904:
20:
118:. Otherwise, if a ship has been assigned a load line by its national government, the draft for that summer load line is used. If the ship has no load line, instead, a maximum draft assigned by its national government, that value is used, if it has been assigned a maximum. Finally, for a ship to which none of the above applies, the value of
892:, net tonnage is used to determine eligibility for registering boats with the federal government. Vessels with net tonnage of five or more are eligible for federal registration and not required to display state registration numbers. Most vessels longer than 25 feet (7.6 m) have net tonnage of five or more.
77:
The
International Convention on Tonnage Measurement of Ships, 1969 was adopted by IMO in 1969. Ships built before that date were given 12 years to migrate from their existing tonnage to use of NT and GT. The phase-in period was provided to allow ships time to adjust economically, since tonnage is
78:
the basis for satisfying manning regulations and safety rules. Tonnage is also the basis for calculating registration fees and port dues. One of the
Convention's goals was to ensure that the new units "did not differ too greatly" from the traditional GRT and NRT units.
54:(NRT) which denoted the volume of the ship's revenue-earning spaces in "register tons", units of volume equal to 100 cubic feet (2.83 m). Net tonnage is used to calculate the port duties and should not be taken as less than 30 per cent of the ship's
727:
338:
859:
470:
114:, the Summer Load Line draft is used, with the exception of cases where that is a timber load line. For passenger ships, the draft used is the deepest subdivision load line assigned in accordance with the
584:
959:
247:
781:
392:
81:
Both NT and GT are obtained by measuring ship's volume and then applying a mathematical formula. Net tonnage is based on "the moulded volume of all cargo spaces of the ship" while
593:
864:
The difference between the cases of 12 of fewer passengers and 13 or more passengers is due to a restriction given in the net tonnage definition that states "...when N
480:
When calculating NT for ships certified to carry 13 or more passengers, an additional term is used in the NT formula. It is based on three additional variables:
115:
956:
85:
is based on "the moulded volume of all enclosed spaces of the ship". In addition, a ship's net tonnage is constrained to be no less than 30% of her
1052:
42:) is a dimensionless index calculated from the total moulded volume of the ship's cargo spaces by using a mathematical formula. Defined in
1150:
256:
786:
397:
526:
111:
181:
69:. Also, unlike the net register tonnage, the net tonnage is unitless and thus can not be defined as "tons" or "net tons".
1048:
47:
1119:
1080:
936:
61:
Net tonnage is not a measure of the weight of the ship or its cargo, and should not be confused with terms such as
1143:
1419:
1574:
1429:
1414:
1178:
734:
345:
1424:
1384:
1056:
722:{\displaystyle NT=K_{2}\times V_{c}\times ({\tfrac {4d}{3D}})^{2}+K_{3}\times (N_{1}+{\frac {N_{2}}{10}})}
1363:
1579:
1136:
1284:
23:
Net tonnage is calculated by measuring a ship's internal volume and applying mathematical formulae.
861:
will not be less than 0.25 GT, and the final value of NT shall not be taken as less than 0.30 GT.
472:
will not be less than 0.25 GT, and the final value of NT shall not be taken as less than 0.30 GT.
1326:
1230:
102:
The net tonnage calculation is based on a number of factors, one of which is the moulded draft
1569:
1220:
1092:
1367:
1331:
1235:
1225:
1033:
132:
51:
8:
1409:
66:
1543:
1470:
1460:
1358:
1310:
62:
1522:
1159:
1115:
1076:
932:
1183:
909:
1199:
1003:
963:
926:
1445:
1389:
1173:
1563:
1455:
1450:
1279:
889:
518:
488:
86:
82:
55:
1517:
1305:
1215:
903:
251:
And then these three values are used to calculate NT using this formula:
1508:
19:
1533:
1503:
1251:
130:
The Net tonnage calculation is defined in
Regulation 4 of Annex 1 of
1128:
1548:
1498:
1493:
1488:
1483:
1047:
146:, the total volume of the ship's cargo spaces in cubic meters (m³),
333:{\displaystyle NT=K_{2}\times V_{c}\times ({\tfrac {4d}{3D}})^{2}}
133:
The
International Convention on Tonnage Measurement of Ships, 1969
1538:
1513:
1478:
1274:
500:, number of passengers in cabins with not more than 8 berths, and
1053:"International Convention on Tonnage Measurement of Ships, 1969"
1034:"International Convention on Tonnage Measurement of Ships, 1969"
854:{\displaystyle K_{2}\times V_{c}\times ({\tfrac {4d}{3D}})^{2}}
465:{\displaystyle K_{2}\times V_{c}\times ({\tfrac {4d}{3D}})^{2}}
162:
The first step in calculating NT is to find the value known as
1527:
579:{\displaystyle K_{3}={\frac {1.25\times (GT+10000)}{10000}}}
44:
1114:(4th ed.). Centreville, MD: Cornell Maritime Press.
1109:
957:
International
Convention on Tonnage Measurement of Ships
122:
is taken as 75 per cent of the moulded depth amidships.
820:
742:
636:
431:
353:
299:
242:{\displaystyle K_{2}=0.2+0.02\times \log _{10}(V_{c})}
116:
International
Convention for the Safety of Life at Sea
1055:. International Maritime Organization. Archived from
1004:"USCG National Vessel Documentation Center, FAQ Page"
789:
737:
596:
529:
400:
348:
259:
184:
899:
152:, the ship's moulded draft amidships in meters, and
783:shall not be taken as greater than unity, the term
853:
775:
721:
578:
464:
386:
332:
241:
176:. It is obtained by using the following formula:
1561:
158:, the ship's moulded depth amidships in metres
1110:Turpin, Edward A.; McEwen, William A. (1980).
110:can be complicated. For ships subject to the
50:in 1969, the net tonnage replaced the earlier
1144:
966:. International Maritime Organization (IMO).
1151:
1137:
993:International Maritime Organization, 1982.
1306:Panama Canal/Universal Measurement System
989:
987:
985:
983:
981:
979:
977:
975:
125:
924:
475:
136:. It is based on three main variables:
97:
18:
918:
776:{\displaystyle ({\tfrac {4d}{3D}})^{2}}
387:{\displaystyle ({\tfrac {4d}{3D}})^{2}}
1562:
1351:
1070:
972:
112:International Convention on Load Lines
106:. The choice of the value to use for
1158:
1132:
1090:
931:, Taylor & Francis, p. 752,
588:Then the net tonnage is calculated:
1049:International Maritime Organization
48:International Maritime Organization
13:
1112:Merchant Marine Officers' Handbook
950:
14:
1591:
1073:American Merchant Seaman's Manual
902:
1091:Singh, Baljit (July 11, 1999).
996:
842:
816:
764:
738:
716:
683:
658:
632:
567:
552:
453:
427:
375:
349:
321:
295:
236:
223:
92:
1:
1179:Length between perpendiculars
1026:
509:, number of other passengers,
394:will not exceed 1, the term
7:
1364:Twenty-foot equivalent unit
1071:Hayler, William B. (2003).
10:
1596:
1311:Thames measurement tonnage
1093:"The world's biggest ship"
1075:. Cornell Maritime Press.
72:
1469:
1438:
1402:
1385:Builder's Old Measurement
1377:
1344:
1319:
1298:
1285:Compensated gross tonnage
1267:
1260:
1244:
1231:Load line (Plimsoll Line)
1208:
1192:
1166:
968:Retrieved 2011-10-17.
925:Stopford, Martin (2009),
880:shall be taken as zero."
895:
883:
169:, a multiplier based on
46:that was adopted by the
1461:Metacentric height (GM)
1184:Length at the waterline
16:Ship cargo space volume
1327:Gross register tonnage
855:
777:
723:
580:
517:, based on the ship's
466:
388:
334:
243:
126:12 or fewer passengers
24:
1420:Standard displacement
1368:Intermodal containers
856:
778:
724:
581:
513:First, a multiplier K
476:13 or more passengers
467:
389:
335:
244:
98:Choice of draft value
22:
1575:Nautical terminology
1332:Net register tonnage
1236:Under keel clearance
787:
735:
594:
527:
398:
346:
257:
182:
52:net register tonnage
1430:Normal displacement
1415:Loaded displacement
1425:Light displacement
1359:Deadweight tonnage
1097:The Times of India
962:2013-12-02 at the
928:Maritime Economics
872:is less than 13, N
851:
839:
773:
761:
719:
655:
576:
462:
450:
384:
372:
330:
318:
239:
63:deadweight tonnage
25:
1580:Ship measurements
1557:
1556:
1518:§ Neopanamax
1499:Handymax/Supramax
1398:
1397:
1340:
1339:
1160:Ship measurements
838:
760:
731:Where the factor
714:
654:
574:
449:
371:
342:Where the factor
317:
1587:
1349:
1348:
1265:
1264:
1153:
1146:
1139:
1130:
1129:
1125:
1106:
1104:
1103:
1086:
1067:
1065:
1064:
1044:
1042:
1041:
1020:
1019:
1017:
1015:
1000:
994:
991:
970:
969:
954:
948:
947:
946:
945:
922:
912:
910:Transport portal
907:
906:
860:
858:
857:
852:
850:
849:
840:
837:
829:
821:
812:
811:
799:
798:
782:
780:
779:
774:
772:
771:
762:
759:
751:
743:
728:
726:
725:
720:
715:
710:
709:
700:
695:
694:
679:
678:
666:
665:
656:
653:
645:
637:
628:
627:
615:
614:
585:
583:
582:
577:
575:
570:
544:
539:
538:
471:
469:
468:
463:
461:
460:
451:
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440:
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422:
410:
409:
393:
391:
390:
385:
383:
382:
373:
370:
362:
354:
339:
337:
336:
331:
329:
328:
319:
316:
308:
300:
291:
290:
278:
277:
248:
246:
245:
240:
235:
234:
219:
218:
194:
193:
1595:
1594:
1590:
1589:
1588:
1586:
1585:
1584:
1560:
1559:
1558:
1553:
1465:
1434:
1394:
1373:
1336:
1315:
1294:
1256:
1240:
1204:
1188:
1162:
1157:
1122:
1101:
1099:
1083:
1062:
1060:
1039:
1037:
1032:
1029:
1024:
1023:
1013:
1011:
1002:
1001:
997:
992:
973:
967:
964:Wayback Machine
955:
951:
943:
941:
939:
923:
919:
908:
901:
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886:
879:
875:
871:
867:
845:
841:
830:
822:
819:
807:
803:
794:
790:
788:
785:
784:
767:
763:
752:
744:
741:
736:
733:
732:
705:
701:
699:
690:
686:
674:
670:
661:
657:
646:
638:
635:
623:
619:
610:
606:
595:
592:
591:
545:
543:
534:
530:
528:
525:
524:
516:
507:
498:
478:
456:
452:
441:
433:
430:
418:
414:
405:
401:
399:
396:
395:
378:
374:
363:
355:
352:
347:
344:
343:
324:
320:
309:
301:
298:
286:
282:
273:
269:
258:
255:
254:
230:
226:
214:
210:
189:
185:
183:
180:
179:
174:
167:
144:
128:
100:
95:
75:
17:
12:
11:
5:
1593:
1583:
1582:
1577:
1572:
1555:
1554:
1552:
1551:
1546:
1541:
1536:
1531:
1525:
1520:
1511:
1506:
1501:
1496:
1491:
1486:
1481:
1475:
1473:
1467:
1466:
1464:
1463:
1458:
1453:
1448:
1446:Inclining test
1442:
1440:
1436:
1435:
1433:
1432:
1427:
1422:
1417:
1412:
1406:
1404:
1400:
1399:
1396:
1395:
1393:
1392:
1390:Moorsom System
1387:
1381:
1379:
1375:
1374:
1372:
1371:
1361:
1355:
1353:
1346:
1342:
1341:
1338:
1337:
1335:
1334:
1329:
1323:
1321:
1317:
1316:
1314:
1313:
1308:
1302:
1300:
1296:
1295:
1293:
1292:
1287:
1282:
1277:
1271:
1269:
1262:
1258:
1257:
1255:
1254:
1248:
1246:
1242:
1241:
1239:
1238:
1233:
1228:
1223:
1218:
1212:
1210:
1206:
1205:
1203:
1202:
1196:
1194:
1190:
1189:
1187:
1186:
1181:
1176:
1174:Length overall
1170:
1168:
1164:
1163:
1156:
1155:
1148:
1141:
1133:
1127:
1126:
1120:
1107:
1088:
1081:
1068:
1045:
1028:
1025:
1022:
1021:
995:
971:
949:
937:
916:
915:
914:
913:
897:
894:
885:
882:
877:
873:
869:
865:
848:
844:
836:
833:
828:
825:
818:
815:
810:
806:
802:
797:
793:
770:
766:
758:
755:
750:
747:
740:
718:
713:
708:
704:
698:
693:
689:
685:
682:
677:
673:
669:
664:
660:
652:
649:
644:
641:
634:
631:
626:
622:
618:
613:
609:
605:
602:
599:
573:
569:
566:
563:
560:
557:
554:
551:
548:
542:
537:
533:
514:
511:
510:
505:
501:
496:
492:
477:
474:
459:
455:
447:
444:
439:
436:
429:
426:
421:
417:
413:
408:
404:
381:
377:
369:
366:
361:
358:
351:
327:
323:
315:
312:
307:
304:
297:
294:
289:
285:
281:
276:
272:
268:
265:
262:
238:
233:
229:
225:
222:
217:
213:
209:
206:
203:
200:
197:
192:
188:
172:
165:
160:
159:
153:
147:
142:
127:
124:
99:
96:
94:
91:
74:
71:
15:
9:
6:
4:
3:
2:
1592:
1581:
1578:
1576:
1573:
1571:
1568:
1567:
1565:
1550:
1547:
1545:
1544:VLCC and ULCC
1542:
1540:
1537:
1535:
1532:
1529:
1526:
1524:
1521:
1519:
1515:
1512:
1510:
1507:
1505:
1502:
1500:
1497:
1495:
1492:
1490:
1487:
1485:
1482:
1480:
1477:
1476:
1474:
1472:
1468:
1462:
1459:
1457:
1456:Angle of loll
1454:
1452:
1449:
1447:
1444:
1443:
1441:
1437:
1431:
1428:
1426:
1423:
1421:
1418:
1416:
1413:
1411:
1408:
1407:
1405:
1401:
1391:
1388:
1386:
1383:
1382:
1380:
1376:
1369:
1365:
1362:
1360:
1357:
1356:
1354:
1350:
1347:
1343:
1333:
1330:
1328:
1325:
1324:
1322:
1318:
1312:
1309:
1307:
1304:
1303:
1301:
1297:
1291:
1288:
1286:
1283:
1281:
1280:Gross tonnage
1278:
1276:
1273:
1272:
1270:
1266:
1263:
1259:
1253:
1250:
1249:
1247:
1243:
1237:
1234:
1232:
1229:
1227:
1224:
1222:
1221:Moulded depth
1219:
1217:
1214:
1213:
1211:
1207:
1201:
1198:
1197:
1195:
1191:
1185:
1182:
1180:
1177:
1175:
1172:
1171:
1169:
1165:
1161:
1154:
1149:
1147:
1142:
1140:
1135:
1134:
1131:
1123:
1121:0-87033-056-X
1117:
1113:
1108:
1098:
1094:
1089:
1084:
1082:0-87033-549-9
1078:
1074:
1069:
1059:on 2009-07-07
1058:
1054:
1050:
1046:
1035:
1031:
1030:
1009:
1005:
999:
990:
988:
986:
984:
982:
980:
978:
976:
965:
961:
958:
953:
940:
938:9780415275576
934:
930:
929:
921:
917:
911:
905:
900:
893:
891:
890:United States
881:
862:
846:
834:
831:
826:
823:
813:
808:
804:
800:
795:
791:
768:
756:
753:
748:
745:
729:
711:
706:
702:
696:
691:
687:
680:
675:
671:
667:
662:
650:
647:
642:
639:
629:
624:
620:
616:
611:
607:
603:
600:
597:
589:
586:
571:
564:
561:
558:
555:
549:
546:
540:
535:
531:
522:
520:
519:gross tonnage
508:
502:
499:
493:
490:
489:gross tonnage
487:, the ship's
486:
483:
482:
481:
473:
457:
445:
442:
437:
434:
424:
419:
415:
411:
406:
402:
379:
367:
364:
359:
356:
340:
325:
313:
310:
305:
302:
292:
287:
283:
279:
274:
270:
266:
263:
260:
252:
249:
231:
227:
220:
215:
211:
207:
204:
201:
198:
195:
190:
186:
177:
175:
168:
157:
154:
151:
148:
145:
139:
138:
137:
135:
134:
123:
121:
117:
113:
109:
105:
90:
88:
87:gross tonnage
84:
83:gross tonnage
79:
70:
68:
64:
59:
57:
56:gross tonnage
53:
49:
45:
41:
37:
33:
29:
21:
1570:Shipbuilding
1410:Displacement
1289:
1111:
1100:. Retrieved
1096:
1072:
1061:. Retrieved
1057:the original
1038:. Retrieved
1036:. 1969-06-23
1012:. Retrieved
1007:
998:
952:
942:, retrieved
927:
920:
887:
863:
730:
590:
587:
523:
512:
503:
494:
484:
479:
341:
253:
250:
178:
170:
163:
161:
155:
149:
140:
131:
129:
119:
107:
103:
101:
80:
76:
67:displacement
60:
43:
39:
35:
31:
27:
26:
1530:(Qatar-max)
1299:Specialized
1290:Net tonnage
93:Calculation
28:Net tonnage
1564:Categories
1509:Malaccamax
1102:2008-04-07
1063:2008-03-23
1040:2008-03-23
1027:References
944:2011-10-17
521:is found,
1534:Seawaymax
1504:Handysize
1439:Stability
1268:Worldwide
1252:Air draft
1226:Freeboard
814:×
801:×
681:×
630:×
617:×
550:×
425:×
412:×
293:×
280:×
221:
208:×
1549:Yamalmax
1494:Chinamax
1489:Capesize
1484:Baltimax
1345:Capacity
1051:(2002).
1008:uscg.mil
960:Archived
1539:Suezmax
1523:Péniche
1514:Panamax
1479:Aframax
1378:Archaic
1352:Current
1320:Archaic
1275:Tonnage
1193:Breadth
888:In the
73:History
1471:Limits
1403:Weight
1261:Volume
1245:Height
1167:Length
1118:
1079:
1010:. 2011
935:
1528:Q-Max
1216:Draft
1209:Depth
1014:7 May
896:Notes
884:Usage
876:and N
572:10000
565:10000
1516:and
1451:List
1200:Beam
1116:ISBN
1077:ISBN
1016:2011
933:ISBN
547:1.25
205:0.02
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868:+ N
212:log
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