Search for ships by port rotation number

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This page is an index of ships by port rotation numbers drawn from the primary records of British shipping prior to 1855.

The registers of British seafarers for the period 1845 to 1854 are held at The National Archives (TNA) and show the person's career at sea, drawn from the crew lists of British ships. The registers use a code made up a port rotation number to identify the ship and a port number for the ship's port of registry. The key to the port numbers is known and this index to the port rotation numbers identifies the ship, so the crew lists can be found.

The crew lists are held at TNA in the series BT 98 in thousands of boxes (pieces) sorted by year, by port of registry and then by ship's name. Without the ship's name, there might be many pieces to search through, each holding up to 100 documents for many different ships.

This search page returns the ship's name with a list of the boxes of crew lists in BT 98 which are likely to hold the crew documents. It also provides links to the FamilySearch films which provide access to images of the documents.

Once the correct document has been found, the matching port rotation number is shown on it, thus completing the loop.

For full details of port rotation numbers, please follow this link: Port Rotation Numbers

How to search for ships by port rotation number

Enter the ship's port rotation number and select either the port name or number from one of the drop-down lists.

Then click .

Reading the results

The results show the ship's name and any data which has been extracted from BT 98, combined with other sources to provide details like registration entries and tonnages. We show the source of the data and if the main source is BT 98, we provide a link to TNA's catalogue.

Some data not found in BT 98 has been deduced from missing numbers. As explained in the full notes, Pete Owens discovered the underlying link between the Port Rotation numbers and the shipping registers for the port. That means that missing data can be deduced. For example, if port rotation numbers 195 and 199 for Whitby match with register entries 25/1840 and 29/1840, then port rotation number 197 would match with 27/1840, which can be identified from BT 162/19 as the ship Henry. We show the source of that data as 'Deduced from BT 98 and other sources'. We show how confident we are in this interpolation by a percentage, (Q) - 99% is best, down to 60% where there is a gap of twenty records.

We also provide links to other CLIP data for ships of that name. One link is for pre-1855 records; the other is for later years (but bear in mind that the ship may not have been extant by then).

Why does a search for a port rotation number fail?

Our data does not provide complete coverage.

We have gathered data from a 10% sample of the crew documents for the period 1845 to 1854 - all of those for 1851. Using the underlying pattern of the data which Pete Owens discovered, we have been able to fill in many of the gaps so the overall coverage is well over 60% and probably much higher for ships registered in the period up to 1851.

We are adding data to cover the period up to 1854 for the larger ports.

Beware! If you are using data from the seafarers' records, please bear in mind that it is often difficult to read the port rotation numbers. Do consider alternative readings and consider referring to newspaper records which may help to confirm which ships arrived or left around that date.

Using the results

Knowing the name of the ship, it is possible to work out which boxes at TNA might contain documents for the ship. We show that in the lower part of the page.

We use a colour code to show how sure we are that documents will be found, as shown in this table.

Be aware Apart from the years from which we have extracted data, there is no guarantee that documents will be found in any box, especially so where we have deduced the ship's name from other data. For some years, we can be fairly sure that the documents are not in that box, because they were not found there when data was extracted. We can not accept liability for the results of any inaccuracy in our data.

Please remember also that the data refers to the port rotation number - not to the ship's name. For example, if the ship was re-registered at the same port, there may well be documents for her after that date, but with a different port rotation number.

Where we have details of when the ship's registration at that port began and/or ended, we have used that to add comments about the years for which there are likely to be documents. For example, if the ship is shown in BT 162/19 as being re-registered in 1850, we will point out that there may be records for her in later years, but with a different port rotation number.

Colour codes for crew list sources
Documents have been found in this reference
Documents may be found in this reference
Documents were not found in this reference for port rotation number nnn
Documents will probably not be found in this reference for port rotation number nnn

There are two link icon buttons against each data item for the document sources:

  shows the TNA reference and provides a link to TNA's catalogue.

  shows the film reference and provides a link to the images on the FamilySearch site.

Be aware. You need an account with FamilySearch for this to work, and to be working from a FamilySearch centre or a FamilySearch Affiliate Library.

against a references indicates that crew name data from that reference is included in the name index (£) for the 1851 records in BT98 made by Family History Indexes.

Data sources

The data comes from a 10% sample of the crew lists in BT 98 for the period 1845 to 1854 - all of the documents for 1851. Most of the transcription was done using the FamilySearch films, working at FamilySearch Affiliate Libraries.

In parallel with gathering data from the crew lists, CLIP compiled indexes of ships pre-1855. One set is from BT 162/19 which lists ships extant in 1850 and the second is from parts of BT 111 which cover the period from the 1820s to 1855. This data is available separately here: Ships pre-1855 and Ships by port

The data from the crew lists was cross-checked during and after transcription by comparing it with data from BT 111 and BT 162, and also against the underlying links to the shipping registers on which the port rotation numbers were based.

Because of this tight cross-checking, the overall accuracy of the transcribed sample data is high - better than 95% - despite the fact that the documents themselves are hard to read and the Victorian clerks made errors (such as typos and confusing the registration dates for a ship). We were able to detect the errors and allow for them, generally by omitting the erroneous data.


The Port Rotation Number Project began when Peter Hamersley contacted CLIP in the summer of 2020 suggesting an index to the port rotation numbers. He has worked with us on the hard slog of extracting the data which makes it all work. We have been delighted to work with him in developing what is a major step forward in researching the crew documents held in BT 98.

We are most grateful to Bruno Pappalardo at TNA who has provided valuable support and assistance.

We thank our volunteer transcribers, Robert Holloway, Laura Hamersley and Janine Hamersley in Australia, Maxwell Crockett in NZ and Myfanwy Gate at the National Library of Wales (NLW). The staff of NLW have been most helpful.

Anglesey Archives have provided invaluable assistance by arranging for FamilySearch Affiliate Library status to provide CLIP with access to the records online.

Please chose the port number or port name

Port number :   

Port name :    

The Port Rotation Number Project began with the initiative of Peter Hamersley with whom we have been delighted to work in carrying through a ground-breaking project.

Click here to see a summary of the ports covered:

The table shows a list of the ports for which we have gathered port rotation number data. These are the columns:

the name of the port;
Port reference number
the reference number for that port, as used with the port rotation numbers;
PR numbers count
the count of port rotation numbers that we have found or deduced;
PR numbers max
the highest port rotation number we have found;
the percentage of the port rotation numbers for this port which we have found, based on the previous numbers.

The percentage shown for each port is the coverage for ships registered in the period from the 1830s to 1851. Within that, for ships registered between 1845 and 1851, the coverage is mostly better than 90%.

We will soon have completed the 400+ films for 1851. Our progress is shown here: Data progress

Port Port reference number PR numbers count PR numbers max %age
ABERDEEN 1 44169063
ABERYSTWYTH 2 28635580
ALDEBURGH 3 254555
ALLOA 113 11433733
ARBROATH 115 22123693
ARUNDEL 4 5311147
AYR 5 659667
BALLINA 122 22100
BANFF 7 21028972
BARNSTAPLE 8 9719350
BEAUMARIS 9 31160351
BELFAST 10 733107568
BERWICK 11 8214257
BIDEFORD 12 20336455
BRIDGWATER 15 19225675
BRIDPORT 17 223857
BRISTOL 18 47872266
CAERNARFON 117 328112629
CARDIFF 20 8516651
CARDIGAN 21 29637179
CARLISLE 22 447657
CARMARTHEN 116 213560
CHEPSTOW 23 439943
CHESTER 24 15022167
CHICHESTER 25 398645
CLEY 26 14723562
COLCHESTER 27 25853847
COLERAINE 28 52520
CORK 29 45898946
COWES 30 21439554
DARTMOUTH 31 72293277
DERBYHAVEN 148 6415840
DOUGLAS 147 9317553
DOVER 33 8421638
DROGHEDA 34 547869
DUBLIN 35 57286566
DUMFRIES 36 17123572
DUNBAR 60 109371
DUNDALK 37 296246
DUNDEE 38 52881165
EXETER 39 24841360
FALMOUTH 40 15323764
FAVERSHAM 41 21651741
FLEETWOOD 126 242788
FOLKESTONE 123 81553
FOWEY 42 16721478
GALWAY 43 216532
GLASGOW 44 1347175776
GLOUCESTER 46 34552965
GOOLE 47 65582379
GRANGEMOUTH 45 4310640
GREENOCK 48 51093854
GRIMSBY 49 769877
GUERNSEY 151 18731559
GWEEK 50 51435
HARTLEPOOL 118 23123598
HARWICH 51 13721065
HASTINGS 84 2818615
HULL 52 53493856
INVERNESS 54 28550656
IPSWICH 55 26145557
IRVINE 56 18226967
JERSEY 152 52088258
KIRKCALDY 57 8428629
KIRKWALL 58 5811948
LANCASTER 59 9917656
LEITH 60 26552650
LERWICK 61 1911816
LIMERICK 67 9822244
LIVERPOOL 62 4180612668
LLANELLI 63 7115745
LONDON 64 5127917155
LYME 66 193063
LYNN 68 28238473
MALDON 69 16828858
MARYPORT 112 14525057
MILFORD 70 16927561
MONTROSE 71 16033248
NEWCASTLE 75 1868306061
NEWHAVEN 74 234254
NEWPORT 72 11218361
NEWRY 73 14431745
PADSTOW 76 17522079
PEEL 149 4417625
PENZANCE 77 11418461
PERTH 114 9419149
PETERHEAD 127 6310565
PLYMOUTH 78 46080057
POOLE 79 13724955
PORT GLASGOW 81 7216643
PORTSMOUTH 80 23962838
PRESTON 109 17328061
PWLLHELI 117 25084929
RAMSEY 150 4127115
RAMSGATE 82 12432438
ROCHESTER 83 33463452
ROSS 111 466768
RUNCORN 120 546385
RYE 84 10337227
SCARBOROUGH 85 22934865
SCILLY 86 9012671
SHIELDS 124 1542158797
SHOREHAM 88 15322867
SLIGO 89 267634
SOUTHAMPTON 90 28648958
SOUTHWOLD 91 153740
ST IVES 87 19727671
ST JOHN, NEW BRUNSWICK 230 310153820
STOCKTON 93 18964229
STORNOWAY 94 3210231
STRANGFORD 125 596295
STRANRAER 95 387550
SUNDERLAND 92 2298431053
SWANSEA 96 23138959
TRALEE 119 31717
TRURO 97 398346
WATERFORD 98 23435665
WELLS 99 325006
WEXFORD 102 13321063
WEYMOUTH 101 10117358
WHITBY 104 46678859
WHITEHAVEN 103 26867839
WICK 105 429444
WIGTOWN 121 9348119
WISBECH 106 14920473
WOODBRIDGE 107 508956
WORKINGTON 128 13853525
YARMOUTH 108 854131065