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CAMPAIGN SUMMARIES OF WORLD WAR 2

GERMAN U-BOATS AT WAR, Part 1 of 6

1939-40

U-boat returning to base in 1939 - probably U.47 (US, click to enlarge)

on to German U-boats,1940-41

 
 

Each Summary is complete in its own right. The same information may therefore be found in a number of related summaries

(for more ship information,  go to Naval History Homepage and type name in Site Search)

 
 

 
 

Pre-War

1935 -  June - Anglo-German Naval Agreement - Germany was allowed to build a fleet up to 35% of British total tonnage and 45% of submarines. Parity in numbers of submarines was allowed if notice was given.

1939 - August - German U-boats and two pocket battleships sailed for their war stations in the Atlantic.

 

1939

SEPTEMBER 1939

Strategic and Maritime Situation

Germany (now including Austria and Czechoslovakia) was restricted to a short North Sea and Baltic coastline. Its exits to the Atlantic passed through the Allied controlled English Channel and North Sea. However, Britain's survival depended on the Atlantic trade routes; Germany's did not. Areas under direct Allied control included Canada and Newfoundland, Bermuda, many of the West Indies, British and French Guiana, islands in the Central and South Atlantic, much of the Atlantic seaboard of Africa, and Gibraltar. Also the waters of Britain and France. The one major defensive gap for the Allies was the lack of bases in Eire to cover the Western Approaches further out into the Atlantic. Britain and her Allies introduced convoys without delay having learned well many of the lessons of World War 1.

The Maritime Belligerents

These were based on the assumption Britain and France were actively allied against the European Axis powers of Germany and Italy. The Royal Navy would be responsible for the North Sea and most of the Atlantic, although the French would contribute some forces. In the Mediterranean, defence would be shared between both Navies.

 The U-boat Threat and the Allied Responses

OBJECTIVE 1 - Defence of trade routes, and convoy organisation and escort, especially to and from Britain.

- Until May 1940 the main threat was from U-Boats operating in the North Sea and South Western Approaches. For a few months two pocket battleships posed a danger in the broader reaches of the Atlantic.

- The first overseas convoys left Britain via the South Western Approaches. From the Thames they sailed through the English Channel (OA) and from Liverpool through the Irish Sea (OB). Later in September convoys left Freetown, Sierra Leone (SL), Halifax, Nova Scotia (HX) and Gibraltar (HG) for the UK.

- In the North Atlantic anti-submarine escorts were provided from Britain out to 200 miles west of Ireland (15W) and to the middle of the Bay of Biscay. U-boats soon operated beyond these limits. British and Allied convoys were also covered for a few hundred miles from Halifax by Canadian warships. The same degree of protection was given to ships sailing from other overseas assembly ports.

- Cruisers and (shortly) armed merchant cruisers sometimes take over as ocean escorts. Particularly fast or slow ships from British, Canadian and other assembly ports sailed independently, as did many hundreds of vessels scattered across the rest of the oceans. Almost throughout the war it was the independently-routed ships and the convoy stragglers that suffered most from the mainly German warships, raiders, aircraft and above all submarines that sought to break the Allied supply lines.

OBJECTIVE 2 - Detection and destruction of surface raiders and U-boats.

- Patrols were carried out by RAF Coastal Command in the North Sea, and by Home Fleet submarines off southwest Norway and the German North Sea bases. RAF Bomber Command prepared to attack German warships in their bases.

- Fleet aircraft carriers were employed on anti-U-boat sweeps in the Western Approaches.

OBJECTIVE 3 - British Naval blockade of Germany

- The British Northern Patrol of old cruisers, followed later by armed merchant cruisers had the unenviable task of covering the area between the Shetlands and Iceland. They suffered heavily at the hands of the U-boats.

- Closer to Germany the first mines were laid by Royal Navy destroyers in the approaches to Germany's North Sea bases. These claimed a few U-boats.

OBJECTIVE 4 - Defence of British coasts.

- Right through until May 1940 U-boats operated around the coasts of Britain and in the North Sea. Scotland's Moray Firth was often a focus for their activities. They attacked with both torpedoes and magnetic mines. Mines were also laid by surface ships and aircraft.

- British East Coast convoys (FN/FS) commenced between the Thames Estuary and the Firth of Forth in Scotland.

- Defensive mine laying began with an anti-U-boat barrier in the English Channel across the Straits of Dover, followed by an East Coast barrier to protect coastal convoy routes. These soon gained results

OBJECTIVE 5 - Escort British, Dominion and Allied troops to France and between Britain, the Dominions and other areas under Allied control.

- An immediate start was made transporting the British Expeditionary Force (BEF) to France. By the end of 1939 the first Canadian troops had arrived in Britain, and by early 1940 Australian, Indian and New Zealand forces were on their way to Egypt and the Middle East. Troop convoys were always heavily escorted, and the Dominion Navies played an important part in protecting the men as they left their home shores. Australian and New Zealand cruisers were particularly active in the Indian Ocean. Their main role was defence against German surface warships, but also the few U-boats initially at sea

 

 

Major Warship Strengths

 

Navies

Royal Navy

French Navy

German Navy

Warship types

Home waters (a)

Atlantic (b)

Atlantic and Channel

European waters

Atlantic station
Battleships

9

-

2

3

2(c)

Carriers

4

-

1

-

-

Cruisers

21

14

3

7

-

Destroyers

82

13

20

22

-

Submarines

21

4

-

41(d)

16

Totals

137

31

26

73

18

 

plus escorts

-

-

plus torpedo boats

-

Notes:

- Royal Navy was a mix of World War 1, modernised and recently completed ships. The French warships allocated to the Atlantic and the German were mainly modern.

(a) Home Fleet commanded by Adm Sir Charles Forbes with 7 capital ships, 2 carriers and 16 cruisers based at Scapa Flow and Rosyth; Channel Force with 2 battleships, 2 carriers and 3 cruisers; Humber Force with 2 cruisers; and various destroyer flotillas.

(b) North Atlantic Command based at Gibraltar with 2 cruisers and 9 destroyers; America and West Indies Command at Bermuda with 4 cruisers; and South Atlantic at Freetown with 8 cruisers and 4 destroyers.

(c) Pocket battleships "Admiral Graf Spee" in the South and "Deutschland" in the North Atlantic.

(d) included U-boats on patrol in the North Sea and British coastal waters.

 
 
 

Declarations of War

3rd - After Germany invaded Poland on the 1st, Britain and France demanded the withdrawal of German forces. The ultimatum expired and at 11.15am on the 3rd, Prime Minister Neville Chamberlain broadcast to announce that Britain was at war with Germany. He formed a War Cabinet with Winston Churchill as First Lord of the Admiralty. France, Australia, New Zealand and India (through the Viceroy) declared war the same day.

Atlantic

Battle of the Atlantic - The six-year long Battle started on the 3rd with the sinking of liner "Athenia" by "U-30" (Lt Lemp) northwest of Ireland. She was mistaken for an armed merchant cruiser, and her destruction led the Admiralty to believe unrestricted submarine warfare had been launched. Full convoy plans were put into operation, but in fact Hitler had ordered the U-boats to adhere to international law and after the "Athenia" incident, tightened controls for a while. Liverpool-out convoy OB4 was the first group of ships to be attacked, with "U-31" sinking one ship on the 16th September. Convoys actually suffered little harm over the next seven months, and most of the losses due to U-boats were among the independently-routed and neutral merchantmen. In the period to March 1940 they sank 222 British, Allied and neutral ships in the Western Approaches to the British Isles, the North Sea and around the coasts of Britain. In the same time they lost 18 of their number, a third of all in commission in September 1939 and more than the number of new boats entering service.

14th - After an unsuccessful attack on carrier "Ark Royal" off the Hebrides, NW Scotland, German "U-39" was depth-charged and sunk by screening destroyers "Faulknor", "Firedrake" and "Foxhound".

17th - Three days after the sinking of "U-39", fleet carrier "COURAGEOUS" was sent to the bottom to the southwest of Ireland by "U-29" with heavy loss of life. Carriers were withdrawn from anti-U-boat patrols as it became accepted that the best chance of sinking U-boats was to attract them to well-defended convoys where the escorts could hunt them down.

20th - After sinking trawlers off the northern Hebrides, German "U-27" was located and sunk by destroyers "Fortune" and "Forester".

Monthly Loss Summary
- 20 British, Allied and neutral ships of 110,000 tons in the Atlantic from all causes; 1 fleet carrier.
- 2 German U-boats.

Europe

German Codes - The British Code & Cipher School moved to Bletchley Park, England, the site of its magnificent successes breaking the German Enigma codes through the 'Ultra' programme . The school built on the work of Polish and later French code-breakers. By April 1940 the first low level Luftwaffe codes were being deciphered. Many months followed before comparable progress was made with Naval codes.

Monthly Loss Summary
33 British, Allied and neutral ships of 85,000 tons in UK waters.

OCTOBER 1939

Atlantic

Americas - The Pan-American Conference established a 300-mile plus security zone off the coasts of the Americas within which all hostile action by the belligerent powers was forbidden.

13th - Two U-boats attacking convoys to the southwest of Ireland were sunk by escorting destroyers. On the 13th, "U-42" was sent to the bottom by "Imogen" and "llex" sailing with Liverpool-out convoy OB17

14th - Next day "Icarus", "Inglefield", "Intrepid" and "Ivanhoe" escorting Kingston, Jamaica/UK convoy KJ3 accounted for "U-45"

Battle of the Atlantic - The first UK/Gibraltar convoy, OG1, sailed in October. Partly because of the loss of "U-42" and "U-45", only three of the intended nine U-boats were available for the first U-boat group attack on a convoy using an on-board tactical commander. Three ships out of the 27 in unescorted convoy HG3 were sunk, but the experiment was repeated only a few times. The first wolf-pack attacks conducted personally by Adm Doenitz from onshore did not start for another year.

Monthly Loss Summary
- 22 British, Allied and neutral ships of 133,000 tons in the Atlantic from all causes.
- 2 German U-boats.

Europe

German Heavy Warships - Battlecruiser "Gneisenau" and other ships of the German Navy sortied on the 8th off Norway to draw the Home Fleet within U-boat and aircraft range. No contact was made.

8th - The anti-U-boat mine barrage in the Strait of Dover was completed and accounted for three U-boats, starting with "U-12" on the 8th.

13th - "U-40" was also mined and sunk in the Strait of Dover.

14th - Returning to Scapa Flow after guarding the Fair Isle passage during "Gneisenau's" recent sortie, anchored battleship "ROYAL OAK" was torpedoed and sunk by "U-47" (Lt-Cdr Prien) in the early hours of the 14th with the loss of 833 men. The Home Fleet moved to Loch Ewe on the W Scottish coast

24th - The third U-boat sunk in the Strait of Dover was "U-16" on the 24th. No more attempts were made to pass through the English Channel and U-boats were forced to sail around the north of Scotland to reach the Atlantic.

Monthly Loss Summary
- 24 British, Allied and neutral ships of 63,000 tons in UK waters.
- 3 German U-boats

NOVEMBER 1939

Atlantic

29th - On patrol to the north of Scotland to support the attempted breakout of German battlecruiser's "Scharnhorst" and "Gneisenau" into the Atlantic, "U-35" was found east of the Shetland Islands and sunk by destroyers "Kashmir", "Kingston" and "Icarus".

Battle of the Atlantic - RAF Coastal Command continued to patrol for U-boats on passage into the Atlantic. Equal priority was now given to attacks, but the crews were not trained and lacked effective anti-submarine bombs. The first success was a joint action with the Royal Navy at the end of January 1940.

Monthly Loss Summary
- 6 British, Allied and neutral ships of 18,000 tons in the Atlantic from all causes; 1 armed merchant cruiser
- 1 German U-boat.

Europe

13th - As U-boat and surface ship-laid mines continued to inflict heavy losses on merchant ships and warships alike, cruiser minelayer "Adventure" and accompanying destroyer "BLANCHE" were mined in the Thames Estuary. "Blanche" was a total loss. More serious casualties followed a week later.

21st - Recently completed light cruiser "Belfast" was badly damaged in the Firth of Forth on a magnetic mine laid by "U-21". With her back broken and machinery mountings shattered she was out of action for three years.

Magnetic Mines - German seaplanes also laid the first magnetic mines off the East Coast and dropped one on tidal flats at Shoeburyness in the Thames Estuary. It was defused on the 23rd November and recovered, a vital step in the battle against a weapon which was causing heavy losses and long shipping delays. In November alone, 27 ships of 121,000 tons were sunk and for a time the Thames Estuary was virtually closed to shipping.

Merchant Shipping War - The first HN/ON convoys sailed between the Firth of Forth and Norway in November covered by the Home Fleet. The convoys were discontinued in April 1940.

Monthly Loss Summary
43 British, Allied and neutral ships of 156,000 tons in UK waters.

DECEMBER 1939

Atlantic

Monthly Loss Summary
- 7 British, Allied and Neutral ships of 38,000 tons in the Atlantic from all causes.
- 1 German pocket battleship - "Graf Spee" following Battle of River Plate.

Europe

4th - Returning from the hunt for the German battle-cruisers after the sinking of "Rawalpindi" on the 23rd November, battleship "Nelson" was damaged by a mine laid by "U-31" off Loch Ewe, northwest Scotland.

4th - On patrol off the Heligoland Bight, submarine "Salmon" (Lt Cdr Bickford) sank outward bound "U-36".

28th - Battleship "Barham" was torpedoed and damaged off the Hebrides by "U-30" (Lt Cdr Lemp)

Merchant Shipping War - By the end of March German aircraft had accounted for 30 vessels of 37,000 tons. Losses from mines remained high - 33 ships of 83,000 tons in December.

Monthly Loss Summary
66 British, Allied and Neutral ships of 152,000 tons in UK waters.

 

1940

JANUARY 1940

Atlantic

30th - Attacking Thames-out convoy 0A80 to the west of the English Channel, “U-55” was destroyed in a joint action by an RAF Sunderland of No 228 Squadron, sloop “Fowey“ and destroyer “Whitshed”. This was the first successful air/sea attack which would not be repeated for another five months.

Monthly Loss Summary
- 9 British, Allied and neutral ships of 36,000 tons in the Atlantic from all causes.
- 1 German U-boat.

Europe

21st - Searching for a reported U-boat off the Moray Firth, destroyer “EXMOUTH” was torpedoed by “U-22” and lost with all hands.

Merchant Shipping War - U-boats were particularly active in the Moray Firth area off the Scottish coast and in the rest of the North Sea through until March 1940. In January alone they sank 14 ships - all neutrals.

Monthly Loss Summary
64 British, Allied and neutral ships of 179,000 tons in UK waters.

FEBRUARY 1940

Atlantic

5th - “U-41” sank one ship from Liverpool-out convoy OB84 south of Ireland, but was then sent to the bottom by the lone escort, destroyer “Antelope”.

23rd - Destroyer “Gurkha” on passage south of the Faeroe Islands encountered “U-53” returning from patrol in the Western Approaches. The U-boat was sunk.

Monthly Loss Summary
- 17 British, Allied and neutral ships of 75,000 tons from all causes
- 2 German U-boats.

Europe

12th - “U-33” on a minelaying operation in the Firth of Clyde, eastern Scotland was sunk by minesweeper “Gleaner”.

18th - In an attack on Norway/UK convoy HN12, destroyer “DARING” was sunk by “U-23” in the northern North Sea, east of the Pentland Firth.

22nd - Royal Navy destroyers laid mines in the North Sea, northwest of the German Frisian Islands. “U-54” was presumed lost in the field.

25th - A week after "Daring's" loss, Norway/UK convoy HN14 was attacked. German “U-63” was sighted by escorting submarine “Narwhal” and sent to the bottom by destroyers “Escort”, “lmogen” and “lnglefield”.

Monthly Loss Summary
- 46 British, Allied and neutral ships of 152,000 tons in UK waters.
- 3 German U-boats

MARCH 1940

Atlantic

20th - British Home Fleet battlecruisers to the north of the Shetlands covered a cruiser sweep into the Skagerrak. German U-boat “U-44” was sighted and sunk by escorting destroyer “Fortune” .

Battle of the Atlantic - U-boats started withdrawing from the Western Approaches in preparation for the German invasion of Norway.

Monthly Loss Summary
- 2 British, Allied and neutral ships of 11,000 tons from all causes
- 1 U-boat.

Europe

11th - “U-31” was bombed and sunk by a RAF Blenheim of Bomber Command in the Heligoland Bight . She was salvaged and recommissioned, but finally lost eight months later.

Merchant Shipping War - Since September 1939, 430,000 tons of shipping had been sent to the bottom by mines around the coasts of Britain - a loss rate only second to U-boats. Now the Royal Navy slowly countered magnetic mines with the introduction of ship-degaussing and 'LL' minesweeping gear.

Monthly Loss Summary
- 43 British, Allied and neutral ships of 96,000 tons in UK waters
- 1 German U-boat

DEFENCE OF TRADE - FIRST SEVEN MONTHS

In the period September 1939 to the end of March 1940, much of the Royal Navy's efforts had been directed to organising the protection of trade both to and from Britain as well as around the British Isles. The small number of U-boats operating out in the Atlantic in the South Western Approaches as well as in the North Sea had had their successes, but mainly against independently-routed shipping. Losses in UK waters were high from both U-boats and mines, but from now on enemy submarines would disappear from UK coastal areas for more than four years until mid-1944. The struggle to keep Britain in the war would move further and further out into the Atlantic and even further afield over the years to come.

Total Losses = 402 British, Allied and neutral ships of 1,303,000 tons (186,000 tons per month)

By Location

Location

Number of British, Allied, neutral ships

Total Gross Registered Tonnage

North Atlantic

75

371,000 tons

South Atlantic

8

49,000 tons

UK waters

319

883,000 tons

By Cause

Causes* in order of tonnage sunk

Number of British, Allied, neutral ships

Total Gross Registered Tonnage

1. Submarines

222

765,000 tons

2. Mines
3. Warships
4. Aircraft
5. Other causes

129
16
30
5

430,000 tons
63,000 tons
37,000 tons
8,000 tons

* The identifying numbers for each cause e.g. "1. Submarines" would be retained for all Trade War summaries, and added to as new weapon types appear e.g. "6. Raiders". The trends in losses due to the different causes could thus be followed

Western Europe was about to erupt. There would be a lull in the Battle of the Atlantic as U-boats were withdrawn for the Norwegian campaign, and before surface raiders started operations and long-range aircraft and U-boats emerge from bases in France and Norway. Around the British Isles, aircraft and mines would continue to account for merchant ships of all sizes, especially during the confused months of May, June and July 1940. During this time German E-boats commenced attacks in coastal waters. The comparatively low monthly average of 186,000 tons of merchant shipping lost in the first seven months would not be seen for any more than a month or two for three long and deadly dangerous years - until mid 1943.

APRIL 1940

Atlantic

10th - “U-50” on patrol off the Shetlands in support of the Norwegian invasion, was sunk by destroyer “Hero”.

Monthly Loss Summary
- 4 British, Allied and neutral ships of 25,000 tons from all causes
- 1 German U-boat.

Europe

German Codes - The Bletchley Park Ultra programme was now decoding some Luftwaffe low-level Enigma codes, partly because of poor German security procedures. There was little evidence the hard-won information influenced the war over the next two violent months.

Norwegian Campaign

9th - Germany invaded Denmark and Norway (Operation 'Weserubung'): Copenhagen was soon occupied and DENMARK surrendered. In Norway, troops landed at Oslo, Kristiansand and Bergen in the south, Trondheim in the centre and Narvik in the north. German Navy forces included a pocket battleship, six cruisers and 14 destroyers for landings at the five Norwegian ports, with battlecruisers “Scharnhorst” and “Gneisenau” covering the two most northerly landings. Thirty U-boats patrolled off Norway and British bases, but throughout the campaign they suffered from major torpedo defects.

10th - First Battle of Narvik - The British 2nd Destroyer Flotilla entered Ofotfiord to attack the German ships assigned to the occupation of Narvik. Several transports were sunk together with two German destroyers, for the loss of two British. On the same day submarine “THISTLE” on patrol off Utsira failed in an attack on “U-4”. Shortly after she was sunk by the same U-boat.

13th - Second Battle of Narvik - Battleship “Warspite” and nine destroyers were sent into the Narvik fiords to finish off the remaining German ships. Submarine “U-64” was surprised and sunk by “Warspite's” Swordfish catapult aircraft as it scouted ahead. The eight surviving German destroyers were all destroyed or scuttled.

14th-16th - The first Allied landings took place between the 14th and 16th. In the north, British troops occupied Harstad in preparation for an attack on Narvik.

15th - As the Harstad-bound troopships approached their destination, escorting destroyers “Brazen” and “Fearless” located and sank “U-49”. Southwest of Stavanger, “U-1” went to the bottom after striking a mine.

27th - Allied plans to attack towards Trondheim and hold central Norway proved impossible. The decision was taken to pull out of central Norway and the evacuation of Andalsnes and Namsos got under way.

Air War - The first mines were laid by RAF Bomber Command off the German and Danish coasts.

Monthly Loss Summary
54 British, Allied and neutral ships of 134,000 tons from all causes.

MAY 1940

Atlantic

Iceland - On the 10th as Germany attacked France and the Low Countries, British Royal Marines landed from two cruisers at Reykjavik, Iceland then part of the Danish Crown. More troops followed to set up air and sea bases that became vital to Britain's defence of the Atlantic supply routes and eventual defeat of the U-boat.

Battle of the Atlantic - U-boats started returning to the Western Approaches and as they did, one of the first ‘Flower’ class corvettes “Arabis” made a depth-charge attack in defence of a Gibraltar/UK convoy. With the closure of the Mediterranean to Allied shipping, the trade routes around Africa and the ports en route took on a new importance. Particularly vital was the West African base at Freetown, Sierra Leone.

Monthly Loss Summary
10 British, Allied and neutral ships of 55,000 tons from all causes.

Europe

Britain - Following a 10th May House of Commons debate on the Norwegian campaign, Prime Minister Neville Chamberlain resigned and Winston Churchill assumed leadership. His only real fear throughout the war was the U-boat threat

Western Front

10th - Germany invaded Holland, Belgium, Luxembourg

13th - The Germans entered France at Sedan. After breaking through, German armour headed west for the Channel to trap the Allied armies now in Belgium and northern France.

20th - German tanks reached the English Channel near Abbeville, shortly turning right and advancing north on the ports of Boulogne, Calais and Dunkirk.

26th May-4th June - Dunkirk Evacuation - Initial plans were to lift off 45,000 men of the British Expeditionary Force over a two-day period. In the next five days, a total of 195,000, both British and French were saved. Every phase of the operation was subject to heavy air, sea and land attack.

29th - Apart from those damaged, three Royal Navy destroyers were sunk in the English Channel off the Dunkirk beaches that day including “GRAFTON” torpedoed by submarine “U-62”

31st - German “U-13” was believed sunk by sloop “Weston” off the English East Coast fishing port of Lowestoft.

Air War - Minelaying continued along the south and east coasts of Britain as well as the waters of Holland, Belgium and northern France during the German Blitzkrieg.

Monthly Loss Summary
90 British, Allied and neutral ships of 231,000 tons from all causes.

JUNE 1940

Atlantic

6th - Three armed merchant cruisers on Northern Patrol were lost to U-boats in the waters between Ireland (R) and Iceland (C) over the next nine days, starting with “CARINTHIA” on the 6th/7th to “U-46”

13th - “SCOTSTOUN” was torpedoed three times by “U-25” and sank north west of the Hebrides

15th - “ANDANIA” was sunk by German “U-A”, a Turkish submarine building in Germany and taken over

Battle of the Atlantic - The Allied loss of Norway brought German warships and U-boats many hundreds of miles closer to the Atlantic convoy routes and in time within close range of the Russian convoys that followed the June 1941 German invasion. Britain's blockade line from the Orkneys to southern Norway was simply outflanked and a new one had to be established between the Shetlands and Iceland. The Royal Navy started the massive task of laying a mine barrage along this line. Within a matter of days the first U-boats were sailing from the Norwegian port of Bergen, while others were sent to patrol as far south as the Canary and Cape Verde Islands off northwest Africa. Italian submarines joined them in this area, but without any early successes. Towards the end of the month, “U-122” and “U-102” were lost off the North Channel separating Northern Ireland from Scotland, possibly on mines according to German sources. It was in this area and throughout the North Western Approaches to the British Isles that such U-boat commanders as Endras, Kretschmer, Prien and Schepke enjoyed the ‘Happy Time' until early 1941. U-boat strength was no greater than at the beginning of the war, and there were never more than 15 boats on patrol out of the 25 operational; the rest were training or on trials. Yet from now until the end of December 1940 they accounted for most of the 315 ships of 1,659,000 tons lost in the Atlantic. Many of these were stragglers, independents or in unescorted convoys, yet it was among the escorted convoys that U-boat tactics were particularly threatening. Instead of attacking submerged where they could be detected by ASDIC, they were operating on the surface at night as 18kt torpedo boats, faster than most of the escorts. And there were few enough of these as many were held back in British waters on anti-invasion duties.

Monthly Loss Summary
- 53 British, Allied and neutral ships of 297,000 tons from all causes; 3 armed merchant cruisers
- 2 German U-boats, dates and causes of loss uncertain.

Europe

German Codes - 'Ultra' was now breaking the Luftwaffe Enigma codes with some regularity, and early in the month had its first major breakthrough when supporting evidence for the Knickebein navigation aid for bombers was obtained. Army codes were more secure because of the greater use of land lines for communications, and the Naval ones would not be penetrated until mid-1941.

4th - end of Dunkirk Evacuation

8th - end of Norwegian Campaign

10th - Italy declared war on Britain and France

22nd - France capitulated

Britain - By early June 1940 the Royal Navy was taking steps to meet the threat of German invasion. Four destroyer flotillas with cruiser support moved south, and escort and other vessels were on patrol offshore. The removal of these escorts from Atlantic convoy duties contributed to the sinking of many merchant ships by U-boats, and eventually they returned to these duties.

Monthly Loss Summary
77 British, Allied and neutral ships of 209,000 tons from all causes.

 

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revised 9/7/11


 

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