Escort aircraft carrier HMS Queen (Navy Photos/Mark Teadham, click to enlarge). Starting with HMS Audacity in late 1941, the escort carriers and long range aircraft slowly closed the air-gaps in the Atlantic in which U-boats operated against Allied convoys.

1939

SEPTEMBER 1939

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.

 

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.

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.

OCTOBER 1939

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

NOVEMBER 1939

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.

DECEMBER 1939

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" after the Battle of the River Plate.

 

1940

JANUARY 1940

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

FEBRUARY 1940

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

MARCH 1940

Battle of the Atlantic - U-boats started withdrawing from the Western Approaches in preparation for the German invasion of Norway. In preparation for the vital transport role she, sister "Queen Mary" and other fast liners played in the Allies strategic moves, the nearly completed "Queen Elizabeth" sailed independently on her maiden voyage from Scotland to New York for conversion to a troopship.

Monthly Loss Summary
- 2 British, Allied and neutral ships of 11,000 tons from all causes
- 1 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 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 disappeared from UK coastal areas for more than four years until mid-1944. The struggle to keep Britain in the war moved 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

By Cause

* The identifying numbers for each cause e.g. "1. Submarines" were 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 can thus be followed

Western Europe was about to erupt. There was 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 emerged from bases in France and Norway. Around the British Isles, aircraft and mines continued 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. (Enemy or E-boat was the English term for German motor torpedo boats or S-boats, not to be confused with the heavily armed torpedo boats or small destroyers with their 'T' designation.) The comparatively low monthly average of 186,000 tons of merchant shipping lost in the first seven months was not seen for any more than a month or two for three long and deadly dangerous years - until mid 1943.

APRIL 1940

Faeroe Islands - On the 13th April, following the German invasion of Norway, an advance guard of Royal Marines was landed on the Faeroe Islands, northwest of the Shetland Islands with the eventual agreement of the Danish Governor.

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

MAY 1940

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. To avoid any possibility of confusion, Winston Churchill always insisted on differentiating between Iceland (C) and Ireland (R).

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.

JUNE 1940

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.

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 were not penetrated until mid-1941.

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.

JULY 1940

French Navy in the Atlantic - Carrier “Hermes” and cruisers “Dorsetshire” and Australian sister-ship “Australia” lay off Dakar, French West Africa on the 8th after negotiations were refused on the future of French battleship “Richelieu”. Attacks made with depth-charges from a fast motorboat fail and a torpedo strike by Swordfish inflicts only minor damage. No action was taken against “Richelieu’s” sister ship “Jean Bart” laying further north at Casablanca, Morocco. In the French West Indies, carrier “Bearn” and two cruisers were immobilised by mainly diplomatic means.

Battle of the Atlantic - Convoys were now being re-routed through the North Western Approaches to the British Isles instead of the south of Ireland and through the Irish Sea. North Channel and the sea lanes leading to it becomes a focal point for all shipping leaving or arriving in British waters.

The following convoys continued: Liverpool out - OB (later replaced by ON's), UK/Gibraltar - OG, Fast Halifax/UK - HX, Gibraltar/UK - HG, Sierra Leone/UK - SL. Thames-out OA convoys were now joining FN East Coast coastal convoys and passing around the north of Scotland before going out through the North Western Approaches. They stopped altogether in October 1940. Slow Sydney, Cape Breton, Canada to UK convoys started in August 1940 with SC1. The limits of the few escorts available were only now pushed out from 15'W to 17'W where they stayed until October 1940. U-boats were patrolling well beyond this range and so many sinkings took place in unescorted convoys or when the ships had dispersed.

Monthly Loss Summary
- 34 British, Allied and neutral ships of 173,000 tons in the Atlantic from all causes; 1 destroyer
- 1 German U-boat.

STRATEGIC & MARITIME SITUATION

Britain's circumstances were transformed. From North Cape in Norway to the Pyrenees at the Spanish border, the coast of Europe was in German hands. Norwegian bases threatened northern Britain. By occupying the Low Countries of Holland and Belgium, and northern France, the south and east coasts of England were now in the front line. From their new French Biscay ports, German maritime forces dominated the South Western Approaches to the British Isles. The British occupation of Iceland took on a new and vital importance. The lack of bases in Eire became more evident. In addition, the majority of French possessions on the Atlantic seaboards of Africa and the Americas were under the control of Vichy France, and thus denied to British forces. Worse still was the danger of their occupation by the Axis powers. The naval situation was similarly transformed. Not only was the French fleet denied to the Allies, but the great fear was that it would be seized by the German and Italian navies and totally alter the naval balance of power. The French Navy refused to make for British ports and most of the modern ships sailed for French North and West Africa. The uncompleted battleships “Jean Bart” and “Richelieu” reached the Atlantic ports of Casablanca in Morocco and Dakar in Senegal respectively.  

AUGUST 1940

Radar - A British scientific mission to the United States carried details of many important developments. Amongst these was the recently invented cavity magnetron, vital for short wavelength radar and the eventual defeat of conventional U-boats in the Battle of the Atlantic.

Battle of the Atlantic - Long range Focke Wulf Kondor bombers started patrols off the coast of Ireland from a base near Bordeaux. As well as spotting for U-boats they attacked and sank many ships, and continued to be a major threat until the introduction of ship-borne aircraft in late 1941 started to counteract them.

Monthly Loss Summary
- 39 British, Allied and neutral ships of 190,000 tons in the Atlantic from all causes; 2 armed merchant cruisers, 1 sloop
- 1 German U-boat.

SEPTEMBER 1940

US Destroyers for British Bases Deal - After months of negotiations, an agreement was announced on the 5th for the transfer of 50 old but valuable US destroyers to the Royal Navy in exchange for British bases in Newfoundland, Bermuda, the West lndies and British Guiana. The first of the "flushdeckers" arrived in Britain towards the end of the month.

1st - Cruiser "Fiji" was torpedoed by "U-32" out in the North Atlantic off Rockall as she escorted troop transports for the Dakar expedition. Her place was taken by Australian heavy cruiser "Australia".

23rd-25th - Dakar Expedition, Operation 'Menace' - Because of Dakar's strategic importance to the North and South Atlantic shipping routes, an expedition was mounted to acquire the port for Allied use. Free French troops led by Gen de Gaulle were carried in ships escorted and supported by units of the Home Fleet and Force H under the command of Vice-Adm John Cunningham. They included battleships "Barham" and "Resolution", carrier "Ark Royal", three heavy cruisers and other smaller ships including Free French. Naval forces at Dakar included the unfinished battleship "Richelieu" and two cruisers recently arrived from Toulon (see below). Attempts to negotiate on the 23rd soon failed and as Vichy French ships tried to leave harbour, shore batteries opened fire, damaging heavy cruiser "Cumberland" and two destroyers. Shortly afterwards, the Vichy submarine "PERSEE" was sunk by gunfire and large destroyer "L'AUDACIEUX" disabled by cruiser "Australia" and beached. A Free French landing was beaten off. Next day, on the 24th, Dakar was bombarded by the warships and "Richelieu" attacked by "Ark Royal's" aircraft. Vichy submarine "AJAX" was sunk by destroyer "Fortune". The bombardment continued on the 25th, but battleship "Resolution" was now torpedoed and badly damaged by submarine "Beveziers" and "Barham" hit by "Richelieu's" 15in gunfire. At this point the operation was abandoned and the Anglo-Free French forces withdrew.

Battle of the Atlantic - Early in the month the first wolf-pack attacks were directed by Adm Doenitz against convoy SC2. Five of the 53 ships were sunk. A similar operation was mounted two weeks later against the 40 ships of HX72. The U-boats present included those commanded by the aces Kretschmer, Preen and Schepke. Eleven ships were lost, seven to Schepke's "U-100" in one night. The German B-Service was instrumental in directing U-boats to the convoys, where they held the advantage as they manoeuvred on the surface between the merchantmen and escorts. Radar was urgently needed so the escorts could detect the U-boats, force them to dive and lose their speed advantage before hunting them with ASDIC.

Monthly Loss Summary
- 53 British, Allied and neutral ships of 272,000 tons in the Atlantic from all causes; 2 escorts
- no German losses

OCTOBER 1940

Battle of the Atlantic - Focke-Wulf Kondor bombers continued to range the waters off Ireland and on the 26th, bombed and damaged the "Empress of Britain", later sunk "U-32" (above). The Luftwaffe's long-range aircraft were now flying from bases in Norway as well as France. Inter-service rivalry between the Luftwaffe and Navy meant the Kondor would never be fully integrated into the Gerrnan effort in the Battle of the Atlantic. Escort limits were only now pushed out to 19W. In a series of wolf-pack attacks on lightly-defended Canada/UK convoys, U-boats sank more than 30 ships from SC7 and HX79 between the 17th and 20th, a rate of loss that would soon have brought Britain to her knees. Fortunately, a number of measures were being taken to ease the dire situation and provide some of the foundations from which Britain and her Allies could go on to hold the U-boat threat in check: (1) The old US destroyers were coming into service and the British building programme was starting to deliver the escorts needed. (2) The need for permanent escort groups to develop and maintain expertise was being accepted, and greater emphasis given to A/S training. (3) Co-operation between RAF Coastal Command and Western Approaches Command was steadily improving. But there was still a long way to go, and vast areas of the Atlantic were without air or sea anti-submarine cover.

Monthly Loss Summary
- 56 British, Allied and neutral ships of 287,000 tons in the Atlantic from all causes; 1 destroyer
- 1 German U-boat.

NOVEMBER 1940

Battle of the Atlantic - Outward-bound OB244 and UK-bound SC11 were attacked by two groups of U-boats west of North Channel. Fifteen merchant ships were sunk, including seven from SC11 by Schepke's "U-100"on the night of the 22nd/23rd. In separate North Atlantic operations, German submarine "U-104" and the Italian "FAA DI BRUNO" were lost. In both cases the circumstances were uncertain, but "U-104" was claimed by corvette "Rhododendron" and the Italian by destroyer "Havelock". "U-104" was the last German U-boat lost until March although the Italians had casualties. By the end of the month they had 26 submarines operating out of Bordeaux, but were never as successful as their ally. Important steps were taken in the air war when an RAF Sunderland equipped with 1.5m wavelength anti-surface vessel (ASV) radar located a U-boat. This was the first success of its kind with a system that was mainly effective by day; contact was lost within two miles of the target. It was the addition of the Leigh light that turned it into a powerful night-time weapon as well. Now Coastal Command was using depth charges instead of ineffective A/S bombs.

Monthly Loss Summary
- 38 British, Allied and neutral ships of 201,000 tons in the Atlantic from all causes; 3 armed merchant cruisers
- 2 German and 1 Italian U-boats.

DECEMBER 1940

Monthly Loss Summary
- 42 British, Allied and neutral ships of 239,000 tons in the Atlantic from all causes; 1 armed merchant cruiser
- 1 Italian U-boat

DEFENCE OF TRADE - April to December 1940

U-boats and now long-range aircraft had taken a heavy toll of British, Allied and neutral shipping in the Atlantic, mainly in the North Western Approaches to the British Isles. Further afield surface raiders had sunk, captured and disrupted shipping as far away as the Pacific. U-boats had also operated with success off West Africa. In UK waters, attacks by aircraft and E-boats had added to the continuous threat from mines. Over half the ships and 40 percent of tonnage had been lost close to home. Vital as the Battle of the Atlantic may have been, there could be no let up in the equally important battle for the coastal convoy routes once the ships reached UK waters. Only heavily escorted transports would use the Mediterranean until 1943.

The monthly loss rate in these months was twice the first seven months of the war, and each form of attack required a different technical and operational response from the Royal Navy and its Allies. The 1940 patterns of assault against the trade routes continued throughout 1941, although the U-boats would move further out into the Atlantic. By year's end they reached the coasts of America.

Total Losses = 878 British, Allied and neutral ships of 3,441,000 tons (382,000 tons per month)

By Location

By Cause

 

1941

JANUARY 1941

Battle of the Atlantic - For the next few months the U-boat's 'Happy Time' continued in the Western Approaches against the poorly defended convoys. Bad weather in January and February fortunately kept the level of sinkings down. Approximately 22 U-boats were operational out of the 90 in commission, and long-range aircraft including the Focke Wulf Kondors still roamed the waters off Ireland spotting for U-boats and sinking ships.

Monthly Loss Summary
- 59 British, Allied and neutral ships of 273,000 tons in the Atlantic from all causes
- 1 Italian U-boat.

FEBRUARY 1941

Battle of the Atlantic - Adm Sir Percy Noble took over as Commander-in-Chief, Western Approaches, just as the command movesd from Plymouth to Liverpool.

Monthly Loss Summary
- 69 British, Allied and neutral ships of 317,000 tons in the Atlantic from all causes
- 1 Italian U-boat.

MARCH 1941

US Lend-Lease - The Bill was passed into law. Britain and her Allies would be able to receive American arms and supplies without immediate payment.

Battle of the Atlantic - On 6th March 1941, faced with the mortal threat of the German U-boat and aircraft offensive in the Atlantic, Winston Churchill issued his famous Battle of the Atlantic directive. Catapult armed merchantmen (CAM) were to be fitted out, merchant ships equipped with AA weapons as a first priority, and more Coastal Command squadrons formed and fitted with radar. Port and dockyard congestion was to be dealt with and the defence of ports greatly improved. These and numerous other matters were to be dealt with as a matter of the very highest priority. The survival of Britain depended on them. Overall direction was to be exercised by a Battle of the Atlantic Committee chaired by the Prime Minister himself.

Monthly Loss Summary
- 63 British, Allied and neutral ships of 365,000 tons in the Atlantic from all causes
- 5 German U-boats-including three of the most experienced commanders.

APRIL 1941

German Aircraft Attacks - In April 1941, aircraft sank 116 ships of 323,000 tons in the Atlantic, off Europe and in the Mediterranean, the highest rate for any month of the whole war. In the first six months of 1941 alone the losses totalled 294 ships of 811,000 tons. These were not only due to the long-range aircraft operating off Ireland from bases in France and Norway, but to attacks in coastal waters where the defences were still weak. More AA weapons were needed for merchantmen, more and better controlled shore-based fighters in coastal areas, and ship-borne aircraft were vital out at sea. The needs were recognised as the Battle of the Atlantic Directive made clear, but would take many months to meet.

Battle of the Atlantic - Over the next few months a number of long awaited ship types and weapons started to be introduced. These would contribute significantly to the eventual defeat of the U-boat. (1) The first Auxiliary Fighter Catapult Ships flying the White Ensign and equipped with a single 'one-way' Hurricane were ready in April 1941. They shot down their first Kondor in August. In May a Hurricane was successfully launched from a Red Ensign Catapult Armed Merchantman (CAM), but they did not claim their first victim until November. CAM-ships were eventually superseded in 1943 by Merchant Aircraft Carriers (MACs) - merchantmen with full flightdecks, but sailing under the Red Ensign and also carrying oil or grain. (2) The final step in the introduction of ship-borne aircraft into the Battle of the Atlantic came in June when the first escort carrier was ready for service. HMS Audacity, converted from a German prize, had a short life, but proved the great value of these vessels. (3) New scientific developments also started to play their part. In May the first high definition, 10cm radar (Type 271) was installed in a corvette. Later still, high frequency, direction finding (HF/DF or 'Huff-Duff') was introduced to supplement the work of the shore stations. It was many months before either system was widely in service, and not until 1942 did they claim their first U-boats. (4) Inter-service co-ordination was further improved when RAF Coastal Command was placed under operational control of the Admiralty.

Monthly Loss Summary
- 48 British, Allied and neutral ships of 282,000 tons in the Atlantic from all causes; 3 armed merchant cruisers
- 2 German U-boats

MAY 1941

This month included a breakthrough in the capture of German Enigma coding material from "U-110", the hunt for and sinking of the "Bismarck", the fearful Royal Navy losses off Crete, continuing confirmation that Russia was about to be attacked by Germany, and further deterioration in relations with Japan. One can only imagine the thoughts and feelings of Prime Minister Churchill and his senior advisers as they responded day-by-day to these momentous developments.

Battle of the Atlantic - Total U-boat strength was now over 100 with 30 operational and the rest undergoing training or trials. Most were active in the North Atlantic, but a small number were concentrated against the weakly-defended shipping off Freetown, Sierra Leone and between there and the Canary Islands to the north. In this area "U-107" (Lt-Cdr Hessler) sank 14 ships of 87,000 tons on one patrol. Other U-boats did almost as well. Royal Navy escort groups could provide cover from UK bases out to 18'W, and those from Iceland the mid-Atlantic gap to 35'W. With the opening of an Escort Force base at St John's, Newfoundland by the Royal Canadian Navy, the rest of the North Atlantic convoy routes could now receive protection. However, continuous escort across the Atlantic was not yet available. Then, around the 20th, unescorted convoy HX126 from Halifax, Nova Scotia was attacked at 40'W and lost heavily. Steps were immediately taken to extend protection and HX129 sailing at the end of the month was the first of the UK-bound convoys to receive regular and continuous cover.

Monthly Loss Summary
- 60 British, Allied and neutral ships of 336,000 tons in the Atlantic from all causes; 1 battlecruiser, 1 destroyer, 1 armed merchant cruiser
- German battleship "Bismarck" and "U-110"

JUNE 1941

Battle of the Atlantic - Following the capture of the “U-100” Enigma material, the Royal Navy tracked down the supply ships already in position to support the "Bismarck" as well as other raiders and U-boats. In 20 days, six tankers and three other ships were sunk or captured in the North and South Atlantic. From then on, distant water U-boats had to be supplied by U-boat 'Milchcows' although the first purpose-built ones would not be ready until 1942.

Monthly Loss Summary
- 70 British, Allied and neutral ships of 329,000 tons in the Atlantic from all causes
- 4 German and 1 Italian U-boats

JULY 1941

Iceland - US forces landed in Iceland to take over the defence of the island and surrounding seas from Britain.

Battle of the Atlantic - Continuous escort was now being provided for convoys to North America and from West Africa. Three new convoys were introduced: UK/North America Fast, ONF; UK/North America Slow, ONS - the two replacing the Outward Bound, 0B convoys; UK/Sierra Leone, OS. Air cover from Ireland, Iceland and Newfoundland was improving, but RAF Coastal Command lacked the aircraft to cover the mid-Atlantic gap. It was in this area, some 800 miles long that the U-boats were now concentrating. Between January and June 1941, North Atlantic merchant shipping losses had averaged 300,000 tons per month. From July to December 1941 they were considerably down at an average level of 104,000 tons. The reasons were varied - evasive convoy routing and more effective aircraft deployment from the 'Ultra’ work, introduction of radars and high frequency direction finding (HF/DF), the availability of more escorts, and continuous escort. Losses due to German aircraft were also well down as many were transferred to the Russian front. 

Monthly Loss Summary
23 British, Allied and neutral ships of 98,000 tons in the Atlantic from all causes

AUGUST 1941

US Navy Close to War - Winston Churchill crossed the Atlantic in battleship "Prince of Wales" to meet President Roosevelt off Argentia, Newfoundland between the 9th and 12th. Together they drafted the Atlantic Charter setting out their aims for war and peace. Discussion also took place on US Navy involvement in the Battle of the Atlantic, which would initially revolve around the supply of US forces in Iceland.

Monthly Loss Summary
- 25 British, Allied and neutral ships of 84,000 tons in the Atlantic from all causes, 3 escorts
- 3 German and 1 Italian U-boats

SEPTEMBER 1941

Battle of the Atlantic - Escort carrier "Audacity" sailed with UK/Gibraltar convoy OG74. Her American-built Martlet fighters shot down the first Kondor to fall victim to an escort carrier, but U-boats still managed to sink five merchantmen. The US Navy started to escort HX and ON convoys between Newfoundland and Mid Ocean Meeting Point (MOMP), south of Iceland, where the Royal Navy took over. Five US destroyers began on the 17th with HX150 (50 ships). Earlier on the 4th, the first incident occurred when US destroyer "Greer" on passage to Iceland was in action with "U-652". There was no damage or loss to either ship. The increased number of U-boats available to Adm Doenitz (approaching 200 with 30 operational) allowed him to establish patrol lines in the Atlantic. It was into these that the two SC convoys 42 and 44 (above), had stumbled with such heavy losses. Convoys SL87 and HG73 also lost badly and the four convoys between them saw a total of 36 merchant ships went down.

Monthly Loss Summary
- 53 British, Allied and neutral ships of 200,000 tons in the Atlantic from all causes, and 1 escort
- 2 German and 2 Italian U-boats

OCTOBER 1941

Battle of the Atlantic - By now the pattern of escort in the North Atlantic with the rapidly growing Royal Canadian Navy and involvement of the US Navy was becoming established. With UK-bound convoys, for example, the RCN provided escort from Halifax to the Western Ocean Meeting Point (WOMP) south of Newfoundland. From there, as far as the Mid Ocean Meeting Point (MOMP) at 22'W, the USN escorted HX, and joint RN/RCN groups the slower SC convoys. RN ships based in Iceland then took over until the convoys were met by Western Approaches escorts operating out of Londonderry, Northern Ireland and the Clyde, Scotland. US Navy and Army Air Force aircraft were now adding to the efforts of the RAF and RCAF by flying escort and patrols from Newfoundland and Iceland. The mid-Atlantic air-gap was narrowing.  

Monthly Loss Summary
- 33 British, Allied and neutral ships of 160,000 tons in the Atlantic from all causes, and 5 escorts including USS Reuben James.
- 2 German and 1 Italian U-boats

NOVEMBER 1941

Battle of the Atlantic - There was a considerable drop in U-boat sinkings in the North Atlantic in the last two months of the year; again the reasons were varied - the increasing number of escorts, the help given by the US Navy, and the increasing effectiveness of land-based aircraft. Escort carrier "Audacity" was also proving her worth. The Allies were also helped by Hitler's orders to Adm Doenitz to transfer large numbers of U-boats to the Mediterranean. These were needed to shore up the Italians and help secure the supply lines to the Axis armies in North Africa. This movement led to a concentration of U-boats off Gibraltar, and to the need to strengthen the HG/SL convoy escorts. After the attacks on HG75 in October, the next HG did not sail until December when "Audacity" was available to close the Britain/Gibraltar air gap.

Monthly Loss Summary
- 11 British, Allied and neutral ships of 55,000 tons in the Atlantic from all causes, 1 cruiser
- 1 German raider, 1 German U-boat and 1 Italian (cause unknown)

DECEMBER 1941

Battle of the Atlantic - The sinking of five U-boats in exchange for two merchant ships in the Battle for Convoy HG76 which for the first time closed the Gibraltar/UK Air-Gap, was a significant victory for the escorts. It proved beyond any doubt the value of escort carrier aircraft against the submarine - as well as the patrolling Focke Wulf Kondors, two of which were shot down.

Monthly Loss Summary
- 11 British, Allied and neutral ships of 57,000 tons in the Atlantic from all causes, 1 escort carrier and 2 escorts
- 5 German U-boats plus two transferring to the Mediterranean

DEFENCE OF TRADE - January to December 1941

Total Losses = 1,299 British, Allied and neutral ships of 4,329,000 tons ( 361,000 tons per month)

By Location

By Cause

1942

JANUARY 1942

Battle of the Atlantic - U-boat strength was up to 250 with 90 operational. Two-thirds were spread across the Atlantic, nearly a quarter in the Mediterranean, and a few on patrol in the Arctic for Russian convoys. It was at this time that Adm Doenitz, with never more than 10 or 12 U-boats at a time, launched Operation' Paukenschlag' ('Drumroll') off the coasts of America. The U-boat commanders enjoyed their second 'Happy Time', especially against the unescorted ships sailing in virtually peace-time conditions off the United States. Warship patrols were started, but the USN found it hard to accept the long, hard-fought lessons of the Royal Navy and established convoys immediately. Atlantic convoys still started and ended at Nova Scotia, so the first U-boats operated off the Canadian coast south of there. Over 40 merchantmen were lost in this area alone in January and February. By this time U-boats were also sinking many ships off the US east coast. On the weapons front, the forward-firing Hedgehog with its 24 A/S mortar bombs started to enter RN service. Its first success did not come until late in the 1942. 

Monthly Loss Summary, including Russian Convoys
- 48 British, Allied and neutral ships of 277,000 tons in the Atlantic from all causes, 3 escorts
- 1 German U-boat.

FEBRUARY 1942

Battle of the Atlantic - U-boats extended Operation 'Paukenschlag' as far south as the Caribbean and started by shelling installations and sinking tankers off Aruba, Curacoa, Trinidad and other oil ports. However, they were still active elsewhere in the Atlantic, and east of Newfoundland a pack of five attacked convoy ON67 (36 ships). Eight ships were lost, of which six were the ever-valuable tankers. The Royal Navy suffered a major setback when U-boats in the Atlantic changed from the Enigma 'Hydra' code to 'Triton'. This would not be broken until December 1942 - a ten month delay. But all was not lost as 'Hydra' was still used in European waters. This, together with signals traffic analysis and the vast amount of experience built up to date, meant that remarkably accurate pictures could be drawn of U-boat operations and intentions.

Monthly Loss Summary
- 73 British, Allied and neutral ships of 430,000 tons in the Atlantic from all causes, 2 corvettes and 2 US destroyers off Newfoundland and the US east coast
- 2 German U-boats

MARCH 1942

Battle of the Atlantic - Losses continued at a high rate in US and West Indian waters with over 40 ships sunk in March, many of them valuable tankers. Over the next few months RN and RCN escorts and a RAF Coastal Command squadron were lent to the Americans. Ten corvettes were also transferred to the US Navy.

Monthly Loss Summary, including Russian Convoys
- 98 British, Allied and neutral ships of 547,000 tons in the Atlantic from all causes
- 1 German destroyer and 5 U-boats, including 2 by US aircraft off Newfoundland

APRIL 1942

Monthly Loss Summary, including Russian Convoys
- 74 British, Allied and neutral ships of 439,000 tons in the Atlantic from all causes, 1 US destroyer mined off Florida
- 2 German U-boats

MAY 1942

Mexico - On the 22nd, Mexico joined most of the Central American and Caribbean republics by declaring war on the Axis powers.

Battle of the Atlantic - U-boat strength approached 300 with over 100 operational. A fairly complete convoy system was being introduced off the US east coast from Florida north, but the submarines were now concentrating in the Caribbean and Gulf of Mexico. They could now spend more time on station assisted by 'Milchcow' supply boats. The result was that Allied losses continued at a high rate, especially among tankers. In the North Atlantic, convoy ONS92 lost seven ships in one night to a pack attack.

Monthly Loss Summary, including Russian Convoys
- 122 British, Allied and neutral ships of 585,000 tons in the Atlantic from all causes, 2 cruisers, 1 destroyer and 1 submarine
- 1 German destroyer, 1 U-boat by US Coast Guard off east coast of America

JUNE 1942

Battle of the Atlantic - In the first six months of 1942, submarines worldwide sank 585 ships of over 3,000,000 tons, mostly in the Atlantic - and a large proportion of these in American waters where losses remained high in the Caribbean and Gulf of Mexico. At the same time the 108 new U-boats entering service far outweighed the 13 sunk in the Atlantic in this period.

Monthly Loss Summary
- 128 British, Allied and neutral ships of 650,000 tons in the Atlantic from all causes, 1 destroyer and 1 submarine
- 2 U-boats by US forces off Cuba and Bermuda

JULY 1942

Battle of the Atlantic - Pending the setting up of support Escort Groups later in the year, vessels allocated mainly to convoy protection were designated by their nationality - "A" for American, "B" for British, "C" for Canadian. The American convoy system was now being extended into the Caribbean and Gulf of Mexico, and merchantmen sinkings went down as U-boat losses started to mount. Nevertheless, with 140 operational U-boats out of a total of 330, the Germans had more than enough to continue the offensive in the North Atlantic as well as maintain concentrations off Sierra Leone, Venezuela and Brazil. For some months to come it was again the tankers that lost heavily, off the coasts of Venezuela and Trinidad. On the 1st of the month, the Change of Operational Control (CHOP) line was introduced for Atlantic convoys. Shipping to the east of 26'W (approximately south of Iceland) was controlled by the British Admiralty and to the west by the US Navy from Washington. In November 1942 it was moved to 47'W (approximately south of Greenland). 

Monthly Loss Summary, including Russian Convoys
- 101 British, Allied and neutral ships of 511,000 tons in the Atlantic from all causes
- 11 German and 1 Italian U-boats, including 2 by RAF Bay of Biscay patrols; 1 by RCAF off Nova Scotia; and 3 by US forces in the Caribbean and off the east coast of America

AUGUST 1942

Battle of the Atlantic - For some time now aircraft of RAF Coastal Command had used the Leigh light searchlight in conjunction with ASV radar to illuminate and attack U-boats at night on the surface. The Germans now introduced the Metox detector which enabled U-boats to pick up the 1.5m wavelength transmissions of the existing ASV sets in time for them to submerge. They thus moved one step ahead of the Allies in the scientific war. The RAF's important Bay of Biscay patrols lost effectiveness accordingly.

Monthly Loss Summary
- 106 British, Allied and neutral ships of 544,000 tons in the Atlantic from all causes, 1 US destroyer by collision off Nova Scotia
- 9 U-boats including 1 by RAF Bay of Biscay patrols; 3 by US aircraft in Gulf of Mexico, Caribbean and off Iceland; 1 Italian by unknown causes, possibly by RAF Bay of Biscay patrols.

SEPTEMBER 1942

Battle of the Atlantic - U-boats continued to operate off Sierra Leone, West Africa and the northern coast of South America where Allied losses remained high. Off Trinidad alone 29 ships of 143,000 tons went down in September. However, the interlocking convoy system was well on the way to being established off the Americas, and was increasing in effectiveness. In September the western termini for Atlantic convoys were moved from the Canadian ports of Halifax, Nova Scotia and Sydney, Cape Breton down to New York. In time, pressure on the port became so great some convoy started to move back to Halifax in March 1943. A long felt need started to be met when Adm Noble formed the first convoy support groups. These highly trained flotillas were used to reinforce the escorts of convoys under heavy attack, and although called Escort Groups should not be confused with the groups of 1941, often temporary in nature and with a diversity of ship types. Some of the new Escort Groups were formed around the escort carriers now entering service - the first since "Audacity" lost in December 1941. Unfortunately none of them were available to fight the Battle of the Atlantic for another six months: they were needed for the invasion of French North Africa.

Monthly Loss Summary, including Russian Convoys
- 102 British, Allied and neutral ships of 531,000 tons in the Atlantic from all causes, 5 escorts
- 1 German raider and 9 U-boats including 3 by US and RAF aircraft in the North Atlantic; 1 by RAF Bay of Biscay patrols; 1 on an RAF-laid mine in the Bay of Biscay

OCTOBER 1942

Battle of the Atlantic - Losses continued high in the North Atlantic, many in the air-gaps on the transatlantic routes which aircraft could not reach from Newfoundland, Iceland, Northern Ireland. Also on the routes to and from Sierra Leone, which were remote from Gibraltar or Freetown. For example, Atlantic convoys HX212 and SC107 lost six and fifteen ships respectively, and Sierra Leone convoy SL125 around thirteen. Apart from escort carriers, more very long range (VLR) aircraft were needed by RAF Coastal Command. Only No 120 squadron was equipped with the VLR B-24 Liberators. In October there were nearly 200 operational U-boats out of a total of 365. German losses were increasing as the effectiveness of Allied air and sea escorts and patrols improved, but nowhere near enough to offset new construction.

Monthly Loss Summary
- 82 British, Allied and neutral ships of 548,000 tons in the Atlantic from all causes, 1 cruiser
- 15 U-boats including 6 by RAF in North Atlantic; 1 by RAF Bay of Biscay patrols; 1 by RAF-laid mine in the Bay of Biscay; 2 by RCAF off Newfoundland; 1 by US aircraft off French Guiana; 1 by unknown causes, possibly by US aircraft

NOVEMBER 1942

Allied Convoy Routes - New fast (F) and slow (S) convoys started in October and November between the UK and North African ports: UK out: KMF and KMS; Home to UK: MKF and MKS. From April 1943 these convoys sailed to and from the Gibraltar area mainly with OS and SL-convoyed ships.

Battle of the Atlantic - World-wide losses in tonnage due to Axis submarines were the highest of any month of the war - 119 ships of 729,000 tons, mostly in the Atlantic. By year's end, submarines in 1942 had accounted for 1,160 ships of 6,266,000 tons or a monthly average of 522,000 tons. Losses in the North and South Atlantic made up most of this total. To deal with this grave threat, a Cabinet Anti-U-boat Warfare Committee (not the 1941 Battle of the Atlantic Committee) was formed under the chairmanship of Prime Minister Winston Churchill. It saw the first need as closing the mid-Atlantic gap once and for all. Steps were taken to further expand Coastal Command and speed up the introduction of VLR aircraft. Adm Sir Max Horton, commander of home-based submarines since 1940 and a World War 1 submariner himself, succeeded Adm Noble as C-in-C, Western Approaches.

Monthly Loss Summary
- British, Allied and neutral ships of 567,000 tons in the Atlantic from all causes, 1 escort carrier, 1 destroyer and 1 corvette
- 7 U-boats including one by US aircraft off Iceland, and one possibly by the RAF in the North Atlantic

DECEMBER 1942

Battle of the Atlantic - Total U-boat strength at year's end approached 400 compared to 250 in January, and this in spite of 86 submarines being lost in 1942. Of the total, over 200 were operational. Many were on passage but the numbers on patrol were still great and increasing. Most were in the North Atlantic or west of Gibraltar although groups operated off West Africa and South America with some success. The Allies could deploy 450 escort vessels of all types against the U-boats: this was a large number but still not enough to curb the menace and go over to the offensive. In December the Royal Navy and its Allies regained an old advantage when after a 10-month gap, the U-boat 'Triton' code for Atlantic operations was broken.

Monthly Loss Summary, including Russian Convoys
- 54 British, Allied and neutral ships of 305,000 tons in the Atlantic from all causes, 3 escorts
- 1 German destroyer and 5 U-boats including 1 each by US and indirectly by RAF aircraft in attacks on HX217; 1 by US Coast Guard in mid-Atlantic