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 It successfully managed train control over most of the British railway system until generally superseded by more sophisticated systems from 1950.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