Steel Corvettes

The Corvette was reborn in the RN out of desperation.

The start of WW2 found the Royal Navy horribly unprepared for a resumption of a U-Boat war, and in particular one in which the U-Boat was no longer a coast hugging gun and torpedo boat with a limited ability to submerge. The submarine was coming of age, it could cruise underwater for long periods, surfacing under cover of darkness to recharge. Range, although still limited, was about to get a terrifying boost with the capture of the French ports, the Atlantic was now wide open to the U-Boats, the RN could not even provide basic escort protection across it.

An early re-introduction of the convoy system, so bitterly contested by the RN in WW1, helped considerably, but the U-Boat tactic of the Wolf Pack had been designed to counter it and as more boats became available the Admiralty began to see just what it had originally feared about convoys: they were just big targets.

British ship building had declined since the First World War, the capacity was simply no longer there to turn out warships in the same numbers, Dalmuir for instance, a purpose built modern yard which had turned out battleships and aircraft carriers, had closed in 1931. Increasing losses of merchantmen meant that they too had to be built, even at the expense of warships.

Nowhere was this lack of capacity more obvious and crippling than in turbine engined ships. Though it may seem madness the dockyards were fixed in traditional practises, one of which was that the turbines were built with the ship, by the ship builder, even the exigencies of war could not persuade the breach of tradition to allow turbine construction to be outsourced.

It would be unfair to imply this was all down to the ship builders, they had expanded capacity in WW1 only to see the government ignore them afterwards, causing unemployment and bankruptcy when there were no longer orders to pay for the extended yards. Many feared a repeat of this at the end of the current crises.


Type IX U-Boat, designed as a Wolf Pack Command ship, 6 torpedo tubes, 22 torpedoes plus an option of ten more in external storage or mines. Range of over 10,000 miles, able to do 78 miles submerged at a time, speed of just over 18 knots surfaced, 7.7 knots submerged.


The convoy system was introduced late in WW1 and turned the battle against the U-Boat, but the Wolf Pack Strategy was designed to overwhelm a convoy's escorts and wreak mayhem on the assembled ships.


Yarrows at Scotstoun on the Clyde, 1932. Yards which had expanded during WW1 faced devestating cuts post war and capacity was lost as yards closed or sold off land, demand for warship construction could not be met when Britain sought to rearm in the late 30's.

 

In 1938 although the talk was of peace it had become obvious that Nazi Germany was massively re-arming and U-Boats were now openly being built in defiance of the treaty and rolling off the slipways at an alarming rate. Typically though the powers that were looked to the previous war and planned to fight the next the same way. In WW1 the greatest losses to the U-Boat had occurred in coastal waters, due to the short range of U-Boats and because the Atlantic is a big ocean to look for ships in, but their arrival and departure points are well known.

So the need was perceived for coastal escorts, and lots of them. The P type Patrol Boat used in WW1 could not be produced now in sufficient time or quantity, but experience had shown the P Class' high speed was redundant when it came to shepherding slow merchant ships up and down the coast to muster points, so it was reasoned a non-turbine vessel could be employed, a long look was taken at the aborted Kil Class, an escort proposed in WW1 based on an existing merchant ship design which could be produced in non specialist yards, or in the unused capacity of larger yards.

In the event by some forward thinking genius or sheer dumb luck the design that was chosen was not that of a coaster, but of a deep sea whaler that had shown it was up to the ravages of the Atlantic Winter: Smith's shipbuilders Southern Pride.

The Flower Class was adopted as the Class name, reflecting the premier escort vessel of WW1, but either through whimsy or some sort of propoganda spoof they were typed not as Sloops, but as Corvettes, which used to be more heavily armed than Sloops, though certainly not in this case!

Incidently both Southern Pride and her sister ship the Southern Gem were armed and operated as Escorts, the Southern Pride was lost June 16 1944, but Southern Gem became the Suderoy VI in 1936 and served as a mine sweeper in the Canadian Navy, surviving the war.


The turbine powered P Class Patrol boat which served as a merchant ship coastal escort in WW1, mass production of a similar ship was beyond the capacity of British yards by 1939


HMS Kildwick, a late addition to the WW1 escort fleet the Kil class were based on a merchant ship design and could utilise non specialist small yards. A similar solution was sought in the run up to WW2

Southern Gem, sister ship of Southern Pride and the basis for the design of the WWII Flower Class Corvette.

Flower Class Corvette

By no stretch of the imagination was the Flower Class Corvette heavily armed, initially they carried only a single 4" gun, salvaged from obsolete ships, and a couple of machine guns. Her main weapon were the depth charges.

A crew of 90 in a ship originally designed for 28 and a tendency to "roll on wet grass" made living conditions on the ships tantamount to a damp hell; but they proved ideal for the role of coastal escort, tough, economical, could be built in a month in a small yard, the Flower was adopted by the Canadians, the Americans, the Frech and the Belgiums, even the Germans, four captured in build in France were completed and pressed into service with the Kriegsmarine.

Top speed was 16 knots in short sprints, sufficient to charge at a submerged U-Boat, but inadequate to pursue on the surface, the general tactic was to force the submarine to dive and keep it down with depth charges while the escorted ships escaped and more capable Sloops, and later Frigates, were called up to make the kill.

With the fall of France the impetus of the U-Boat war switched to deep water, often beyond the Western Approaches. U-Boats no longer had to risk the dash through the English Channel, or the gruelling long haul up around the Faeroes Gap of the Denmark Strait, under the constant threat of air attack. The need to escort ships deeper into the Atlantic put a huge strain on an already overworked escort fleet and the Flowers were forced to take up the strain.

The Flower Class remained in production throughout the war, despite it's drawbacks, it was also produced abroad, there are many variants to the original design, and in that it is acting as designed: soaking up spare resources. But the basic design remained largely the same, except it was modified with a longer Forecastle to improve sea keeping in the Atlantic, and the Bridge and Charthouse was improved. AA weapons were increased when available, though this was usually just a pom-pom. Originally fitted with mine sweeping gear as well as depth charges this was discarded and allowed 70 depth charges and up to four throwers to be fitted in additional to twin racks deploying astern.

The effectiveness of the Flower was vastly improved with radar. Initially SW1C and SW2C were tried, but these sets were useless against small U-Boat contacts, but in 1943 the 271 became increasingly available in it's distinctive lantern cupola, in good conditions even a periscope could be picked up and the night was no longer the safe hunting ground for the Wolf Pack.

The Flower played as big a part in the defence of this country as the Spitfire, but while the Spitfire was a sleek thoroughbred the Flower was a Junkyard dog.

Flower Class, Original Specification

Displacement 950 tons
Dimensions 62.5 x 10.0 x 3.5 meters (205 x 33 x 11.5 feet)
Propulsion Single shaft;
2 fire tube Scotch boilers;
1 4-cyl. triple expansion steam engine, 2750 hp.;
16 knots
Range 3500 nm. at 12 knots

Crew 85
Radar None at first, then SW1C or 2C (later) Finally 271
Sonar Type 123A, later Type 127DV
Armament 1 x 4" BL MKIX single
2 x 0.50 cal machine gun in twin mount
2 Lewis .303 cal machine guns in twin mounts
2 MKII depth charge throwers
2 depth charge rails with 40 depth charges.

Originally fitted with minesweeping gear, later removed.

Fuel 230 Tons Oil, consumption: 0.5 tons per hour at 10 Knots

Later fits varied widely, some were converted to full minesweepers (usually the unmodified early ships), most gained extra Oerlikons or machine guns and the forward firing Hedgehog spindle mortar in addition to their original fit. The area of operation often dictated what the ship carried, those involved in the Mediterranean and the Russian convoys had priority. The mast, positioned forward of the Bridge, was moved behind the Bridge in most modified versions.

I have attached a table of British built Flowers at the bottom of this page, this does not include thouse built in Canada and elsewhere.

Most Flowers were sold off post war, though some saw service as weather ships for a while, although rugged and reliable they were simply too small to be able to mount modern ASW weapons, and far too slow, by the war's end submarines could even outrun the Flower submerged on a snorkel, and faster boats were to come. But if Athens had it's wooden wall of ships to defend it then in the darkest days of Britain's need we had the steel wall of Flowers.


The Flower Class Corvette, designed by Smiths

HMS Columbine, an early Flower, foremast before the Bridge, 2 pdr Pom-Pom the only AA defence. Radar has been fitted aft the Bridge.


HMCS Sackville, like many Flowers she was later modified to extend the bow. Other changes included moving the mast aft of the Bridge and improving the weather proofing of the superstructure. These changes were incorporated during build in later ships. Canada had no warship yards and embraced the Flower as they could build it in their own yards, the Flower was the foundation for the Canadian Navy.

USS Saucy, formerly HMS Arabis, even the American Navy adopted the Flower as a stop gap until it could build up it's own escort fleet. Shown here Saucy has been refitted with US guns and radar.

The Germans captured four Flowers in France and converted them to Patrol Boats with very heavy AA weaponry.

HMCS Sackville, preserved as part of Canada's heritage.

Castle Class Corvette

The Castle was an improved Flower Class design proposed by the same builder: Smiths, it had a greater length and beam to improve sea keeping, and a strengthened bow to take the new Squid Anti-Submarine Mortar, otherwise it was essentially the same ship with a single screw reciprocating steam engine.

Smiths also designed a much improved version, the River Class, but the Castle was designed to follow on from the Flower using small yards. 44 were constructed, and another 14 were in build but cancelled. They were poor at manouvering, particularly at low speed which was needed for operation of the Squid and they were not particularly succesful, considered very underpowered and hard to keep on course. But they show a surprising longevity post war despite that.

Specifications:

Engines: 2 x Admiratly 3 drum boilers, 1 x triple expansion reciprocating engine, single shaft, 2750 ihp

Speed 16.5 knots

Range: 9000 miles at 10 knots, 480 tons of oil

Length: 252 ft overall, Beam 36ft 8", Draught 13ft 6"

Displacement: 1060 tons unloaded, 1630 full load.

Armament: 1 x 4" gun, 2 x twin Oerlikon, up to 6 single Oerlikon (but usually only 2), 1 x three barrel 12" Squid, Depth charge rails and throwers with 15 depth charges.

Complement: 120

Radar: Type 272 and later 277 on some

Sonar: 144Q and 147B for the Squid.

Cost: (Rushen Castle) £119, 140 14sh 10d (One hundred and Nineteen thousand, one hundred and forty pounds fourteen shillings and ten pence)

Those Castles which survived the war were reclassified as Frigates in 1948 and changed pennant numbers accordingly, however it is unlikely any saw service as frigates, most were probably employed in various auxilliary duties such as wreck and ordanance disposal and colonial guard ships. Four went on to serve as Atlantic weather ships, replacing Flowers which were previously on station, these were the Oakham Castle, Amberley Castle, Rushen Castle and Pevensey Castle.

In 1948 with the penant change to Frigate and the Flowers sold the RN's brief flirtation with the Corvette Class ended. Another ship would appear that could have taken the title of Corvette, the Type 14 Blackwood Class, but instead they were designated as Second Rate Frigates.

HMS St Thomas Castle
The Castle Class were a larger version of the Flower, designed for better sea keeping and to mount the forward firing Squid mortar and it's associated sonars. But the power plant was the same as for the lighter Flower, itself under-powered, and the result was lack lustre performance, although championed still by those who served on them they lacked the manouverablility needed for a good submarine killer.

Although handsome ships the Castle Class like HMS Flint Castle here lacked power for speed and manouverability. The business end of the ship can be seen just aft the forward turret, the triple barrelled Squid Mortar peeking up over it's barbette. Strangely many survived to become Frigates, but that may have been more due to the fact they were so economical to operate.

HMS Empire Shelter, one of two Castles converted to Rescue Ships which operated with convoys.
Name
Pennant
Pennant
Completed
Disposal
Allington Castle K689 F89 Jun 1944 1958 Scrapped
Alnwick Castle K405 F105 Nov 1944 1958 Scrapped
Amberly Castle K386 F286 Nov 1944 1958 Air Ministry
Arnprior K494   Cancelled Cancelled
Bamborough Castle K412 F12 May 1944 1959 Scrapped
Barnard Castle K694   Jan 1945 Empire Shelter, Convoy Rescue 1955 Scrapped
Berkeley Castle K387 F387 Nov 1943 1956 Scrapped
Bowmanville K493   Cancelled Cancelled
Caistor Castle K690 F690 Sep 1944 1956 Scrapped
Carisbrooke Castle K379 F379 Nov 1943 1958 Scrapped
Copper Cliff K495   Cancelled Cancelled
Denbigh Castle K696   Dec 1944 Feb 1945 Sunk
Dumbarton Castle K388 F388 Feb 1944 1961 Scrapped
Farnham Castle K413 F413 Jan 1945 1960 Scrapped
Flint Castle K383 F383 Dec 1943 1958 Scrapped
Gorey Castle K529 F386 May 1945 1958 Scrapped
Guildford Castle K378   Mar 1944 Sold 1946
Hadleigh Castle K355 F355 Sep 1943 1959 Scrapped
Hedingham Castle K396   May 1944 1944 Canada Navy
Hespeler K489   Cancelled Cancelled
Hever Castle K521   Aug 1944 1949 Chinese Navy
Humberstone K497   Cancelled Cancelled
Huntsville K499   Cancelled Cancelled
Hurst Castle K416   Jun 1944 Sep 1944 Sunk
Kenilworth Castle K420 F420 Nov 1943 1959 Scrapped
Kincardine K490   Cancelled Cancelled
Knaresborough Castle K389 F389 Apr 1944 1956 Scrapped
Lacaster Castle K691 F691 Sep 1944 1960 Scrapped
Launceston Castle K397 F397 Jun 1944 1959 Scrapped
Leaside K492   Cancelled Cancelled
Leeds Castle K384 F384 Feb 1944 1958 Scrapped
Maiden Castle K443   Nov 1944 Empire Lifeguard Convoy Rescue 1955 Scrapped
Morpeth Castle K693 F693 Jul 1944 1960 Scrapped
Nunnery Castle K446   Oct 1944 1949 Chinese Navy
Oakham Castle K530 F530 Dec 1944 1958 Air Ministry
Oxford Castle K692 F692 Mar 1944 1960 Scrapped
Petrolia K498   Cancelled Cancelled
Pevensey Castle K449 F449 Jun 1944 1958 Air Ministry
Pembroke Castle K450   Jun 1944 1952 Chinese Navy
Portchester Castle K362 F362 Nov 1943 1958 Scrapped
Rayleigh Castle K695   Oct 1944 1962 Scrapped
Rising Castle K398   Jun 1944 1946 Uruguay Navy
Rushen Castle K372 F372 Feb 1944 1958 Air Ministry
Sandgate Castle K373   May 1944 1946 Sold
Scarborough Castle K536   Jan 1945 1945 Sold
Sherbourne Castle K453   Jul 1944 1946 Sold
Shrewsbury Castle K474   Aug 1943 1943 Norwegian Navy
St Thomas K488   Cancelled Cancelled
Tamworth Castle K393   Jul 1944 1946 French Navy
Tillsonberg K496   Cancelled Cancelled
Tintagel Castle K399 F399 Apr 1944 1958 Scrapped
Totnes Castle K447   Sep 1944 1959 Scrapped
Walmer Castle K460   Sep 1944 1946 Sold
Wolvesey Castle K461   Jun 1944 1947 Sold
York Castle K537   Feb 1945 1955 Scrapped

 

  British built Flower Class Corvettes
Corvette Name Pennant No. Shipyard Origin Date Of Commission Fate
Abelia K184 Harland & Wolff 28.11.40 Norway as Andenes
Acanthus K01 Ailsa 26.5.41 To the Free French as Aconite
Aconite K58 Ailsa 31.3.41  
Alisma K185 Harland & Wolff 17.12.40  
Alyssum K100 Brown:Kincaid 3.3.41 To the Free French as Alysse
Sunk 9 Feb 1942
Amaranthus K17 Fleming & Fergusun 17.10.40  
Anchusa K186 Harland & Wolff 15.1.41  
Anemone K48 Blyth:Clark 22.4.40  
Arabis K73 Harland & Wolff 14.2.40 To the USN as Saucy
Arbutus K86 Blyth:Clark 5.6.40 Sunk 5 Feb 1942
Armeria K187 Harland & Wolff 16.1.41  
Arrowhead K145 Marine Industries, Quebec 22.11.1940 To Canada as Arrowhead
Asphodel K56 Brown:Kincaid 25.5.40 Sunk 10 Mar 1944
Aster K188 Harland & Wolff 12.2.40  
Aubrietia K96 Brown:Kincaid 5.9.40  
Auricula K12 Brown:Kincaid 14.11.40 Sunk 6 May 1942
Azalea K25 C.W. & G.:Holmes 8.7.40  
Balsam K72 Brown:Clark 30.5.42  
Begonia K66 C.W. & G.:Holmes 18.9.40 To the USN as Impulse
Bellwort K114 Brown:Kincaid 11.8.41  
Bergamot K189 Harland & Wolff 15.2.41  
Betony K274 A.Hall 31.8.43  
Bittersweet K182 Marine Industries, Quebec 23.1.1941 To Canada as Bittersweet
Bluebell K80 Fleming & Ferguson 24.4.40 Sunk 17 Feb 1945
Borage K120 Brown:Kincaid 22.11.41  
Bryony K192 Harland & Wolff 04.06.42  
Burdock K126 Crown: N.E. Marine 14.12.40  
Burgloss K306 J.Crown 8.11.43  
Buttercup K193 Harland & Wolff 10.4.41 To Norway as Buttercup
Burnet K348 Ferguson 10.3.44  
Calendula K28 Harland & Wolff 21.3.40 To the USN as Ready
Camellia K31 Harland & Wolff 4.5.40  
Campanula K18 Fleming & Ferguson 23.5.40  
Campion K108 Crown:Clark 26.4.41  
Candytuft K09 Grangemouth:N.E.Marine 8.7.40 To the USN as Tenacity
Carnation K00 Grangemouth:N.E.Marine 3.9.40 To the Netherlands as Frisco
Celandine K75 Grangemouth:Ailsa 28.12.40  
Charlock K395 Ferguson 10.3.44  
Chrysanthemum K195 Harland & Wolff 11.4.41 To the Free French as Commandant Drogou
Clarkia K88 Harland & Wolff 7.3.40  
Clematis K36 Hill:Richardson W. C. 22.4.40  
Clover K134 Fleming & Ferguson 30.1.41  
Coltsfoot K140 Hall 12.5.41  
Columbine K94 Hill:Richardson W. C. 13.8.40  
Convolvulus K45 Hill:Richardson W. C. 21.9.40  
Coreopsis K32 Inglis:Kincaid 23.5.40 To Greece as Kriezis
Coriander K183 Hall, Russell & Co 16.9.1941 To the Free French as Commandant Detroyat
Cowslip K196 Harland & Wolff 23.5.40  
Crocus K49 Inglis:Kincaid 28.5.41  
Cyclamen K83 Lewis 26.6.40  
Dahlia K59 Lewis 31.10.40  
Delphinium K77 Robb:Ailsa 6.6.40  
Dianella K07 Lewis 3.9.40  
Dianthus K95 Robb:Ailsa 9.7.40  
Dittany K279 Collingwood 31.5.43  
Eglantine K197 Harland & Wolff 27.8.41 To Norway as Eglantine
Erica K50 Harland & Wolff 18.6.40 Sunk 9 Feb 1943
Eyebright K150 Canadian Vickers 26.11.1940 To Canada as Eyebright
Fennel K194 Marine Industries, Quebec 15.5.1941 To Canada as Fennel
Fleur de Lys K122 Smiths Dock 26.8.1940 Sunk 14 Oct 1941
Freesia K43 Harland & Wolff 3.10.40  
Fritillary K199 Harland & Wolff 22.7.41  
Gardenia K99 Simons 10.4.40 Sunk 9 Nov 1942
Genista K200 Harland & Wolff 24.7.41  
Gentian K90 Harland & Wolff 6.8.40  
Geranium K16 Simons 23.4.40  
Gladiolus K34 Smiths Dock 24.1.40 Sunk 17 Oct 1941
Gloxinia K22 Harland & Wolff 2.7.40  
Godetia(i) K72 Smiths Dock 8.5.40 Sunk 6 Sep 1940
Godetia(ii) K226 Crown:Clark 24.9.41  
Heartsease K15 Harland & Wolff 20.4.40 To the USN as Courage
Heather K69 Harland & Wolff 17.9.40  
Heliotrope K03 Crown:N.E.Marine 5.6.40 To the USN as Surprise
Hepatica K159 Davie Shipbuilding, Quebec 15.5.1941 To Canada as Hepatica
Hibiscus K24 Harland & Wolff 6.4.40 To USN as Spry
Hollyhock K64 Crown: N.E.Marine 19.8.40 Sunk 9 Apr 1942
Honesty K285 Kingston 28.5.43  
Honeysuckle K27 Ferguson 22.4.40  
Hyacinth K84 Harland & Wolff 19.8.40 To Greece as Apostolis
Hyderabad (Nettle) K212 Hall 23.9.41  
Hydrangea K39 Ferguson 4.9.40  
Jasmine K23 Ferguson 14.1.41  
Jonquil K68 Fleming & Ferguson 9.7.40  
Kingcup K33 Harland & Wolff 31.10.40  
La Malouine K46 Smiths 29.6.40  
Larkspur K82 Fleming & Ferguson 5.9.40 To the USN as Fury
Lavender K60 Hall 27.11.40  
Linaria K282 Midland 22.6.43  
Lobelia K05 Hall 15.2.41  
Loosestrife K105 Hall Russell 25.8.41  
Lotus (i) K93 Hall:Ailsa 17.1.42 To the Free French as Commandant d'Estienne d'Orves
Lotus (ii) K130 H.Robb 9.5.42  
Mallow K81 Harland & Wolff 22.5.40 To Yugoslavia as Nada
Marguerite K54 Hall Russell 8.7.40  
Marigold K87 Hall Russell 4.9.40 Sunk 9 Dec 1942
Mayflower K191 Canadian Vickers 15.5.1941 To Canada as Mayflower
Meadowsweet K144 Hill:Richardson W. C. 28.3.42  
Mignonette K38 Hall Russell:N.E.Marine 28.1.41  
Mimosa K11 Hill:Richardson W.C. 18.1.42 To the Free French as Mimosa
Sunkk 9 Jun 1942
Monkshood K207 Fleming & Ferguson 17.4.41  
Montbretia K208 Fleming & Ferguson 27.5.41 To Norway as Montbretia
Myosotis K65 Lewis 30.5.41  
Narcissus K74 Lewis 29.3.41  
Nasturtium K107 Smiths 26.9.40  
Nigella K19 Philip:Clark 21.9.40  
Orchis K76 Harland & Wolff 15.10.40 Sunk 21 Aug 1944
Oxlip K123 Inglis:Kincaid 28.8.41  
Pennywort K111 Inglis:Kincaid 18.10.41  
Pentstemon K61 Philip:Clark 18.1.41  
Peony K40 Harland & Wolff 4.6.40 To Greece as Sakhtouris
Periwinkle K55 Harland & Wolff 24.2.40  
Petunia K79 Robb:Kincaid 19.9.40  
Picotee K63 Harland & Wolff 19.7.40 Sunk 12 Aug 1941
Pimpernel K71 Harland & Wolff 16.11.40  
Pink K137 Robb:Ailsa:N.E.Marine 16.2.42  
Polyanthus K47 Robb:Kincaid 30.11.40 Sunk 21 Sep 1943
Poppy K213 Hall 20.11.41  
Potentilla K214 Simons 18.12.41 To Norway as Potentilla
Primrose K91 Simons 8.5.40  
Primula K14 Simons 22.6.40  
Renonculus K117 Simons 25.6.41 To the Free French as Renoncule
Rhododendron K78 Harland & Wolff 2.9.40  
Rockrose K51 Hill:Richardson W. G. 26.7.41  
Rose K102 Simons 22.9.41 To Norway as Rose
Rosebay K286 Kingston 28.7.43  
Salvia K97 Simons 6.8.40 Sunk 24 Dec 1942
Samphire K128 Smiths Dock 14.4.41 Sunk 30 Jan 1943
Saxifrage K04 Hill:Richardson W. C. 24.10.41  
Smilax K280 Collingwood 21.6.43  
Snapdragon K10 Simons 3.9.40 Sunk 19 Dec 1942
Snowberry K166 Davie Shipbuilding, Quebec 26.11.1940 To Canada as Snowberry
Snowdrop K67 Smiths Dock 12.5.41  
Snowflake K211 Smiths Dock 31.10.40  
Spikenard K198 Davie Shipbuilding, Quebec 15 May 1941 To Canada as Spikenhard
Sunk 11 Feb 1942
Spiraea K08 Inglis:Kincaid 12.2.41  
Starwort K20 Inglis:Kincaid 12.5.41  
Statice K281 Collingwood 20.9.43  
Stonecrop K142 Smiths Dock 22.8.41  
Sundew K57 Lewis 28.5.41 To Free French as Roselys
Sunflower K41 Smiths Dock 19.8.40  
Sweetbriar K209 Smiths Dock 26.6.41  
Tamarisk K216 Fleming & Ferguson 28.7.41 To Greece as Tompazis
Thyme K210 Smiths Dock 25.7.41  
Trillium K172 Canadian Vickers ltd 31 Oct 1940 To Canada as Trillium
Tulip K29 Smiths Dock 4.9.40  
Verbena K85 Smiths Dock 1.10.40  
Veronica K37 Smiths Dock 17.10.40 To USN as Temptress
Vervain K190 Harland & Wolff 12.3.41 Sunk 20 Feb 1945
Vetch K132 Smiths Dock 27.5.41  
Violet K35 Simons 30.12.40  
Wallflower K44 Smiths Dock 14.11.40  
Windflower K155 Davie Shipbuilding, Quebec 4.7.1940 (Launch, not commissioned) To Canada as Windflower??
Sunk 12 Dec 1941
Willowherb K283 Midland 30.8.43  
Woodruff K53 Simons 28.2.41  
Zinnia K98 Smiths Dock 28.11.40 Sunk 23 Aug 1941