479:
260:
463:
282:
179:
77:
36:
392:
337:
and an alarm (either a bell, speaker that mimics a bell sound or an electronic siren), attached to a mast. At most crossings, the signals will activate about 30 seconds before the train arrives but there are sensors measuring speed so that the crossing knows when to activate; so, the slower the train
514:
Before this invention, the circuits used for activating a crossing's warning devices were very simple, activated whenever a train came within a fixed distance (hundreds or thousands of feet) of the crossing. This method required that the crossing be designed to accommodate a train approaching at the
356:
Automatic crossings generally have no or half-width barriers to prevent cars and pedestrians becoming trapped on the tracks with no escape, and manually-operated crossings have full-width barriers (either 2 or 4 arms which block the whole road). However, a number of counties automate fully-closed
360:
The time interval may be controlled by a level crossing predictor, an electronic device which is connected to the rails of a railroad track, and activates the crossing's warning devices (lights, bells, gates, etc.) at a consistent interval prior to the arrival of a train at a level crossing.
353:(or "gate" in the US) added to the signal, which descend over the road and block entry. The barriers will be fully lowered 15 to 20 seconds before the train arrives (US), and will rise and the signals will shut off once the end of the train clears the island circuit.
547:, the voltage measured will be proportional to the impedance. The absolute magnitude of this voltage and its rate of change can then be used to compute the amount of time remaining before the train arrives at the crossing, assuming it is running at a constant speed.
523:
All level crossing predictors rely on the changes in the electrical characteristics of the rails that occur as a train approaches the point at which the predictor is connected to the rails (the feedpoint). A railroad track occupied by a train or other electrical
364:
Crossbucks also may have legends saying, for example: "RAIL ROAD CROSSING" (United States), "RAIL WAY CROSSING" (Australia and New
Zealand), "PELIGRO FERROCARRIL" (Latin America, meaning DANGER RAILWAY), or be wordless (Canada and many other countries).
322:
Level crossings can be operated in various ways. In some countries such as the UK, the warning devices are more often than not activated by remote control, I.e. an operator pressing buttons. However, the majority of countries have automated systems.
1053:
442:. A red steel target disc, slightly less than two feet in diameter, serving as a pendulum was attached. A red light in the center of the target illuminated, and with each swing of the target a mechanical gong sounded.
515:
track speed limit, which leads to longer warning times for trains approaching the crossing at lower speeds. Very slow trains could have many minutes of warning time, thus delaying highway traffic unnecessarily.
569:
A predictor circuit in the middle of nowhere is usually terminated with a dead short across the rails at the outer ends. This assumes that there are no ordinary track circuits for block signalling purposes.
1251:
573:
Two predictor circuits may overlap, with tuned circuits used for one predictor to jump over the other. The tuned loops would be a dead short for one predictor, and an open circuit for the other.
550:
The crossing's warning devices are activated when the computed time for the train to reach the crossing is equal to the programmed threshold time. The earliest level crossing predictors used
326:
Automated level crossings are found in most developed nations and vary greatly, but this page in particular is specific to the United States. Such equipment works as follows:
189:
918:
1008:
703:
998:
943:
511:), and patented in 1966, the design goal of the level crossing predictor was to provide a consistent warning time for trains approaching a level crossing.
357:
crossings anyway despite the obvious dangers; however, many such crossings are accompanied by obstacle detection sensors to ensure the tracks are clear.
602:
478:
1271:
908:
94:
49:
1266:
1225:
346:) there is also a flashing white light, which means that it is possible to pass the level crossing at a higher speed than generally allowed.
801:
1068:
626:
1063:
1013:
983:
1256:
988:
743:
141:
1362:
1357:
1246:
439:
241:
223:
160:
63:
958:
113:
1215:
1033:
696:
1281:
1261:
854:
532:
shaped like a hairpin. As the train approaches the feedpoint, the area enclosed by the inductor diminishes, thus reducing the
120:
1083:
1048:
844:
98:
1312:
1297:
753:
338:
is, the longer the delay and the faster the train is, the earlier the crossing activates. In some countries (such as the
973:
763:
127:
1367:
738:
689:
295:
201:
55:
1377:
1342:
1332:
1322:
1317:
1307:
938:
768:
109:
1418:
1372:
1327:
1230:
1088:
933:
885:
733:
728:
504:
1413:
1382:
1352:
1347:
1337:
1302:
1028:
953:
859:
821:
500:
205:
1220:
1387:
1185:
1170:
928:
900:
720:
446:
259:
87:
1165:
1155:
1023:
1018:
748:
508:
485:
412:
287:
1392:
826:
816:
778:
773:
675:
372:
in the US are now requiring the use of this type of equipment at all newly constructed level crossings.
445:
The new model, combining sight, motion and sound was dubbed the "Magnetic
Flagman" and produced by the
462:
948:
428:
270:
134:
1175:
1058:
540:
420:
416:
407:" was the nickname given to a type of crossing signals once common in North America, named for the
291:
788:
712:
525:
566:
A predictor includes a short "island" track which just covers the width of the level crossing.
1210:
1114:
890:
607:
496:
404:
396:
386:
266:
1276:
1205:
1180:
1160:
978:
424:
551:
431:
railroad, invented it in 1909 for safer railroad level crossings. He utilized alternating
281:
1003:
849:
836:
582:
555:
339:
330:
316:
1407:
1190:
1078:
880:
669:
432:
17:
1124:
968:
875:
806:
758:
587:
350:
309:
1150:
544:
27:
Devices used to warn pedestrians and drivers of incoming trains at level crossings
811:
76:
1200:
1073:
1038:
796:
639:
533:
369:
1109:
592:
469:
334:
1195:
1119:
597:
529:
408:
343:
313:
1140:
1043:
1145:
993:
963:
681:
391:
265:
Signal device with flashing lights mounted on a cantilever, on the
923:
543:
source to the rails, and measuring the voltage which results. By
390:
539:
This inductance can be measured by connecting a constant-current
913:
436:
685:
554:
to perform this calculation, but modern equipment uses digital
172:
70:
29:
188:
deal primarily with the United States and do not represent a
411:-like motion it used to signal the approach of a train.
197:
1290:
1239:
1133:
1097:
899:
868:
835:
787:
719:
101:. Unsourced material may be challenged and removed.
627:Marketing brochure by Westinghouse Rail Systems
697:
186:The examples and perspective in this article
8:
1009:Interoperable Communications Based Signaling
944:Automatic Train Protection (United Kingdom)
64:Learn how and when to remove these messages
704:
690:
682:
672:on the National Museum of American History
242:Learn how and when to remove this message
224:Learn how and when to remove this message
161:Learn how and when to remove this message
499:in the late 1950s at the request of the
909:Advanced Civil Speed Enforcement System
619:
308:are the electronic warning devices for
1069:Train Protection & Warning System
655:. Harmon Industries. 2001. p. 1.
7:
802:Integrated Electronic Control Centre
99:adding citations to reliable sources
1064:Train automatic stopping controller
984:Continuous Automatic Warning System
349:At many crossings, there will be a
744:Communications-based train control
495:First developed in concept by the
25:
45:This article has multiple issues.
477:
461:
290:signal and barrier on Argentine
280:
258:
177:
75:
34:
1226:Westinghouse Brake & Signal
989:Contrôle de vitesse par balises
855:North American railroad signals
528:can be viewed as a single-turn
86:needs additional citations for
53:or discuss these issues on the
1084:Transmission balise-locomotive
1049:Sistema Controllo Marcia Treno
959:Automatische treinbeïnvloeding
845:Application of railway signals
1:
1034:Punktförmige Zugbeeinflussung
754:European Train Control System
676:Rail Crossing Warning Systems
399:" signal photographed in 2007
329:The basic signal consists of
974:Chinese Train Control System
764:Radio Electronic Token Block
653:HXP-3 Field Reference Manual
739:Centralized traffic control
497:Stanford Research Institute
200:, discuss the issue on the
1435:
939:Automatic train protection
472:, pictured in October 2009
384:
1231:Westinghouse Rail Systems
1089:Transmission Voie-Machine
934:Automatic train operation
886:Track circuit interrupter
734:Automatic block signaling
729:Absolute block signalling
505:Southern Pacific Railroad
484:Rail crossing signals in
1029:Pulse code cab signaling
954:Automatic Warning System
860:Railway semaphore signal
822:Solid State Interlocking
501:Southern Pacific Company
110:"Level crossing signals"
929:Automatic train control
447:Magnetic Signal Company
1105:Level crossing signals
1024:Positive Train Control
1019:Linienzugbeeinflussung
749:Direct traffic control
509:Union Pacific Railroad
507:, now merged into the
486:Northeast, Minneapolis
400:
306:Level crossing signals
827:Westlock Interlocking
817:Rail operating centre
779:Train order operation
774:Track Warrant Control
640:U.S. patent 3,246,143
394:
18:Grade crossing signal
949:Automatic train stop
429:interurban streetcar
271:Trout Lake, Michigan
206:create a new article
198:improve this article
95:improve this article
670:America on the move
541:alternating current
421:Southern California
417:mechanical engineer
331:flashing red lights
292:Belgrano Norte Line
789:Signalling control
713:Railway signalling
468:Warning device in
401:
1401:
1400:
1211:Smith and Yardley
387:Wigwag (railroad)
252:
251:
244:
234:
233:
226:
208:, as appropriate.
171:
170:
163:
145:
68:
16:(Redirected from
1426:
1419:Safety equipment
1277:Transport Canada
1161:General Electric
1098:Crossing signals
979:Cityflo 650 CBTC
901:Train protection
706:
699:
692:
683:
657:
656:
649:
643:
642:
636:
630:
624:
552:analog computers
481:
465:
425:Pacific Electric
284:
262:
247:
240:
229:
222:
218:
215:
209:
181:
180:
173:
166:
159:
155:
152:
146:
144:
103:
79:
71:
60:
38:
37:
30:
21:
1434:
1433:
1429:
1428:
1427:
1425:
1424:
1423:
1414:Level crossings
1404:
1403:
1402:
1397:
1286:
1235:
1129:
1093:
895:
869:Train detection
864:
831:
783:
715:
710:
666:
661:
660:
651:
650:
646:
638:
637:
633:
625:
621:
616:
579:
564:
556:microprocessors
521:
493:
492:
491:
490:
489:
482:
474:
473:
466:
455:
389:
383:
378:
317:level crossings
303:
302:
301:
300:
299:
285:
276:
275:
274:
263:
248:
237:
236:
235:
230:
219:
213:
210:
195:
182:
178:
167:
156:
150:
147:
104:
102:
92:
80:
39:
35:
28:
23:
22:
15:
12:
11:
5:
1432:
1430:
1422:
1421:
1416:
1406:
1405:
1399:
1398:
1396:
1395:
1393:United Kingdom
1390:
1385:
1380:
1375:
1370:
1365:
1360:
1355:
1350:
1345:
1340:
1335:
1330:
1325:
1320:
1315:
1310:
1305:
1300:
1294:
1292:
1288:
1287:
1285:
1284:
1279:
1274:
1269:
1264:
1259:
1254:
1249:
1243:
1241:
1237:
1236:
1234:
1233:
1228:
1223:
1218:
1213:
1208:
1203:
1198:
1193:
1188:
1183:
1178:
1173:
1168:
1163:
1158:
1153:
1148:
1143:
1137:
1135:
1131:
1130:
1128:
1127:
1122:
1117:
1112:
1107:
1101:
1099:
1095:
1094:
1092:
1091:
1086:
1081:
1076:
1071:
1066:
1061:
1056:
1051:
1046:
1041:
1036:
1031:
1026:
1021:
1016:
1011:
1006:
1004:Integra-Signum
1001:
996:
991:
986:
981:
976:
971:
966:
961:
956:
951:
946:
941:
936:
931:
926:
921:
916:
911:
905:
903:
897:
896:
894:
893:
888:
883:
878:
872:
870:
866:
865:
863:
862:
857:
852:
850:Cab signalling
847:
841:
839:
833:
832:
830:
829:
824:
819:
814:
809:
804:
799:
793:
791:
785:
784:
782:
781:
776:
771:
766:
761:
756:
751:
746:
741:
736:
731:
725:
723:
717:
716:
711:
709:
708:
701:
694:
686:
680:
679:
673:
665:
664:External links
662:
659:
658:
644:
631:
618:
617:
615:
612:
611:
610:
605:
600:
595:
590:
585:
583:Level crossing
578:
575:
563:
562:Implementation
560:
520:
517:
483:
476:
475:
467:
460:
459:
458:
457:
456:
454:
453:Modern devices
451:
435:pulling on an
433:electromagnets
385:Main article:
382:
379:
377:
374:
340:Czech Republic
286:
279:
278:
277:
264:
257:
256:
255:
254:
253:
250:
249:
232:
231:
192:of the subject
190:worldwide view
185:
183:
176:
169:
168:
151:September 2013
83:
81:
74:
69:
43:
42:
40:
33:
26:
24:
14:
13:
10:
9:
6:
4:
3:
2:
1431:
1420:
1417:
1415:
1412:
1411:
1409:
1394:
1391:
1389:
1386:
1384:
1381:
1379:
1376:
1374:
1371:
1369:
1366:
1364:
1363:North America
1361:
1359:
1356:
1354:
1351:
1349:
1346:
1344:
1341:
1339:
1336:
1334:
1331:
1329:
1326:
1324:
1321:
1319:
1316:
1314:
1311:
1309:
1306:
1304:
1301:
1299:
1296:
1295:
1293:
1289:
1283:
1280:
1278:
1275:
1273:
1270:
1268:
1265:
1263:
1260:
1258:
1255:
1253:
1250:
1248:
1245:
1244:
1242:
1240:Organisations
1238:
1232:
1229:
1227:
1224:
1222:
1219:
1217:
1214:
1212:
1209:
1207:
1204:
1202:
1199:
1197:
1194:
1192:
1191:Progress Rail
1189:
1187:
1184:
1182:
1179:
1177:
1174:
1172:
1169:
1167:
1164:
1162:
1159:
1157:
1154:
1152:
1149:
1147:
1144:
1142:
1139:
1138:
1136:
1134:Manufacturers
1132:
1126:
1123:
1121:
1118:
1116:
1113:
1111:
1108:
1106:
1103:
1102:
1100:
1096:
1090:
1087:
1085:
1082:
1080:
1079:Trainguard MT
1077:
1075:
1072:
1070:
1067:
1065:
1062:
1060:
1057:
1055:
1052:
1050:
1047:
1045:
1042:
1040:
1037:
1035:
1032:
1030:
1027:
1025:
1022:
1020:
1017:
1015:
1012:
1010:
1007:
1005:
1002:
1000:
997:
995:
992:
990:
987:
985:
982:
980:
977:
975:
972:
970:
967:
965:
962:
960:
957:
955:
952:
950:
947:
945:
942:
940:
937:
935:
932:
930:
927:
925:
922:
920:
917:
915:
912:
910:
907:
906:
904:
902:
898:
892:
889:
887:
884:
882:
881:Track circuit
879:
877:
874:
873:
871:
867:
861:
858:
856:
853:
851:
848:
846:
843:
842:
840:
838:
834:
828:
825:
823:
820:
818:
815:
813:
810:
808:
805:
803:
800:
798:
795:
794:
792:
790:
786:
780:
777:
775:
772:
770:
767:
765:
762:
760:
757:
755:
752:
750:
747:
745:
742:
740:
737:
735:
732:
730:
727:
726:
724:
722:
721:Block systems
718:
714:
707:
702:
700:
695:
693:
688:
687:
684:
678:on UP website
677:
674:
671:
668:
667:
663:
654:
648:
645:
641:
635:
632:
628:
623:
620:
613:
609:
606:
604:
603:Manufacturers
601:
599:
596:
594:
591:
589:
586:
584:
581:
580:
576:
574:
571:
567:
561:
559:
557:
553:
548:
546:
542:
537:
535:
531:
527:
518:
516:
512:
510:
506:
502:
498:
487:
480:
471:
464:
452:
450:
448:
443:
441:
438:
434:
430:
426:
422:
418:
414:
410:
406:
398:
393:
388:
381:First devices
380:
375:
373:
371:
366:
362:
358:
354:
352:
347:
345:
341:
336:
332:
327:
324:
320:
318:
315:
311:
310:road vehicles
307:
297:
296:Florida Oeste
293:
289:
283:
272:
268:
261:
246:
243:
228:
225:
217:
207:
203:
199:
193:
191:
184:
175:
174:
165:
162:
154:
143:
140:
136:
133:
129:
126:
122:
119:
115:
112: –
111:
107:
106:Find sources:
100:
96:
90:
89:
84:This article
82:
78:
73:
72:
67:
65:
58:
57:
52:
51:
46:
41:
32:
31:
19:
1221:Union Switch
1125:Wayside horn
1104:
969:Catch points
876:Axle counter
807:Interlocking
759:Moving block
652:
647:
634:
622:
588:Boom barrier
572:
568:
565:
549:
538:
522:
513:
494:
444:
402:
367:
363:
359:
355:
348:
328:
325:
321:
305:
304:
238:
220:
211:
187:
157:
148:
138:
131:
124:
117:
105:
93:Please help
88:verification
85:
61:
54:
48:
47:Please help
44:
1383:Switzerland
1358:New Zealand
1353:Netherlands
1059:Slide fence
812:Lever frame
488:, July 2018
413:Albert Hunt
298:, July 2012
273:, July 2015
1408:Categories
1291:By country
1074:Train stop
1039:RS4 Codici
797:Block post
614:References
534:inductance
519:Technology
121:newspapers
50:improve it
1298:Australia
1151:AŽD Praha
1110:Crossbuck
1014:Crocodile
629:(archive)
593:Crossbuck
545:Ohm's Law
470:Australia
335:crossbuck
202:talk page
56:talk page
1388:Thailand
1196:Safetran
1186:Magnetic
1171:Griswold
1120:E-signal
598:E-signal
577:See also
530:inductor
440:armature
409:pendulum
344:Slovakia
314:railroad
267:Soo Line
214:May 2021
196:You may
1333:Germany
1323:Finland
1308:Belgium
1303:Bavaria
1206:Siemens
1181:Hitachi
1156:Federal
1141:Adtranz
1044:SelTrac
891:Treadle
837:Signals
376:History
351:barrier
135:scholar
1378:Sweden
1373:Poland
1368:Norway
1338:Greece
1328:France
1313:Canada
1216:Thales
1146:Alstom
1115:Wigwag
994:EBICAB
964:Balise
608:Wigwag
405:Wigwag
397:Wigwag
370:states
137:
130:
123:
116:
108:
1348:Japan
1343:Italy
1318:China
1252:AREMA
1201:Saxby
1054:SACEM
999:IIATS
924:ATACS
769:Token
526:shunt
503:(the
427:(PE)
368:Many
204:, or
142:JSTOR
128:books
1272:IRSE
1267:HMRI
1176:Hall
919:ASFA
914:ALSN
437:iron
415:, a
333:, a
114:news
1282:UIC
1262:FRA
1257:ERA
1247:AAR
1166:GRS
423:'s
419:at
342:or
312:at
288:GRS
269:in
97:by
1410::
558:.
536:.
449:.
319:.
294:,
59:.
705:e
698:t
691:v
403:"
395:"
245:)
239:(
227:)
221:(
216:)
212:(
194:.
164:)
158:(
153:)
149:(
139:·
132:·
125:·
118:·
91:.
66:)
62:(
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
