# Castle-class trawler

The Castle-class minesweeper was a highly seaworthy naval trawler adapted for patrol, anti-submarine warfare and minesweeping duties and built to Admiralty specifications. Altogether 197 were built in the United Kingdom between 1916 and 1919, with others built in Canada, India and later New Zealand. Many saw service in the Second World War.

## First World War

The Castle class originated with the commercial trawler Raglan Castle of 1915, taken up for Royal Navy service. The design was adapted by Smith's Dock Company Ltd to Admiralty requirements for building in quantity.
During World War I, 145 were built in the United Kingdom for the Admiralty. The names of the vessels were derived from the official crew rosters of ships at the Battle of Trafalgar. Non-standard ships included in the class varied between 236 GRT and 276 GRT, with dimensions varying between 35.8 and 38.3 m (117 and 126 ft) length and 6.71 and 7.17 m (22.0 and 23.5 ft) beam. The first standard vessel, Nathaniel Cole, was delivered in May 1917. After the war 52 further ships on order were completed as fishing vessels and many of the minesweepers were converted for commercial use. 20 ships were also cancelled, but many were completed by the shipbuilders for commercial owners.
The Admiralty also ordered 60 Castle-class trawlers from Canadian shipyards, the TR series, which were loaned to the Royal Canadian Navy for seaward defence of the east coast of Canada. Some entered service with the United States Navy. Nine ships were also built in India with teak planking on steel frames.

## Second World War

Many Castle-class trawlers were among the civilian trawlers requisitioned by the Royal Navy for use in World War II. The majority were employed as minesweepers, with others serving as auxiliary patrol vessels, boom defense vessels, danlayers, Essos (fuel carriers), torpedo recovery vessels and water carriers. Many had multiple roles over the course of the war. After the end of the war, most of those that had survived were either sold or returned to their owners.

### German captured

Early in World War II, ten Canadian-built trawlers that had been sold into commercial service after World War I with a number of European countries were captured by the Germans when they overran France, Belgium and Norway and put in Kriegsmarine service.

### New Zealand additions

In 1940, the New Zealand Government, facing a requirement for minesweepers to operate in home waters, directed the building of 13 Castle-class naval trawlers in New Zealand to add to the two vessels, James Cosgrove and Wakakura, they had previously purchased. The Castle-class design was chosen over more modern alternatives because it was simple enough to be built with the country's limited ship construction facilities.

## Ships in class
### Non-standard

| Ship | Builder | Launched | Completed | Fate | Second World War | Second World War Loss |
| Daniel Harrington (FY3505) | Smiths Dock | 8 February 1917 | April 1917 | Sold 1920 | Lucienne Jeanne (FY1769) | Mined 24 October 1941 in the Thames estuary |
| Daniel Henley (FY3503) | Smiths Dock | 24 January 1917 | March 1917 | Sold 4 May 1920 | Kilgerran Castle | 2 December 1940 bombed south of Cobh at 51.21N, 08.35W. |
| Festing Grindall (FY3501) | Smiths Dock | 9 January 1917 | March 1917 | Sold 11 May 1920, wrecked 4 October 1928. | | |
| George Aunger (FY3611) | Cook, Welton & Gemmell | 20 September 1917 | January 1918 | Sold 1922. Wrecked 1930 May Isl., Firth of Forth | | |
| Hugh Black (FY3602) | Cook, Welton & Gemmell | 10 May 1917 | August 1917 | Sold 1923. Wrecked 1950 off Iceland | Ogano (FY803) | |
| James Berry (FY3603) | Cook, Welton & Gemmell | 10 May 1917 | August 1917 | Sold 1922. Scrapped 1953 at Granton | Montamo (4.171) | |
| James Hunniford (FY3504) | Smiths Dock | 24 January 1917 | March 1917 | Sold 1920 | Ethel Taylor | Mined 22 November 1940 off the Tyne |
| James Johnson (FY3506) | Smiths Dock | 8 February 1917 | April 1917 | Sold 1922 | | 1941 mined and sunk 4 nmi (7.4 km; 4.6 mi) from Spurn Point |
| John Anderson (FY3610) | Cook, Welton & Gemmell | 20 September 1917 | December 1917 | Sold 1922. Scrapped 1957 at Barrow | Charles Doran (FY597) | |
| John Brennan (FY3609) | Cook, Welton & Gemmell | 4 September 1917 | January 1918 | Sold 1922. Foundered 1956 off Faeroe Islands | Osako (FY580) | |
| John Brice (FY3608) | Cook, Welton & Gemmell | 22 August 1917 | January 1918 | Sold 1924. Scrapped 1952 at Grays | Beaulne Verneuil | |
| John Brooker (FY3605) | Cook, Welton & Gemmell | 9 June 1917 | December 1917 | Sold 1921. Scrapped 1962 | Loch Park (FY1835) | |
| John Burlingham (FY3600) | Cook, Welton & Gemmell | 21 April 1917 | July 1917 | Sold 1920. Scrapped 1961 at Krimpen | Rehearo (FY1794) | |
| John Gillman (FY3502) | Smiths Dock | 9 January 1917 | March 1917 | Sold 1920. Scrapped 1955 | | |
| Richard Bagley (FY3604) | Cook, Welton & Gemmell | 9 June 1917 | September 1917 | Sold 1921. Scrapped 1954 | Malacolite (FY796) | |
| Robert Betson (FY3601) | Cook, Welton & Gemmell | 21 April 1917 | July 1917 | Sold 1920 | Remillo | Mined 27 February 1941 in the Humber |
| Thomas Blackthorn (FY3606) | Cook, Welton & Gemmell | 7 July 1917 | December 1917 | Loaned to United States Navy 1919, sold 1922, wrecked 1923 Buckton Cliff, Filey | | |
| Thomas Buckley (FY3607) | Cook, Welton & Gemmell | 7 July 1917 | December 1917 | Loaned to United States Navy 1919, sold 1922. Scrapped 1960 at Charlestown | Ceylonite (FY1853) | |

### Standard

| Ship | Builder | Launched | Completed | Fate | Second World War | WWII Loss |
| Alexander Palmer (FY3517) | Smiths Dock | 21 May 1917 | June 1917 | Sold 1922 to Spain. Shelled and sunk at Málaga by Almirante Cervera ( Spanish Navy) 9 October 1936. | | |
| Alexander Scott (FY3530) | Smiths Dock | 3 August 1917 | September 1917 | Sold 4 May 1920. Scrapped 1956 at Milford Haven | Alexander Scott (FY515) | |
| Andrew Anderson (FY4405) | Cook, Welton & Gemmell | 15 August 1919 | April 1920 | Completed as fishing vessel, sold 13 February 1922, wrecked 1949 near Castillo de San Sebastian | | |
| Andrew Apsley (FY4298) | Cook, Welton & Gemmell | 2 June 1919 | December 1919 | Completed as fishing vessel, sold 13 October 1919 | Milford Earl | Bombed 8 December 1941 off east coast of Scotland |
| Andrew Sack (FY3523) | Smiths Dock | 5 July 1917 | August 1917 | Sold 1924. Not in LR 1959. | North Ness (4.100) | |
| Arthur Cavanagh (FY3677) | Bow McLachlan | 8 May 1918 | 28 May 1918 | Sold 1925. Scrapped 1962 | Arthur Cavenagh (FY566) | |
| Arthur Lessimore (FY3510) | Smiths Dock | 9 March 1917 | May 1917 | Sold 1924 | Irvana (FY663) | Bombed 16 January 1942 off Great Yarmouth |
| Benjamin Cooke (FY3667) | Bow McLachlan | October 2017 | 1 November 1917 | Sold 1922. Scrapped 1953 at Barrow-in-Furness | Namur | |
| Benjamin Stevenson (FY3522) | Smiths Dock | 19 June 1917 | July 1917 | Sunk 18 August 1917 by gunfire 40 mi (64 km) east of Fetlar, Shetlands | | |
| Charles Antram (FY4401) | Cook, Welton & Gemmell | 18 June 1919 | February 1920 | Completed as fishing vessel, sold 1922, scrapped 1959 at Troon. | Flanders (FY600) | |
| Charles Boyes (FY3593) | Cook, Welton & Gemmell | 1 October 1917 | June 1918 | Sold 1921 | Charles Boyes (FY3677) | Mined 25 May 1940 in the North Sea |
| Charles Chappell (FY3662) | Bow McLachlan | 19 June 1917 | July 1917 | Sold 1922 to Greek owners as S.Nicola, later Nikolaos L. Captured by German Navy April 1941 | 11.V.2 – German | Wrecked 24 September 1941 at Myrina, Lemnos Island. |
| Charles Donelly (FY3679) | Bow McLachlan | 28 June 1918 | 12 July 1918 | Sold 4 May 1920. Scrapped 1953 in Glasgow. | Pelagos (4.103) | |
| Charles Legg (FY4213) | J P Rennoldson | 19 November 1918 | 20 January 1919 | Sold 1923. Scrapped 1959 | Milford Countess (FY564) | |
| Daniel Clowden (FY4446) | George Brown | 13 November 1919 | 13 November 1919 | Completed as fishing vessel, sold 8 August 1919. Scrapped 1952. | Daniel Clowden (FY531) | |
| Daniel Dick (FY4488) | J P Rennoldson | 17 May 1920 | 25 August 1920 | Completed as fishing vessel, sold 1921. Scrapped 1955. | Clyth Ness (FY1596) | |
| Daniel Leary (FY4221) | C Rennoldson | 30 July 1919 | 9 July 1920 | Completed as fishing vessel, sold 1923, wrecked 1934 and scrapped. | | |
| David Dillon (FY4484) | J P Rennoldson | May 2019 | 28 July 1919 | Completed as fishing vessel, sold 28 July 1919, scrapped 1958 | Edward Walmsley (FY624) | |
| David Ogilvie (FY3514) | Smiths Dock | 7 May 1917 | June 1917 | Sold 1919. Not in LR 1951. | David Ogilvie (FY720) | |
| Denis Casey (FY3711) | Ailsa | 13 December 1917 | 19/03/1918 | Sold July 1920. Wrecked 1926 in Galway Bay. | | |
| Dominick Addison (FY4296) | Cook, Welton & Gemmell | 2 April 1919 | November 1919 | Completed as fishing vessel, sold 1919. Scrapped 1960 at Boom. | Gadfly (FY517) | |
| Dominick Dubine (FY3726) | J P Rennoldson | 14 March 1918 | 15 May 1918 | Sold 4 May 1920. Scrapped 1952 at Dieppe. | Fructidor (AD52) – French | |
| Domque Gentile (FY3793) | Ailsa | 5 August 1918 | October 1918 | Sold 1921, believed scrapped 1978 | Santiago Rusinol – Spanish | |
| Edward Cattelly (FY4459) | Ailsa | 17 March 1919 | May 1919 | Completed as fishing vessel, sold 1919 | Loch Naver | Lost 6 May 1940 in collision off Hartlepool |
| Edward Collingwood (FY3675) | Bow McLachlan | 9 April 1918 | 26 April 1918 | Sold 1922. Scrapped 1953. | T.R. Ferrens (FY532) | |
| Edward Gallagher (FY4216) | C Rennoldson | 14 February 1919 | August 1919 | Completed as fishing vessel Ebor Downs, sold 1919, scrapped 1958 at Dublin | Cardiff Castle (FY512) | |
| Egilias Akerman (FY4294) | Cook, Welton & Gemmell | 18 March 1919 | November 1919 | Completed as fishing vessel, sold 1919 | Computator (FY635) | Sunk 21 January 1945 in collision with HMS Vanoc off Normandy |
| Emmanuel Camelaire (FY3717) | Ailsa | 25 April 1918 | May 1918 | Sold 1921, Scrapped 1957 at Milford Haven. | Brabant (FY586) | |
| Francis Conlin (FY4458) | Ailsa | 21 January 1919 | March 1919 | Completed as fishing vessel Inverythan, sold 1919, scrapped 1978 in Greece | Miranda – Greek | |
| Frederick Bush (FY3594) | Cook, Welton & Gemmell | 14 March 1918 | June 1918 | Sold 1922, foundered east of Ireland on 1 November 1928. | | |
| George Adgell (FY4402) | Cook, Welton & Gemmell | 18 June 1919 | January 1920 | Completed as fishing vessel, sold 1920, scrapped 1953 at Preston. | George Adgell (FY1926) | |
| George Aiken (FY4291) | Cook, Welton & Gemmell | 19 December 1918 | August 1920 | Completed as fishing vessel, sold 1919, scrapped 1971 in Spain | Santa Urbana – Spanish | |
| George Clarke (FY3714) | J P Rennoldson | 2 October 1917 | December 1917 | Loaned to United States Navy 1919, sold 1923, scrapped 1960 at Charlestown. | Lady Stanley (4.233) | |
| George Cochran (FY3721) | Cook, Welton & Gemmell | 28 June 1918 | December 1918 | Loaned to United States Navy 1919, sold 1920, went missing at sea 1929 | | |
| George Corten (FY3697) | Cox & Co | 1918 | 6 February 1919 | Sold 1921 | Northcoates (FY548) | Sank 2 December 1944 during a storm while under tow off Littlehampton |
| George Cousins (FY4461) | Ailsa | 13 June 1919 | August 1919 | Completed as fishing vessel, sold 1919, scrapped 1956. | George Cousins (FY627) | |
| George Darby (FY3681) | Bow McLachlan | 24 September 1918 | 21 October 1918 | Sold 1923, sold for breaking up 1967 – also reported as wrecked 1968. | Guimera – Spanish | |
| George Greaves (FY3790) | George Brown | 1919 | 12 May 1919 | Completed as fishing vessel, sold 1919 | Raglan Castle (FY631) | |
| George Greenfield (FY3787) | George Brown | 11 September 1918 | 15 October 1918 | Sold 1921. Lost off Sisargas Islands, Spain 1947. | Pacifico – Spanish | |
| George Harris (FY3854) | Hepple & Co | 20 September 1918 | 12 December 1918 | Sold 11 May 1920. Scrapped 1955 at Bombay. | Laxmii (Royal Indian Navy) | |
| Giovanni Guinti (FY3792) | Ailsa | 31 May 1918 | July 1918 | Sold 1920. Wrecked 1937 off Iceland. | | |
| Griffith Griffith (FY3780) | Cook, Welton & Gemmell | 27 August 1918 | March 1919 | Sold 11 May 1920, foundered near Badagara, India in 1925. | | |
| Henry Chevallier (FY3673) | Bow McLachlan | 13 March 1918 | 3 April 1918 | Sold 1922. Scrapped at Bo'ness 1958. | Ligny (FY1765) | |
| Henry Cory (FY3698) | Cox & Co | 1919 | 28 May 1919 | Completed as fishing vessel, sold 1919, scrapped 1959. | Caliban (FY803) | |
| Isaac Arthan (FY4297) | Cook, Welton & Gemmell | 1 May 1919 | January 1920 | Completed as fishing vessel, sold 1921, scrapped 1959 at Boom. | Loch Buie (FY688) | |
| Isaac Heath (FY3829) | J P Rennoldson | 9 July 1918 | 21 August 1918 | Sold 1920, scrapped 1958. | Teroma (FY527) | |
| James Burgess (FY3653) | C Rennoldson | 31 August 1917 | October 1917 | Sold 1920. Scrapped 1956 at Briton Ferry. | Beaumaris Castle (FY993) | |
| James Cepell (FY3718) | George Brown | 29 March 1918 | May 1918 | Sold 1925, wrecked 1952 near Ouessant. | Antioche II (AD285) – French | |
| James Chapman (FY3694) | George Brown | 8 September 1917 | November 1917 | Sold 1923, Wrecked 1966 at Salvora Island | Oceano Atlantico – Spanish | |
| James Christopher (FY3715) | J P Rennoldson | 14 January 1918 | 27 March 1918 | Sold 1923 | Marsona (FY714) | Mined 4 August 1940 off Cromarty |
| James Connor (FY3700) | Harkness | 19 July 1917 | October 1917 | Sold 1922 to Spain. Shelled and sunk at Málaga by Almirante Cervera ( Spanish Navy) 9 October 1936. | | |
| James Cosgrove (FY3716) | Ailsa | 5 March 1918 | April 1918 | Sold 1919. Scuttled 1952. | James Cosgrove (RNZN) | |
| James Dinton (FY3678) | Bow McLachlan | 10 May 1918 | 29 May 1918 | Sold 1922. Scrapped 1959. | Milford Duke (Z125) | |
| James Gill (FY4217) | C Rennoldson | 17 February 1919 | November 1919 | Completed as fishing vessel, sold 1919, scrapped 1954 at Dublin. | Milford Duchess (FY613) | |
| James Green (FY3537) | Smiths Dock | 3 October 1917 | November 1917 | Sold 1922. Scrapped 1947 at London. | Laverock | |
| James Laveney (FY4215) | Chambers | 1919 | 30 October 1919 | Completed as fishing vessel, sold 1925. Scrapped 1952. | La Blanche II (AD186) – French | |
| James Lay (FY4222) | Fletcher & Fearnall | 1918 | 4 November 1918 | Sold 1920. Scrapped 1960. | James Lay (FY667) | |
| James Peake (FY3540) | Smiths Dock | 17 October 1917 | November 1917 | Sold 1923, wrecked 1935 at Speeton. | | |
| James Pond (FY3515) | Smiths Dock | 21 May 1917 | June 1917 | Sunk 15 February 1918 by German destroyers in the Dover Straits | | |
| James Robertson (FY3159) | Smiths Dock | 6 June 1917 | July 1917 | Sold 1922. Scrapped 1960 at Barrow. | Capstone (FY1555) | |
| James Seckar (FY3526) | Smiths Dock | 20 July 1917 | August 1917 | Foundered 25 September 1917 in the Atlantic, last seen at 46°30′N 12°00′W﻿ / ﻿46.500°N 12.000°W﻿ / 46.500; -12.000 | | |
| James Sibbald (FY3525) | Smiths Dock | 20 July 1917 | August 1917 | Sold 1919. Scrapped 1957 at Milford Haven. | Our Bairns (FY1566) | |
| John Aikenhead (FY4292) | Cook, Welton & Gemmell | 19 December 1918 | November 1919 | Completed as fishing vessel, sold 1919 | Polly Johnson | Bombed 29 May 1940 off Dunkirk |
| John Ashley (FY4293) | Cook, Welton & Gemmell | 18 March 1919 | November 1919 | Completed as fishing vessel, sold 1919, scrapped at Gateshead 1952. | | |
| John Baptish (FY3596) | Cook, Welton & Gemmell | 29 April 1918 | July 1918 | Sold 1921 | John Baptish | mined Coningbeg Lightvessel 9 September 1940 |
| John Bateman (FY3599) | Cook, Welton & Gemmell | 29 April 1918 | August 1918 | Sold 1922. Scrapped 1964 in Spain. | Pesquerias Cantabricas No.1 – Spanish | |
| John Bomkworth (FY3597) | Cook, Welton & Gemmell | 29 May 1918 | July 1918 | Sold 1922 to Spain. Wrecked 24 December 1930. | | |
| John Bullock (FY3651) | C Rennoldson | 9 July 1917 | September 1917 | Sold 1921. Wrecked 1947 Fladda Island. | Flying Admiral | |
| John Campbell (FY3695) | George Brown | 1 November 1917 | December 1917 | Sold 1923. Wrecked 1925 on Tory Island. | | |
| John Casewell (FY3713) | Ailsa | 3 October 1917 | November 1917 | Sold 4 May 1920. Wrecked 1921 Castletownbere, Cork. | | |
| John Cattling (FY3676) | Bow McLachlan | 12 April 1918 | 29 April 1918 | Sold 4 May 1920. Scrapped 1957 at Hamburg. | John Cattling (FY536) | |
| John Chivers (FY3671) | Bow McLachlan | 17 December 1917 | December 1917 | Sold 1922 to Spain, scrapped 1971. | | |
| John Church (FY3668) | Bow McLachlan | 16 October 1917 | November 1917 | Sold 1920. Deleted 1962. | Txit-Ona - Spanish | |
| John Clavell (FY4480) | Hepple & Co | 14 August 1919 | 18 October 1920 | Completed as fishing vessel, sold 1921, 1977 | Denis | |
| John Collins (FY3712) | Ailsa | 19 November 1917 | December 1917 | Loaned to United States Navy 1919, sold 1920, scrapped 1963 in Suez. | | |
| John Cooper (FY3699) | Harkness | 5 July 1917 | September 1917 | Sold 1922 | Permartin Secondo | Sank in collision 3 January 1944 |
| John Davis (FY3682) | Bow McLachlan | 25 September 1918 | 22 October 1918 | Sold 1922. Wrecked Skirza Head 1939. | | |
| John Dormond (FY4485) | J P Rennoldson | August 1919 | 15 October 1919 | Completed as fishing vessel, sold 1922, foundered off Scotland 1927. | | |
| John Gauntlet (FY3779) | C Rennoldson | 12 August 1918 | March 1919 | Sold 11 May 1920, wrecked Malindi, India 1922. | | |
| John Geoghan (FY3794) | Cook, Welton & Gemmell | 9 October 1918 | November 1918 | Sold 1921, scrapped Milford Haven 1957. | Congre (AD92) – French | |
| John Graham (FY3778) | Ailsa | 27 July 1918 | January 1919 | Loaned to USN 1919, sold 1921, scrapped 1955 at Troon. | Eastcoates (FY1771) | |
| John Gregory (FY3789) | George Brown | 14 February 1919 | 2 May 1919 | Completed as fishing vessel, sold 1919, scrapped 1954. | Nadine (AD57) – French | |
| John Gulipster (FY3782) | Cook, Welton & Gemmell | 24 September 1918 | April 1919 | Completed as fishing vessel, sold 1919, scrapped 1956 at Ghent. | Comitatus (FY633) | |
| John Kidd (FY3508) | Smith's Dock Co | 20 February 1917 | May 1917 | Sold 11 May 1920, deleted from LR 1950. | Rotherslade (FY1822) | |
| John Lewis (FY4219) | C Rennoldson | 1919 | 30 March 1920 | Completed as fishing vessel, sold 1921, scrapped 1955. | Harry Melling (FY538) | |
| John Lyons (FY3511) | Smiths Dock | 23 March 1917 | May 1917 | Sold 1922. Not in LR 1951. | Les Illattes – French | |
| John Pollard (FY3516) | Smiths Dock | 21 May 1917 | June 1917 | Sold 4 May 1920, scrapped 1956 at Briton Ferry. | Grosmont Castle | |
| John Thorling (FY3527) | Smiths Dock | 20 July 1917 | September 1917 | Sold 1925, scrapped 1959 at Rotterdam. | Concertator (FY637) | |
| Joseph Barratt (FY3586) | Cook, Welton & Gemmell | 2 November 1917 | March 1918 | Sold 1920 | Tilbury Ness | Bombed 1 November 1940 in the Thames estuary |
| Joseph Button (FY3584) | Cook, Welton & Gemmell | 17 December 1917 | April 1918 | Sold 1920 | Joseph Button | Mined 22 Oct 1940 off Aldeburgh |
| Joseph Connell (FY3696) | George Brown | 20 December 1917 | February 1918 | Sold 1922, wrecked 1931 east of Cape Clear Lighthouse. | | |
| Joseph Giddice (FY3786) | George Brown | 24 October 1918 | 12 December 1918 | Sold 1922, scrapped 1952 at Monmouthshire. | | |
| Joseph Gordon (FY3785) | George Brown | 29 June 1918 | August 1918 | Sold 1922. Scrapped 1952. | Grouin Du Cou (AD276)- French | |
| Joseph Hodgkins (FY3855) | Hepple & Co | 18 December 1918 | 20 June 1919 | Completed as fishing vessel, sold 1919, sank 1921 off Isle of Man. | | |
| Joshua Arabin (FY4299) | Cook, Welton & Gemmell | 1 May 1919 | October 1919 | Completed as fishing vessel, sold 1920, scrapped at Milford Haven 1957. | De La Pole (FY558) | |
| Matthew Cassady (FY4457) | Ailsa | 18 December 1918 | February 1919, | Completed as fishing vessel Inverdon, sold 1919, wrecked 6 December 1926 at Sandoe. | | |
| Matthew Flynn (FY3745) | Hepple & Co | 17 October 1917 | 23 February 1918 | Sold 1921, sunk as target in Australia 1953. | Commiles (FY636) | |
| Michael Ging (FY3784) | George Brown | 11 May 1918 | June 1918 | Sold 1922, wrecked at Arringa 1927. | | |
| Michael Griffith (FY3781) | Cook, Welton & Gemmell | 5 September 1918 | April 1919 | Sold 1921, wrecked 7nm S Barra Head 1953. | Michael Griffith (FY567) | |
| Michael Maloney (FY3513) | Smiths Dock | 7 May 1917 | June 1917 | Stranded 19 February 1920 at Egersundl, Norway | | |
| Morgan Jones (FY3845) | Fletcher & Fearnall | 10 March 1918 | March 1918 | Sold 1920, scrapped 1957 at Troon. | Morgan Jones (4.114) | |
| Nathaniel Cole (FY3507) | Smiths Dock | 20 February 1917 | May 1917 | Foundered 6 February 1918 off Buncrana, Lough Swilly | | |
| Neil Smith (FY3524) | Smiths Dock | 5 July 1917 | August 1917 | Sold 1921, scrapped 1956 at Dublin. | Neil Smith (FY529) | |
| Oliver Pickin (FY3518) | Smiths Dock | 21 May 1917 | July 1917 | Sold 1922, scrapped 1956. | Damito (FY521) | |
| Patrick Bowe (FY3591) | Cook, Welton & Gemmell | 17 January 1918 | May 1918 | Sold 1922 to Spain. Wrecked Arosa Bay 1 September 1931. | | |
| Patrick Cullen (FY4460) | Ailsa | 31 March 1919 | June 1919 | Completed as fishing vessel, sold 1919, wrecked 1928 at St Kilda. | | |
| Patrick Donovan (FY4487) | J P Rennoldson | 20 February 1920 | 20 June 1920 | Completed as fishing vessel, sold 1922, wrecked 1934 off Grimsby. | | |
| Peter Blumberry (FY3583) | Cook, Welton & Gemmell | 18 October 1917 | February 1918 | Sold 1921, lost in explosion off Dingle 1933. | | |
| Peter Carey (FY4445) | George Brown | 25 June 1919 | October 1919 | Completed as fishing vessel, sold 1919, scrapped 1959. | Peter Carey (FY537) | |
| Peter Hall (FY3795) | Ailsa | 6 November 1918 | December 1918 | Sold 1922, scrapped 1954 at Barrow-in-Furness. | Alvis (FY4118) | |
| Peter Killen (FY4207) | Duthie Torry | 1919 | 31 March 1919 | Completed as fishing vessel, sold 1919, scrapped 1957 at Charlestown. | Sir John Lister (FY622) | |
| Peter Lovett (FY3509) | Smiths Dock | 9 March 1917 | May 1917 | Sold 1922 | | Sank off Tod Head 19 May 1940 |
| Philip Godby (FY3783) | Cook, Welton & Gemmell | 24 September 1918 | May 1919 | Completed as fishing vessel, sold 1919 | Togimo | Sunk 11 February 1940 by gunfire from U-47 west of Cornwall |
| Phineas Beard (FY3588) | Cook, Welton & Gemmell | 17 November 1917 | March 1918 | Sold 1920 | Phineas Beard | Bombed 8 December 1941 off Lunan Bay |
| Richard Bacon (FY3587) | Cook, Welton & Gemmell | 2 November 1917 | March 1918 | Sold 1922, scrapped 1954 at Milford Haven. | Commodator (FY634) | |
| Richard Crofts (FY3720) | Cook, Welton & Gemmell | 13 June 1918 | December 1918 | Sold 1921. Wrecked 20 Feb 1953 at Cornaig Beg. | Richard Crofts (FY530) | |
| Richard Cundy (FY4462) | Ailsa | 12 August 1919 | October 1919 | Completed as fishing vessel, sold 1920 | River Clyde | Mined 5 August 1940 off Aldeburgh |
| Richard Roberts (FY3520) | Smiths Dock | 6 June 1917 | July 1917 | Sold 11 May 1920, wrecked near Touriñan 29 July 1922. | | |
| Robert Bowen (FY3595) | Cook, Welton & Gemmell | 14 March 1918 | July 1918 | Sold 1920 | Robert Bowen | Bombed 9 February 1940 off Aberdeen |
| Robert Cloughton (FY3672) | Bow McLachlan | 18 December 1917 | December 1917 | Boom defence vessel Coronet 1933, Scrapped 1953 at Northam. | | |
| Robert Davidson (FY3725) | C Rennoldson | 30 November 1917 | January 1918 | Sold 1921 | Inasi - Spanish | |
| Samuel Dawson (FY4486) | J P Rennoldson | 24 November 1919 | 5 February 1920 | Completed as fishing vessel, sold 1922 | Sotirios - Greek | Sunk April 1941 by German aircraft in North Evoicos. |
| Samuel Drake (FY3683) | Bow McLachlan | 5 November 1918 | 26 November 1918 | Sold 1924. Scrapped 1946 at Paull. | Southcoates (4.140) | |
| Samuel Green (FY3791) | George Brown | 30 April 1919 | July 1919 | Completed as fishing vessel, sold 1919 and converted to yacht; used as floating restaurant Cruz at Leith. Was "abandoned" from 2007 to 2018, restored into a 1920s style luxury hotel and renamed to Ocean Mist, permanently docked at 14 The Shore, Leith. | Ocean Rover | |
| Samuel Spencer (FY3533) | Smiths Dock | 17 September 1917 | October 1917 | Sold 1921, Not in 1950 LR. | Pen-Men - French | |
| Siam Duffy (FY3684) | Bow McLachlan | 6 November 1918 | 27 November 1918 | Loaned to United States Navy 1919, sold 1922 | Fontenoy | Bombed 19 November 1940 off Lowestoft |
| Thomas Adney (FY4295) | Cook, Welton & Gemmell | 2 April 1919 | November 1919 | Completed as fishing vessel, sold 1919, went missing at sea 3 September 1920 | | |
| Thomas Alexander (FY4404) | Cook, Welton & Gemmell | 18 July 1919 | June 1920 | Completed as fishing vessel, sold 1920, scuttled 1956 off Albany, Washington. | Ben Dearg (FY690) | |
| Thomas Allen (FY4403) | Cook, Welton & Gemmell | 18 July 1919 | March 1920 | Completed as fishing vessel, sold 1922, scrapped 1963 at Hamburg. | Milford Prince (FY614) | |
| Thomas Altoft (FY4300) | Cook, Welton & Gemmell | 2 June 1919 | January 1920 | Completed as fishing vessel, sold 1920, wrecked Glas Island, Scalpay 8 November 1947. | Thomas Altoft (FY552) | |
| Thomas Bartlett (FY3598) | Cook, Welton & Gemmell | 29 May 1918 | August 1918 | Sold 11 May 1920 | Thomas Bartlett (FY553) | Mined 28 May 1940 off Calais |
| Thomas Booth (FY3592) | Cook, Welton & Gemmell | 14 February 1918 | June 1918 | Sold 1920. Scrapped 1955 at Milford Haven. | | |
| Thomas Boudige (FY4406) | Cook, Welton & Gemmell | 15 August 1919 | August 1920 | Completed as fishing vessel, sold 1921, scrapped 1956 at Dublin. | Darnett Ness (FY542) | |
| Thomas Chambers (FY3670) | Bow McLachlan | 1 December 1917 | December 1917 | Sold 1922. Scrapped 1959 at Bruges. | Lorraine (4.170) | |
| Thomas Connolly (FY3589) | Cook, Welton & Gemmell | 29 November 1917 | April 1918 | Sold 1920 | Thomas Connolly (Z141) | Mined 17 December 1940 off Sheerness |
| Thomas Crofton (FY3661) | Bow McLachlan | 18 June 1917 | July 1917 | Sold 4 May 1920. Scrapped 1946. | Gwmaho (Z135) | |
| Thomas Daniels (FY3680) | Bow McLachlan | 10 July 1918 | 12 August 1918 | Sold 1922. Wrecked 1 March 1927 Cairns of Coll. | | |
| Thomas Dowding (FY3724) | C Rennoldson | 16 November 1917 | December 1917 | Sold 1923. Scrapped 1953. | Ben Bheulah (FY1681) | |
| Thomas Goble (FY3539) | Smiths Dock | 17 October 1917 | November 1917 | Sold 1922. Scrapped 1959. | Cotsmuir (FY550) | |
| Thomas Green (FY4218) | C Rennoldson | 28 May 1919 | January 1920 | Completed as fishing vessel, sold 1920 | Caerphilly Castle | Sunk by enemy aircraft 27 January 1941 off western Ireland. |
| Thomas Hankins (FY3828) | J P Rennoldson | 10 May 1918 | 19/06/1918 | Sold 11 May 1920. | | Sunk 20 November 1939 by U-33 14 mi (23 km) northwest of Tory Island |
| Thomas Laundry (FY4212) | J P Rennoldson | 21 October 1918 | 27 November 1918 | Loaned to United States Navy 1919, sold 11 May 1920 | B.R.Lothe - Norwegian | Stranded 3 March 1944 off Mørekysten, Norway. |
| Thomas Lawrie (FY4214) | Chambers | 1919 | 1 October 1919 | Completed as fishing vessel, sold 1925 | Les Barges II - French | Sunk 21 November 1939 by U-41 west of France. |
| Thomas Leeds (FY4210) | Duthie Torry | June 1919 | 12 September 1919 | Completed as fishing vessel, sold 1919, wrecked 20 October 1955 near Ten Mile Beacon, Lagos. | Thomas Leeds (FY520) | |
| Thomas Robins (FY3531) | Smiths Dock | 3 September 1917 | September 1917 | Sold 4 May 1920, wrecked 19 November 1938 Westray Sound, Orkney Island. | | |
| Thomas Twiney (FY3528) | Smiths Dock | 20 July 1917 | September 1917 | Sold 1922, wrecked August 1935 on Powder House Rock, Culzean Bay. | | |
| Timothy Crawley (FY3710) | Ailsa | 4 October 1917 | November 1917 | Sold 11 May 1920. Scrapped 1956 at Bo'ness. | Loch Long | |
| Valentine Bower (FY3654) | C Rennoldson | 1 October 1917 | November 1917 | Sold 1923. Scrapped 1960. | Milford King (FY1573) | |
| Walter Burke (FY3532) | Smiths Dock | 3 September 1917 | September 1917 | Sold 1922. Scrapped 1976. | Toralla - Spanish | |
| William Beatty (FY3534) | Smiths Dock | 17 September 1917 | October 1917 | Sold 4 May 1920 | | sunk 14 November 1939 by U-41 north of Flannan Island. |
| William Beeton (FY3652) | C Rennoldson | 20 July 1917 | September 1917 | To Maltese Government 1921 | Apuania - Italian | |
| William Bell (FY3590) | Cook, Welton & Gemmell | 17 January 1918 | May 1918 | Sold 1920. Scrapped 1946 at Troon. | William Bell (FY1727) | |
| William Brady (FY3585) | Cook, Welton & Gemmell | 17 December 1917 | May 1918 | Sold 1920. Scrapped 1960 at Gateshead. | William Brady (4.112) | |
| William Browis (FY3582) | Cook, Welton & Gemmell | 18 October 1917 | January 1918 | Sold 1922. Scrapped 1960 at St Davids. | Milford Queen (FY615) | |
| William Bunce (FY3538) | Smiths Dock | 3 October 1917 | November 1917 | Sold 1920. Scrapped 1956. | William Bunce | |
| William Caldwell (FY3719) | Cook, Welton & Gemmell | 12 June 1918 | November 1918 | Loaned to USN 1919, sold 11 May 1920. Scrapped 1957 at Granton. | William Caldwell (Z142) | |
| William Cale (FY3666) | Bow McLachlan | 19 September 1917 | October 1917 | Sold 1922. Scrapped 1955 at Troon. | William Cale (FY535) | |
| William Carberry (FY4479) | Hepple & Co | 28 June 1919 | 13 December 1919 | Completed as fishing vessel, sold 1919. Wrecked 1935 off River Muros. | | |
| William Carr (FY3674) | Bow McLachlan | 15 March 1918 | 4 April 1918 | Sold 1921 | Nazareth (FY1815) | |
| William Carrick (FY3665) | Bow McLachlan | 18 September 1917 | October 1917 | To Indian Government 1920 | | |
| William Chaseman (FY3529) | Smiths Dock | 3 August 1917 | September 1917 | Sold 4 May 1920. Scrapped 1947. | Radnor Castle (FY511) | |
| William Coburne (FY3664) | Bow McLachlan | 24 July 1917 | August 1917 | Sold 1920. Foundered 1928 off Slyne Head. | | |
| William Cowling (FY3663) | Bow McLachlan | 23 July 1917 | August 1917 | Sold 1922 | Notre Dame De Laghet (FL 08) - German Navy | War loss September 1943. |
| William Cummins (FY3669) | Bow McLachlan | 17 November 1917 | November 1917 | Sold 1925. Scrapped 1957. | Niblick | |
| William Darnold (FY3722) | Cook, Welton & Gemmell | 11 July 1918 | December 1918 | Loaned to United States Navy 1919, sold 11 May 1920, wrecked 4 October 1924 off Birsay, Orkney Islands | | |
| William Downes (FY3723) | C Rennoldson | 5 November 1917 | December 1917 | Sold 1921. | | Foundered 16 September 1941 off Rosslare. |
| William Drake (FY4483) | J P Rennoldson | 1919 | 19 May 1919 | Completed as fishing vessel Ebor Court, sold 1919, wrecked 1 November 1929 on Port Eynon Point. | | |
| William Flemming (FY3746) | Hepple & Co | 12 February 1918 | 18 May 1918 | Sold 4 May 1920 | Tranio (FY3526) | Bombed 26 June 1941 while under tow off Smith's Knoll |
| William Griffths (FY3788) | George Brown | 19 November 1918 | 21 February 1919 | Completed as fishing vessel, sold 1919, stranded 13 August 1923 in Galway Bay. | | |
| William Hannam (FY4206) | Duthie Torry | November 1918 | 20 February 1919 | Sold 1920, sank 1957 off Kiberg, Norway. | William Hannam (Z129) | |
| William Humphries (FY4205) | Duthie Torry | October 1918 | 24 December 1918 | Sold 1921 | | Sunk 21 November 1939 by U-33 75 mi (121 km) northwest from Rathlin Island. |
| William Knight (FY4208) | Duthie Torry | April 1919 | 19 June 1919 | Completed as fishing vessel, sold 1919 | Cobbers | Bombed 3 March 1941 in the North Sea |
| William Lambkin (FY4209) | Duthie Torry | May 1919 | 16 July 1919 | Completed as fishing vessel, sold 1919, scrapped 1972. | Tiburon - Spain | |
| William Leek (FY4211) | J P Rennoldson | August 1918 | 10 October 1918 | Sold 11 May 1920. Scrapped 1956. | Hildina (FY541) | |
| William Loft (FY4220) | C Rennoldson | 30 August 1919 | May 1920 | Completed as fishing vessel, sold 1923, scrapped 1954. | Tamora (FY643) | |
| William Mannell (FY3512) | Smiths Dock | 23 March 1917 | June 1917 | Sold 11 May 1920, lost 1949 off Portaleen. | William Mannel (FY1665) | |
| William Spencer (FY3521) | Smiths Dock | 19 June 1917 | July 1917 | Sold 1924. Scrapped 1960 at Fife. | Astros (Z130) | |
| William Symons (FY3535) | Smiths Dock | 1 October 1917 | October 1917 | Sold 1922. Scrapped 1959 at Hemiksem. | Lephreto (FY519) | |
| William Wilmot (FY3536) | Smiths Dock | 1 October 1917 | November 1917 | Sunk September 1920 in collision with SS Meissonier in the Irish Sea | | |

### Cancelled

| Ship | Builder | Fate | Second World War |
| Alexander Colville (FY4455) | George Brown | | |
| Alexander Dunbar (FY4493) | Hepple & Co | | |
| Collin Craig (FY4451) | George Brown | | |
| Ephraim Bright (FY4407) | Cook, Welton & Gemmell | Completed as fishing vessel. BU 1955. | Mai |
| James Baird (FY4411) | Cook, Welton & Gemmell | Completed as fishing vessel. BU 1959. | Ijuin (FY612) |
| James Boyle (FY4414) | Cook, Welton & Gemmell | | |
| James Coile (FY4454) | George Brown | | |
| John Benson (FY4409) | Cook, Welton & Gemmell | Completed as fishing vessel. BU 1955. | Kari Solmundarson |
| John Chatway (FY4447) | George Brown | | |
| John Coombe (FY4453) | George Brown | | |
| John Creighton (FY4449) | George Brown | | |
| Joseph Crowell (FY4448) | George Brown | | |
| Joseph Doe (FY4494) | Hepple & Co | | |
| Matthew Berryman (FY4412) | Cook, Welton & Gemmell | Completed as fishing vessel. BU 1962. | Righto (FY604) |
| Richard Bane (FY4410) | Cook, Welton & Gemmell | Completed as fishing vessel. BU 1956. | Rudilais (FY528) |
| Walter Cane (FY4456) | George Brown | | |
| William Bennett (FY4408) | Cook, Welton & Gemmell | Completed as fishing vessel. BU 1952. | Njordur |
| William Burte (FY4413) | Cook, Welton & Gemmell | Completed as fishing vessel. BU 1962. | Reboundo (FY602) |
| William Cable (FY4450) | George Brown | | |
| William Coran (FY4452) | George Brown | | |

### Canadian-built

See TR series minesweeping trawler.

### Indian-built

| Ship | Builder | Launched | Completed | Fate |
| Bombay | Bombay Dockyard | 21 September 1919 | 1919 | Completed as unarmed minesweeper or fishing vessel |
| Calcutta | Burn & Co | 1919 | 1919 | Completed as unarmed minesweeper or fishing vessel |
| Colombo | Burn & Co | 1919 | 1919 | Completed as unarmed minesweeper or fishing vessel |
| Jubbulpore | Bombay Dockyard | | | Cancelled 1919 |
| Kennery | Bombay Dockyard | 1919 | 1919 | Completed as unarmed minesweeper or fishing vessel |
| Kidderpore | Bombay Dockyard | 1919 | 1919 | Completed as unarmed minesweeper or fishing vessel |
| Madras | Burn & Co | 1919 | 1920 | Completed as unarmed minesweeper or fishing vessel |
| Salsette | Bombay Dockyard | 1919 | 1919 | Completed as unarmed minesweeper or fishing vessel |
| Sealdah | Bombay Dockyard | 1919 | 1919 | Completed as unarmed minesweeper or fishing vessel |

### New Zealand-built

See Castle class trawlers of the Royal New Zealand Navy.