 - 2
897:5 - 5
774:Notes
735:1-4-1
672:2-2-1
659:3-1-1
646:1-3-1
604:Class
577:. The
504:Sends
459:Sends
392:Sends
251:stages
228:Euston
2147:Japan
2142:Italy
2117:China
2051:AREMA
2000:Saxby
1853:SACEM
1798:IIATS
1723:ATACS
1568:Token
913:token
175:, or
157:clear
149:. A
81:by a
2071:IRSE
2066:HMRI
1975:Hall
1718:ASFA
1713:ALSN
1468:ISBN
1449:ISBN
1430:ISBN
1411:ISBN
1313:ISBN
1163:ISBN
748:2-3
724:1-4
711:3-2
698:4-1
633:3-1
548:2-1
537:2-1
501:Box
456:Box
436:3-1
425:3-1
389:Box
342:The
125:down
2081:UIC
2061:FRA
2056:ERA
2046:AAR
1965:GRS
1049:16
238:'s
230:to
177:IBS
2209::
1384:.
1277:.
1234:.
1216:.
1186:.
1157:.
1143:^
1104:^
1029:9
1018:7
984:6
854:8
790:2
779:1
685:5
620:4
545:A
534:B
526:1
523:A
515:1
512:B
481:2
478:B
470:2
467:A
433:B
422:A
414:1
411:B
403:1
400:A
120:up
1504:e
1497:t
1490:v
1476:.
1457:.
1438:.
1419:.
1388:.
1321:.
1281:.
1238:.
1190:.
1171:.
744:0
720:9
707:8
694:7
681:6
668:5
655:4
642:3
629:2
616:1
41:.
34:.
20:)
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