Twentieth Fleet Sweeping Flotilla (Royal Navy)
c. August-October, 1918 – April, 1919
The flotilla was created some time between 1 August and 1 November, 1918, when it joined the Sixth Fleet Sweeping Flotilla, which had been clearing mines near Harwich since early 1918. By 1 November 20 F.S.F. was found "temporarily detached to Granton", but bearing the parenthetical base of Felixstowe. By 1 December, Granton is no longer mentioned, suggesting it was back at Felixstowe.
|Operating from Felixstowe|
April, 1919 – May, 1919
The Flotilla, along with the 6th, 12th and 19th, moved on to the Dutch port of Scheveningen some time in April, 1919.
|Operating from Scheveningen|
May, 1919 – ?
The Supplement to the Monthly Navy List at this juncture ceased bothering to print detailed information on minesweeping formations, though list Blackburn as one of seven sloops now based in Southampton, with the other three being detailed to unspecified "Mine Clearance Service". Reference is made to a separate Mine Clearance Service Weekly Return which has not been located.
- Supplement to the Monthly Navy List. (August, 1918). p. 13 and Supplements through May 1919, except no September or October 1918 edition was found, which makes the earliest history of this formation difficult to establish reliably.
- Supplement to the Monthly Navy List. (May, 1919). p. 14 and Supplements through X.
- Supplement to the Monthly Navy List. (June, 1919). pp. 15, 18.
- Dittmar, F.J.; Colledge, J.J. (1972). British Warships 1914–1919. London: Ian Allan.
|British Minesweeping Formations|
|First | Second | Third | Fourth|
|Fleet Sweeping Flotillas|
|First | Second | Third | Sixth | Seventh | Eighth | Ninth | Tenth|
|Eleventh | Twelfth | Thirteenth | Fifteenth | Sixteenth | Eighteenth | Nineteenth|
|Twentieth | Twenty-first | Twenty-second | Twenty-third | Twenty-fourth|