Winning WW2's Most Important Battle - Battle of the Atlantic Full Documentary

0:00The Second World War featured many important land battles on a colossal scale. They involved

0:05hundreds of thousands of participants, ranged across hundreds of miles and

0:09inflicted the most terrible destruction. But none of them were as long-running,

0:13as vast or as crucial to allied victory as that fought at sea in the Atlantic,

0:18where for four years Allied navies and civilian sailors fought a life or death

0:23struggle against Germany’s U-boats. This is the story of how it was fought, and how it was won.

0:45The Second World War was only hours old when the U-Boat menace began to show itself. On the

0:51evening of September 3rd 1939 the passenger liner SS Athenia was mistaken for a warship,

0:57torpedoed and sunk by U-30 with the loss of 118 passengers and crew. This was followed

1:04swiftly by the losses of the aircraft carrier HMS Courageous on September 17th

1:09and battleship Royal Oak in an audacious raid on Scapa flow a few weeks later.

1:14But the real danger to Britain was not the losses of these large capital ships,

1:18but the sinkings of increasing amounts of civilian merchant ships- more than 200 of them by the end

1:23of 1939. For Germany, the logic behind these attacks was brutally simple – sink the merchant

1:30ships and you deprive Britain of the essential food and war materiel they carried. And if you

1:36sink the merchant ships faster than the Allies could replace them, eventually Britain would run

1:41out of ships, severing the link to the US and its colonies completely and crippling its war effort.

1:48Keen to bring this about, Germany attacked merchant shipping with a variety of different

1:52weapons, including aircraft, mines, disguised merchant raiders and at various times the major

1:59surface ships of the kriegsmarine itself, with mixed results. But overwhelmingly, the principal

2:07weapon in the war against Allied shipping was the submarine, which ultimately accounted for 68% of

2:13Allied shipping sunk during the war. cxxc In the early months of the war the U-Boat

2:17force under the leadership of Karl Donitz, found itself tasked to support the invasion of Norway,

2:23but after that campaign concluded Donitz’s boats were released into the Atlantic. Their

2:27crews were delighted to find large amounts of Allied shipping sailing independently as

2:33Britain struggled to find enough convoy escorts to protect them all. It did not take long for

2:39losses began to mount. 130 ships- more than half a million tons of shipping – was sunk in

2:45the Atlantic and waters around Britain in June, as the U-boat offensive added to damage done to

2:49British coastal traffic by mines and aircraft As summer turned to autumn, the U Boats grew

2:55bolder, for the first time beginning to co-ordinate their assaults, forming up

2:59as wolfpacks to attack Allied convoys in night-time surface attacks. One of the

3:04first major targets was the slow west-bound convoy SC7, which was mauled by a pack of U-boats led by

3:10Otto Kretschmer’s U-99 over three days in October 1940, losing 20 of its 35 merchant ships. Shortly

3:19afterwards, the fast convoy HX79 was similarly attacked, losing 12 out of 50 ships. These were

3:26terrible disasters for the Allies, exposing poorly co-ordinated escort ships- of which

3:31there weren’t enough-, an over-reliance on ASDIC sonar that could not detect a surfaced submarine,

3:36and merchant ships that were too slow. By the end of the year, 3.6 million tons

3:42of allied shipping had been sunk in the North Atlantic and the waters around Britain. This

3:47outstripped British merchant ship production by almost three million tons for the year,

3:52even before adding losses suffered elsewhere. It had been a brutal few months, and there was no

3:59let up in the new year, with a new monthly record of 517,000 tons of shipping lost in March 1941.

4:08Firmly on the back foot, the British scrambled to respond. New merchant shipping was ordered from

4:14the US and as an escort stop gap 50 old American vessels were procured in the ‘destroyers for

4:19bases’ agreement in September 1940. In British shipyards, dozens of flower class corvettes were

4:26under construction and would join the fe w that were already in service, but these would take time

4:31to build, and in the mean time prodigious numbers of merchant ships continued to be

4:36sunk- with monthly losses still above 400,000 tons a month by June. The situation was dire.

4:44But for the second half of 1941, the Allies had two breakthroughs which eased the pressure. The

4:50first was the cracking of the German Naval Enigma code for the first time in early 1941

4:55by a team led by Alan Turing at Bletchley Park. This allowed the Allies to anticipate

5:00U-boat positions, and route convoys around them for large parts of the rest of the war.

5:06The second major breakthrough for the Allies was the growing influence of the

5:09United States on the Atlantic, even as they remained formally at peace with the Axis.

5:15After winning re-election in November 1940, President Roosevelt implemented the Lend Lease

5:20Act to make it easier for the British to obtain US supplies and approved the construction of a

5:25vast new class of merchantmen that would come to be known as the ‘Liberty ship’.

5:30In April, the President went a step further and authorized the US Navy to play a more active role

5:35in protecting American trade to Britain, extending a ‘security zone’ to 26 degrees west and occupying

5:42Iceland. As German U-boats were then operating as far west as 38 degrees, this brought American

5:49ships into potential conflict. After the sinking of a US merchant vessel by a U-boat in May,

5:56and an attack on the destroyer Greer in September, President Roosevelt issued a

6:01‘shoot on sight’ order and the US Navy began to directly escort Allied convoys through the

6:06western half of the Atlantic. This stretched the notion of ‘neutrality’ to breaking point, and it

6:12did not take long for American ships to get caught up in the fighting. On October 17th the destroyer

6:18Kearny was damaged during a battle with a U boat, before two weeks later while escorting convoy

6:23HX156 near Iceland, the USS Reuben James was torpedoed and sunk with the loss of 100 sailors.

6:32Despite this loss, the effect of the US’s assertive protection of its trade, combined

6:37with gradually stronger British resources, was to make life much tougher for the U-boats,

6:42who found fewer lone merchant ships and struggled to continue their success in

6:46early 1941 for the rest of the year. Shipping losses in the Atlantic dropped dramatically,

6:52down to just 85,000 tons in November- at a time when the number of operational U-boats

6:57had almost quadrupled, from 22 in January to 80 by December. This was an important Allied success,

7:05preventing a costly six months from becoming a devastating year, but it still left Britain

7:11with a lot less shipping than before. Total tonnage lost during 1941 in the Atlantic was

7:16almost 3.3 million tons – again comfortably outstripping British production even before

7:23factoring in losses in other theatres. And it was about to get much worse.

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8:53On December 10th 1941, Germany declared war on the United States in the aftermath of the

8:59Pearl Harbour attack. For Admiral Donitz’s U-boat campaign, this was fantastic news- now

9:05his boats were free to range across the Atlantic supported by new Type 14 fuel tanker submarines

9:11to attack the vast amounts of American shipping sailing up and down its eastern seaboard and in

9:16the Caribbean. And unlike the increasingly difficult to attack allied convoys in the

9:21mid-atlantic, almost all of it was unescorted. Within weeks of war being declared, Donitz’s

9:27boats unleashed a devastating wave of sinkings in the western Atlantic. Tonnage lost in January

9:33more than trebled from November, and by the spring more than half a million tons of merchant shipping

9:39was being lost in the Atlantic each month. The US Navy, under its new commander in

9:44chief Ernest King, struggled to get to grips with the problem, being slow to

9:48introduce convoys along their eastern coast and slow to provide adequate escort vessels

9:53and air cover. And so the sinkings continued – peaking at more than 650,000 tons of shipping

9:59losses in June - 7 times more than November 1941. At this point President Roosevelt intervened and

10:07ordered the navy to get its merchant shipping into convoy. After they did, losses dropped sharply.

10:14But after six months of carnage, serious damage to the Allied war effort had been done nonetheless.

10:21For example, of crucial concern to the US was the transport of Bauxite ore from British and Dutch

10:26Guyana, which was used to make the aluminium needed for aircraft production. According to

10:31the historian Phillips Payson O’Brien, General George Marshall, the US army chief of staff,

10:36reported in mid 1942 that 22% of the US’s Bauxite transporting fleet was sunk between January and

10:43June. At around the same time, 1942 estima tes for US aircraft production were revised

10:49downwards from 60,000 to 48,000 aircraft – a drop of 20% percent. O’Brien suggests that the

10:57German Navy could therefore be said to have ‘destroyed’ 12,000 US aircraft, by preventing

11:02them from being built in the first place. When you extrapolate this across all 6.1m tons of

11:09shipping that had been sunk in the Atlantic by the end of 1942, you end up with huge amount of Allied

11:15guns, tanks and aircraft that never make it to the front line in American, British or Soviet hands.

11:23And the impact of the U-Boats was not felt just in the direct losses of materiel through sunken

11:28ships, but also in the colossal response they provoked in the American war economy. Alarmed by

11:34the dangers of losing control of the Atlantic, President Roosevelt intervened to prioritise

11:39aircraft and naval escort forces, ordering in December 1942 that 462 escort vessels were to

11:46be built by the end of 1943. On top of this was the massive ongoing expansion in merchant

11:52ship construction, with nearly a thousand ships scheduled to be added in 1943 alone

11:58as the Liberty ship program came to fruition. The resources for these enormous projects had

12:05to come from somewhere, and they came from other parts of the US’s military buildup. According

12:10to O’Brien, The proportion of war production allocated for the army dropped from 35% in January

12:161942 to 20% by December, with the planned size of the US army’s infantry force in 1943 cut by 40%.

12:26The German offensive in 1942 in the Atlantic had struck a powerful blow against the Allies,

12:32probably the most serious in the west since the fall of France in 1940. They had sunk

12:38huge amounts of war material, and put control of the Atlantic in question. With the ability

12:44of the US to build up strength in Europe, and supply Britain and the soviet union

12:48with crucial war materiel at stake, It was a battle the allies could not afford to lose.

12:54During this time, the bulk of the US Navy’s resources in both aviation and escort vessels

12:59remained in the pacific, and it took until July, after a six-m onth masscacre on the east coast,

13:05for the intervention of President Roosevelt to force Admiral King to divert resources to put

13:11Atlantic traffic in convoy. After this, losses plummeted- 3 ships were sunk in this region in

13:17July, and none thereafter for the rest of 1942. Instead, the U-boats shifted their focus back to

13:24the mid-atlantic, plying their deadly trade again in the gap between air cover from east and west.

13:31But as they did so, the Germans found that the sands were shifting under their

13:35feet as American naval production began vto accelerate. Sliding out of shipyards

13:40with increasing frequency was a superweapon that would power the Allies the victory. I’m talking,

13:45of course, about the Liberty ship. The liberty ship originated as a

13:51British design, brough over to the US in the early months of the war and put into

13:56production after Roosevelts re-election in November 1940 and his transformation

14:00of the US into the arsenal of democracy. In its final design every focus was given

14:06to making the ship as cheap and as quick to construct as possible, to maximise the

14:11number built in the shortest possible time. Large sections would be pre-fabricated and then welded

14:18instead of riveted together, the deck would be steel instead of wood, the anchor chains would

14:22be shortened and only the minimum of heating and lighting installed. The ships would not

14:28be given radio direction finders, fire detectors, emergency generators, gyrocompasses or radios for

14:34their lifeboats. They would be incredibly basic, but able nonetheless to steam at 11 kts carrying

14:40a cargo of 7000 tons. And there would be lots of them. Initially Roosevelt had ordered a 260

14:48ship program, but as America’s own entry into the war loomed closer that target was revised

14:54upwards- eventually eighteen different shipyards would take part in liberty ship construction.

15:00The first completed example- the SS Patrick Henry - was launched on September 27th 1941 on what was

15:07dubbed ‘liberty ship’ day, and production only sped up from there. At the Fairfield shipyard

15:14in Baltimore, the first Liberty ship took 245 days to complete- the 20th, just 120 days and

15:21by the time they completed their 50th ship, production time was down to just 58 day- with

15:27a dozen ships a month being launched. On the west coast things were moving even quicker under the

15:32supervision of Henry Kaiser, an industrialist who was determined to produce the ships faster

15:38and faster. The average production time at Kaiser’s Portland Oregon yard was down to 47

15:44days by its 36th vessel, and in October 1942 the yard turned out the SS Joseph E Teal after just

15:5110 days of construction. Not to be outdone the next month, Kaiser’s yard in Richmond California,

15:57went one better, organising a huge effort to launch the Robert E. Peary just 4 days,

16:0315 hours and 29 seconds after laying her keel. All of this production speed came at a cost

16:09though. The hasty production process, combined with low temperatures and rough seas on typical

16:14convoy routes led to an alarming number of incidents involving the spontaneous cracking

16:19of Liberty ship hulls, beginning in 194 2 and extending all the way to the end of the war.

16:25By late 1944 558 US merchant ships had suffered some form of structural failure – of which 407

16:33were liberty ships. Some of these incidents took place in the relative safety of coastal waters,

16:39but others happened at sea with disastrous consequences. On November 7th 1942 the JLM Curry’s

16:46hull cracked in two while part of convoy RA-53 and it had to be abandoned. Another catastrophic

16:52failure a year later caused fatalities when the John P. Gaines broke in half while travelling

16:57from the Aleutian islands to Seattle, and 11 of her crew were lost. It was a problem all the way

17:04into 1944, taking dozens of liberty ships out of commission at a time. But considering the scale

17:10of production by this stage – it hardly mattered. To put this next bit into context – between the

17:17years of 1922 and 1937 shipyards in the United States completed two new dry cargo ships- in

17:25total, not per year. Well before the second world war began, the US government had begun to increase

17:31this number, beginning a program of 50 new ships a year in 1937 to provide 4 and a half million

17:37tons of new merchant shipping by 1947. But as war in Europe loomed, these plans were soon revised

17:44upwards to 100 ships in 1939 and then 200 ships a year in August 1940. But even at this stage, still

17:5292% of US-flagged merchant ships were more than 20 years old, having been constructed during the

17:58first world war. Then the liberty ship came along. As the 20 new shipyards were steadily completed

18:05and the 160 slipways they contained brought into service, shipbuilding spiked. In September

18:121942, 93 merchant ships were launched across the country, including 67 libertys. This was

18:28more than a million tons of new shipping added in one month – equivalent to approximately Britain’s

18:33entire annual output of merchant shipping in the whole of 1940. For the year as a

18:39whole American shipyards added 8million tons of merchant shipping to the pool- more than

18:45seven times the figure from 1941 and enough to single-handedly cancel out every loss inflicted

18:51by German and Japanese interdiction during 1942. And they weren’t done there. In 1943 the Liberty

18:57ship programme reached its frankly absurd peak – the equivalent of 3 ships a day were launched

19:03for a total of 19.2 million tons of new merchant shipping, the majority of which were liberties.

19:10This was- and I can’t stress this enough- 41 percent of the total merchant ships built by

19:15the US between 1915 and 1945- in a single year. By the end of the war the US had constructed

19:225000 merchant ships, of which 2710 were liberty ships, making it easily the most

19:29ships ever built to a single design. And it wasn’t just in the construction

19:33of civilian merchant shipping where the Allies were making huge strides.

19:38During the six months when German focus was on the American coast, the Royal Navy had quietly

19:42built up its strength. Dozens of flower class corvettes had entered service on top of the 118

19:49commissioned in 1941, and many escorts had been refitted with more advanced radar and weaponry

19:55like the hedgehog anti submarine mortar. In the air it was a similar story: RAF coastal commands

20:01strength rose from 28 aircraft in July 1942 to 118 by the start of 1943, with new very long

20:10range B-24’s being delivered possessing advanced Radar sets and weaponry to find and sink U-boats.

20:18As well as possessing more and better weaponry, the co-ordination between air and sea assets

20:23had improved dramatically by late 1942, and so did the speed of Allied convoys.

20:29Allied convoys by this stage were generally colossal flotillas of more than 60 vessels,

20:34as it was recognised that fewer, larger convoys were easier to escort effectively. Equally if

20:40not more important was Convoy speed. As German U boats could only travel about 8 knots submerged,

20:46the faster a convoy could travel, the less chance that an enemy submarine would be able

20:50to intercept it. Between October 1942 and May 1943, faster convoys suffered 50% less

20:58casualties than their slower counterparts, and as more US-built Liberty ships came into service,

21:03the proportion of traffic that could travel at a faster pace increased.

21:07The result of all of this was that Allied convoys became tougher to catch and tougher to attack,

21:12and the number of ships proceeding independently dwindled. In August 1942 the number of ships sunk

21:22in convoy exceeded that of those sunk unescorted for the first time- simply because there were

21:28so few left sailing independently in the key battleground of the north Atlantic. The

21:32efforts of three Allied navies had squeezed the space for the u boats to operate in and removed

21:37the easy supply of prey- if the U boats wanted to do serious damage to allied trade in 1943,

21:44they would have to do so by attacking these bigger and better escorted convoys head on.

21:50They would do so at least with the largest fleet of U-boats yet. By the start of 1943,

21:57the Kriegsmarine had 212 submarines operational, and in March 1943 made their

22:02first large scale convoy attack of the year. 41 U boats were deployed in three wolfpacks,

22:09to intercept the convoys HX229 and SC 122 as they crossed the mid Atlantic gap,

22:15totalling 110 merchant ships between them. Over three days and nights a titanic battle

22:22took place in which 22 allied merchant ships were sunk for the loss of just one U-boat.

22:28It was a striking success for the U-boats, and raised the terrifying prospect in London that

22:34perhaps the German navy was now strong enough to make convoy ineffective, which if true could

22:39destabilise the entire war effort. But in truth, the fears were overblown. Even after the highest

22:47monthly losses of the entire war, 96% of those that travelled in convoy in the first three months

22:53of 1943 arrived safely at their destination. The size of the U boat force that had been

23:00committed to the battle was also not something the Kriegsmarine could keep up constantly. Large

23:05numbers of boats had to return to port to rest and rearm, and it took until the end of April

23:10for Admiral Donitz to deploy a large force, for a second attempt at severing the Atlantic link, with

23:1650 boats launched against Convoy ONS5. This time though, the U-Boats would not get off so lightly.

23:25ONS5 was repeatedly attacked from April 29th – 6th May, losing 12 of its 43 merchant

23:32ships in the process. But its escorts, under the leadership of 30-year-old Commander Peter Gretton,

23:38struck back hard, sinking seven U-boats and seriously damaging seven others. It was a

23:44masterclass in convoy defence- utilising all of the Allied technological advances in the shape of

23:50direction finding and radar, as well as hundreds of hours spent relentlessly practicing tactics and

23:56co-ordination between escorting ships. -

23:59The reality was, for all the apparent success of March 1943, by that year the Atlantic had become

24:06an incredibly lethal environment for U-boats, who were caught between powerful convoy escorts

24:11and virtually omnipresent Allied air power across almost the entire ocean. By the end of what became

24:17known as ‘Black May’, 43 U boats had been sunk and 73 more damaged. Though they had inflicted

24:25casualties on the Allies, the losses were totally disproportionate. More U boats had been sunk in

24:30one month than in the entirety of 1941, at a rate three times higher than any other month on record.

24:39This is ofte n presented as the ‘turning point’ in the battle of the Atlantic,

24:44but really it was the end of it. Faced with such colossal losses, Donitz had no choice

24:50but to pull his boats back from further direct attacks on Allied convoys after May 1943.But the

24:57brutal reality was that if they couldn’t attack convoys, then the U boat arm no longer had any way

25:02of impacting allied merchant shipping. This was immediately borne out in the statistics. Shipping

25:08losses plummeted to just 30,000 tons in June 1943, and after a brief increase the following month,

25:15never again rose to even early war levels. Indeed the tables were soon turned completely,

25:21with U boats becoming the prey of new Allied ‘hunter-killer’ groups of escort carriers and

25:26destroyers. Harried and hunted by Allied air and sea assets almost from the moment they left port,

25:32Donitz’s boats were unable to meaningfully effect Allied shipping and began to suffer

25:37devastating losses even without large scale battles. In the last two years of fighting

25:42from the start of May 1943, 554 U-boats were sunk. It was a crushing and total allied victory. It was

25:51a victory not won in May 1943 but over the course of four years preceding it, by shipyard workers,

25:58codebreakers, naval planners, scientists and engineers, and the merchant and military

26:03sailors of dozens of nations, including all the major powers. The dramatic events

26:09of ‘Black May’ did not decide the battle of the Atlantic, but revealed who had already won it,

26:14through industrial and technological might. But it was a victory won at huge materiel and

26:21human cost. By the middle of 1944, 20 million tons of Allied shipping had been sunk- 16m of

26:27it in the waters of the Atlantic. More than 46,000 civilian merchant sailors died on

26:33the allied side, at a casualty rate that was much higher than those in the armed navies.

26:39It was even worse on the Axis side. The 762 total U boats lost had taken 28,000 men with

26:45them- a casualty rate of 75%, which was the the highest of any branch of any armed service,

26:53anywhere in the world during world war 2. Victory in the Atlantic in 1943 did not

26:59involve the destruction of a German Army Group as Stalingrad did, or liberate vast swathes of

27:04territory as was happening in North Africa and Italy, but it laid the logistical foundation for

27:10the enormous allied advances yet to come. Control of the Atlantic allowed the unhindered transport

27:15of American troops and materiel for the largest amphibious invasion in history in June 1944,

27:21and it enabled the shipments of huge amounts of Lend Lease support to the Soviet Union.

27:26This included hundreds of thousands of trucks, as well as the high-octane aviation fuel and

27:31aluminium critical for aircraft production- of which the Soviets had little. This support

27:37played a key role in the transformation of the Red Army into an offensive, mobile force

27:42capable of sweeping through Eastern Europe. Allied victory in WW2, when it eventually

27:51came in 1945, was built on a foundation laid in the Atlantic.