We’re back with another video on the longest and most important battle of the Second World War:
the Battle of the Atlantic. In the last episode, we covered the battle from the
declaration of war on September 3rd, 1939, to the official entry of the US in December 1941.
If you haven’t seen that video, we suggest you check it out first.
You’d be forgiven for assuming that, by January of 1942, the Kriegsmarine had lost
the Battle of the Atlantic. Backed up by the Canadians, Free French, Norwegians, and others,
the British seemed to have all they needed to protect their convoys from U-boat attacks.
The entry of the US into the war could only have won them the battle faster, right? *Wrong*.
The US Navy entered the Second World War with Admiral Ernest King at its head.
Some people believed he was a brilliant naval strategist,
and this may be true, but he was also *absolutely contemptible*.
When King wasn’t abusing his subordinates, he was dogging the boys by trying to sleep with
their wives. Worst of all, he hated the British and refused to listen when they gave him advice.
If the US had stayed out of the war, this wouldn’t have been a problem, but they didn’t,
and as U-boats started hunting US ships just off the American coast, the problem only grew. King
was completely unwilling to heed British advice on how to save his ships from German torpedoes.
The Kriegsmarine designated it Operation Drumbeat, but they spoke of it as the “Second Happy Time.”
Operation Drumbeat was a devastating Kriegsmarine success. Against the advice of the British and
Canadians, King had his anti-submarine patrols organised on a tight schedule. No one dared to
question the tough disciplinarian, sticking to the timings like glue. It took the U-boats mere
hours to figure out the patrol schedule, and with that information, they simply avoided the patrols.
Finding targets at night was easy for the U-boats. Without an enforced blackout,
coastal cities shone like beacons, and every time a merchant ship passed between
a U-boat and the bright city lights, it cast a silhouette. All the U-boats had to do was
shoot at the silhouette and watch the fireworks. The British had warned King of this risk,
but he decided not to call for blackouts. City officials were worried that blackouts
would lose them tourist dollars, which was more concerning than destroyed ships and dead sailors.
The Second Happy Time only lasted until June 1942, a period of six months. But over 600 ships
and three million tons of shipping were lost off the American coastline. King eventually utilised
British tactics, but only after trialling them himself and losing thousands of American lives.
The Second Happy Time was the last major Kriegsmarine victory.
Following the US adoption of tried-and-tested British and Canadian tactics,
the Battle of the Atlantic began shifting in favour of the Allies.
In large part, this was due to the up-and-coming RAF Coastal Command.
Always the third wheel to the lavishly supplied Bomber and Fighter Commands, Coastal Command
spent the first half of the war “making do” with ineffective weapons and understrength squadrons.
Coastal Command’s medium-range Avro Ansons and Bristol Blenheims posed a definite
threat to U-boats, but couldn’t make it far offshore. This created the “Mid-Atlantic Gap,”
a huge section of ocean that Allied aircraft couldn’t get to. It was a U-boat playground.
This all changed when large numbers of American-made B-24 “Liberator” planes
began arriving in Britain. When stripped of unnecessary gun turrets and loaded up with
extra fuel, the Liberator had an immense range. Coastal Command had some successes attacking
U-boats in the Bay of Biscay — *finally* convincing the Air Marshals of their worth.
At first, only a few squadrons received Liberators,
but their impact was immediate. The Liberator’s range closed the mid-Atlantic gap for good,
and U-boat losses to aircraft skyrocketed. Thirty U-boats were sunk in 1942,
and over a hundred more were too badly damaged to stay on patrol.
It might surprise you, but one of Coastal Command’s most potent weapons was a huge
spotlight. It was called the “Leigh Light,” and was strapped to the wings of anti-submarine
planes for night-time use. These aircraft had previously been fitted with rudimentary radar,
but U-boats would often disappear from the display when they got too close,
leaving the pilots clueless as to where they’d gone. By turning on the immensely powerful Leigh
Light, the pilots could pick out U-boats on the surface, and line up a bombing run.
You’d think the U-boats would simply dive underwater to avoid the bombs,
but it wasn’t so easy. Before mid-1943, U-boats travelled submerged during the day to avoid being
located, and surfaced at night to replenish air and recharge batteries. Liberators with
Leigh Lights effectively stole the cover of the night from the Kriegsmarine and forced
them to switch their routine around. Surfacing during the day, the U-boats traded knowledge
of their location for a chance to shoot the Liberators down with AA-guns. This rarely worked.
New anti-submarine weapons were also deployed in 1943. One was the Mark 24 “Fido” Mine.
Developed by the US Navy, a Fido was an acoustically-guided *torpedo* that could
“home-in” on a U-boat using the engine noise. Planes dropped Fidoes into the water when a U-boat
was spotted and left it to do the rest. The weapon was very successful, with a kill rate of 18%.
This was almost double the kill rate of a normal bombing run.
It wasn’t just planes that got a new, advanced weapons loadout; ships did too. Many convoy
escorts were equipped with Hedgehogs — a set of 24 forward-firing mortars.
Once an escort ship had located a U-boat, it charged while plotting the U-boat’s position
using sonar. When the distance between the vessels was so close that sonar signal was lost,
the escort fired the Hedgehog — 24 pressure-activated bombs that landed
in a circular shape around the U-boat’s location. These bombs only went off if they hit the U-boat,
meaning they didn’t mess up sonar readings as normal depth charges did.
It was a few months before captains were confident that Hedgehogs worked as well as
their depth charges. But by mid-1943, hundreds of Hedgehogs had been deployed, and experienced
captains were using them to full effect, sinking, on average, one U-boat for every five shots.
This was far better than the hit rate for standard depth charges, which was one in 80.
Development of submarine detection and countermeasure tech had been
producing results since 1940, but by 1943 several factors started coming together.
New technologies had been rolled out across the Allied Atlantic fleets,
shipbuilding was reaching a crescendo, and long-range aircraft now dominated the skies.
Allied technology was developing at a far greater pace than the Kriegsmarine could handle.
Even worse a problem for Germany was the Allied industrial capacity.
Allied factories were manufacturing a huge number of long-range aircraft,
light aircraft carriers, and convoy escorts.
By mid-1943, the Allies had far better technology AND far more ships and planes to use it.
This culminated in “Black May,” which marked the defeat of the Kriegsmarine in the Battle of the
Atlantic. Forty-one U-boats, representing 25% of the total U-boat strength at sea at the time,
were sunk during May 1943. They were destroyed while attacking convoys, by Allied air cover
and well-organised escort ships. Donitz was shocked and ordered the U-boats to withdraw
to deal with the losses. The Kriegsmarine would never enter the Atlantic in high numbers again.
This devastating blow was the result of a “convergence of technologies.” All the Allied
research and development programs seemed to pay off *at the same time* as hundreds of new ships
and thousands of planes were made available. This combination doomed the U-boat fleet.
Donitz was rocked by the defeat, exclaiming: “The enemy holds every trump card, covering all areas
with long-range air patrols and using location methods against which we still have no warning.
The enemy knows all our secrets and we know none of his.”
The Battle of the Atlantic was a tonnage war, a game governed by brutal mathematics.
The Kriegsmarine had to sink Allied ships faster than they could be replaced. By May 1943,
the US was launching three *Liberty*-class cargo ships every day. Combined, Britain and
the US were manufacturing over 300 planes every day, while Canadian shipyards were completing
thousands of repairs. German shipyards were commissioning only 20 new U-boats *per month*.
Even under the best possible conditions, the U-boats just couldn’t sink enough Allied ships.
Neither could they rapidly replace their losses, with German naval
industry being completely outclassed by the combined industrial might of the Allies.
By 1943, the Kriegsmarine had lost the tonnage war, but they stayed in the fight
right up to Germany’s surrender. Even Donitz suspected he had already lost, but he still
sent the Kriegsmarine into the Atlantic, and his sailors battled on, against impossible odds.
It’s estimated that Germany lost 47 warships, 783 submarines, and 30,000 Kriegsmarine sailors
and officers during the Battle of the Atlantic. The Allies lost 175 warships,
3,500 merchant ships, 36,200 military sailors, and over 30,000 civilian mariners in the battle.
At the end of the war, Rear Admiral Leonard Murray,
the Canadian North Atlantic Commander-in-Chief, remarked,
"[T]he Battle of the Atlantic was not won by any Navy or Air Force, it was won by the courage,
fortitude and determination of the British and Allied Merchant Navy."
THAT was the incredible story of the Battle of the Atlantic, the most underrated battle of the
ENTIRE Second World War. But what do YOU think? At what point do YOU think the Kreigsmarine had lost?
Was Donitz right to keep sending U-boats out, even when Germany was being invaded?
Do YOU think that the battle would have turned out differently if Coastal Command
had what it needed right from the start? Let us know in the comments!