247:
Once operational, the latter newspaper called it "the greatest safeguard devised for shipping in modern history". According to a 1921 trade magazine, leader cables had five functions: "to enable a ship to make a good landfall in thick weather, to lead a ship up the harbor, to lead a ship from open water through a restricted channel to open water on the far side, to give warning of outlying dangers, and to assist a vessel to keep a straight course from port to port and thus save fuel." In 1922, the publication
286:(low-power radio transmitters) at strategic locations. Those beacons are analogous to lighthouses, but can be "seen" in all weather, and are used for navigation in the same way as regular lighthouses. The first successful application of these radio beacons as "radio fog signals" were three stations installed near New York in 1921. In 1924, there were eleven stations in operation in the United States and nearly three hundred ships suitably equipped. By 1930, an article in the
78:
199:
winter of 1919–1920, crews found that the cable had broken in a total of fifty-two different places due to the strain placed on it while it was being laid. The damage was irreparable. Going back to the drawing board, engineers tested 150-foot segments of three different types of cable and used the results to design a new full-size pilot cable. The Navy ordered 87,000 feet of cable from the
Simplex Wire and Cable Company in Boston.
22:
126:
225:, all of which had to be raised to the surface so the pilot cable could be laid underneath them. The installation of the cable was completed on August 6, 1920, and by August 28, electrical tests showed that both the sending and receiving circuits were functioning properly. The Navy tested the cable using the seagoing tug
152:, where he conducted early experiments with underwater pilot cables. His results were sufficiently promising that he recommended further development to Commander Stanford C. Hooper. In October, 1919 Commander Hooper instructed A. Crossley, an expert radio aid, to develop and test the concept on a larger scale at the
69:, and bad weather could close the channel for days. Ships were forced to wait at the harbor's entrance for conditions to clear. These delays cost shipping companies substantial amounts of money, with each ship costing between $ 500 and $ 4000 per hour it was stopped (roughly $ 5,700 to $ 46,000 in 2013 dollars).
133:
The pilot cable required a series of prior discoveries and inventions. In 1882, A. R. Sennett patented the use of a submerged electrical cable to communicate with a ship at a fixed location. Around the same time
Charles Stevenson patented a means of navigating ships over an electrically charge cable
116:
hung on opposite sides of the ship, and fed through an amplifier into a headset (see diagram, below). By switching between coils, the relative strength of the signal on each side could be compared. The ship maintained a course parallel to the cable by maneuvering to keep the signal strength constant.
269:
Despite the media hype, it appears that the
Ambrose Channel pilot cable never met with large scale commercial success. Initially, some contemporaries of the cable proposed that it be extended several miles past the Ambrose light. Such plans never came to fruition, as advances in technology rendered
260:
expressed the belief that navigation cables would become common for both ships and aircraft: "...there is a future for the audio cable... Its fullest usefulness at
American ports and elsewhere waits, however, on that large appreciation of radio devices for sea as well as air navigation which pilots,
246:
The cable was well received. Even before the New London tests, the
Washington Post called it "the greatest development in marine travel since the invention of the steam turbine" and the Los Angeles Times declared the technology to be "one of the greatest peacetime gifts that science has devised."
255:
boasted about the money saved by the cable as well as the ease of using it. The cable itself was paid for using public funds, but it was the responsibility of ship owners to outfit their vessels with receiving equipment. Installation of the cable cost roughly $ 50,000 and the listening apparatus
198:
was fitted with receiving equipment and attempted to follow the cable out of the channel. Unfortunately, it was unable to detect a signal past the 1,000 foot mark, where a break in the cable had prevented the signal from continuing. The break in the cable was repaired, but over the course of the
312:
viewed it as a step toward applying radio cable technology in vast swaths of everyday life, including guiding aircraft and navigating and powering automobiles. The
Ambrose Channel cable was removed from the channel and used in testing an early system of
105:(cycles per second) current at 400 volts, resulting in an alternating electromagnetic field along the length of the cable that could be detected to approximately a thousand yards away. The current was mechanically keyed to send the word "NAVY" in
45:
that provided an audio tone for guiding ships in and out of port at times of low visibility. The cable was laid during 1919 and 1920; it had been removed from the channel and replaced by wireless technology by the end of the 1920s.
274:
reported ships navigating the
Channel blindly without making any reference to the cable. In that year, Marriott publicly complained that navigation cables still had unrealized potential for guiding ships.
85:
The
Ambrose leader cable was an armored cable with a single internal conductor (see picture) that acted like a long radio antenna laid on the channel floor. It originated at
1544:
243:
from
October 6 through October 9. The ship's windows were covered with canvas and the captains took turns navigating using only the audio cues from the cable.
173:
191:
laid a pilot cable composed of 2,000 feet of leaded and armored cable, 2,000 feet of leaded cable, and 83,000 feet of standard rubber-insulated cable. The
1289:
1549:
1005:
1539:
1529:
1116:
256:
installed on each ship using the channel cost $ 1,200, compared with hourly costs of delays that ranged from $ 500 to $ 4,000.
318:
222:
153:
58:
42:
1534:
1444:
184:
Following the successful tests at New London, the Navy proceeded to large scale testing in
Ambrose Channel late in 1919. The
213:. The ship arrived in New York on July 31, 1920. Ambrose Channel was already crossed by three telegraph cables, owned by
1524:
1519:
164:
for later tests. Both types of vessel picked up the signal and followed the underwater test cable without problem.
236:
associations, governmental bureaus, naval attaches, and others" for a public demonstration on board the destroyer
298:
293:
declared that "wireless aids and echo sounding have superseded ". Today, more modern navigation tools such as
90:
1183:
896:
129:
Two-stage vacuum-tube amplifier alternately takes input from inductance coils (top) hung on each side of ship.
279:
172:
192:
289:
1318:
Putnam, George (June 15, 1924), "Radio Fog Signals for the Protection of Navigation; Recent Progress",
156:. Crossley installed a longer version of the cable that Marriott had designed. He used a wooden-hulled
77:
1323:
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21:
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38:
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stated that the cable's first two years of operation had been successful. Also in 1922,
1327:
1258:
308:
Earl Hanson, one of the key players in designing the Ambrose Channel cable, writing for
1346:
1042:
233:
113:
86:
1370:, vol. 1, no. 3, Doubleday, Doran, Incorporated, pp. 247–248, July 1922
125:
1513:
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1124:
321:
later tried a similar system briefly before also abandoning it in favor of wireless.
214:
157:
66:
232:. It then invited "representatives of various radio companies, shipping interests,
135:
101:
offshore. It was powered by a generator at Fort Lafayette that produced 500
1434:
317:. The cable found no more success in that role than it did in guiding ships. The
1388:
314:
149:
139:
1478:
Wood, Robert (Jan 30, 1930), "New Air Device Guides Landings in Thickest Fog",
1320:
Proceedings of the National Academy of Sciences of the United States of America
1148:, vol. 2, no. 3, Hennessy Radio Publications Corporation, p. 8
106:
1170:"Power to Come by Radio: Radio Powered & Controlled Ships and Submarines"
278:
Leader cable systems appear to have been made obsolete by the refinement of
185:
161:
1472:, vol. 1, no. 3, Doubleday, Doran, Incorporated, pp. 249–251
1355:
1336:
1156:"Finding Aircraft Landing Stations by Means of Audio Frequency Receivers"
998:
Blind Landings: Low-Visibility Operations in American Aviation, 1918–1958
1188:, For sale by the Superintendent of Documents, U. S. Govt. Print. Off.,
392:, p. 51. Other voltages may have been used in subsequent operation.
1425:
1267:
1417:
1092:
Davis, Edward (Jul 10, 1922), "Fifteen Minutes of Radio Each Day",
1015:
Cooper, F. G. (August 8, 1930), "Aids to Navigation, Lecture III",
261:
both on the sea and in the air, expect, but do not as yet demand."
294:
171:
102:
76:
20:
1142:"Vessels Now Guided Through Fog by New System of Radiotelegraphy"
1193:
302:
25:
A period depiction of the Ambrose Channel pilot cable in action.
1185:
History of Communications-Electronics in the United States Navy
1283:, vol. 99, no. 16, pp. 14–15, October 16, 1920
945:
Armstrong, Robert (February 3, 1930), "Fog Menace Overcome",
160:
for the first round of tests before moving to a steel-hulled
138:. The method became practical when Earl Hanson adapted early
1277:"Steamer travels into New York on a submerged radio "rail""
1383:, vol. 59, no. 1534, p. xiv, May 23, 1924,
984:
St. Nicholas: an Illustrated Magazine for Boys and Girls
65:. Delays posed a major problem for shipping en route to
1497:
Yates, Raymond Francis; Pacent, Louis Gerard (1922),
1055:"Piloting Vessels by Electrically Energized Cables"
1027:"Piloting Vessels by Electrically Energized Cables"
824:
1436:Flying People: Bringing You Safe Flying, Every Day
1303:"Warship Guided into Port by Radio Piloting Cable"
1031:Journal of the American Society of Naval Engineers
1466:"The Audio Piloting Cable in the Ambrose Channel"
696:
684:
636:
57:is the only shipping channel into and out of the
1079:, New York Times Company, 1921, pp. 161–163
521:
1201:"Navy to Try Marvelous Los Angeles Invention",
1059:Proceedings of the Institute of Radio Engineers
1019:, vol. 78, no. 4055, pp. 978–988
928:
840:
672:
441:
1322:, vol. 10, no. 6, pp. 211–218,
756:
660:
624:
401:
804:
202:Once complete, the cable was loaded onto the
8:
148:was a radio pioneer employed by the Navy in
1290:"Guides Ships In Fog By Cable In The Water"
880:
453:
1364:"Radio Fog Signals and the Radio Compass"
1345:
1335:
1266:
954:"Radio Beacon Guides Craft Through Fog",
916:
648:
620:
608:
596:
584:
572:
556:
544:
532:
437:
425:
413:
389:
377:
365:
81:The Cable was composed of several layers.
1454:"Fog Tamed in Plan to Hasten Shipping",
457:
124:
1404:"5,000,000 Volt Artificial Lightning",
986:, vol. 48, no. 2, p. 173
812:
792:
780:
768:
744:
732:
708:
560:
509:
497:
485:
473:
353:
334:
270:the pilot cable obsolete. By 1929 the
924:
892:
876:
864:
852:
836:
808:
720:
1545:History of radio in the United States
920:
912:
461:
305:help ships navigate Ambrose Channel.
176:Commander R. F. McConnell on the USS
7:
1017:Journal of the Royal Society of Arts
908:
341:
1253:(2676): 760–762, 10 February 1921,
1182:Howeth, Captain Linwood S. (1963),
1115:Geselowitz, Michael N. (May 2009).
1101:Gaulois, George (August 28, 1920),
93:), then extended 16 miles down the
1489:Signaling and communicating at sea
1069:Essentially same article as above.
1048:Essentially same article as below.
1043:10.1111/j.1559-3584.1921.tb03628.x
978:Bond, A. Russell (December 1920),
966:"The "Leader" Cable at Portsmouth"
14:
1168:Hanson, Earl C. (November 1934),
1412:(408): 61–62, February 2, 1929,
1312:, pp. 1, 6, October 7, 1920
1221:Marriott, Robert H. (May 1924),
1211:"Invents cable to pilot ships",
1154:Hanson, Earl C. (May 19, 1919),
142:circuits to amplify the signal.
16:Electromagnetic navigational aid
1550:Port of New York and New Jersey
1296:, p. 23, September 7, 1919
1025:Crossley, A. (February 1921a),
994:"Chap. 2: Places to Land Blind"
319:Blind Landing Experimental Unit
59:Port of New York and New Jersey
43:Port of New York and New Jersey
1503:, The Century Co., p. 296
1176:, pp. 696–699, 120a. 136a
1103:"New York's Radio Pilot Cable"
958:, p. MR9, August 18, 1929
1:
1464:Wilhelm, Donald (July 1922),
1053:Crossley, A. (August 1921b),
112:A ship received by a pair of
1223:"As It Was in the Beginning"
1121:IEEE Today's Engineer Online
180:with the "Hanson apparatus".
35:Ambrose Channel leader cable
1389:10.1126/science.59.1534.x.s
1205:, pp. II1, Sep 8, 1919
31:Ambrose Channel pilot cable
1566:
972:, McGraw-Hill, p. 951
1243:"The Leader Cable System"
1140:Gordon, Ortherus (1922),
73:Description and operation
1540:History of communication
1530:History of New York City
1487:Woods, David L. (1980),
1094:The Atlanta Constitution
825:Science News-Letter 1929
168:Installation and testing
121:Research and development
91:Verrazano-Narrows Bridge
1500:The complete radio book
1406:The Science News-Letter
980:"The Radio Pilot-Cable"
881:Yates & Pacent 1922
280:radio direction finding
265:Obsolescence and legacy
41:at the entrance to the
1433:Perry, Graham (2004),
1123:. IEEE. Archived from
964:Bennett, J.J. (1921),
697:Los Angeles Times 1920
685:Los Angeles Times 1919
637:Los Angeles Times 1920
181:
130:
89:(near the present day
82:
37:, was a cable laid in
26:
1535:History of navigation
1480:Chicago Daily Tribune
1377:"Science News: Items"
1337:10.1073/pnas.10.6.211
992:Conway, Erik (2008),
522:Nautical Gazette 1920
290:Royal Society of Arts
282:and the placement of
175:
154:New London Naval Base
128:
80:
24:
1281:The Nautical Gazette
1117:"Robert H. Marriott"
929:Current History 1921
841:Radio Broadcast 1922
673:Washington Post 1919
442:Current History 1921
1328:1924PNAS...10..211P
1259:1921Natur.106..760.
1109:, pp. 195, 210
1107:Scientific American
757:New York Times 1920
661:New York Times 1920
625:New York Times 1920
402:New York Times 1920
97:to the vicinity of
1525:Maritime transport
1439:, kea publishing,
1310:The New York Times
1215:, February 8, 1925
1162:, pp. 489–490
867:, pp. 995–996
805:Baltimore Sun 1929
623:, pp. 38–39;
310:Popular Mechanics,
182:
146:Robert H. Marriott
131:
83:
33:, also called the
27:
1520:Navigational aids
1213:Los Angeles Times
1203:Los Angeles Times
1174:Popular Mechanics
1160:Aerial Age Weekly
1070:
1049:
1007:978-0-8018-8960-8
947:Los Angeles Times
575:, pp. 40–41.
535:, pp. 38–39.
416:, pp. 46–47.
380:, pp. 44–45.
99:Lightship Ambrose
1557:
1504:
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1268:10.1038/106760a0
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987:
973:
970:Electrical World
959:
949:
932:
919:, pp. 1–2;
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211:Boston Navy Yard
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1510:
1509:
1508:
1496:
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1477:
1470:Radio Broadcast
1463:
1456:Washington Post
1453:
1447:
1432:
1418:10.2307/3904529
1403:
1375:
1368:Radio Broadcast
1362:
1317:
1305:
1301:
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1275:
1241:
1232:
1230:
1227:Radio Broadcast
1220:
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1200:
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1167:
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1114:
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1091:
1082:
1080:
1076:Current History
1073:
1052:
1024:
1014:
1008:
991:
977:
963:
953:
944:
935:
927:, p. 489;
923:, p. 100;
907:
903:
891:
887:
875:
871:
863:
859:
851:
847:
835:
831:
823:
819:
811:, p. 215;
803:
799:
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751:
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454:Geselowitz 2009
452:
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396:
388:
384:
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372:
364:
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352:
348:
340:
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327:
288:Journal of the
267:
258:Radio Broadcast
253:Radio Broadcast
170:
123:
114:induction coils
95:Ambrose Channel
75:
63:commercial port
61:, an important
55:Ambrose Channel
52:
39:Ambrose Channel
17:
12:
11:
5:
1563:
1561:
1553:
1552:
1547:
1542:
1537:
1532:
1527:
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1512:
1511:
1507:
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1494:
1484:
1475:
1461:
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1445:
1430:
1401:
1373:
1360:
1315:
1299:
1294:New York Times
1286:
1273:
1239:
1218:
1208:
1198:
1179:
1165:
1151:
1137:
1127:on 4 July 2013
1112:
1098:
1089:
1071:
1050:
1022:
1012:
1006:
989:
975:
961:
951:
941:
934:
933:
931:, p. 162.
917:Armstrong 1930
911:, p. 13;
901:
885:
883:, p. 296.
869:
857:
855:, p. 213.
845:
829:
817:
815:, p. xiv.
797:
785:
783:, p. 251.
773:
771:, p. 249.
761:
749:
747:, p. 249.
737:
735:, p. 249.
725:
713:
711:, p. 951.
701:
689:
677:
665:
653:
651:, p. 290.
649:Crossley 1921a
641:
629:
621:Crossley 1921a
613:
609:Crossley 1921a
601:
597:Crossley 1921a
589:
585:Crossley 1921a
577:
573:Crossley 1921a
565:
563:, p. 250.
559:, p. 40;
557:Crossley 1921a
549:
545:Crossley 1921a
537:
533:Crossley 1921a
525:
514:
512:, p. 250.
502:
500:, p. 250.
490:
488:, p. 250.
478:
466:
464:, p. 523.
446:
440:, p. 34;
438:Crossley 1921a
430:
426:Crossley 1921a
418:
414:Crossley 1921a
406:
394:
390:Crossley 1921a
382:
378:Crossley 1921a
370:
366:Crossley 1921b
358:
356:, p. 249.
346:
333:
326:
323:
301:, and lighted
266:
263:
169:
166:
122:
119:
87:Fort Lafayette
74:
71:
51:
48:
15:
13:
10:
9:
6:
4:
3:
2:
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1533:
1531:
1528:
1526:
1523:
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1518:
1517:
1515:
1502:
1501:
1495:
1491:, Arno Press
1490:
1485:
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1476:
1471:
1467:
1462:
1458:, Sep 7, 1919
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1028:
1023:
1018:
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1009:
1003:
1000:, JHU Press,
999:
995:
990:
985:
981:
976:
971:
967:
962:
957:
956:Baltimore Sun
952:
948:
943:
942:
940:
939:
938:Cited sources
930:
926:
922:
918:
915:, p. 5;
914:
910:
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902:
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889:
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762:
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750:
746:
741:
738:
734:
729:
726:
723:, p. 72.
722:
717:
714:
710:
705:
702:
698:
693:
690:
686:
681:
678:
675:, p. 21.
674:
669:
666:
662:
657:
654:
650:
645:
642:
638:
633:
630:
626:
622:
617:
614:
611:, p. 43.
610:
605:
602:
599:, p. 43.
598:
593:
590:
587:, p. 42.
586:
581:
578:
574:
569:
566:
562:
558:
553:
550:
547:, p. 40.
546:
541:
538:
534:
529:
526:
523:
518:
515:
511:
506:
503:
499:
494:
491:
487:
482:
479:
476:, p. 250
475:
470:
467:
463:
459:
458:Marriott 1924
455:
450:
447:
444:, p. 161
443:
439:
434:
431:
428:, p. 36.
427:
422:
419:
415:
410:
407:
403:
398:
395:
391:
386:
383:
379:
374:
371:
368:, p. 280
367:
362:
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355:
350:
347:
343:
338:
335:
332:
331:
324:
322:
320:
316:
311:
306:
304:
300:
296:
292:
291:
285:
284:radio beacons
281:
276:
273:
272:Baltimore Sun
264:
262:
259:
254:
250:
244:
242:
241:
235:
231:
230:
224:
220:
216:
215:Western Union
212:
208:
207:
200:
197:
196:
190:
187:
179:
174:
167:
165:
163:
159:
155:
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147:
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137:
127:
120:
118:
115:
110:
108:
104:
100:
96:
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67:New York City
64:
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49:
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44:
40:
36:
32:
23:
19:
1499:
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1250:
1246:
1231:, retrieved
1226:
1212:
1202:
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1125:the original
1120:
1106:
1093:
1081:, retrieved
1075:
1065:(4): 273–294
1062:
1058:
1037:(1): 33–59,
1034:
1030:
1016:
997:
983:
969:
955:
946:
937:
936:
904:
895:, Chap. 28,
888:
872:
860:
848:
832:
820:
813:Science 1924
800:
793:Wilhelm 1922
788:
781:Wilhelm 1922
776:
769:Wilhelm 1922
764:
759:, p. 6.
752:
745:Wilhelm 1922
740:
733:Wilhelm 1922
728:
716:
709:Bennett 1921
704:
692:
680:
668:
663:, p. 6.
656:
644:
632:
627:, p. 6.
616:
604:
592:
580:
568:
561:Wilhelm 1922
552:
540:
528:
517:
510:Wilhelm 1922
505:
498:Wilhelm 1922
493:
486:Wilhelm 1922
481:
474:Wilhelm 1922
469:
449:
433:
421:
409:
404:, p. 6.
397:
385:
373:
361:
354:Wilhelm 1922
349:
337:
329:
328:
309:
307:
287:
277:
271:
268:
257:
252:
248:
245:
239:
228:
205:
201:
194:
188:
183:
177:
144:
136:galvanometer
132:
111:
84:
53:
34:
30:
28:
18:
1146:Radio World
925:Hanson 1919
893:Howeth 1963
877:Hanson 1934
865:Cooper 1930
853:Putnam 1924
837:Putnam 1924
809:Putnam 1924
721:Gordon 1922
315:autolanding
249:Radio World
150:Puget Sound
140:vacuum tube
1514:Categories
1446:0951895869
921:Perry 2004
913:Davis 1922
462:Woods 1980
325:References
221:, and the
107:Morse Code
50:Background
1397:239868841
1083:29 August
909:Wood 1930
342:Bond 1920
186:minelayer
162:submarine
1356:16586927
1194:64062870
134:using a
1426:3904529
1381:Science
1347:1085624
1324:Bibcode
1255:Bibcode
1233:5 March
1229:: 51–59
1131:15 June
234:pilots'
229:Algorma
209:in the
195:O'Brien
1443:
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1247:Nature
1192:
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240:Semmes
223:police
217:, the
206:Pequot
178:Semmes
158:launch
1422:JSTOR
1393:S2CID
1306:(PDF)
330:Notes
303:buoys
295:radar
1441:ISBN
1352:PMID
1235:2018
1190:LCCN
1133:2013
1085:2013
1002:ISBN
238:USS
227:USS
219:Army
204:USS
193:USS
29:The
1414:doi
1385:doi
1342:PMC
1332:doi
1263:doi
1251:106
1039:doi
897:§16
299:GPS
189:Ord
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