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 Naval WWII    
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anemone
DONCASTER S. YORKS, UK
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E-9 Cmd Sgt Major


Posts: 5960
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Corvettes
Posted on: 7/18/2016 5:05:34 AM
CORVETTE

Definition and Description
A corvette may be defined as:
“A small, cheap vessel that can be produced quickly, and is equipped for anti-submarine operations.”

Corvettes were used by the British as small, cheap ships that could provide anti-submarine escort for convoys. Two main types of corvette were produced, the Castle class and the Flower class. They were based on the design of a commercial whale catcher, and were fitted with asdic and depth charges. One 4" deck gun was fitted forrard with a 2 pdr pompom aft, for fighting a surfaced U-boat. Later versions were also fitted with radar.

Development and History
The corvette was conceived in 1939 as a small anti-submarine vessel for use in coastal waters built at every available shipyard in the country. The vessels had excellent sea-keeping abilities, and when faced with a shortage of seagoing escorts they were also assigned to ocean convoy routes. Despite being uncomfortable vessels to sail in due to their severe roll motion (it was said that they would ‘roll on wet grass’) they were able to operate in conditions that would have damaged destroyers. These ships will always be associated with the battle of the Atlantic, and were operated by many Allied nations.

Operational Notes
The ships were well adapted for hunting submerged U-boats, with modern anti-submarine equipment and good sea-keeping qualities. They were weak against surfaced U-boats, however, as their maximum speed of only 16 knots was not sufficient to catch a U-boat on the surface and their small (4 inch) deck gun was matched by a similar weapon on the U-boat. In addition, their slow speed meant that after any prolonged hunt the ship could not quickly rejoin the convoy.

This thread has been opened for the express purpose for members to discuss the pros and cons of these custom built Convoy Escort Vessels-either British,Canadian or Elsewhere built.

Regards

Jim .
---------------
Pro Patria Saepe Pro Rege Semper

George
Centre Hastings, ON, Canada
top 5
E-9 Cmd Sgt Major
Posts: 5313

Re: Corvettes
Posted on: 7/18/2016 6:31:55 AM
Certainly not the best ASW escort vessel Jim. River class frigates were much better. RCN sailors called them "twin screw corvettes" but they were bigger and better suited to ASW.

But the frigates took longer to build and required greater maintenance so it was the venerable corvette that stepped in to fill the void, a huge void in the case of the RCN.

EDIT: frigates and destroyers cost over twice as much to build as a corvette. Was that a factor in its selection too?

This is HMCS Sackville which is a floating museum in Halifax.

Hard to believe that this ship and others like it were charge with escorting thousands of ships to Great Britain and back.

Harder to believe that such a small craft was able to handle the high seas that it encountered.



The Canadian built corvettes were slightly different than the British designs which necessitated upgrading. When Britain placed orders with Canadian shipyards and the RCN placed its orders, the shipyards geared up for the initial British design. But Britain realized that there were deficiencies in the first corvettes and ordered changes.

Canadian shipyards could not respond that quickly and many of the corvettes built in Canada required changes later in the war. They were also deficient in armament and detection equipment that was on the British corvettes.

anemone
DONCASTER S. YORKS, UK
top 5
E-9 Cmd Sgt Major


Posts: 5960
http:// 82.44.47.99
Re: Corvettes
Posted on: 7/18/2016 6:54:58 AM
General Specifications for 1942 models

Displacement: 1,015 long tons (1,031 t; 1,137 short tons)
Length: 208 ft (63.4 m)o/a
Beam: 33 ft (10.1 m)
Draught: 11 ft (3.35 m)

Propulsion:
single shaft
2 × water tube boilers
1 × 4-cylinder triple-expansion reciprocating steam engine
2,750 ihp (2,050 kW)

Speed: 16 knots (29.6 km/h)
Range: 3,500 nautical miles (6,482 km) at 12 knots (22.2 km/h)

Complement: 90

Sensors and
processing systems:
1 × Type 271 SW2C radar
1 × Type 144 sonar

Armament:
1 × 4 inch BL Mk.IX single gun
1 × 2-pounder. Mk.VIII single "pom-pom" AA gun
2 × 20 mm Oerlikon single
1 × Hedgehog A/S mortar
4 × Mk.II depth charge throwers
2 depth charge rails with 70 depth charges

NB 1940 models were built with mast in front of bridge

Regards

Jim
---------------
Pro Patria Saepe Pro Rege Semper

anemone
DONCASTER S. YORKS, UK
top 5
E-9 Cmd Sgt Major


Posts: 5960
http:// 82.44.47.99
Re: Corvettes
Posted on: 7/18/2016 8:28:19 AM
The Flower Class Corvette

With war appearing more and more inevitable, the British Admiralty embarked on a course of rearmament. One ship type that they would need in vast numbers was small escorts for coastal convoys. For this they turned to the firm of Smith's Dock who took the design of one of their whale catchers and modified it into what was to become the classic Second World War small ship - the Flower Class Corvette.

The Flower as designed was 205' overall, with a beam of 33' and a top speed of 16 knots. Their speed may not have been great, but it was greater than that of a submerged U-Boat, and they could turn inside anything else afloat.
Armament consisted of a 4" gun on the bow and (if they were lucky) a 2pdr Pom-Pom in a bandstand aft, this was initially rounded off with a pair of Lewis machine guns on the bridge. Many went to sea with a quadruple .50 machine gun mount in place of the 2pdr, and many more Royal Canadian Navy Flowers originally mounted a pair of twin .50s in this position. Eventually 20mm Oerlikons replaced the bridge guns. These early Flowers looked very much like quaint little merchantmen masquerading as warships with their short focsle, merchant type bridge, large vents around the funnel and on the engine room casing.

Canadian Flowers

Concurrent with Britain rearming, Canada began to look for ways in which she could also bolster her small navy (six destroyers). Although they wanted to be a 'big ship navy', the decision was made to build Flowers in Canada as the design was simple enough for small yards with no experience in warship construction (this was also the rationale in many of Britain's yards).

Canadian Flowers differed from their British cousins in many small details, most visible of which was the resiting of the aft bandstand from its original position in front of the engine room skylight, to aft of it. this was to allow the 2pdr a wider arc of fire without fear of hitting the mainmast.

As Canada was short of minesweepers, It was decided to fit the first 54 RCN Flowers with minesweeping gear, consequently the stern was squared off to provide increased space for the winch, davits, floats and depth charge racks. A second method of increasing space was one that benefitted the crew in a way not originally anticipated when the galley was moved from its position at the extreme end of the engine room casing to directly behind the bridge. This drastically shortened the distance that the mess attendants had to travel to pick up their meals. On early RN corvettes the crews still had to walk all the way to the rear of the casing regardless of the weather.

Improvements

Experience soon showed that although the Flowers were excellent sea-boats, they were also very wet and had an excessively lively motion to them, somewhat akin to a cork. While nothing could be done about the latter characteristic, the former was alleviated by extending the fo'c'sle aft to abreast the funnel. This also gave additional space to the growing complement that were required for all the additional weapons and sensors that were now coming into widespread use.

Another change was in the appearance of the bridge. Gone was the mercantile bridge with its narrow walkways and enclosed compass house. In its place was an open bridge with wide wings mounting 20mm Oerlikons on each side and a Type 271 Radar on the rear.

Type 271 was one of the great innovations of the sea war, and it allowed the previously blind escorts to see at night and in fog. Now they could become the hunters. Usually mounted at the rear of the bridge and offset to port to allow a view directly astern, the 271 'lantern' is a feature readily apparent on most Commonwealth ships so fitted.

Sadly the RCN was slow to adopt 271, instead they turned to their own scientists and asked them to come up with a comparable set. This they did in record time, which was quite the achievement and says a lot about their skill. However the SW1C only worked well in ideal conditions, in operational use it was an utter failure, and its upgrade, SW2C was no better.

A second failure of the RCN Staff was its deciding to wait and see if the RN modifications were beneficial, and then arguing over who was responsible for carrying them out. This had the sad result that RCN Flowers soldiered on with the short foc'sle and no radar well after their RN cousins had been so fitted.

RN-Owned, RCN-Manned

This isn't strictly true, there were nine RCN Flowers that were as well equipped as any RN Flower. When Canada agreed to allow construction of Flowers in Canadian yards, Britain ordered ten for their own use. These ten were built to the British design, and as such differed from their RCN sisters in the details mentioned above. Upon completion, they were manned for passageto the UK by men intended for transfer to other RCN ships already based in the UK. Once they arrived in England, the RCN was asked to leave these men where they were, and to take over operational use of these ten Flowers. This had the curious result that they were British ships, with Canadian names and Canadian crews, but all expenses paid for by the British. As a result of this, the nine survivors (Windflower was sunk in 1941), were upgraded well ahead of other RCN Flowers. TThese ten ships can be distinguished by their British appearance, and Flower name – RCN owned corvettes took on the name of Canadian cities and towns.

One other result of the RCN taking over these ships was to have consequences in how RCN escorts were viewed by the RN. The British took no account for the fact that these ten ships were undermanned and untrained, instead they took this to be an indication of the state of the RCN and this was to cloud their judgement on the ability of the RCN for the next 2-3 years. Another complaint was that RCN escorted convoys had higher losses than their RN cousins. Although true, nothing was made of the fact that the RCN also escorted the bulk of the slow SC convoys, and consequently they spent more time within range of the wolf packs.

After the 'poor showing' of the RCN in covering SC42 the decision was made to withdraw the RCN from the North Atlantic and move them to the Gibralter run and also to have as many trained to RN standards as possible. Once this was accomplished the RCN returned to the North Atlantic and ultimately were responsible for escorting half of all convoys between Britain and North America.

Increased Endurance Flowers

Starting with HMS Samphire in 1942, new-build Flowers were completed with increased flair to the bows to improve their seakeeping. Tthese ships can be readily told apart from their earlier sisters by the added height to the bow, as well as the raised platform for the 4" gun to clear the new bow. With the raising of the bow, the bridge also was raised a level. Later the gun platform was enlarged and extended aft to allow for the installation of the hedgehog mount on the starboard side, with R.U. stowage on the port side.

The RCN also constructed their later batches to this design, and when the US entered the war, some were transferred to them and manned by the USCG . These USCG Flowers had various changes made to their appearance. Some had unshielded 4" guns, US radars, new bridge, an added 3" gun at the rear of the casing and numerous other changes.

An interesting little sidelight is that Canada built Flowers for Britain, that were then transferred to the US, at the same time that Britain gave other Flowers to Canada in return for minesweepers that Canada was building for the RN in return for some frigates that Britain was building for the RCN. This actually made sense as it best utilized the industrial capacity of each country in such a way as to allow for continuous production without the need to retool for the new ship types needed by each nation.

Regards

Jim
---------------
Pro Patria Saepe Pro Rege Semper

George
Centre Hastings, ON, Canada
top 5
E-9 Cmd Sgt Major
Posts: 5313

Re: Corvettes
Posted on: 7/18/2016 10:31:29 AM

Quote:
Sadly the RCN was slow to adopt 271, instead they turned to their own scientists and asked them to come up with a comparable set. This they did in record time, which was quite the achievement and says a lot about their skill. However the SW1C only worked well in ideal conditions, in operational use it was an utter failure, and its upgrade, SW2C was no better.

A second failure of the RCN Staff was its deciding to wait and see if the RN modifications were beneficial, and then arguing over who was responsible for carrying them out. This had the sad result that RCN Flowers soldiered on with the short foc'sle and no radar well after their RN cousins had been so fitted.


Source please Jim. OK I found it. It came from CBRNP, a British military research association.


Sounds like a British rationale or one by a Canadian with RN training, because to Canadian students of the war, the story would be that the British withheld the type 271 centimetric radar until they had completed fitting their own ships.

Destroyers were equipped before corvettes and truthfully I think that the RN was hard pressed to equip their own ships with this radar.

And arguably, Type 271 is the single most important technological development responsible for winning the Battle of the Atlantic.

And then had the temerity to suggest that the Canadians were inefficient and had one weapon, to ram. For an ASW navy that was sailing blind, it is almost too true. Once a u-boat submerged, the Canadians were looking for it by guess and by golly.

Type 271 became available in mid-1941.

The RCN had begun to fit its destroyers with type 286 which could sometimes find a sub. It was better than nothing.

At the same time only about 25% of the RCN Corvettes were equipped with any radar at all.

Canada was desperate and began to produce SWICK which was a terrible radar, no better and perhaps worse than Type 286. SWICK was based on the same technology but the operators did not trust it at all.

Again, better than no radar at all so SWICK was rushed into production and into the corvettes.

Should Canada have waited because the Brits were testing Type 271 at the same time as SWICK was developed?

Possibly but the RCN was doing what it was asked to do by the British and were rushing ships and barely trained men into the escort service.

If they had waited, perhaps type 271 would have been forthcoming but communication between the Admiralty and the Commonwealth navies was not always the best. Britain felt that these navies were adjuncts to their own to be used as they saw fit.

RCN wanted the best technology but it wasn't forthcoming. It had been requested.

So it is disingenuous to suggest that the RCN was "slow to adopt", the Type 271 centimetric radar.


George


anemone
DONCASTER S. YORKS, UK
top 5
E-9 Cmd Sgt Major


Posts: 5960
http:// 82.44.47.99
Re: Corvettes
Posted on: 7/18/2016 11:10:45 AM
Quote

"Sadly the RCN was slow to adopt 271, instead they turned to their own scientists and asked them to come up with a comparable set. This they did in record time, which was quite the achievement and says a lot about their skill. However the SW1C only worked well in ideal conditions, in operational use it was an utter failure, and its upgrade, SW2C was no better.

If they had waited, perhaps type 271 would have been forthcoming; but communication between the Admiralty and the Commonwealth navies was not always the best. Britain felt that these navies were adjuncts to their own to be used as they saw fit."


George-In what way is this statement disingenuous ???? BTW If I told you the source I would have to shoot myself-it was not CBRNP.

Regards

Jim
---------------
Pro Patria Saepe Pro Rege Semper

George
Centre Hastings, ON, Canada
top 5
E-9 Cmd Sgt Major
Posts: 5313

Re: Corvettes
Posted on: 7/18/2016 12:23:15 PM
Jim, the narrative is being passed around from web site to web site then because I found exactly the same sentences on CBRNP.

[Read More]

Please don't shoot yourself but as I have said before, if articles are to be copied and pasted verbatim then the source should be cited every time. I need to be able to separate your thoughts from those of another author Jim.

If it was a Canadian site then I would like to see who the author was. You see there were two navies in the Canadian scene. The professionals of the RCN who had trained with the RN have been known to belittle and slander the "reserve" navy, the RCNVR whose crews were nearly all reservists and who were charged with manning the corvettes.

Even Percy Nelles, head of the RCN would never say NO to the RN. He had served with them and if the RN said jump, he said how high. He is responsible for overly extending the RCN at times.


You asked why I considered the statement disingenuous and it is because it clearly ignores the complicity of the RN in the huge deficiencies in detection equipment of the RCN.

Even Nelles insisted that the problems that the RCN experienced while assuming more and more of convoy escort duty were related to lack of modern radar. The RN of course said no, it's all to do with training.

The statement "tutt-tutts" at Canada's employment of SWICK and implies that had the country not been impatient that the type 271 radar would have become available. Meanwhile as I said, the RCN was fighting blind and receiving criticism from the RN who regarded them as "enthusiastic amateurs" and merchant ships were sunk on their watch.

So disingenuous indeed. There is another side to the story.


George




anemone
DONCASTER S. YORKS, UK
top 5
E-9 Cmd Sgt Major


Posts: 5960
http:// 82.44.47.99
Re: Corvettes
Posted on: 7/18/2016 1:11:34 PM
Yes- you are absolutely correct; but if you will we'll let sleeping dogs lie-it was a long time ago.I accept that I took a partisan view- instead of being scrupulously fair-you have long been vexed by the RN's attitude to the RCN-"enthusiastic amateurs" as you put it-so your loyalty staggers me at times.Pity that you had Percy Nelles as head of the RCN-you could have done with a Curry-a quite different kettle of fish.

According to Marc Milner it was May 1942 that the first 100 271 sets were authorised for the RCN-a drop in the ocean-but RCN officers tended to be loyal to their own equipment-corvettes having to wait till early 1943-a pretty tenuous business.The Admiralty ought to have been told emphatically-no radar-no escort.We British are a set of "chancing" Arabs.

Regards

Jim
---------------
Pro Patria Saepe Pro Rege Semper

George
Centre Hastings, ON, Canada
top 5
E-9 Cmd Sgt Major
Posts: 5313

Re: Corvettes
Posted on: 7/18/2016 2:16:29 PM
Correct Jim. The heads of the RCN felt that the destroyers needed the better radar first.

They had always dreamed of a "blue water" navy. I often wonder whether they saw those comparatively small corvettes as an embarrassment to a navy that aspired to something greater.

When the RCN was pulled from convoy duty, the corvettes headed to England for refit and for training. There is no doubt that the training helped. The RCN had been telling the RN that it had not had time to properly train the crews in ASW tactics nor had they had sufficient work-up time before the ships were sent on escort, a kind of learning on the job.

While in England the RCN vessels received modern equipment and were deployed on Mediterranean runs where they did very well.

Tony German, author of "The Sea is at Our Gates" points out that while the RCN was off the Atlantic runs that there were some catastrophic losses in convoys with British and American escorts.

He contends that since the RCN had been taking nearly 50% of the convoys that they were quite likely to be on duty as a wolf pack discovered them.

The Admiralty pulled the RCN after a couple of particularly costly convoys, blaming poor tactics and morale. RCN sailors were adamant that it was equipment that was holding them back.


But even with the British and Americans handling the duties on the Atlantic run, the wolf packs ran wild on several occasions and these were ships with the best radar and weapons.

It seems then that at that stage of the war, if you were going to escort a lot of convoys, then your chances of meeting up with a wolf pack were enhanced and with that comes significant losses.

The best chance for a convoy was to be re-routed around the u-boats.


Please don't be staggered by my loyalty. There is no doubt that the RCN crews were under trained and severely overworked and had poor detection equipment.

There is ample evidence that tactics employed when u-boats were encountered were not always up to snuff.

But I am also prepared to reject the views of the Admiralty who we must remember, pressured Canada to accept more and more duties.

e.g. Even as the 2nd happy time was in progress and u-boats were in the Gulf of St. Lawrence and RCN vessels were on station off the east coast of the US and down to the Caribbean, there was a request for RCN Corvettes to join Operation Husky. And they did.

I forget the exact number of ships but 18-20 corvettes participated in Husky. They were desperately needed off our own coast but off they went. I sometimes wonder whether the RCN chiefs knew just how hard pressed their new navy was to do all the tasks requested.

And I must also reject your statement that, "RCN officers tended to be loyal to their own equipment."

Officers and men alike had little good to say about SWICK or SWICK 2. As merchant ship after merchant ship went down on a corvette's watch, men were in tears because they could not locate the u-boats.

Other than radar, what was there about the Corvette that was Canadian and sparked loyalty?



And sometimes I think that some people at the Admiralty had no clue at all of what they were asking of the RCN.


So there's my rant. Let us discuss the mighty Corvette then and the unglamorous service that they rendered during the Battle of the Atlantic.


George
Centre Hastings, ON, Canada
top 5
E-9 Cmd Sgt Major
Posts: 5313

Re: Corvettes
Posted on: 7/18/2016 2:32:12 PM
Life on the mess deck of a Corvette.

Apparently this deck smelled of a mix of sweat and vomit and perhaps food.

Note the hammocks above. These were a most uncomfortable vessel.




George
Centre Hastings, ON, Canada
top 5
E-9 Cmd Sgt Major
Posts: 5313

Re: Corvettes
Posted on: 7/19/2016 5:26:14 PM
This is a short tour in pictures of HMCS Sackville.

She is Flower class but as seen, she has received her refit with better radar and weapons.

Amazing what they can cram into such a small space.

[Read More]


George

anemone
DONCASTER S. YORKS, UK
top 5
E-9 Cmd Sgt Major


Posts: 5960
http:// 82.44.47.99
Re: Corvettes
Posted on: 11/3/2016 8:57:05 AM
Ditto George -short picture tour of HMS Anemone (K48) which commenced convoy escort duties in 1940 until 1944



[Read More]

Regards

Jim
---------------
Pro Patria Saepe Pro Rege Semper

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