WEBVTT

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Right now I want you to just close your eyes

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for a second. Okay. And imagine your surroundings

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just entirely changing. You are sealed inside

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this steel tube. Very small steel tube. Exactly.

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Hundreds of feet below the surface of the freezing,

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violent Atlantic Ocean. No windows at all. None.

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The air you're breathing is thick. It's heavy

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and metallic. Saturated with this inescapable

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smell of raw diesel fumes, unwashed bodies, and

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that sharp acidic tang of battery acid. It's

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a sensory nightmare. Truly. The curved steel

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walls inches from your face are constantly sweating

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with condensation. The space is so incredibly

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cramped that to get any sleep at all, you have

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to share a narrow, still warm bunk with a crewmate

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who just, you know, rolled out of it to take

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a shift. Right, hot bunking. Yeah. And you can

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hear the ocean pressure groaning against the

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hull, literally compressing the metal around

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you. And somewhere out there in the pitch black,

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freezing water hundreds of feet above. Someone

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is actively hunting you. Yes. a surface warship

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is dropping high explosives trying to kill you.

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It's an environment that the human brain is just

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fundamentally not wired to handle. Not for days,

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let alone months at a time. Yeah. And yet tens

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of thousands of people lived, fought, and died

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in exactly those conditions. The story of the

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German U -boat isn't just, you know, a catalog

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of torpedoes and tonnage and diesel engines.

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Right. Bigger than that. Much bigger. It is a

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story of rapid, almost desperate technological

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arms races, massive geopolitical gambles, institutional

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stubbornness, and At its very core, the absolute

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limits of human, physical, and psychological

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endurance. Which is exactly our mission for today's

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Deep Dive. We are taking you on this immersive

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journey into the claustrophobic, terrifying,

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and historically massive world of the undersea

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boat. Literally the undersea boat. The undersea

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boat. And looking at the massive stack of sources

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we have on the table today. We've got declassified

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operational logs, technical blueprints, century

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-old historical records. We're going to trace

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this phenomenal engineering arc. It really is

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an arc from a very clunky start. Yeah. We're

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looking at how a clumsy, highly experimental,

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and frankly dangerous iron tube evolved into

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this stealthy apex predator that nearly brought

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global empires to their knees. Not once, but

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twice in the 20th century. And looking at the

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earliest records here, the very beginning of

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this technology is a lot earlier and significantly

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humbler than you might think. Oh, yeah. We are

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going all the way back to 1850. That's right.

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A full decade before the American Civil War.

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Wow. Long before internal combustion engines

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were even a reality. A Bavarian artillery non

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-commissioned officer named Wilhelm Bauer designed

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this rudimentary three man submersible. The Brandtosher.

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The Brandtosher, which roughly translates to

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fire diver. It was constructed in keel, essentially

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out of sheet iron, and the propulsion system

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was entirely manual. I mean, two men literally

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turning a massive treadmill -like wheel to spin

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a propeller while the third guy steered. I am

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looking at the sketches of the Brandtasher in

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these historical archives, and it looks less

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like a weapon of war and more like a floating

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iron coffin. Which is pretty much what it was.

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Exactly what it became. Because this is 1850.

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The metallurgy, understanding of buoyancy, the

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sealing mechanisms. Our tech just wasn't there

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yet. It wasn't. On February 1st, 1851, during

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a test dive in the Keel Harbor, the hull just

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gave way. It sank right to the bottom. But miraculously,

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the crew survived. Really? How? Bauer and his

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two men waited in the freezing darkness for hours.

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As the water slowly filled the cabin, it equalized

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the air pressure enough so they could eventually

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force the hatch open and swim to the surface.

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That is terrifying. Just sitting in the dark

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waiting for the water to rise. Right. But while

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the men lived, the brandtoucher itself was lost

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to the mud for decades. And that very public

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terrifying failure essentially put a pin in German

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submarine development for half a century. A figure

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year gap. Yeah. The naval establishment looked

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at that sinking and concluded that submarines

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were just a suicidal novelty. There is a massive

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gap in the historical record before we see the

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next major milestone. Right. It isn't until 1903

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that the Friedrich Krupp Germania Werft dockyard,

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again in Kiel, completes the first fully functional

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engine powered German built submarine. They called

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it the 4L. The trout. The trout. It was a tiny

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vessel about 13 meters long, powered by an electric

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motor. And you would logically think that having

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a fully functional submarine in 1903 would cause

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the German military to immediately snatch it

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up. You would think so. But the sources show

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the exact opposite. Kripp literally had to sell

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the 4L to the Russian Imperial Navy because the

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German Navy wanted absolutely nothing to do with

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it. What's fascinating here is how institutional

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stubbornness almost made Germany completely miss

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out on the very weapon that would ultimately

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define their entire naval strategy. Came down

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to one guy, right? Exactly. The reason the German

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Navy rejected the Forell comes down to the singular

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vision of Grand Admiral Alfred von Tirpitz. Tirpitz.

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Tirpitz was the architect of the German Imperial

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Navy, and he had absolutely zero interest in

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submarines. He was utterly obsessed with building

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a massive high -ceased fleet of expensive, heavily

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armored battleships. To rival the British. Precisely,

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to directly challenge the supremacy of the British

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Royal Navy. We really need to put Tirpitz's mindset

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into the context of the era for you listening.

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At the turn of the 20th century, battleships

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were the ultimate status symbol of a global empire.

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They were the nuclear deterrence of their day.

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Right. If you wanted to be taken seriously on

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the world stage, you needed massive floating

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steel castles with huge guns. To Terpitz, and

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really to most of the traditional naval establishment,

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submarines were viewed as dirty, ungentlemanly,

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cowardly weapons. Will naval battles were supposed

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to be fought out in the open? Broadside to broadside,

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where you could look your enemy in the eye. Terpitz

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was looking at the ocean purely through the lens

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of traditional sea power. He couldn't or wouldn't

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see the asymmetric value of a vessel that could

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bypass thick armor by simply hiding beneath the

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waves and striking from below. So what changed

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his mind? It actually took foreign intervention.

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and essentially capitalist peer pressure to force

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his hand. Krupp, acting as a private arms dealer,

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received an order from Russia for three larger,

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much more capable submarines, known as the Karp

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class. And when Tirpitz saw foreign navies actively

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buying German engineering while his own navy

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lagged behind, he reluctantly realized Germany

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needed at least one submarine purely for testing

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and evaluation to understand what they might

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be up against. And that highly reluctant order

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becomes the SMU -1. officially commissioned in

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December 1906. Let's really look at this machine

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because Germany is now the last major Navy on

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earth to adopt submarines. They were way behind

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the curve. The U -1 was a 238 ton vessel. It

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featured a double hull. an inner pressure hole

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to keep the crew alive, and an outer hydrodynamic

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hole to shape the water flow. Its armament was

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incredibly light, just a single 45 centimeter

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torpedo tube in the bow. And when it dove underwater,

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it ran on an electric motor powered by massive

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banks of lead acid batteries, which was standard

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practice. But the real engineering puzzle was

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surface propulsion. You need an engine to run

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on the surface and recharge those batteries.

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Right. And for the U -1, they chose a Kerding

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kerosene engine. The choice of kerosene over

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gasoline is a critical engineering detail. Early

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submarines and other navies often used gasoline

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engines. Which seems insane. It was. Gasoline

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has a horrifyingly low flash point. The fumes

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would accumulate in the enclosed bilge of a submarine,

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and the slightest spark from an electrical switch

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would cause a catastrophic explosion. So kerosene

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was vastly safer to store inside a sealed tube.

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It was, and much more powerful and compact than

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steam power, which required massive boilers.

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Okay, let's unpack this kerosene situation, because

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while it didn't explode, it introduced a fatal

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tactical flaw. Very fatal. A kerosene engine

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does not burn cleanly. The combustion process

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produce a massive, thick, highly visible plume

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of bright white exhaust smoke. Huge problem.

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Reading through the naval testing logs, this

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smoke trail could be seen from miles away on

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a flat ocean horizon. It is essentially the equivalent

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of playing a high stakes game of hide and seek

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in a forest, but you are strapped to a white

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smoke grenade that goes off every time you take

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a breath. That's a perfect analogy. It entirely

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robbed the submarine of its primary tactical

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asset. A submarine on the surface is not a battleship.

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It has no armor. None. It is incredibly slow,

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low to the water, and vulnerable to even light

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deck guns. Its only defest mechanism is stealth,

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the ability to vanish before the enemy can get

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a firing solution. If a British destroyer can

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see your white smoke trail from 10 miles away,

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they know exactly where you are, where you're

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heading, and how fast. You're no longer a hunter.

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Your target practice. So the German engineers

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are looking at this white smoke problem and pulling

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their hair out. They tried to brute force the

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solution in 1908 with the U2 class. Make it bigger.

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Exactly. Make the boat bigger, add four torpedo

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tubes, and stuff more batteries inside so it

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can stay underwater longer and hide the smoke.

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But the kerosene engines are incredibly temperamental,

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constantly breaking down. It isn't until between

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1910 and 1912 that propulsion technology finally

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catches up to the tactical need. The diesel engine.

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Reliable heavy -duty marine diesel engines from

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companies like MAN and Germania Berg finally

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become available. The shift to diesel is the

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breakthrough moment. Because diesel fuel is safe

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to store, incredibly energy dense, and crucially,

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it can be tuned to burn relatively cleanly without

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that massive white smoke plume. It fundamentally

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revolutionized the U -boats viability. The German

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Navy immediately recognized the potential and

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placed orders for 23 diesel -powered U -boats

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across several classes. U -19, U -23, U -27,

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and U -31. These were much larger vessels, around

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650 tons, built specifically to accommodate the

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heavier, more robust diesel engines. And they

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featured larger, more lethal 50 centimeter torpedo

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tubes. So we have this narrative arc from 1850

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to 1914. Germany starts late, fumbles through

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a half century of disinterest, stumbles over

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the kerosene smoke issue. But by the eve of World

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War One, they have quietly accumulated 48 submarines

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across 13 different classes. They finally have

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a functional, stealthy underwater fleet. This

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is still entirely untested in large -scale combat.

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No one really knows how a submarine is going

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to perform in a massive geopolitical conflict.

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Which leads us to the explosive shock of 1914.

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The first global submarine war. The opening months

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of World War I completely shattered the naval

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establishment's illusions about the submarine.

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In September 1914, just weeks into the conflict,

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the German SM U -21 intercepted the British light

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cruiser HMS Pathfinder. And what happened? The

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U -boat fired a single self -propelled torpedo.

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It struck the Pathfinders magazine, causing a

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massive internal explosion, and the cruiser sank

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in minutes. This was a monumental milestone in

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human history. It was the very first time a warship

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had ever been sunk by a submarine using a self

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-propelled torpedo. And if the sinking of the

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Pathfinder wasn't a loud enough wake -up call

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for the traditional battleship admirals, what

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happened a couple of weeks later on September

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22nd absolutely broke traditional naval doctrine

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in half. I'm looking at the action report of

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the SMU -9, commanded by Otto Wedegen. He's patrolling

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the North Sea and spots three British warships

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sailing in a line. And these aren't small patrol

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boats. No, these are armored cruisers. The HMS

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Abaker, Cressy, and Hogue. Massive. Thousands

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of tons of steel bristling with guns, crewed

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by thousands of men. The U -9 lines up a shot

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and fires. The torpedo hits the Abaker. And here

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is where the asymmetric horror of submarine warfare

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reveals itself. The British captains were so

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unaccustomed to the threat of submarines that

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when the Abaker exploded, they assumed it had

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struck a stationary naval mine. So following

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traditional naval rescue protocols, the Cressy

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and the Hogue stopped their engines and moved

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in close to pull survivors out of the water.

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They became sitting ducks. Wettigan, peering

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through his periscope, likely couldn't believe

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his luck. He calmly reloads his tubes, maneuvers

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his tiny 500 ton submarine, and sinks the Hogue.

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And then he reloads again and sinks the Cressy.

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Three massive warships, the pride of the British

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fleet, sent to the bottom of the ocean in a single

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afternoon by one tiny sub. The psychological

00:12:40.269 --> 00:12:43.230
impact of this on the British Royal Navy was

00:12:43.230 --> 00:12:46.210
devastating. They were so utterly spooked by

00:12:46.210 --> 00:12:49.590
the realization that their massive, expensive

00:12:49.590 --> 00:12:51.970
ships could be effortlessly picked off by an

00:12:51.970 --> 00:12:55.250
invisible enemy that they actually ordered the

00:12:55.250 --> 00:12:58.029
matey British grand fleet to retreat from the

00:12:58.029 --> 00:13:01.070
North Sea. They hid in the safer waters of Northern

00:13:01.070 --> 00:13:04.830
Ireland. It completely upended centuries of naval

00:13:04.830 --> 00:13:07.649
doctrine. The battleship was suddenly vulnerable.

00:13:07.899 --> 00:13:10.419
However, while the U -boats were proving devastating

00:13:10.419 --> 00:13:13.379
against warships, their interactions with civilian

00:13:13.379 --> 00:13:16.259
merchant shipping were incredibly bizarre by

00:13:16.259 --> 00:13:18.779
modern standards. Very bizarre. Initially, U

00:13:18.779 --> 00:13:20.659
-boats were ordered to operate under the constraints

00:13:20.659 --> 00:13:23.539
of maritime law known as the prize rules or cruiser

00:13:23.539 --> 00:13:26.480
rules. I was reading the operational logs detailing

00:13:26.480 --> 00:13:28.980
these prize rules, and it genuinely reads like

00:13:28.980 --> 00:13:31.360
high seas chivalry from a pirate novel. It's

00:13:31.360 --> 00:13:33.679
almost comical in the context of an industrialized

00:13:33.679 --> 00:13:36.379
world war. Let's walk through how an attack on

00:13:36.379 --> 00:13:38.240
a cargo ship was actually supposed to happen

00:13:38.240 --> 00:13:40.740
under these rules. Under the prize rules, a U

00:13:40.740 --> 00:13:43.240
-boat captain could not simply stay hidden underwater

00:13:43.240 --> 00:13:45.799
and fire a torpedo into the side of a merchant

00:13:45.799 --> 00:13:48.909
ship. That was considered piracy. Exactly. Instead,

00:13:49.029 --> 00:13:51.769
the U -boat had to surface, exposing itself entirely,

00:13:52.570 --> 00:13:55.289
approach the merchant vessel visibly, and signal

00:13:55.289 --> 00:13:58.210
the ship to stop its engines. And then they would

00:13:58.210 --> 00:14:00.370
physically send a boarding party across the water

00:14:00.370 --> 00:14:03.149
in a small dinghy to inspect the merchant ship's

00:14:03.149 --> 00:14:05.250
cargo ledger. They were looking specifically

00:14:05.250 --> 00:14:09.100
for contraband of war. munitions, weapons, military

00:14:09.100 --> 00:14:11.679
supplies. If the cargo was purely civilian, they

00:14:11.679 --> 00:14:14.179
had to let the ship go. But if they found contraband,

00:14:14.320 --> 00:14:17.200
they had to allow the entire civilian crew enough

00:14:17.200 --> 00:14:20.700
time to safely evacuate into their wooden lifeboats

00:14:20.700 --> 00:14:23.399
and row clear of the vessel. Only after the crew

00:14:23.399 --> 00:14:26.059
was physically safe could the U -boat sink the

00:14:26.059 --> 00:14:29.080
ship. which they usually did by planting explosive

00:14:29.080 --> 00:14:31.659
scuttling charges in the hull or using their

00:14:31.659 --> 00:14:34.419
deck gun to save their precious expensive torpedoes.

00:14:34.460 --> 00:14:36.700
That is very polite destruction. Excuse me, Captain,

00:14:36.700 --> 00:14:39.139
I need to check your cargo manifests. Ah, I see

00:14:39.139 --> 00:14:41.440
you have artillery shells. Please calmly board

00:14:41.440 --> 00:14:43.899
your lifeboat so I can blow up your ship. That's

00:14:43.899 --> 00:14:47.139
literally how it worked. On October 20th, 1914,

00:14:47.379 --> 00:14:50.120
the SMU -17 became the first submarine to sink

00:14:50.120 --> 00:14:53.460
a merchant ship, the SS Glitra, entirely following

00:14:53.460 --> 00:14:56.299
these polite rules. Nobody died. But doing this

00:14:56.299 --> 00:14:59.019
in a fragile submarine is basically suicidal.

00:14:59.320 --> 00:15:01.320
Completely. The British started arming their

00:15:01.320 --> 00:15:03.759
merchant ships with hidden deck guns. Right.

00:15:03.960 --> 00:15:06.500
A U -boat would surface to politely ask for the

00:15:06.500 --> 00:15:09.120
cargo manifest, and the merchant ship would suddenly

00:15:09.120 --> 00:15:11.960
drop a canvas tarp, reveal a four -inch artillery

00:15:11.960 --> 00:15:14.600
piece, and blow the unarmored U -boat out of

00:15:14.600 --> 00:15:16.860
the water. It only took a handful of Singh things

00:15:16.860 --> 00:15:19.159
before the German high command realized the prize

00:15:19.159 --> 00:15:21.659
rules were getting their own men killed. The

00:15:21.659 --> 00:15:24.500
broader strategic picture of the war also forced

00:15:24.500 --> 00:15:27.860
a radical change in doctrine. By early 1915,

00:15:27.980 --> 00:15:30.700
the German hopes for a quick, decisive victory

00:15:30.700 --> 00:15:33.870
in France had completely evaporated. The Western

00:15:33.870 --> 00:15:36.250
Front had devolved into a horrific, stagnant,

00:15:36.409 --> 00:15:39.590
blood -soaked deadlock of trench warfare. Germany

00:15:39.590 --> 00:15:42.009
desperately needed a way to break the stalemate.

00:15:42.330 --> 00:15:44.269
The naval command looked at the British Isles

00:15:44.269 --> 00:15:46.610
and realized a fundamental geographic weakness.

00:15:47.629 --> 00:15:49.789
Britain was an island that relied entirely on

00:15:49.789 --> 00:15:52.049
sea trade to feed its population and supply its

00:15:52.049 --> 00:15:55.330
war machine. If Germany could sever those transatlantic

00:15:55.330 --> 00:15:57.769
supply lines, they could literally starve the

00:15:57.769 --> 00:16:00.309
United Kingdom out of the war. But to achieve

00:16:00.309 --> 00:16:03.149
a blockade of that magnitude, they couldn't afford

00:16:03.149 --> 00:16:05.570
the vulnerabilities or the time -consuming nature

00:16:05.570 --> 00:16:09.330
of the prize rules. So in February 1915, Germany

00:16:09.330 --> 00:16:12.230
drops the hammer. They initiate the first campaign

00:16:12.230 --> 00:16:14.509
of unrestricted submarine warfare. The polite

00:16:14.509 --> 00:16:17.690
rules are thrown out the window. U -boat captains

00:16:17.690 --> 00:16:20.029
are given the green light to sink any merchant

00:16:20.029 --> 00:16:23.090
ship even neutral vessels flying American or

00:16:23.090 --> 00:16:26.149
Dutch flags in the war zone around Britain without

00:16:26.149 --> 00:16:29.090
any warning whatsoever. Spot the silhouette through

00:16:29.090 --> 00:16:31.690
the periscope, calculate the speed, and fire.

00:16:31.889 --> 00:16:33.669
And what's amazing looking at the numbers is

00:16:33.669 --> 00:16:36.610
that Germany only had about 29 U -boats available

00:16:36.610 --> 00:16:38.909
for this campaign. And due to maintenance and

00:16:38.909 --> 00:16:41.269
travel time, usually no more than seven were

00:16:41.269 --> 00:16:42.830
actually patrolling around the British Isles

00:16:42.830 --> 00:16:45.659
at any one time. Yet the impact was globally

00:16:45.659 --> 00:16:48.340
catastrophic, and it led directly to one of the

00:16:48.340 --> 00:16:51.200
most infamous diplomatic crises of the 20th century.

00:16:52.039 --> 00:16:55.960
In May 1915, a U -boat spotted the massive British

00:16:55.960 --> 00:16:59.019
ocean liner, the RMS Lusitania, off the coast

00:16:59.019 --> 00:17:01.879
of Ireland. Operating under unrestricted rules,

00:17:02.220 --> 00:17:05.880
the U -boat fired a single torpedo. The resulting

00:17:05.880 --> 00:17:09.559
explosion, compounded by a second massive internal

00:17:09.559 --> 00:17:12.160
explosion, the cause of which is still debated

00:17:12.160 --> 00:17:15.160
by historians, sank the massive liner in just

00:17:15.160 --> 00:17:18.759
18 minutes. Over a thousand civilians died. including

00:17:18.759 --> 00:17:21.920
128 American citizens. The international backlash

00:17:21.920 --> 00:17:24.880
was instantaneous. The United States was completely

00:17:24.880 --> 00:17:27.859
outraged. President Woodrow Wilson sent furious

00:17:27.859 --> 00:17:30.019
diplomatic cables. The political pressure was

00:17:30.019 --> 00:17:32.339
so intense and the fear of America entering the

00:17:32.339 --> 00:17:34.880
war was so high that the German Kaiser was forced

00:17:34.880 --> 00:17:37.119
to intervene. He ordered a halt to the unrestricted

00:17:37.119 --> 00:17:39.859
campaign, commanding the U -boats to leave passenger

00:17:39.859 --> 00:17:42.339
liners alone and to only attack definitively

00:17:42.339 --> 00:17:44.599
armed merchant ships. They ended up sending a

00:17:44.599 --> 00:17:46.579
large portion of the U -boat fleet down to the

00:17:46.579 --> 00:17:48.609
Mediterranean. where there were fewer American

00:17:48.609 --> 00:17:50.450
ships just to keep them out of trouble. It began

00:17:50.450 --> 00:17:52.970
a prolonged agonizing diplomatic shell game.

00:17:53.390 --> 00:17:56.190
By early 1916, the German military pushed back.

00:17:56.569 --> 00:17:58.769
The land war was bleeding the country dry. They

00:17:58.769 --> 00:18:00.750
convinced the Kaiser to allow the U -boats back

00:18:00.750 --> 00:18:02.990
into the waters around the British Isles under

00:18:02.990 --> 00:18:05.990
a complex set of strict engagement rules designed

00:18:05.990 --> 00:18:08.369
to avoid angering the Americans. But the ocean

00:18:08.369 --> 00:18:12.230
is a chaotic place. In March 1916, a U -boat

00:18:12.230 --> 00:18:15.200
commander mistakenly identified a cross -channel

00:18:15.200 --> 00:18:18.559
passenger ferry, the SS Sussex, as a troop transport

00:18:18.559 --> 00:18:20.720
and torpedoed it. While the ship didn't sink,

00:18:21.059 --> 00:18:23.539
50 people were killed, including several Americans.

00:18:24.000 --> 00:18:26.319
Once again, Washington threatened to completely

00:18:26.319 --> 00:18:29.000
sever diplomatic ties, bringing them to the brink

00:18:29.000 --> 00:18:32.740
of war. Germany capitulated again, fully abandoning

00:18:32.740 --> 00:18:34.839
unrestricted attacks and ordering the U -boats

00:18:34.839 --> 00:18:37.579
to strictly follow the old, dangerous prize rules.

00:18:37.759 --> 00:18:39.940
But the prize rules simply couldn't exert enough

00:18:39.940 --> 00:18:42.670
economic pressure to win the war. By the end

00:18:42.670 --> 00:18:45.750
of 1916, Germany is staring into the abyss. The

00:18:45.750 --> 00:18:48.009
Battle of the Somme and Verdun had resulted in

00:18:48.009 --> 00:18:50.809
millions of casualties. The British naval blockade

00:18:50.809 --> 00:18:52.869
of Germany was causing widespread starvation

00:18:52.869 --> 00:18:55.970
among German civilians. Desperation entirely

00:18:55.970 --> 00:18:58.869
consumed the German High Command. They looked

00:18:58.869 --> 00:19:02.009
at their fleet, now boasting over 120 operational

00:19:02.009 --> 00:19:05.089
U -boats, and they made a cold mathematical and

00:19:05.089 --> 00:19:07.470
massively consequential strategic gamble. The

00:19:07.470 --> 00:19:09.710
German Admiralty presented a memorandum to the

00:19:09.710 --> 00:19:12.849
Kaiser. They openly acknowledged that if they

00:19:12.849 --> 00:19:15.630
restarted unrestricted submarine warfare and

00:19:15.630 --> 00:19:17.789
began sinking neutral American ships without

00:19:17.789 --> 00:19:20.430
warning, the United States would almost certainly

00:19:20.430 --> 00:19:22.920
declare war. They accepted that as a hard fact,

00:19:23.000 --> 00:19:25.160
but they presented a mathematical calculation.

00:19:25.380 --> 00:19:27.700
I am looking at the actual logic of this gamble,

00:19:28.039 --> 00:19:31.099
and it is terrifyingly clinical. Yeah. When we

00:19:31.099 --> 00:19:33.740
talk about shipping losses, the logs constantly

00:19:33.740 --> 00:19:37.559
refer to gross register tons or GRT. For you

00:19:37.559 --> 00:19:39.880
listening, a gross register ton isn't actually

00:19:39.880 --> 00:19:41.880
a measurement of weight. It's a measurement of

00:19:41.880 --> 00:19:44.980
internal volume. One GRT equals 100 cubic feet

00:19:44.980 --> 00:19:47.990
of enclosed space. It represents how much cargo

00:19:47.990 --> 00:19:50.630
a ship can physically hold. Right. So the German

00:19:50.630 --> 00:19:53.109
Admiralty calculated the exact caloric needs

00:19:53.109 --> 00:19:55.609
of the British population and the material needs

00:19:55.609 --> 00:19:57.920
of their military. They promised the Kaiser that

00:19:57.920 --> 00:20:00.220
if they unleashed the U -boats without restrictions,

00:20:00.579 --> 00:20:03.259
they could sink 600 ,000 gross register tons

00:20:03.259 --> 00:20:05.480
of shipping every single month. The logic was

00:20:05.480 --> 00:20:08.119
brutal, but clear. Sink that much shipping and

00:20:08.119 --> 00:20:10.380
the United Kingdom would be starved into complete

00:20:10.380 --> 00:20:12.839
economic and military collapse within six months.

00:20:13.259 --> 00:20:15.920
They bet the entire outcome of World War One

00:20:15.920 --> 00:20:18.700
on the belief that they could knock Britain out

00:20:18.700 --> 00:20:20.799
of the fight before the United States had the

00:20:20.799 --> 00:20:24.849
time to draft, train, equip. and physically transport

00:20:24.849 --> 00:20:27.609
a massive army across the Atlantic Ocean. It

00:20:27.609 --> 00:20:30.049
was a race against the clock. So on February

00:20:30.049 --> 00:20:33.750
1st, 1917, they rolled the dice. The U -boats

00:20:33.750 --> 00:20:36.349
were unleashed with orders to sink everything

00:20:36.349 --> 00:20:39.089
that moved. And Washington reacted exactly as

00:20:39.089 --> 00:20:41.609
Germany predicted. Two days later, the U .S.

00:20:41.750 --> 00:20:44.309
severed diplomatic relations. And on April 6th,

00:20:44.309 --> 00:20:47.269
1917, the United States officially declared war

00:20:47.269 --> 00:20:49.309
on the German Empire. But here's the crazy part

00:20:49.309 --> 00:20:51.009
of the history. For the first few months, the

00:20:51.009 --> 00:20:53.269
German mathematics were actually working. It

00:20:53.269 --> 00:20:56.390
was an absolute slaughter. In April alone, U

00:20:56.390 --> 00:20:59.750
-Boat sank a staggering 860 ,000 tons of shipping.

00:21:00.000 --> 00:21:02.059
they were systematically bleeding the British

00:21:02.059 --> 00:21:04.759
supply lines dry. The British Admiralty was panicking,

00:21:04.839 --> 00:21:06.720
calculating that they only had a few weeks of

00:21:06.720 --> 00:21:09.160
grain reserves left for the entire nation. The

00:21:09.160 --> 00:21:11.099
German gamble was on the verge of succeeding

00:21:11.099 --> 00:21:13.380
until the British finally implemented a fundamental

00:21:13.380 --> 00:21:15.819
shift in naval doctrine that changed maritime

00:21:15.819 --> 00:21:19.819
logistics forever. Prior to this, merchant captains

00:21:19.819 --> 00:21:22.259
argued that sailing in groups was too slow and

00:21:22.259 --> 00:21:25.519
made them an easier target. Ships sailed independently,

00:21:26.039 --> 00:21:27.759
relying on the vastness of the ocean to hide.

00:21:27.930 --> 00:21:30.950
But a lone cargo ship is utterly defenseless

00:21:30.950 --> 00:21:34.390
against a U -boat. Exactly. Let's really look

00:21:34.390 --> 00:21:37.269
at how convoys work. Because it's not just about

00:21:37.269 --> 00:21:39.349
grouping ships together, it's about altering

00:21:39.349 --> 00:21:41.190
the geometry of the ocean. That's a good way

00:21:41.190 --> 00:21:43.390
to put it. If you have 50 ships scattered across

00:21:43.390 --> 00:21:45.589
the Atlantic, a U -boat is almost guaranteed

00:21:45.589 --> 00:21:47.890
to bump into one of them eventually. But if you

00:21:47.890 --> 00:21:50.630
pack all 50 ships tightly together, you leave

00:21:50.630 --> 00:21:53.150
thousands of square miles of the ocean completely

00:21:53.150 --> 00:21:55.569
empty. The U -boat now has to actively search

00:21:55.569 --> 00:21:58.200
for this one specific grouping. And when they

00:21:58.200 --> 00:22:01.480
finally find it, they realize these 50 slow cargo

00:22:01.480 --> 00:22:04.079
ships are surrounded by a screen of heavily armed

00:22:04.079 --> 00:22:06.720
naval destroyers equipped with hydrophones and

00:22:06.720 --> 00:22:09.700
depth charges. To get to the soft, chewy center

00:22:09.700 --> 00:22:12.299
of the convoy, the U -boat has to expose itself

00:22:12.299 --> 00:22:15.740
to lethal anti -submarine forces. The introduction

00:22:15.740 --> 00:22:19.099
of widespread convoys in the summer of 1917 was

00:22:19.099 --> 00:22:21.680
the immediate antidote to the unrestricted campaign.

00:22:22.359 --> 00:22:24.920
Shipping losses plummeted from over 800 ,000

00:22:24.920 --> 00:22:28.279
tons a month down to around 300 ,000 tons. That

00:22:28.279 --> 00:22:30.299
was still a heavy bleed, but it wasn't the fatal

00:22:30.299 --> 00:22:32.630
hemorrhage Germany required. The mathematical

00:22:32.630 --> 00:22:35.730
gamble had failed. Britain survived. The massive

00:22:35.730 --> 00:22:37.970
industrial and manpower might of the United States

00:22:37.970 --> 00:22:40.450
began pouring into France. The German home front

00:22:40.450 --> 00:22:42.549
collapsed under the weight of the British blockade.

00:22:42.589 --> 00:22:45.890
And in October 1918, the U -boat fleet was officially

00:22:45.890 --> 00:22:48.650
recalled to port. The end of the war brings staggering

00:22:48.650 --> 00:22:50.930
statistics. Looking at the final tallies, Germany

00:22:50.930 --> 00:22:54.210
built 373 U -boats over the course of the conflict.

00:22:54.589 --> 00:22:58.069
Of those, 178 were lost to enemy action or maritime

00:22:58.069 --> 00:23:00.900
accidents. The human cross was severe. Over 5

00:23:00.900 --> 00:23:04.339
,000 enlisted sailors and 512 officers died in

00:23:04.339 --> 00:23:07.160
those freezing, claustrophobic iron tubes. But

00:23:07.160 --> 00:23:08.859
the amount of destruction they inflicted on the

00:23:08.859 --> 00:23:11.059
world was unprecedented. Those U -boats sank

00:23:11.059 --> 00:23:14.039
10 pre -dreadnought battleships, 18 cruisers,

00:23:14.079 --> 00:23:17.160
and an absolutely mind blowing 5 ,708 merchant

00:23:17.160 --> 00:23:20.940
and fishing vessels. Over 11 million gross registered

00:23:20.940 --> 00:23:23.240
tons of shipping sent to the bottom of the ocean.

00:23:24.039 --> 00:23:26.500
So what does this all mean for the history of

00:23:26.500 --> 00:23:29.329
warfare? It means that in the span of just four

00:23:29.329 --> 00:23:32.670
years, this highly experimental, initially rejected

00:23:32.670 --> 00:23:35.390
technology proved itself capable of threatening

00:23:35.390 --> 00:23:38.789
the economic survival of global empires. It created

00:23:38.789 --> 00:23:41.450
legends out of ordinary men. Look at a commander

00:23:41.450 --> 00:23:44.609
like Lothar von Arnold de La Perrier. He remains

00:23:44.609 --> 00:23:46.829
the most successful submarine commander in all

00:23:46.829 --> 00:23:50.529
of recorded history. He sank 195 individual ships,

00:23:50.750 --> 00:23:54.430
totaling over 450 ,000 tons. And what's wild

00:23:54.430 --> 00:23:57.349
is that he rarely used his torpedoes. He achieved

00:23:57.349 --> 00:23:59.829
most of his sinkings by surfacing his U -boat

00:23:59.829 --> 00:24:02.849
and precisely targeting ships with his 88 -millimeter

00:24:02.849 --> 00:24:05.569
deck gun, which was vastly cheaper and more efficient.

00:24:05.710 --> 00:24:08.130
We also witnessed the rapid forced evolution

00:24:08.130 --> 00:24:10.869
of naval engineering to meet incredibly specific

00:24:10.869 --> 00:24:13.829
tactical needs. The U -boat stopped being a single

00:24:13.829 --> 00:24:16.150
generalized design. Right, when the German army

00:24:16.150 --> 00:24:18.589
captured the coastal ports of Belgium. The naval

00:24:18.589 --> 00:24:21.809
engineers quickly drafted the UBI class, tiny

00:24:21.809 --> 00:24:25.250
130 -ton coastal submarines specifically designed

00:24:25.250 --> 00:24:27.089
to operate in the shallow, treacherous waters

00:24:27.089 --> 00:24:29.230
of the English Channel. They developed the UC

00:24:29.230 --> 00:24:31.849
class specifically to sneak out at night and

00:24:31.849 --> 00:24:34.890
lay fields of explosive naval mines outside British

00:24:34.890 --> 00:24:37.349
ports. When the unrestricted warfare campaign

00:24:37.349 --> 00:24:40.250
demanded massive numbers of boats, they standardized

00:24:40.250 --> 00:24:43.269
the UC to the design. marrying torpedoes and

00:24:43.269 --> 00:24:45.529
mine laying capabilities into a highly producible

00:24:45.529 --> 00:24:47.769
platform. And for the long -range patrols into

00:24:47.769 --> 00:24:50.589
the deep Atlantic western approaches, they scaled

00:24:50.589 --> 00:24:53.190
everything up to create the massive UB furry

00:24:53.190 --> 00:24:56.230
class. It was an absolute master class in rapid

00:24:56.230 --> 00:24:59.130
military engineering and adaptation under pressure.

00:25:00.009 --> 00:25:03.769
But then November 1918 arrives. The armistice

00:25:03.769 --> 00:25:05.970
is signed. And the terms dictated by the Allies

00:25:05.970 --> 00:25:08.829
regarding the U -boats were absolute and uncompromising.

00:25:09.069 --> 00:25:11.130
Every single surviving German submarine was to

00:25:11.130 --> 00:25:13.329
be immediately surrendered to Allied ports. Most

00:25:13.329 --> 00:25:15.730
were studied and then unceremoniously scrapped.

00:25:15.809 --> 00:25:17.529
And when the Treaty of Versailles finalized in

00:25:17.529 --> 00:25:21.329
1919, the hammer comes down hard. Under the terms

00:25:21.329 --> 00:25:24.130
of the treaty, the nation of Germany is explicitly

00:25:24.130 --> 00:25:26.990
entirely forbidden from designing, building,

00:25:27.150 --> 00:25:29.869
or even owning a single submarine, period. The

00:25:29.869 --> 00:25:32.650
story of the U -boat is legally over. or so the

00:25:32.650 --> 00:25:34.970
Allies believed. But engineering knowledge doesn't

00:25:34.970 --> 00:25:37.569
just evaporate because a treaty is signed. This

00:25:37.569 --> 00:25:40.509
brings us to a fascinating era of espionage,

00:25:40.809 --> 00:25:43.690
loopholes, and covert military preservations

00:25:43.690 --> 00:25:47.769
banning from 1919 to 1939. Because if you are

00:25:47.769 --> 00:25:50.750
a naval architect, how do you keep your nation's

00:25:50.750 --> 00:25:53.269
submarine engineering skills sharp and your blueprints

00:25:53.269 --> 00:25:56.049
updated when your country is legally banned from

00:25:56.049 --> 00:25:57.950
making them? This is where the story turns into

00:25:57.950 --> 00:26:00.829
a geopolitical spy thriller. The answer is, you

00:26:00.829 --> 00:26:03.569
offshore the entire operation. The massive German

00:26:03.569 --> 00:26:05.690
shipbuilding conglomerate, corrupt the same company

00:26:05.690 --> 00:26:08.690
that built the 4L back in 1903, sets up a dummy

00:26:08.690 --> 00:26:10.990
corporation. They establish a front design office

00:26:10.990 --> 00:26:13.509
called the Ingenieurskontor vor Sheepsbouw, or

00:26:13.509 --> 00:26:16.890
the IVS. And crucially, they headquarter this

00:26:16.890 --> 00:26:18.950
front company in The Hague, in the Netherlands.

00:26:19.309 --> 00:26:21.750
The IVS was a brilliant piece of state -sponsored

00:26:21.750 --> 00:26:24.210
evasion. To the outside world, it was simply

00:26:24.210 --> 00:26:27.380
a Dutch marine engineering firm. But behind closed

00:26:27.380 --> 00:26:30.299
doors, it was staffed entirely by veteran German

00:26:30.299 --> 00:26:33.480
U -boat designers. The IVS allowed Germany to

00:26:33.480 --> 00:26:36.059
maintain its commanding lead in submarine technology

00:26:36.059 --> 00:26:39.019
by designing, developing, and secretly overseeing

00:26:39.019 --> 00:26:41.559
the construction of advanced submarines for other

00:26:41.559 --> 00:26:44.140
sovereign nations. I just marvel at the sheer

00:26:44.140 --> 00:26:47.319
audacity of this shell game. They took a national,

00:26:47.579 --> 00:26:50.039
highly classified military program, picked it

00:26:50.039 --> 00:26:52.220
up, and hid it in plain sight in a completely

00:26:52.220 --> 00:26:53.819
different country. Let's look at what they were

00:26:53.819 --> 00:26:57.079
actually building. Between 1927 and 1931, the

00:26:57.079 --> 00:26:59.720
IVS designed the Vetahinen class submarine for

00:26:59.720 --> 00:27:02.440
the Finnish Navy. To the British and French observers,

00:27:02.940 --> 00:27:05.450
Finland was just modernizing its fleet. But looking

00:27:05.450 --> 00:27:07.990
at the classified blueprints, the Vettahinen

00:27:07.990 --> 00:27:11.630
was actually the secret, fully functioning prototype

00:27:11.630 --> 00:27:13.869
for what would eventually become the legendary

00:27:13.869 --> 00:27:16.990
German type SEV U -boat, the backbone of the

00:27:16.990 --> 00:27:19.829
World War II fleet. In 1933, they built a tiny,

00:27:20.069 --> 00:27:22.990
highly maneuverable 250 ton coastal sub for Finland

00:27:22.990 --> 00:27:25.630
called the Vesiko. That was the prototype for

00:27:25.630 --> 00:27:28.349
the German type too. They designed a massive,

00:27:28.710 --> 00:27:32.569
ocean going 750 ton submarine built in a Spanish

00:27:32.569 --> 00:27:35.140
shipyard, which was later sold to Turkey. That

00:27:35.140 --> 00:27:37.500
vessel became the direct prototype for the heavy

00:27:37.500 --> 00:27:39.940
German Type I. And it wasn't just paper designs.

00:27:40.420 --> 00:27:42.420
German engineers and disguised naval officers

00:27:42.420 --> 00:27:44.819
were actually traveling abroad to participate

00:27:44.819 --> 00:27:47.519
in the sea trials of these foreign -built submarines.

00:27:47.900 --> 00:27:50.279
They were gathering hands -on, practical data

00:27:50.279 --> 00:27:53.940
on dive times, maneuverability, and engine reliability.

00:27:54.359 --> 00:27:57.079
If we connect this to the bigger picture, this

00:27:57.079 --> 00:27:58.980
outsourcing of research and development was the

00:27:58.980 --> 00:28:01.740
most critical factor in Germany's eventual naval

00:28:01.740 --> 00:28:04.410
resurgence. It meant that when Adolf Hitler eventually

00:28:04.410 --> 00:28:06.509
tore up the restrictions of the Versailles Treaty,

00:28:06.990 --> 00:28:09.049
the German Navy didn't have to start from scratch.

00:28:09.410 --> 00:28:12.109
They hadn't suffered a 20 -year atrophy of institutional

00:28:12.109 --> 00:28:15.109
knowledge. They had fully tested, debugged, state

00:28:15.109 --> 00:28:17.009
-of -the -art blueprints sitting in a drawer,

00:28:17.289 --> 00:28:19.569
completely ready for mass production. The secret

00:28:19.569 --> 00:28:22.170
did eventually leak out, of course. In the late

00:28:22.170 --> 00:28:24.589
1920s, an investigative journalist uncovered

00:28:24.589 --> 00:28:27.009
the covert funding flowing to these front companies,

00:28:27.569 --> 00:28:29.920
sparking the Lohmann affair. It caused a massive

00:28:29.920 --> 00:28:32.240
political scandal and forced the head of the

00:28:32.240 --> 00:28:35.400
German Navy to resign in disgrace. But he was

00:28:35.400 --> 00:28:39.759
quietly replaced by Admiral Eric Rader, who expertly

00:28:39.759 --> 00:28:42.740
smoothed over the political fallout and just

00:28:42.740 --> 00:28:44.799
kept the secret program running in the shadows.

00:28:45.259 --> 00:28:47.220
The real paradigm shift, however, happened in

00:28:47.220 --> 00:28:50.670
1935. The British government, attempting to appease

00:28:50.670 --> 00:28:52.890
an increasingly aggressive Germany and trying

00:28:52.890 --> 00:28:55.009
to manage treaty breaches they could no longer

00:28:55.009 --> 00:28:58.289
enforce, signed the Anglo -German Naval Agreement.

00:28:58.690 --> 00:29:01.630
Britain formally, legally permitted Germany to

00:29:01.630 --> 00:29:04.130
build a submarine fleet, provided its total tonnage

00:29:04.130 --> 00:29:06.930
didn't exceed 45 % of the British submarine fleet.

00:29:07.109 --> 00:29:09.230
The ink was barely dry on that agreement before

00:29:09.230 --> 00:29:11.970
the newly reformed German Navy, the Kriegsmarine,

00:29:12.069 --> 00:29:13.750
revealed exactly what they had been doing in

00:29:13.750 --> 00:29:16.519
the Netherlands for 15 years. Within a single

00:29:16.519 --> 00:29:19.539
week of the treaty being signed, Germany officially

00:29:19.539 --> 00:29:22.200
commissioned the U -1, a fully realized Type

00:29:22.200 --> 00:29:25.279
2 coastal submarine. Over the next 12 months,

00:29:25.759 --> 00:29:28.220
utilizing the IVS blueprints, they commissioned

00:29:28.220 --> 00:29:31.240
an astonishing 36 U -boats. But as this new fleet

00:29:31.240 --> 00:29:33.880
rapidly takes shape on the slipways, a massive

00:29:33.880 --> 00:29:36.859
fundamental debate erupts inside the German Naval

00:29:36.859 --> 00:29:39.319
High Command. On one side, you have the Old Guard

00:29:39.319 --> 00:29:41.980
fleet commander, Eric Rader. On the other side,

00:29:42.059 --> 00:29:44.519
you have the newly appointed head of the submarine

00:29:44.519 --> 00:29:47.799
section, a veteran World War I U -boat commander

00:29:47.799 --> 00:29:50.920
named Karl Dunitz. Dunitz and Rader had fundamentally

00:29:50.920 --> 00:29:53.940
incompatible visions for how the inevitable next

00:29:53.940 --> 00:29:57.500
war would be fought. Dunitz, looking at the geopolitics,

00:29:57.819 --> 00:29:59.859
firmly believed that war with Great Britain was

00:29:59.859 --> 00:30:02.539
coming, regardless of Hitler's political assurances

00:30:02.539 --> 00:30:05.019
to the contrary. And as a veteran, Dunitz knew

00:30:05.019 --> 00:30:07.039
that fighting Britain meant fighting a relentless

00:30:07.039 --> 00:30:10.059
commerce war against heavily defended supply

00:30:10.059 --> 00:30:13.140
convoys. Therefore, Dunitz passionately argued

00:30:13.140 --> 00:30:15.940
that the Navy should use every single ounce of

00:30:15.940 --> 00:30:18.599
their allotted treaty tonnage to mass produce

00:30:24.160 --> 00:30:27.660
He believed that sheer quantity, utilizing coordinated

00:30:27.660 --> 00:30:30.140
group tactics, was the only way to overwhelm

00:30:30.140 --> 00:30:35.420
the British supply lines. He argues for a mix.

00:30:35.779 --> 00:30:38.140
A bunch of tiny Type IIs for defending the Baltic

00:30:38.140 --> 00:30:41.480
coast, some medium Type Cs for the North Sea,

00:30:41.880 --> 00:30:45.180
and a fleet of these massive, long -range, heavily

00:30:45.180 --> 00:30:49.319
-armed, 750 -ton Type IIs. U -boats to project

00:30:49.319 --> 00:30:51.960
power deep into the Atlantic. But the reality

00:30:51.960 --> 00:30:54.099
of testing these boats quickly revealed some

00:30:54.099 --> 00:30:56.740
glaring engineering flaws. I was reading the

00:30:56.740 --> 00:30:58.819
sea trial reports for the big Type I and the

00:30:58.819 --> 00:31:01.599
early Type VII models and they had a nearly fatal

00:31:01.599 --> 00:31:05.450
design flaw. Terrible maneuverability. The maneuverability

00:31:05.450 --> 00:31:07.769
issue stemmed from the rudder design. Both the

00:31:07.769 --> 00:31:10.750
Type I and the early Type VII featured a single

00:31:10.750 --> 00:31:13.069
centrally mounted rudder located behind twin

00:31:13.069 --> 00:31:15.190
propellers. Because the single rudder wasn't

00:31:15.190 --> 00:31:17.130
positioned directly in the high pressure wash

00:31:17.130 --> 00:31:19.470
of the spinning propeller blades, the water flow

00:31:19.470 --> 00:31:21.849
over the control surface was weak. This meant

00:31:21.849 --> 00:31:24.349
the submarines had an agonizingly wide turning

00:31:24.349 --> 00:31:26.849
radius and were sluggish to respond to the helm,

00:31:27.069 --> 00:31:29.750
particularly at slow underwater speeds when quick

00:31:29.750 --> 00:31:32.240
evasion is a matter of life and death. Furthermore,

00:31:32.539 --> 00:31:36.000
on the Type 7, the single central rudder physically

00:31:36.000 --> 00:31:38.640
blocked the interior stern of the boat. This

00:31:38.640 --> 00:31:41.220
meant the single rear -firing torpedo tube had

00:31:41.220 --> 00:31:43.859
to be mounted externally outside the pressurized

00:31:43.859 --> 00:31:46.400
hull. Which means once you fire that rear torpedo

00:31:46.400 --> 00:31:49.740
in combat, it's gone. You can't reload a tube

00:31:49.740 --> 00:31:51.779
that is bolted to the outside of the hull while

00:31:51.779 --> 00:31:54.420
you are underwater. The engineers quickly realized

00:31:54.420 --> 00:31:57.140
Raider's massive Type I was a lumbering failure,

00:31:57.140 --> 00:31:59.839
and they scrapped the entire class after building

00:31:59.839 --> 00:32:02.559
just two. To replace it, they designed a much

00:32:02.559 --> 00:32:06.099
better heavy submarine, the Type IX. And for

00:32:06.099 --> 00:32:08.500
Dunitz's favorite medium boats, they heavily

00:32:08.500 --> 00:32:11.380
upgraded the design to create the Type VIAB.

00:32:11.680 --> 00:32:14.900
The VIAB featured dual rudders positioned directly

00:32:14.900 --> 00:32:17.359
behind the twin propellers. This instantly solved

00:32:17.359 --> 00:32:19.720
the sluggish steering. More importantly, using

00:32:19.720 --> 00:32:21.599
dual rudders cleared out the central space at

00:32:21.599 --> 00:32:23.779
the stern, allowing the engineers to mount the

00:32:23.779 --> 00:32:26.500
rear torpedo tube inside the pressure hull, meaning

00:32:26.500 --> 00:32:28.460
the crew could now physically reload it during

00:32:28.460 --> 00:32:31.660
a battle. By early 1939, with Hitler pushing

00:32:31.660 --> 00:32:34.480
for expansion, the German Navy formally launched

00:32:34.480 --> 00:32:38.000
Plan Z, an incredibly ambitious long -term naval

00:32:38.000 --> 00:32:40.700
construction program. The dream was to build

00:32:40.700 --> 00:32:44.720
a massive surface fleet supported by 249 modern

00:32:44.720 --> 00:32:47.519
U -boats aiming to directly challenge the Royal

00:32:47.519 --> 00:32:50.900
Navy by the mid -1940s. But geopolitical reality

00:32:50.900 --> 00:32:53.880
moves faster than shipyard construction. When

00:32:53.880 --> 00:32:57.200
Germany invaded Poland in September 1939, triggering

00:32:57.200 --> 00:33:00.359
the outbreak of World War II, Plan Z was immediately

00:33:00.359 --> 00:33:03.500
scrapped. The Grand Fleet didn't exist. Germany

00:33:03.500 --> 00:33:05.839
entered the second global conflict with only

00:33:05.839 --> 00:33:08.220
56 commissioned U -boats. And the numbers get

00:33:08.220 --> 00:33:10.000
even tighter when you look at the operational

00:33:10.000 --> 00:33:13.099
capabilities. Of those 56 boats, more than half

00:33:13.099 --> 00:33:15.579
were the tiny Type 2 coastal subs that didn't

00:33:15.579 --> 00:33:17.599
have the fuel capacity to leave the North Sea.

00:33:17.680 --> 00:33:20.740
Only 22 U -boats actually possessed the operational

00:33:20.740 --> 00:33:23.039
range to navigate around Scotland and reach the

00:33:23.039 --> 00:33:25.839
deep waters of the Atlantic Ocean. It is an incredibly

00:33:25.839 --> 00:33:29.539
small, fragile force assigned an impossibly monumental

00:33:29.539 --> 00:33:32.359
task. But before we dive into the grand strategy,

00:33:32.299 --> 00:33:34.380
and the massive convoy battles of the Atlantic,

00:33:34.839 --> 00:33:37.019
we need to take a massive step back. We need

00:33:37.019 --> 00:33:39.400
to look at the human element. We need to understand

00:33:39.400 --> 00:33:41.819
what it actually meant for a human being to exist

00:33:41.819 --> 00:33:44.720
inside one of those 22 boats. This is a crucial

00:33:44.720 --> 00:33:48.019
pivot. The strategic maps and tonnage statistics

00:33:48.019 --> 00:33:51.000
often obscure the grim reality of the technology.

00:33:51.160 --> 00:33:53.059
Okay, let's unpack this. I want you to really

00:33:53.059 --> 00:33:55.480
visualize this space. We're going to take a walking

00:33:55.480 --> 00:33:58.339
tour. From the very front to the very back of

00:33:58.339 --> 00:34:02.259
a standard German type -ceph U -boat, the workhorse

00:34:02.259 --> 00:34:05.500
of the fleet. You have to imagine a hollow reinforced

00:34:05.500 --> 00:34:09.480
steel pipe roughly 220 feet long, but the actual

00:34:09.480 --> 00:34:12.360
pressurized living space inside is much smaller.

00:34:12.760 --> 00:34:14.480
Packed into this pipe is thousands of pounds

00:34:14.480 --> 00:34:16.940
of complex machinery, high -voltage electrical

00:34:16.940 --> 00:34:20.019
systems, explosive warheads, and between 40 to

00:34:20.019 --> 00:34:22.400
50 unwashed men. Let's start at the absolute

00:34:22.400 --> 00:34:25.429
front, the bow torpedo room. The bow torpedo

00:34:25.429 --> 00:34:27.730
room was arguably the most vital space on the

00:34:27.730 --> 00:34:30.210
boat, housing the four forward -firing torpedo

00:34:30.210 --> 00:34:32.989
tubes. It was also, paradoxically, the primary

00:34:32.989 --> 00:34:35.090
living and sleeping quarters for the lowest -ranking

00:34:35.090 --> 00:34:37.210
sailors and the torpedo mechanics. The space

00:34:37.210 --> 00:34:39.730
utilization was extreme. Below the metal floor

00:34:39.730 --> 00:34:41.849
plates, four heavy spare torpedoes were stored

00:34:41.849 --> 00:34:43.969
in the bilge, but there was no room to store

00:34:43.969 --> 00:34:46.869
the remaining spares below deck. So two additional

00:34:46.869 --> 00:34:49.250
spare torpedoes were suspended by heavy chains

00:34:49.250 --> 00:34:52.010
directly in the middle of the living space, hanging

00:34:52.010 --> 00:34:54.400
right above the floor. Try to picture trying

00:34:54.400 --> 00:34:57.900
to sleep in this room. Bunks are crammed tightly

00:34:57.900 --> 00:35:00.440
against the curving steel hull, weaving between

00:35:00.440 --> 00:35:03.059
valves and grease covered torpedo loading mechanisms.

00:35:03.599 --> 00:35:05.699
And there are nowhere near enough bunks for the

00:35:05.699 --> 00:35:08.480
40 men on board. The U -boat crews operated on

00:35:08.480 --> 00:35:11.500
a strict system of hot -bunking. Three men would

00:35:11.500 --> 00:35:14.550
share two bunks in rotating shifts. The absolute

00:35:14.550 --> 00:35:16.909
moment one exhausted sailor got out of bed to

00:35:16.909 --> 00:35:18.690
go stand his watch in the freezing rain on the

00:35:18.690 --> 00:35:20.889
bridge, you would immediately climb into his

00:35:20.889 --> 00:35:22.949
spot, pulling up sheets that were literally still

00:35:22.949 --> 00:35:25.429
damp and warm from his body heat. And you are

00:35:25.429 --> 00:35:29.190
trying to sleep with a one and a half ton high

00:35:29.190 --> 00:35:32.329
explosive torpedo swaying on chains just inches

00:35:32.329 --> 00:35:34.750
from your head. The only tiny silver lining for

00:35:34.750 --> 00:35:36.789
these guys was that once the boat actually engaged

00:35:36.789 --> 00:35:39.530
in combat, fired a torpedo, and winched a scare

00:35:39.530 --> 00:35:41.809
off the chains and into the tube, the physical

00:35:41.809 --> 00:35:44.349
room opened up slightly, granting them just a

00:35:44.349 --> 00:35:46.630
few more inches of breathing room. Moving aft

00:35:46.630 --> 00:35:49.110
from the torpedo room, you pass through a heavy,

00:35:49.269 --> 00:35:51.909
watertight, circular bulkhead door into the forward

00:35:51.909 --> 00:35:54.869
quarters. This space was slightly more comfortable,

00:35:55.230 --> 00:35:57.750
reserved exclusively for the officers and chief

00:35:57.750 --> 00:36:00.829
petty officers. It was quieter, but the air was

00:36:00.829 --> 00:36:03.780
still dense. Beneath the wooden floorboards of

00:36:03.780 --> 00:36:07.079
this entire section lay the first of two massive

00:36:07.079 --> 00:36:10.539
battery compartments. Dozens of enormous lead

00:36:10.539 --> 00:36:13.280
acid battery cells that powered the boat's electric

00:36:13.280 --> 00:36:15.699
motors while submerged. The captain of the U

00:36:15.699 --> 00:36:17.639
-boat didn't even get a private cabin. He had

00:36:17.639 --> 00:36:20.280
a small, curtained -off bunk right in the passageway.

00:36:20.599 --> 00:36:22.929
However... His bunk was strategically located

00:36:22.929 --> 00:36:25.510
directly across from the two most important intelligence

00:36:25.510 --> 00:36:28.090
gathering compartments on the vessel. The radio

00:36:28.090 --> 00:36:30.289
room, packed with transmission gear and the Enigma

00:36:30.289 --> 00:36:32.550
cipher machine, and the hydrophone listening

00:36:32.550 --> 00:36:35.510
room. Where the sonar operator sat in absolute

00:36:35.510 --> 00:36:38.130
silence, listening for the faint rhythmic thumping

00:36:38.130 --> 00:36:41.650
of distant ship propellers. Continuing aft, you

00:36:41.650 --> 00:36:43.530
step through another heavy bulkhead into the

00:36:43.530 --> 00:36:46.030
absolute nerve center of the U -boat. The control

00:36:46.030 --> 00:36:49.199
room. This space is chaotic. It's the widest

00:36:49.199 --> 00:36:51.320
part of the pressure hull, but it is crammed

00:36:51.320 --> 00:36:54.480
with equipment. Right in the center is the thick

00:36:54.480 --> 00:36:57.260
steel shaft of the main observation periscope.

00:36:57.539 --> 00:37:00.059
The curved walls are completely covered in an

00:37:00.059 --> 00:37:03.639
overwhelming array of large brass valves, massive

00:37:03.639 --> 00:37:06.679
hand wheels, and depth gauges used to control

00:37:06.679 --> 00:37:09.480
the dive planes, the rudder, and the complex

00:37:09.480 --> 00:37:12.019
system of ballast and trim tanks that allow the

00:37:12.019 --> 00:37:15.050
sub to sink and level out. Beneath the floor

00:37:15.050 --> 00:37:17.429
plates here is the storage magazine for the heavy

00:37:17.429 --> 00:37:19.710
artillery shells used by the deck gun outside.

00:37:20.130 --> 00:37:21.750
And if you stand in the center and look straight

00:37:21.750 --> 00:37:24.110
up, you see a vertical cylindrical metal tube

00:37:24.110 --> 00:37:26.429
with a ladder. This leads up into the conning

00:37:26.429 --> 00:37:29.309
tower. The conning tower is a fascinating piece

00:37:29.309 --> 00:37:32.070
of structural engineering. It sits outside the

00:37:32.070 --> 00:37:34.429
main cylindrical body of the submarine, protruding

00:37:34.429 --> 00:37:36.449
upwards to form the base of the bridge structure

00:37:36.449 --> 00:37:38.849
you see on the surface. But it is heavily armored

00:37:38.849 --> 00:37:41.389
and completely sealed inside the boat's pressure

00:37:41.389 --> 00:37:44.840
hull. During a submerged torpedo attack, the

00:37:44.840 --> 00:37:46.860
captain would leave the main control room and

00:37:46.860 --> 00:37:49.719
climb up into this cramped tower. It housed the

00:37:49.719 --> 00:37:52.119
attack periscope, which was thinner than the

00:37:52.119 --> 00:37:54.900
main periscope, to create a much smaller, less

00:37:54.900 --> 00:37:58.400
visible wake of white water on the surface. But

00:37:58.400 --> 00:38:01.789
crucially, The conning tower also housed the

00:38:01.789 --> 00:38:05.010
mechanical analog data solver. Yes, the data

00:38:05.010 --> 00:38:06.929
solver. We have to explain this because it's

00:38:06.929 --> 00:38:09.849
a marvel of 1930s engineering. This isn't a digital

00:38:09.849 --> 00:38:12.230
computer with microchips. It is a dense heavy

00:38:12.230 --> 00:38:15.050
box packed full of intricate interlocking gears,

00:38:15.269 --> 00:38:17.610
cams, and spinning dials. The captain looks through

00:38:17.610 --> 00:38:20.159
the periscope. estimates the enemy ship's speed,

00:38:20.400 --> 00:38:23.019
distance, and angle on the bow, and calls out

00:38:23.019 --> 00:38:25.639
those numbers. The operator physically cranks

00:38:25.639 --> 00:38:28.179
those numbers into the gears. The box instantly

00:38:28.179 --> 00:38:30.659
performs complex trigonometry in real time to

00:38:30.659 --> 00:38:32.659
calculate exactly what angle the torpedo needs

00:38:32.659 --> 00:38:34.739
to steer to intercept the moving target miles

00:38:34.739 --> 00:38:37.420
away, and it automatically transmits that steering

00:38:37.420 --> 00:38:40.079
data via electrical cables directly into the

00:38:40.079 --> 00:38:42.159
gyro compass of the torpedo sitting in the tube.

00:38:42.340 --> 00:38:44.860
It's a mechanical brain doing deadly math. And

00:38:44.860 --> 00:38:46.719
just above the captain's head in the conning

00:38:46.719 --> 00:38:49.699
tower is the main watertight hatch that opens

00:38:49.699 --> 00:38:52.239
out onto the open air bridge, where the lookouts

00:38:52.239 --> 00:38:54.860
would stand tied to the railing in freezing Atlantic

00:38:54.860 --> 00:38:58.039
storms, scanning the horizon for smoke or aircraft.

00:38:58.409 --> 00:39:00.409
Moving back down the ladder into the control

00:39:00.409 --> 00:39:02.789
room and continuing aft, you enter the aft crew

00:39:02.789 --> 00:39:05.489
quarters. This small space is where the petty

00:39:05.489 --> 00:39:08.170
officers slept alongside the boat's diesel mechanics.

00:39:08.489 --> 00:39:10.389
It is also where you find the single solitary

00:39:10.389 --> 00:39:12.769
toilet facility designed to service the entire

00:39:12.769 --> 00:39:15.929
50 -man crew for a patrol lasting up to two months.

00:39:16.429 --> 00:39:19.750
Beside it is a tiny claustrophobic galley, essentially

00:39:19.750 --> 00:39:22.389
two electric hot plates and a small sink where

00:39:22.389 --> 00:39:24.809
the boats cook miraculously prepared three meals

00:39:24.809 --> 00:39:27.860
a day. Below the floorboards here is the second

00:39:27.860 --> 00:39:30.639
massive bank of lead acid batteries. And finally,

00:39:30.719 --> 00:39:32.840
at the very back of the living space, you open

00:39:32.840 --> 00:39:34.840
a heavy door and enter a completely different

00:39:34.840 --> 00:39:37.679
world, the engine room. This space is dominated

00:39:37.679 --> 00:39:40.719
by two massive, hulking marine diesel engines

00:39:40.719 --> 00:39:42.940
used for high -speed surface running and charging

00:39:42.940 --> 00:39:44.980
the batteries. When these engines were running,

00:39:45.280 --> 00:39:47.840
the noise was absolutely physically deafening.

00:39:48.000 --> 00:39:50.659
You couldn't speak. Communication was strictly

00:39:50.659 --> 00:39:53.219
through shouting directly into someone's ear

00:39:53.219 --> 00:39:56.920
or using hand signals. The engines consumed colossal,

00:39:57.059 --> 00:39:59.440
staggering amounts of oxygen to run, which had

00:39:59.440 --> 00:40:01.860
to be constantly piped in through an open hatch

00:40:01.860 --> 00:40:04.400
from the bridge above. And regarding the exhaust,

00:40:04.639 --> 00:40:07.340
A submarine needs the ability to crash dive in

00:40:07.340 --> 00:40:09.260
less than 30 seconds if an airplane appears.

00:40:10.099 --> 00:40:12.239
They couldn't have a traditional tall exhaust

00:40:12.239 --> 00:40:15.199
pipe sticking up into the sky. Instead, the scorching

00:40:15.199 --> 00:40:17.719
hot diesel exhaust was routed down and mixed

00:40:17.719 --> 00:40:20.360
directly into the turbulent seawater as it exited

00:40:20.360 --> 00:40:23.840
the hull. This instantly cooled the gas and defused

00:40:23.840 --> 00:40:26.219
the smoke, significantly reducing the boat's

00:40:26.219 --> 00:40:28.860
visual signature on the surface. Behind the deafening

00:40:28.860 --> 00:40:31.780
diesels lies the final compartment, the electrical

00:40:31.780 --> 00:40:34.590
room. This space housed the massive electric

00:40:34.590 --> 00:40:37.150
motors. When the submarine dove beneath the waves,

00:40:37.349 --> 00:40:39.690
the diesels were shut off and the crew engaged

00:40:39.690 --> 00:40:41.949
clutches to connect the propeller shafts to these

00:40:41.949 --> 00:40:44.570
electric motors. They drew power from the battery

00:40:44.570 --> 00:40:46.889
banks, allowing the U -boat to glide through

00:40:46.889 --> 00:40:49.650
the water in near absolute silence. Alternatively,

00:40:50.170 --> 00:40:52.070
when the boat was on the surface running the

00:40:52.070 --> 00:40:55.070
loud diesel engines, these electric motors were

00:40:55.070 --> 00:40:58.010
spun in reverse, acting as giant electrical generators

00:40:58.010 --> 00:41:01.210
to pump juice. back into the exhausted batteries

00:41:01.210 --> 00:41:03.730
hidden under the floorboards. On the larger Type

00:41:03.730 --> 00:41:06.250
9X boats, you would pass through one more door

00:41:06.250 --> 00:41:09.550
into a dedicated aft torpedo room. But on the

00:41:09.550 --> 00:41:12.349
standard Type 7, the single rear torpedo tube

00:41:12.349 --> 00:41:14.909
was simply crammed right into the chaotic space

00:41:14.909 --> 00:41:16.949
of the electric motor room. You really have to

00:41:16.949 --> 00:41:19.909
synthesize all of this to imagine the sensory

00:41:19.909 --> 00:41:22.690
overload of this environment. It is inescapable.

00:41:22.989 --> 00:41:25.389
The overwhelming smell of unburnt diesel fuel

00:41:25.389 --> 00:41:28.179
permeates your clothing and your hair. The sharp,

00:41:28.199 --> 00:41:30.800
metallic tang of battery acid is always in the

00:41:30.800 --> 00:41:33.219
air, and if seawater ever leaks into the battery

00:41:33.219 --> 00:41:35.960
compartment, that acid instantly reacts to create

00:41:35.960 --> 00:41:38.820
lethal chlorine gas. Add to that the smell of

00:41:38.820 --> 00:41:41.300
50 terrified, sweating men who haven't had a

00:41:41.300 --> 00:41:44.280
shower in six weeks. Add the claustrophobia of

00:41:44.280 --> 00:41:47.300
not seeing the sun. And imagine the sheer terror

00:41:47.300 --> 00:41:49.639
of a depth charge attack. You are sitting in

00:41:49.639 --> 00:41:51.079
the dark, the lights have shattered, and you

00:41:51.079 --> 00:41:53.719
can hear the metal hull of your ship audibly

00:41:53.719 --> 00:41:56.460
groaning and popping as it shrinks under the

00:41:56.460 --> 00:41:58.840
crushing pressure of the deep ocean, waiting

00:41:58.840 --> 00:42:01.159
for the next explosion. The psychological toll

00:42:01.159 --> 00:42:04.130
is... almost impossible to comprehend. Yet it

00:42:04.130 --> 00:42:07.210
was from inside these hellish, claustrophobic

00:42:07.210 --> 00:42:10.329
metal tubes that the German Navy launched the

00:42:10.329 --> 00:42:12.789
Battle of the Atlantic, the longest, most complex

00:42:12.789 --> 00:42:15.329
and arguably most crucial continuous military

00:42:15.329 --> 00:42:17.550
campaign of World War II. Which brings us to

00:42:17.550 --> 00:42:20.150
the operational reality of the conflict spanning

00:42:20.150 --> 00:42:22.690
the early triumphs and the eventual catastrophic

00:42:22.690 --> 00:42:26.230
collapse between 1939 and 1943. Winston Churchill,

00:42:26.289 --> 00:42:28.250
the British prime minister, later wrote in his

00:42:28.250 --> 00:42:30.469
memoirs that the only thing that really frightened

00:42:30.469 --> 00:42:32.849
me during the war was the U -boat peril. And

00:42:32.849 --> 00:42:34.989
looking at the sheer volume of shipping destroyed

00:42:34.989 --> 00:42:37.789
in those early years, it is incredibly easy to

00:42:37.789 --> 00:42:41.949
see why. The U -boats of World War II were vastly

00:42:41.949 --> 00:42:44.809
technologically superior to their ancestors from

00:42:44.809 --> 00:42:47.190
the First World War. For starters, the hulls

00:42:47.190 --> 00:42:49.769
were constructed using high -tension steel alloys,

00:42:50.190 --> 00:42:52.550
and critically, they were fully welded together

00:42:52.550 --> 00:42:55.170
rather than bolted with traditional rivets. Under

00:42:55.170 --> 00:42:58.150
extreme underwater pressure, rivets can pop or

00:42:58.150 --> 00:43:01.340
shear off. causing catastrophic leaks. A welded

00:43:01.340 --> 00:43:04.199
hull fuses the metal into a single, seamless,

00:43:04.440 --> 00:43:07.280
flexible tube, allowing the Type 7 to safely

00:43:07.280 --> 00:43:10.000
dive significantly deeper to evade depth charges.

00:43:10.639 --> 00:43:12.820
To increase their operational range without taking

00:43:12.820 --> 00:43:15.679
up valuable interior space, the designers attached

00:43:15.679 --> 00:43:18.559
large saddle tanks to the exterior sides of the

00:43:18.559 --> 00:43:21.199
pressure hull to hold massive reserves of diesel

00:43:21.199 --> 00:43:23.440
fuel. But the true game changers of this era

00:43:23.440 --> 00:43:25.519
were the advancements in weaponry and tactical

00:43:25.519 --> 00:43:28.079
communication. Let's examine the primary weapon,

00:43:28.380 --> 00:43:31.320
the torpedo. Early in the war, U -boats predominantly

00:43:31.320 --> 00:43:34.860
relied on the classic G7A model. This was a complex

00:43:34.860 --> 00:43:37.300
weapon powered by a miniature, steam -powered

00:43:37.300 --> 00:43:39.760
internal combustion engine running on compressed

00:43:39.760 --> 00:43:42.579
air and decaline fuel. It was fast, reliable,

00:43:42.800 --> 00:43:45.659
and carried a massive warhead. But it had a glaring

00:43:45.659 --> 00:43:48.659
tactical flaw. As the exhaust gases vented into

00:43:48.659 --> 00:43:50.940
the water, it left a highly visible, foaming

00:43:50.940 --> 00:43:53.159
white trail of bubbles pointing directly back

00:43:53.159 --> 00:43:55.460
to the submarine that fired it. To solve this,

00:43:55.760 --> 00:43:59.480
German engineers introduced the G7E, an electrically

00:43:59.480 --> 00:44:02.179
propelled torpedo powered by internal batteries.

00:44:02.739 --> 00:44:05.019
It was slightly slower than the air -driven model

00:44:05.019 --> 00:44:08.059
and had a shorter range, but it left absolutely

00:44:08.059 --> 00:44:11.079
zero wake. It was a completely silent, invisible

00:44:11.079 --> 00:44:14.050
killer in the water. perfectly suited for terrifying

00:44:14.050 --> 00:44:16.130
daylight attacks where the victim wouldn't even

00:44:16.130 --> 00:44:18.250
know they were under fire until the hull exploded.

00:44:19.130 --> 00:44:21.530
But perhaps the most devastating and mathematically

00:44:21.530 --> 00:44:25.269
complex innovation of the early war was the magnetic

00:44:25.269 --> 00:44:27.969
pistol. Yes, let's talk about the magnetic pistol

00:44:27.969 --> 00:44:30.070
because this completely shifts the physics of

00:44:30.070 --> 00:44:32.610
how you destroy a ship. A classic traditional

00:44:32.610 --> 00:44:35.760
torpedo relies on a contact detonator. The torpedo

00:44:35.760 --> 00:44:37.840
has to physically slam its nose into the vertical

00:44:37.840 --> 00:44:40.119
steel side of a ship to trigger the explosive,

00:44:40.440 --> 00:44:42.719
punching a massive hole in the side below the

00:44:42.719 --> 00:44:45.139
water line. That is obviously devastating and

00:44:45.139 --> 00:44:47.579
often sinks the ship. But a magnetic pistol doesn't

00:44:47.579 --> 00:44:50.119
need to hit the ship at all. It is a sensor designed

00:44:50.119 --> 00:44:52.699
to detect the massive disturbance in the Earth's

00:44:52.699 --> 00:44:55.599
natural magnetic field caused by the huge steel

00:44:55.599 --> 00:44:59.099
mass of a passing cargo ship. The U -boat captain

00:44:59.099 --> 00:45:01.619
calculates the depth of the enemy ship's keel

00:45:01.619 --> 00:45:04.019
and sets the torpedo to run several feet deeper

00:45:04.019 --> 00:45:06.519
than the ship itself. The torpedo passes completely

00:45:06.519 --> 00:45:09.139
underneath the ship. The sensor detects the magnetic

00:45:09.139 --> 00:45:11.559
shadow of the steel above it and it detonates

00:45:11.559 --> 00:45:13.739
the warhead in the open water directly under

00:45:13.739 --> 00:45:16.199
the center of the hull. Why is an explosion in

00:45:16.199 --> 00:45:18.280
the water worse than an explosion against the

00:45:18.280 --> 00:45:20.659
side of the ship? It comes down to basic fluid

00:45:20.659 --> 00:45:23.889
dynamics and structural physics. A massive steel

00:45:23.889 --> 00:45:27.050
cargo ship's structural integrity relies entirely

00:45:27.050 --> 00:45:29.389
on the water beneath it, supporting its immense

00:45:29.389 --> 00:45:32.789
weight evenly, from bow to stern. When a large

00:45:32.789 --> 00:45:35.030
torpedo warhead detonates directly beneath the

00:45:35.030 --> 00:45:38.110
keel, it instantly vaporizes the water, creating

00:45:38.110 --> 00:45:42.039
a massive, rapidly expanding void. A giant bubble

00:45:42.039 --> 00:45:44.760
of gas in the ocean, directly beneath the dead

00:45:44.760 --> 00:45:46.880
center of the ship. For a microscopic fraction

00:45:46.880 --> 00:45:48.980
of a second, the middle of the heavy steel ship

00:45:48.980 --> 00:45:51.480
is suspended in mid -air inside that gas bubble,

00:45:51.860 --> 00:45:54.559
with absolutely no water supporting it. The sheer

00:45:54.559 --> 00:45:57.000
unsupported gravity of the heavy bow and the

00:45:57.000 --> 00:46:00.260
heavy stern causes the steel keel to literally

00:46:00.260 --> 00:46:03.579
snap in half under its own immense weight. The

00:46:03.579 --> 00:46:06.539
gas elbow then collapses, a massive geyser of

00:46:06.539 --> 00:46:08.460
water shoots upward through the cracked hull,

00:46:08.940 --> 00:46:11.519
and the ship sinks almost instantly. Breaking

00:46:11.519 --> 00:46:14.199
a ship's back from underneath is infinitely more

00:46:14.199 --> 00:46:16.039
lethal and efficient than punching a hole in

00:46:16.039 --> 00:46:19.599
its side. The tactical goal was absolute efficiency.

00:46:20.099 --> 00:46:23.739
One torpedo, one sunken ship. Armed with these

00:46:23.739 --> 00:46:26.400
silent torpedoes and devastating magnetic detonators

00:46:26.400 --> 00:46:28.500
and equipped with sophisticated short - and long

00:46:28.500 --> 00:46:31.320
-wave radio transmitters, Carl Donitz was finally

00:46:31.320 --> 00:46:33.699
able to implement the terrifying doctrine he

00:46:33.699 --> 00:46:36.340
had envisioned before the war, the Wolf Pack

00:46:36.340 --> 00:46:39.179
Tactics. The Atlantic Ocean is massive. A single

00:46:39.179 --> 00:46:41.340
U -boat might patrol for weeks without seeing

00:46:41.340 --> 00:46:44.070
a ship. Under the Wolfpack Doctrine, Donets would

00:46:44.070 --> 00:46:46.869
order dozens of U -boats to spread out in a massive

00:46:46.869 --> 00:46:49.449
staggered line stretching hundreds of miles across

00:46:49.449 --> 00:46:52.130
the likely paths of the convoy routes. When one

00:46:52.130 --> 00:46:54.170
single U -boat eventually spotted the smoke of

00:46:54.170 --> 00:46:56.969
a convoy, its strict orders were not to attack.

00:46:57.309 --> 00:46:59.550
Instead, that single submarine would remain on

00:46:59.550 --> 00:47:02.650
the surface, hold down below the horizon, and

00:47:02.650 --> 00:47:05.969
act as a shadow. It would use its radio to continuously

00:47:05.969 --> 00:47:09.050
transmit the convoy's speed, heading, and defensive

00:47:09.050 --> 00:47:11.630
composition back to naval headquarters in France.

00:47:11.829 --> 00:47:14.210
Headquarters would then broadcast a homing signal,

00:47:14.650 --> 00:47:16.869
calling in every single other U -boat in the

00:47:16.869 --> 00:47:19.389
sector. Over the course of a day or two, five,

00:47:19.469 --> 00:47:22.429
ten, or sometimes twenty U -boats would converge

00:47:22.429 --> 00:47:24.889
on the convoy's position. They would wait for

00:47:24.889 --> 00:47:28.179
the cover of absolute darkness. Then, acting

00:47:28.179 --> 00:47:30.659
in coordination, they would all surface simultaneously

00:47:30.659 --> 00:47:32.659
and charge into the middle of the convoy at high

00:47:32.659 --> 00:47:35.039
speed on their diesel engines. By attacking at

00:47:35.039 --> 00:47:37.260
night on the surface from multiple directions

00:47:37.260 --> 00:47:39.960
simultaneously, they completely overwhelmed the

00:47:39.960 --> 00:47:42.119
defensive screens of the British escort destroyers.

00:47:42.360 --> 00:47:44.960
In 1940, the geopolitical map shifted heavily

00:47:44.960 --> 00:47:47.719
in Germany's favor. After the rapid successful

00:47:47.719 --> 00:47:50.039
invasions of France and Norway, the German Navy

00:47:50.039 --> 00:47:53.019
gained access to massive, direct coastal bases

00:47:53.019 --> 00:47:55.730
right on the Atlantic Ocean. places like Lorient

00:47:55.730 --> 00:47:59.190
and Brest in France. This meant U -boats no longer

00:47:59.190 --> 00:48:01.650
had to waste weeks navigating the dangerous,

00:48:02.010 --> 00:48:04.630
heavily mined choke points around the north of

00:48:04.630 --> 00:48:06.750
the British Isles to reach the open hunting grounds.

00:48:07.369 --> 00:48:09.030
They could simply sail straight out into the

00:48:09.030 --> 00:48:11.730
deep water. This period of early success became

00:48:11.730 --> 00:48:14.530
legendary among the submarine crews. They referred

00:48:14.530 --> 00:48:17.389
to it as the happy time -de -glue -glue -clichet

00:48:17.389 --> 00:48:20.119
site. They were devastating British convoys at

00:48:20.119 --> 00:48:22.980
night with near impunity. But their strategic

00:48:22.980 --> 00:48:25.739
success was constantly diluted by political interference

00:48:25.739 --> 00:48:29.280
from the very top. Adolf Hitler, despite his

00:48:29.280 --> 00:48:32.420
military successes on land, had a paranoid, almost

00:48:32.420 --> 00:48:35.280
irrational fear of an allied amphibious invasion

00:48:35.280 --> 00:48:38.440
of Norway to reclaim the territory. Ignoring

00:48:38.440 --> 00:48:40.840
Donitz's pleas to concentrate all forces in the

00:48:40.840 --> 00:48:43.679
crucial Atlantic convoy routes, Hitler constantly

00:48:43.679 --> 00:48:46.079
meddled in naval deployment. He forced the Navy

00:48:46.079 --> 00:48:48.460
to keep a significant portion of their most capable

00:48:48.460 --> 00:48:51.059
U -boats uselessly parked in the freezing remote

00:48:51.059 --> 00:48:53.000
fjords of the Arctic Circle to guard against

00:48:53.000 --> 00:48:55.139
an invasion that wasn't coming. Furthermore,

00:48:55.420 --> 00:48:57.719
when the Italian Navy struggled in the Mediterranean,

00:48:58.179 --> 00:49:00.599
Hitler ordered dozens of U -boats to navigate

00:49:00.599 --> 00:49:02.900
the incredibly dangerous skates of Gibraltar

00:49:02.900 --> 00:49:05.380
to support Erwin Rommel's land forces in North

00:49:05.380 --> 00:49:08.159
Africa. Every U -boat sent to the Mediterranean

00:49:08.159 --> 00:49:10.820
or the Arctic was a U -boat removed from the

00:49:10.820 --> 00:49:13.059
primary objective of starving Britain. But the

00:49:13.059 --> 00:49:15.179
narrative drastically shifts again in December

00:49:15.179 --> 00:49:18.059
1941, when the Japanese attack Pearl Harbor in

00:49:18.059 --> 00:49:20.519
the United States officially enters the war against

00:49:20.519 --> 00:49:23.460
the Axis powers. Looking at the history, you

00:49:23.460 --> 00:49:26.039
would logically expect the US Navy to look at

00:49:26.039 --> 00:49:28.059
the massive shipping losses the British suffered

00:49:28.059 --> 00:49:30.420
over the previous two years, copy the British

00:49:30.420 --> 00:49:33.219
homework, and instantly mandate the convoy system

00:49:33.219 --> 00:49:36.400
along the American coastline. Right. wrong. In

00:49:36.400 --> 00:49:38.619
what historians look back on as an incredible

00:49:38.619 --> 00:49:41.519
display of institutional naval arrogance, the

00:49:41.519 --> 00:49:43.739
commander of the US fleet, Admiral Ernest King,

00:49:44.320 --> 00:49:46.880
aggressively resisted the implementation of convoys.

00:49:47.159 --> 00:49:50.429
It was a staggering miscalculation. The prevailing

00:49:50.429 --> 00:49:53.690
belief among some top U .S. naval brass was that

00:49:53.690 --> 00:49:56.469
their fast, heavily armed destroyers were better

00:49:56.469 --> 00:49:59.610
utilized going on the offensive, actively hunting

00:49:59.610 --> 00:50:02.750
U -boats in the open ocean rather than passively

00:50:02.750 --> 00:50:06.170
playing defense by escorting slow, lumbering

00:50:06.170 --> 00:50:08.929
cargo ships. Consequently, merchant ships were

00:50:08.929 --> 00:50:11.530
ordered to simply sail independently along the

00:50:11.530 --> 00:50:13.369
standard shipping lanes of the American Eastern

00:50:13.369 --> 00:50:15.989
seaboard. Which meant these isolated, defenseless

00:50:15.989 --> 00:50:17.889
cargo ships were sailing right off the coast

00:50:17.889 --> 00:50:20.469
of New York, New Jersey and Florida. And to make

00:50:20.469 --> 00:50:23.329
matters worse, the coastal cities hadn't instituted

00:50:23.329 --> 00:50:26.130
wartime blackouts. They were still fully illuminated.

00:50:26.610 --> 00:50:28.530
The U -boat commanders who crossed the Atlantic

00:50:28.530 --> 00:50:31.150
couldn't believe their luck. They initiated what

00:50:31.150 --> 00:50:33.710
they called the Second Happy Time in early 1942.

00:50:34.090 --> 00:50:36.170
They didn't even need to use complex targeting

00:50:36.170 --> 00:50:38.130
math. They would just sit a few miles offshore

00:50:38.130 --> 00:50:40.710
at night and watch as massive American oil tankers

00:50:40.710 --> 00:50:42.630
perfectly silhouetted themselves against the

00:50:42.630 --> 00:50:45.309
bright neon lights of Miami or Atlantic City.

00:50:45.489 --> 00:50:47.789
It was an absolute shooting gallery. They feasted

00:50:47.789 --> 00:50:50.090
on undefended shipping all along the coast and

00:50:50.090 --> 00:50:52.510
pushed deep into the Gulf of Mexico. But the

00:50:52.510 --> 00:50:56.369
tide of an industrial war is fickle. By mid -1942,

00:50:56.750 --> 00:50:59.349
the sheer unsustainable volume of sunken American

00:50:59.349 --> 00:51:02.309
ships finally forced Admiral King to relent.

00:51:02.590 --> 00:51:05.409
The U .S. Navy implemented a rigid interlocking

00:51:05.409 --> 00:51:08.010
coastal convoy system, immediately pushing the

00:51:08.010 --> 00:51:10.389
U -boots away from the shorelines and back into

00:51:10.389 --> 00:51:13.010
the treacherous mid -Atlantic gap. And this is

00:51:13.010 --> 00:51:15.150
where the grand turning point of the submarine

00:51:15.150 --> 00:51:18.809
war begins. The climax of this entire technological

00:51:18.809 --> 00:51:21.150
and strategic struggle occurred over the course

00:51:21.150 --> 00:51:25.099
of 1941 to 1943. and it began in the shatters

00:51:25.099 --> 00:51:27.800
of intelligence. The British code breakers at

00:51:27.800 --> 00:51:30.179
Bletchley Park, aided by the capture of several

00:51:30.179 --> 00:51:32.900
code books from damaged submarines, managed to

00:51:32.900 --> 00:51:35.820
fundamentally crack the German naval Enigma cipher.

00:51:36.000 --> 00:51:38.460
This is a massive silent victory. By reading

00:51:38.460 --> 00:51:41.320
the daily Enigma transmissions, the British Admiralty

00:51:41.320 --> 00:51:43.199
could suddenly see the locations of the waiting

00:51:43.199 --> 00:51:45.980
Wolfpeck patrol lines on their maps. They began

00:51:45.980 --> 00:51:49.119
secretly routing the massive supply convoys hundreds

00:51:49.119 --> 00:51:51.420
of miles out of their way, completely bypassing

00:51:51.420 --> 00:51:53.500
the waiting submarines. The German commanders

00:51:53.500 --> 00:51:55.900
were baffled as the ocean seemingly emptied of

00:51:55.900 --> 00:51:58.539
targets. But even when the Germans changed their

00:51:58.539 --> 00:52:00.559
cipher keys and locked the British out of reading

00:52:00.559 --> 00:52:02.900
the actual messages, the Allies had developed

00:52:02.900 --> 00:52:06.780
another equally devastating technological countermeasure.

00:52:07.159 --> 00:52:09.920
The U -boat's greatest tactical asset, their

00:52:09.920 --> 00:52:13.760
ability to coordinate via long range radio, became

00:52:13.760 --> 00:52:16.389
their fatal flaw. Because every time a U -boat

00:52:16.389 --> 00:52:18.769
keyed its microphone to transmit a sighting report,

00:52:19.110 --> 00:52:21.510
it sent a burst of electromagnetic energy into

00:52:21.510 --> 00:52:24.769
the atmosphere. The Allies introduced a technology

00:52:24.769 --> 00:52:27.650
called high -frequency direction finding, commonly

00:52:27.650 --> 00:52:30.570
nicknamed Huffduff. They installed these highly

00:52:30.570 --> 00:52:33.110
sensitive radio antennas on the masts of the

00:52:33.110 --> 00:52:35.809
escort destroyers protecting the convoys. Let's

00:52:35.809 --> 00:52:37.809
explain how Huffduff actually kills a submarine.

00:52:38.469 --> 00:52:40.710
When a U -boat surfaces on the horizon to radio

00:52:40.710 --> 00:52:43.539
the Wolf Pack, The Huftuff antenna on a British

00:52:43.539 --> 00:52:46.000
destroyer picks up the signal. The operator gets

00:52:46.000 --> 00:52:48.559
a direct line of bearing pointing exactly toward

00:52:48.559 --> 00:52:50.840
the origin of the transmission. If two different

00:52:50.840 --> 00:52:52.980
ships in the convoy pick up the same signal,

00:52:53.320 --> 00:52:55.920
they simply draw two lines on a map. Where those

00:52:55.920 --> 00:52:58.400
lines cross triangulation is exactly where the

00:52:58.400 --> 00:53:00.909
U -boat is sitting. The escort commander instantly

00:53:00.909 --> 00:53:03.849
detaches a fast destroyer to race down that bearing.

00:53:04.510 --> 00:53:07.010
The U -boat commander, completely unaware he's

00:53:07.010 --> 00:53:10.210
been triangulated, suddenly sees a massive warship

00:53:10.210 --> 00:53:13.210
bearing down on him at 30 knots, dropping depth

00:53:13.210 --> 00:53:15.190
charges before the rest of the Wolf Pack can

00:53:15.190 --> 00:53:17.630
even arrive. And when the allied destroyers hunted

00:53:17.630 --> 00:53:19.929
them down, they weren't just relying on old fashioned

00:53:19.929 --> 00:53:23.829
depth charges anymore. They deployed new, terrifying

00:53:23.829 --> 00:53:27.610
anti -submarine weapons, most notably the hedgehog

00:53:27.610 --> 00:53:30.900
system. Right, the hedgehog. A standard depth

00:53:30.900 --> 00:53:33.340
charge is basically a barrel of explosives dropped

00:53:33.340 --> 00:53:35.860
off the back of a ship. It uses a hydrostatic

00:53:35.860 --> 00:53:39.039
fuse to explode at a preset depth. But the problem

00:53:39.039 --> 00:53:41.619
is, as a destroyer drives over a submarine to

00:53:41.619 --> 00:53:44.139
drop the depth charge off the stern, the noise

00:53:44.139 --> 00:53:46.920
of its own propellers completely blinds its sonar.

00:53:47.099 --> 00:53:49.539
For crucial minutes, the destroyer loses track

00:53:49.539 --> 00:53:51.460
of where the sub is, giving the U -boat a chance

00:53:51.460 --> 00:53:54.380
to turn and evade. The depth charges explode,

00:53:54.579 --> 00:53:56.800
churning up the water, but you never really know

00:53:56.800 --> 00:53:59.179
if you hit anything. The Hedgehog solved that

00:53:59.179 --> 00:54:01.860
geometry problem entirely. Instead of dropping

00:54:01.860 --> 00:54:04.320
barrels off the back, the Hedgehog was a massive

00:54:04.320 --> 00:54:06.619
mortar system mounted on the front deck of the

00:54:06.619 --> 00:54:09.739
destroyer. It fired a circular grid of dozens

00:54:09.739 --> 00:54:12.800
of smaller, highly explosive projectiles hundreds

00:54:12.800 --> 00:54:15.219
of feet ahead of the attacking ship, right where

00:54:15.219 --> 00:54:18.179
the sonar operator was pointing. Crucially, these

00:54:18.179 --> 00:54:21.139
projectiles didn't use depth fuses. They used

00:54:21.139 --> 00:54:23.539
contact fuses. They sank rapidly through the

00:54:23.539 --> 00:54:26.019
water, and they only detonated if they physically

00:54:26.019 --> 00:54:28.619
struck the steel hull of the submarine. Therefore,

00:54:28.820 --> 00:54:31.280
if a destroyer fired a hedgehog volley and the

00:54:31.280 --> 00:54:33.920
crew heard an underwater explosion, they knew

00:54:33.920 --> 00:54:36.599
with absolute terrifying certainty that they

00:54:36.599 --> 00:54:39.320
had scored a lethal hit. All of these allied

00:54:39.320 --> 00:54:41.940
countermeasures, the enigma code breaking, the

00:54:41.940 --> 00:54:44.579
Huff -Duff triangulation, the deployment of long

00:54:44.579 --> 00:54:46.500
-range radar -equipped patrol planes covering

00:54:46.500 --> 00:54:49.219
the Mid -Atlantic Gap, and the lethal accuracy

00:54:49.219 --> 00:54:51.880
of the hedgehog, all violently converged in the

00:54:51.880 --> 00:54:54.639
spring of 1943. It culminated in a month the

00:54:54.639 --> 00:54:58.079
German Navy remembers simply as Black May. The

00:54:58.079 --> 00:55:00.260
U -boat losses became absolutely catastrophic.

00:55:00.659 --> 00:55:02.400
The Wolf Packs were trying to attack heavily

00:55:02.400 --> 00:55:04.400
defended convoys and were being slaughtered.

00:55:04.480 --> 00:55:07.119
Germany was losing submarines vastly faster than

00:55:07.119 --> 00:55:09.260
their shipyards could build them, and worse,

00:55:09.639 --> 00:55:11.719
vastly faster than they were sinking Allied merchant

00:55:11.719 --> 00:55:14.860
ships. The economic math had inverted. On May

00:55:14.860 --> 00:55:18.559
24th, 1943, Karl Donitz looked at the horrific

00:55:18.559 --> 00:55:21.079
casualty reports and made the painful decision

00:55:21.079 --> 00:55:23.659
to officially halt the Atlantic campaign, ordering

00:55:23.659 --> 00:55:26.219
his surviving boats to retreat. The golden age

00:55:26.219 --> 00:55:29.099
of the Wolfpack was definitively over. The final

00:55:29.099 --> 00:55:31.880
toll of the war is incredibly grim. The U -boat

00:55:31.880 --> 00:55:34.699
sank nearly 3 ,000 Allied ships over six years,

00:55:34.980 --> 00:55:38.980
but the cost was staggering. Of the 11 ,181 German

00:55:38.980 --> 00:55:41.280
U -boats that entered operational service, an

00:55:41.280 --> 00:55:44.380
astonishing 785 were destroyed by Allied action.

00:55:44.780 --> 00:55:46.800
The hunters had definitively become the hunted.

00:55:47.219 --> 00:55:49.619
Over 30 ,000 U -boat crewmen lost their lives,

00:55:50.000 --> 00:55:53.079
a casualty rate of nearly 75%, one of the highest

00:55:53.079 --> 00:55:55.480
of any military branch in any nation during the

00:55:55.480 --> 00:55:57.949
war. But the German High Command, facing the

00:55:57.949 --> 00:56:00.110
prospect of losing the war entirely, refused

00:56:00.110 --> 00:56:02.230
to give up on the submarine concept. This leads

00:56:02.230 --> 00:56:04.829
us directly into a fascinating era of rapid frantic

00:56:04.829 --> 00:56:07.960
engineering. We enter part six. Desperate innovations

00:56:07.960 --> 00:56:11.280
covering 1943 to 1945. This raises an important

00:56:11.280 --> 00:56:13.719
question for military historians. What exactly

00:56:13.719 --> 00:56:15.860
happens when a sophisticated military machine

00:56:15.860 --> 00:56:18.199
realizes its primary weapon is obsolete, but

00:56:18.199 --> 00:56:20.539
the war of survival is still raging? It drives

00:56:20.539 --> 00:56:22.780
a furious, almost desperate scramble for radical

00:56:22.780 --> 00:56:25.099
technological leaps. The fundamental problem

00:56:25.099 --> 00:56:28.000
was obvious. The U -boats needed to get drastically

00:56:28.000 --> 00:56:30.599
faster underwater, and they needed to stay hidden

00:56:30.599 --> 00:56:33.150
underwater significantly longer. The surface

00:56:33.150 --> 00:56:35.489
of the ocean now entirely belonged to allied

00:56:35.489 --> 00:56:38.710
aircraft equipped with microwave radar. Surfacing

00:56:38.710 --> 00:56:41.010
to run the diesel engines, even at night, was

00:56:41.010 --> 00:56:43.510
practically a death sentence. To solve this,

00:56:43.929 --> 00:56:46.150
the engineers looked backward to a concept developed

00:56:46.150 --> 00:56:50.110
before the war. Back in 1940, a brilliant eccentric

00:56:50.110 --> 00:56:53.010
engineer named Helmuth Walter had designed an

00:56:53.010 --> 00:56:55.820
experimental submarine called the V -80. or the

00:56:55.820 --> 00:56:59.539
type XVAA. Walter didn't want to use heavy electric

00:56:59.539 --> 00:57:01.559
batteries for underwater travel. He wanted to

00:57:01.559 --> 00:57:03.599
use a revolutionary high -speed turbine. But

00:57:03.599 --> 00:57:05.659
a turbine requires combustion, which requires

00:57:05.659 --> 00:57:08.920
oxygen. So Walter powered his turbine using highly

00:57:08.920 --> 00:57:11.559
concentrated hydrogen peroxide. This is a concept

00:57:11.559 --> 00:57:14.280
known as air independent propulsion, or AIP.

00:57:14.619 --> 00:57:17.269
It's a holy grail of submarine design. Because

00:57:17.269 --> 00:57:19.769
hydrogen peroxide is a highly unstable chemical

00:57:19.769 --> 00:57:22.110
that violently breaks down into water and pure

00:57:22.110 --> 00:57:24.690
oxygen, Walter's engine essentially supplied

00:57:24.690 --> 00:57:27.170
its own oxygen for combustion while entirely

00:57:27.170 --> 00:57:29.429
submerged. It didn't need a snorkel. It didn't

00:57:29.429 --> 00:57:32.190
need to surface. The performance of this experimental

00:57:32.190 --> 00:57:35.869
boat was absolutely staggering. Submerged, running

00:57:35.869 --> 00:57:38.630
on the Walter turbine, the submarine could exceed

00:57:38.630 --> 00:57:41.489
speeds of 20 knots. To put that into perspective

00:57:41.489 --> 00:57:44.789
for you, a standard battery -powered Type 7 U

00:57:44.789 --> 00:57:47.570
-boat maxed out at an absolute sprint of about

00:57:47.570 --> 00:57:51.210
6 knots underwater and usually cruised at a painfully

00:57:51.210 --> 00:57:55.130
slow, creeping 4 knots just to save battery life.

00:57:55.369 --> 00:57:58.579
The Walter boat was a rocket ship. It could literally

00:57:58.579 --> 00:58:01.320
outrun many allied surface warships while remaining

00:58:01.320 --> 00:58:03.860
completely invisible beneath the waves. It sounds

00:58:03.860 --> 00:58:06.460
like the ultimate wonder weapon, the technological

00:58:06.460 --> 00:58:08.320
silver bullet that could have won the Battle

00:58:08.320 --> 00:58:10.940
of the Atlantic. But the reality of wartime logistics

00:58:10.940 --> 00:58:14.159
intervened, revealing a fatal flaw. Once the

00:58:14.159 --> 00:58:15.800
Walter submarine burned through its internal

00:58:15.800 --> 00:58:18.440
supply of volatile hydrogen peroxide fuel, it

00:58:18.440 --> 00:58:21.000
was dead in the water. Unlike lead -acid electric

00:58:21.000 --> 00:58:22.679
batteries, which should be recharged indefinitely

00:58:22.679 --> 00:58:24.559
by simply running the onboard diesel engines

00:58:24.559 --> 00:58:27.019
on the surface, hydrogen peroxide was a highly

00:58:27.019 --> 00:58:29.920
refined exotic chemical. It could not be manufactured

00:58:29.920 --> 00:58:34.360
at sea. And by 1944, a heavily bombed, resource

00:58:34.360 --> 00:58:37.039
-starved Germany simply did not possess the massive

00:58:37.039 --> 00:58:40.480
specialized industrial capacity required to synthesize

00:58:40.480 --> 00:58:42.800
the millions of gallons of high -grade hydrogen

00:58:42.800 --> 00:58:46.460
peroxide necessary to fuel an entire operational

00:58:46.460 --> 00:58:49.619
fleet of these submarines. The Navy ordered 24

00:58:49.619 --> 00:58:51.619
of them, but they only managed to build three

00:58:51.619 --> 00:58:55.019
prototypes and none ever saw combat. But the

00:58:55.019 --> 00:58:57.400
engineering effort wasn't a total loss. While

00:58:57.400 --> 00:58:59.320
the chemical engine was a logistical failure,

00:59:00.000 --> 00:59:01.900
the physical design of the Walter submarines

00:59:01.900 --> 00:59:04.880
was brilliant. To store all that massive volume

00:59:04.880 --> 00:59:07.260
of hydrogen peroxide fuel, Walter had designed

00:59:07.260 --> 00:59:10.659
holes that were very large, very deep, and incredibly

00:59:10.659 --> 00:59:13.019
streamlined for high -speed underwater travel.

00:59:13.280 --> 00:59:15.579
The German naval architects looked at these blueprints

00:59:15.579 --> 00:59:17.820
and realized they could simply take that massive

00:59:17.820 --> 00:59:20.179
hydrodynamic hole design and instead of filling

00:59:20.179 --> 00:59:22.099
the massive lower decks with exotic chemical

00:59:22.099 --> 00:59:25.219
fuels, just pack the space wall to wall with

00:59:25.219 --> 00:59:27.860
an unprecedented number of massive conventional

00:59:27.860 --> 00:59:30.610
lead acid batteries. And that pragmatic pivot

00:59:30.610 --> 00:59:33.769
became the Type XE -1, universally known as the

00:59:33.769 --> 00:59:36.670
Electroboot. This vessel represents a massive

00:59:36.670 --> 00:59:39.610
fundamental turning point in global naval architecture.

00:59:40.289 --> 00:59:41.949
Every submarine we have discussed up to this

00:59:41.949 --> 00:59:44.889
point, from the U -1 to the Type 7, was essentially

00:59:44.889 --> 00:59:47.730
a surface ship that possessed the neat tactical

00:59:47.730 --> 00:59:50.630
trick of occasionally diving underwater for short,

00:59:50.769 --> 00:59:53.369
slow periods to execute an attack or hide from

00:59:53.369 --> 00:59:55.429
a destroyer. Their primary mode of travel was

00:59:55.429 --> 00:59:57.829
on the surface. The ElectroBoot was different.

00:59:58.170 --> 01:00:02.230
It was the first true modern submarine. Its streamlined

01:00:02.230 --> 01:00:05.010
shape and massive battery capacity meant it was

01:00:05.010 --> 01:00:08.010
designed primarily, fundamentally, to operate

01:00:08.010 --> 01:00:11.170
underwater. It boasted unprecedented underwater

01:00:11.170 --> 01:00:13.750
speed and could remain completely submerged for

01:00:13.750 --> 01:00:16.550
days at a time without surfacing. Recognizing

01:00:16.550 --> 01:00:19.030
that this was their only hope, the German Armaments

01:00:19.030 --> 01:00:21.610
Ministry completely overhauled submarine production

01:00:21.610 --> 01:00:24.460
to build the Type XE1. To circumvent the constant

01:00:24.460 --> 01:00:26.619
devastating allied bombing raids on the coastal

01:00:26.619 --> 01:00:29.500
shipyards, they pioneered a radical new manufacturing

01:00:29.500 --> 01:00:32.059
system. The submarine was not built in a single

01:00:32.059 --> 01:00:34.780
dockyard. Instead, it was constructed in massive,

01:00:35.320 --> 01:00:38.199
completely prefabricated steel sections at heavy

01:00:38.199 --> 01:00:40.780
engineering factories scattered deep inland across

01:00:40.780 --> 01:00:43.659
Germany. These completed, fully wired chunks

01:00:43.659 --> 01:00:46.760
were then transported by rail or barge to concrete

01:00:46.760 --> 01:00:49.539
bunkers on the coast for final rapid assembly.

01:00:49.760 --> 01:00:51.699
It was an incredible industrial achievement.

01:00:51.920 --> 01:00:54.699
Alongside a smaller, highly maneuverable coastal

01:00:54.699 --> 01:00:57.820
version known as the Type XE3, the Electra Boot

01:00:57.820 --> 01:00:59.780
were intended to completely turn the tide of

01:00:59.780 --> 01:01:02.500
the naval war, rendering allied radar and escorts

01:01:02.500 --> 01:01:05.340
obsolete. But again, it was a profound case of

01:01:05.340 --> 01:01:08.239
too little. Too late. The complex new system

01:01:08.239 --> 01:01:10.500
suffered from teething problems, and the logistics

01:01:10.500 --> 01:01:14.000
network was collapsing. Only two massive Type

01:01:14.000 --> 01:01:16.920
Xs ever actually set out on an active combat

01:01:16.920 --> 01:01:19.320
patrol before the complete collapse of the German

01:01:19.320 --> 01:01:22.840
military and the surrender in May 1945. But because

01:01:22.840 --> 01:01:25.260
those revolutionary electroboot were taking entirely

01:01:25.260 --> 01:01:28.139
too long to design and build, the Navy desperately

01:01:28.139 --> 01:01:30.280
needed a start gap measure to keep their existing,

01:01:30.300 --> 01:01:33.079
aging, highly vulnerable fleet of Type Cs and

01:01:33.079 --> 01:01:35.750
Type Niancs alive in the Atlantic. And here's

01:01:35.750 --> 01:01:37.989
where it gets really interesting, because they

01:01:37.989 --> 01:01:41.030
resorted to a piece of captured technology. Back

01:01:41.030 --> 01:01:43.769
in 1940, during the invasion of the Netherlands,

01:01:44.250 --> 01:01:46.449
the Germans captured several Dutch submarines

01:01:46.449 --> 01:01:48.889
in dry dock. They were equipped with a unique,

01:01:49.170 --> 01:01:51.449
highly experimental device called a schnorkel.

01:01:51.659 --> 01:01:54.820
or a snorkel. For three years, the arrogant German

01:01:54.820 --> 01:01:58.059
high command completely ignored the device. But

01:01:58.059 --> 01:02:01.360
by late 1943, desperate for a way to let their

01:02:01.360 --> 01:02:03.579
boats breathe without exposing them to radar,

01:02:04.039 --> 01:02:07.619
they rushed to install massive folding snorkels

01:02:07.619 --> 01:02:10.139
onto every U -boat they had. The snorkel was

01:02:10.139 --> 01:02:12.880
essentially a heavy retractable double pipe system

01:02:12.880 --> 01:02:15.179
that was raised up on a hydraulic hinge. The

01:02:15.179 --> 01:02:17.400
top of the pipe sat just above the crests of

01:02:17.400 --> 01:02:19.420
the ocean waves, while the massive steel hull

01:02:19.420 --> 01:02:21.579
of the submarine remained safely submerged at

01:02:21.579 --> 01:02:24.250
periscope depth. One pipe actively sucked in

01:02:24.250 --> 01:02:26.809
fresh atmospheric air to feed the massive diesel

01:02:26.809 --> 01:02:29.730
engines, and the other pipe forcefully blew the

01:02:29.730 --> 01:02:32.889
heavy exhaust gases out into the ocean. In theory,

01:02:32.949 --> 01:02:35.269
it was an elegant tactical solution. It allowed

01:02:35.269 --> 01:02:37.590
the U -boats to run their powerful diesel engines,

01:02:37.929 --> 01:02:40.670
travel at faster speeds, and recharge their depleted

01:02:40.670 --> 01:02:42.969
batteries without ever exposing their vulnerable

01:02:42.969 --> 01:02:45.969
hulls on the surface. It sounds perfect on paper.

01:02:46.119 --> 01:02:48.239
But reading the accounts from the engineers and

01:02:48.239 --> 01:02:50.460
the sailors who had to actually use these things,

01:02:50.920 --> 01:02:53.440
in practice, operating a snorkel in the North

01:02:53.440 --> 01:02:56.320
Atlantic was a physical and psychological nightmare.

01:02:56.619 --> 01:02:59.780
For starters, the pipe created immense hydrodynamic

01:02:59.780 --> 01:03:02.579
drag. The submarine could only use the snorkel

01:03:02.579 --> 01:03:05.460
at a maximum speed of about 8 knots. If they

01:03:05.460 --> 01:03:07.900
pushed the engines any faster, the sheer physical

01:03:07.900 --> 01:03:10.320
force of the water rushing against the pipe would

01:03:10.320 --> 01:03:12.800
literally snap it clean off the deck, flooding

01:03:12.800 --> 01:03:15.480
the boat. Furthermore, the acoustic reality of

01:03:15.480 --> 01:03:18.219
running massive, vibrating diesel engines while

01:03:18.219 --> 01:03:21.019
completely submerged meant the noise echoed through

01:03:21.019 --> 01:03:23.579
the water and completely deafened the U -boat's

01:03:23.579 --> 01:03:25.940
own highly sensitive hydrophone listening arrays.

01:03:26.239 --> 01:03:28.739
By using the snorkel to hide from radar, they

01:03:28.739 --> 01:03:30.920
made themselves completely blind to the approach

01:03:30.920 --> 01:03:34.300
of allied sonar destroyers. And then there was

01:03:34.300 --> 01:03:36.559
the acute physical danger to the crew itself.

01:03:37.300 --> 01:03:39.980
The Atlantic Ocean is never flat. It is a chaotic

01:03:39.980 --> 01:03:43.119
environment of massive swells. The air intake

01:03:43.119 --> 01:03:45.380
pipe of the snorkel was equipped with an automatic

01:03:45.380 --> 01:03:47.760
float valve on the top. This valve was designed

01:03:47.760 --> 01:03:50.639
to instantly snap shut if a large ocean wave

01:03:50.639 --> 01:03:52.719
crashed over the top of the pipe, preventing

01:03:52.719 --> 01:03:55.119
thousands of gallons of seawater from pouring

01:03:55.119 --> 01:03:57.139
directly into the engine room and sinking the

01:03:57.139 --> 01:03:59.360
boat. This is the part that genuinely gives me

01:03:59.360 --> 01:04:02.539
claustrophobia. Imagine the scenario. The boat

01:04:02.539 --> 01:04:06.380
is submerged at periscope depth. The two massive

01:04:06.380 --> 01:04:09.500
2 ,000 horsepower diesel engines are roaring,

01:04:10.139 --> 01:04:12.300
demanding colossal staggering amounts of oxygen

01:04:12.300 --> 01:04:15.800
every single second to maintain combustion. Suddenly

01:04:15.800 --> 01:04:19.139
a large wave rolls over the snorkel mast. The

01:04:19.139 --> 01:04:21.860
float valve slams shut to stop the water, but

01:04:21.860 --> 01:04:24.059
the massive diesel engines don't magically stop

01:04:24.059 --> 01:04:26.730
running the instant that valve closes. They keep

01:04:26.730 --> 01:04:29.090
firing. And because the air intake pipe is sealed

01:04:29.090 --> 01:04:31.469
off, those engines instantly start desperately

01:04:31.469 --> 01:04:33.730
sucking huge volumes of air right out of the

01:04:33.730 --> 01:04:36.289
only place left, the sealed crew compartments.

01:04:36.489 --> 01:04:38.969
Because the entire interior volume of the pressure

01:04:38.969 --> 01:04:41.429
hull was utilized as an air buffer, the engines

01:04:41.429 --> 01:04:43.889
would instantaneously draw thousands of cubic

01:04:43.889 --> 01:04:46.369
feet of air out of the living spaces. It created

01:04:46.369 --> 01:04:48.989
a sudden, violent, extreme drop in barometric

01:04:48.989 --> 01:04:51.710
pressure, a vacuum effect inside the submarine.

01:04:51.900 --> 01:04:54.699
The physical trauma of this on the human body

01:04:54.699 --> 01:04:57.539
is horrifying. The pressure drop was so severe

01:04:57.539 --> 01:04:59.599
and so instantaneous that it would literally

01:04:59.599 --> 01:05:02.940
suck the air out of the sailor's lungs. The extreme

01:05:02.940 --> 01:05:04.960
pressure differential between the inside of the

01:05:04.960 --> 01:05:07.039
sailor's heads and the cabin air could instantly

01:05:07.039 --> 01:05:10.019
burst the eardrums of every man on board causing

01:05:10.219 --> 01:05:13.320
agonizing, incapacitating pain and permanent

01:05:13.320 --> 01:05:15.559
hearing loss. The diesel engines would eventually

01:05:15.559 --> 01:05:18.019
choke out and stall from the lack of oxygen,

01:05:18.599 --> 01:05:21.099
plunging the boat into total silence and darkness,

01:05:21.519 --> 01:05:24.400
leaving a terrified, bleeding crew gasping for

01:05:24.400 --> 01:05:26.559
breath until the wave passed and the valve opened

01:05:26.559 --> 01:05:29.480
again, rushing air back in. It was a terrifying,

01:05:29.800 --> 01:05:32.719
deeply flawed mechanical device born of absolute

01:05:32.719 --> 01:05:36.389
sheer strategic desperation. Ultimately, neither

01:05:36.389 --> 01:05:39.030
the stopgap terror of the snorkel nor the technological

01:05:39.030 --> 01:05:41.010
miracle of the electroboot could prevent the

01:05:41.010 --> 01:05:43.550
total military and economic collapse of the Third

01:05:43.550 --> 01:05:46.110
Reich. With the unconditional surrender of Germany

01:05:46.110 --> 01:05:49.829
in May 1945, the story of the U -boat as a weapon

01:05:49.829 --> 01:05:52.829
of global terror came to an abrupt, definitive

01:05:52.829 --> 01:05:56.449
end. In an echo of the end of World War I, hundreds

01:05:56.449 --> 01:05:58.730
of surviving surrendered U -boats were towed

01:05:58.730 --> 01:06:00.849
out into the deep Atlantic by the victorious

01:06:00.849 --> 01:06:04.230
Allies and systematically sunk by naval gunfire

01:06:04.230 --> 01:06:06.989
and explosives during Operation Deadlight. But

01:06:06.989 --> 01:06:09.730
you cannot permanently suppress brilliant engineering.

01:06:10.469 --> 01:06:13.400
The knowledge remains. Which brings us to our

01:06:13.400 --> 01:06:16.480
final act, exploring the post -war era from 1945

01:06:16.480 --> 01:06:19.320
to the present day. Following the devastation

01:06:19.320 --> 01:06:21.559
of World War II, the new nation of West Germany

01:06:21.559 --> 01:06:23.960
is, for a second time in a century, strictly

01:06:23.960 --> 01:06:26.659
banned from possessing a submarine fleet. But

01:06:26.659 --> 01:06:29.139
the geopolitical tectonic plates are shifting

01:06:29.139 --> 01:06:31.360
drastically. The Soviet Union and the West divide

01:06:31.360 --> 01:06:35.539
in Europe. The Cold War begins. By 1954 and 1955,

01:06:36.079 --> 01:06:38.039
West Germany is formally integrated into the

01:06:38.039 --> 01:06:40.190
NATO alliance. The Western allies look at the

01:06:40.190 --> 01:06:42.190
map and realize they have a massive strategic

01:06:42.190 --> 01:06:44.289
vulnerability in the Baltic Sea, right on the

01:06:44.289 --> 01:06:46.670
border of the Soviet Bloc. They desperately need

01:06:46.670 --> 01:06:48.969
the Germans to help secure it. So the restrictions

01:06:48.969 --> 01:06:51.329
are lifted and the newly formed Bundesmarine

01:06:51.329 --> 01:06:53.710
is given permission to design and build a small

01:06:53.710 --> 01:06:57.570
fleet of specialized 350 ton coastal defense

01:06:57.570 --> 01:07:00.070
submarines. And the German engineers immediately

01:07:00.070 --> 01:07:02.389
set out to solve the unique tactical problems

01:07:02.389 --> 01:07:05.510
of the Baltic Sea. Their first major post -war

01:07:05.510 --> 01:07:08.309
attempts were the Type 201 and Type 202 classes.

01:07:08.559 --> 01:07:11.440
The Baltic is notoriously shallow, making it

01:07:11.440 --> 01:07:13.900
an ideal environment for the deployment of thousands

01:07:13.900 --> 01:07:16.679
of bottom -dwelling magnetic naval mines. To

01:07:16.679 --> 01:07:19.099
counter this threat, the German designers decided

01:07:19.099 --> 01:07:21.619
to build the pressure hulls of these new submarines

01:07:21.619 --> 01:07:24.800
out of a completely revolutionary non -magnetic

01:07:24.800 --> 01:07:27.469
high -tension steel alloy. The theory was that

01:07:27.469 --> 01:07:29.510
a non -magnetic hull would allow the submarine

01:07:29.510 --> 01:07:31.949
to sail safely over magnetic minefields without

01:07:31.949 --> 01:07:33.829
triggering them, and it would also make them

01:07:33.829 --> 01:07:36.050
completely invisible to the magnetic anomaly

01:07:36.050 --> 01:07:38.969
detectors flown by Soviet anti -submarine patrol

01:07:38.969 --> 01:07:41.750
planes. It was a brilliant, highly advanced idea

01:07:41.750 --> 01:07:44.949
in theory. In theory. But in practice, metallurgy

01:07:44.949 --> 01:07:48.309
is a cruel mistress. By 1963, operational testing

01:07:48.309 --> 01:07:50.929
revealed that this new wonder metal was an absolute

01:07:50.929 --> 01:07:53.449
disaster. The non -magnetic steel was highly

01:07:53.449 --> 01:07:55.710
susceptible to severe galvanic corrosion and

01:07:55.710 --> 01:07:58.909
saltwater. Microcracks began forming uncontrollably

01:07:58.909 --> 01:08:02.030
all over the structural pressure hulls. The integrity

01:08:02.030 --> 01:08:04.690
of the submarines was failing so rapidly that

01:08:04.690 --> 01:08:07.469
the Navy literally had to resort to coating the

01:08:07.469 --> 01:08:11.369
exterior hulls in thick zinc paint just to try

01:08:11.369 --> 01:08:13.650
and physically slow down the rotting of the metal.

01:08:13.989 --> 01:08:16.130
They were forced into a terrifying routine of

01:08:16.130 --> 01:08:18.590
constantly taking the boats into deep water and

01:08:18.590 --> 01:08:20.750
retesting how far they could safely dive before

01:08:20.750 --> 01:08:23.380
the hull threatened to implode. It was a massive,

01:08:23.720 --> 01:08:26.079
embarrassing engineering failure, forcing them

01:08:26.079 --> 01:08:28.739
to scrap the exotic material entirely and go

01:08:28.739 --> 01:08:30.979
back to the drawing board to design the Type

01:08:30.979 --> 01:08:34.359
205 using highly reliable, traditional high -tension

01:08:34.359 --> 01:08:37.000
steel. But the hallmark of modern German engineering

01:08:37.000 --> 01:08:39.659
is rapid iteration and recovery from failure.

01:08:40.079 --> 01:08:42.640
By 1968, having perfected their designs with

01:08:42.640 --> 01:08:44.840
traditional materials, they launched the Type

01:08:44.840 --> 01:08:47.520
209. And the Type 209 is arguably one of the

01:08:47.520 --> 01:08:49.840
most commercially and tactically successful submarine

01:08:49.840 --> 01:08:52.609
designs of the entire late 20... century. Germany

01:08:52.609 --> 01:08:55.510
realized a massive gap in the global arms market

01:08:55.510 --> 01:08:58.569
while their own defense needs only required small

01:08:58.569 --> 01:09:01.829
coastal subs. Dozens of allied and non -aligned

01:09:01.829 --> 01:09:05.069
navies around the world, nations with long coastlines

01:09:05.069 --> 01:09:08.130
but limited budgets, desperately needed reliable,

01:09:08.130 --> 01:09:10.949
modern, medium -sized diesel -electric submarines

01:09:10.949 --> 01:09:13.149
to protect their waters. But they simply couldn't

01:09:13.149 --> 01:09:15.270
afford the massive research and development costs

01:09:15.270 --> 01:09:18.210
to design them internally. So German shipyards

01:09:18.210 --> 01:09:20.750
created the Type 209 not just as a submarine,

01:09:21.050 --> 01:09:24.449
but as a highly customizable modular export platform.

01:09:24.529 --> 01:09:27.229
It became an absolute global juggernaut of arms

01:09:27.229 --> 01:09:30.170
exportation. The designers offered the Type 209

01:09:30.170 --> 01:09:32.189
in five different size variants ranging from

01:09:32.189 --> 01:09:35.329
a compact 1 ,000 tons up to an ocean -going 1

01:09:35.329 --> 01:09:37.189
,500 tons. You could basically order it off a

01:09:37.189 --> 01:09:39.489
menu. The Hellenic Navy of Greece immediately

01:09:39.489 --> 01:09:42.189
recognized the value and bought four. By the

01:09:42.189 --> 01:09:45.149
year 2002, German shipyards had constructed an

01:09:45.149 --> 01:09:48.069
astonishing 51 of these U -boats for 13 different

01:09:48.069 --> 01:09:50.210
sovereign navies across the globe. The political

01:09:50.210 --> 01:09:52.350
and geographic reach is incredible. They built

01:09:52.350 --> 01:09:55.130
them for the Argentinian Navy, who ordered massive,

01:09:55.289 --> 01:09:58.970
custom 2 ,000 -ton versions for deep ocean patrols.

01:09:59.069 --> 01:10:01.250
They engineered highly customized, politically

01:10:01.250 --> 01:10:04.050
sensitive variants for the Israeli Navy, which,

01:10:04.170 --> 01:10:06.609
due to complex geopolitical optics at the time,

01:10:06.970 --> 01:10:08.930
were actually physically assembled in shipyards

01:10:08.930 --> 01:10:12.069
in England by Vickers using the German blueprints.

01:10:12.890 --> 01:10:15.430
The historical arc here is truly incredible.

01:10:15.670 --> 01:10:17.890
Over the span of half a century, Germany went

01:10:17.890 --> 01:10:20.529
from being a nation globally legally banned from

01:10:20.529 --> 01:10:22.989
even touching a submarine blueprint of Versailles

01:10:22.989 --> 01:10:25.729
to becoming the single preeminent exporter of

01:10:25.729 --> 01:10:28.630
advanced non -nuclear submarines in the entire

01:10:28.630 --> 01:10:30.930
world. And they haven't stopped pushing the boundaries

01:10:30.930 --> 01:10:33.689
of physics and engineering. This brings us squarely

01:10:33.689 --> 01:10:35.970
into the modern era of naval warfare defined

01:10:35.970 --> 01:10:39.050
by the highly advanced Type 212, Type 214, and

01:10:39.050 --> 01:10:42.079
Type 218 submarines. The defining hallmark of

01:10:42.079 --> 01:10:45.279
these modern 21st century U -boats is the successful

01:10:45.279 --> 01:10:47.539
return to the holy grail of submarine design,

01:10:48.239 --> 01:10:51.619
air independent propulsion, or AIP. If we look

01:10:51.619 --> 01:10:54.399
back at Helmuth Walters failed, highly volatile

01:10:54.399 --> 01:10:58.000
hydrogen peroxide turbine from the 1940s, we

01:10:58.000 --> 01:11:00.739
see that the fundamental strategic concept, a

01:11:00.739 --> 01:11:03.319
submarine generating its own power to stay submerged

01:11:03.319 --> 01:11:05.539
indefinitely without needing outside atmospheric

01:11:05.539 --> 01:11:08.880
air, was absolutely correct. The idea was sound.

01:11:09.100 --> 01:11:11.699
The chemical technology simply took 60 years

01:11:11.699 --> 01:11:14.079
of development to finally catch up. Exactly.

01:11:14.340 --> 01:11:16.680
Instead of relying on a dangerous, explosive

01:11:16.680 --> 01:11:19.500
chemical reaction like hydrogen peroxide, the

01:11:19.500 --> 01:11:22.720
modern Type 212 utilizes highly advanced aerospace

01:11:22.720 --> 01:11:25.439
-grade hydrogen fuel cells. These cells take

01:11:25.439 --> 01:11:27.420
compressed liquid hydrogen and liquid oxygen

01:11:27.420 --> 01:11:29.840
stored safely in specialized tanks outside the

01:11:29.840 --> 01:11:31.880
pressure hull and combine them chemically to

01:11:31.880 --> 01:11:33.859
generate massive amounts of direct electrical

01:11:33.859 --> 01:11:36.149
current to run the propulsion motors. The only

01:11:36.149 --> 01:11:38.630
physical byproduct of this entire chemical process

01:11:38.630 --> 01:11:41.090
is pure distilled water, which is simply pumped

01:11:41.090 --> 01:11:43.109
out into the ocean or used by the crew. There

01:11:43.109 --> 01:11:46.109
are no massive, vibrating, air -breathing diesel

01:11:46.109 --> 01:11:48.189
engines required to charge the batteries while

01:11:48.189 --> 01:11:50.829
underwater. Because the fuel cells have virtually

01:11:50.829 --> 01:11:53.970
no moving mechanical parts, these modern submarines

01:11:53.970 --> 01:11:57.470
are incredibly, almost impossibly quiet. They

01:11:57.470 --> 01:12:00.550
emit practically zero acoustic signature, making

01:12:00.550 --> 01:12:03.119
them the ultimate stealth hunters. They can remain

01:12:03.119 --> 01:12:05.100
completely submerged, patrolling the deep ocean

01:12:05.100 --> 01:12:07.199
without ever needing to raise a snorkel mast

01:12:07.199 --> 01:12:09.779
or break the surface for literally weeks at a

01:12:09.779 --> 01:12:12.140
time. They are currently the spearhead of the

01:12:12.140 --> 01:12:15.119
modern German and Italian navies, while the export

01:12:15.119 --> 01:12:17.979
variant, the Type 214, has been sold to South

01:12:17.979 --> 01:12:20.699
Korea, Portugal, and Turkey. And the massive,

01:12:20.739 --> 01:12:23.520
highly advanced Type 218 is currently being custom

01:12:23.520 --> 01:12:25.760
-billed for the Republic of Singapore. It is

01:12:25.760 --> 01:12:28.239
a profound, sprawling technological journey.

01:12:28.489 --> 01:12:31.090
We have traced the U -boat from Wilhelm Bauer's

01:12:31.090 --> 01:12:34.670
1850 brand -toucher, a leaky, terrifying iron

01:12:34.670 --> 01:12:37.310
coffin powered by a human treadmill that plummeted

01:12:37.310 --> 01:12:39.590
to the bottom of Keele Harbor on its very first

01:12:39.590 --> 01:12:41.369
dive through the brutal industrial slaughter

01:12:41.369 --> 01:12:43.810
of the Atlantic wolf packs, and finally arriving

01:12:43.810 --> 01:12:47.069
at these ultra -quiet, fuel -cell -powered leviathans

01:12:47.069 --> 01:12:49.909
that are currently silently patrolling the coastlines

01:12:49.909 --> 01:12:52.430
of the modern world. It really is a profound

01:12:52.430 --> 01:12:55.689
testament to relentless engineering. adaptation

01:12:55.689 --> 01:12:59.229
and the harsh realities of warfare. We've spent

01:12:59.229 --> 01:13:02.770
the last hour looking at over a century of human

01:13:02.770 --> 01:13:06.130
beings pushing the absolute breaking limits of

01:13:06.130 --> 01:13:08.350
their own physical and psychological endurance.

01:13:08.609 --> 01:13:10.710
We've talked about the agonizing claustrophobia,

01:13:10.829 --> 01:13:13.210
the deafening noise, the sheer terror of depth

01:13:13.210 --> 01:13:16.029
charges exploding in the dark, the foul air and

01:13:16.029 --> 01:13:18.270
the bursting eardrums. All of that suffering,

01:13:18.609 --> 01:13:20.729
all that endurance is required just to survive

01:13:20.729 --> 01:13:24.050
inside these fragile metal tubes suspended beneath

01:13:24.050 --> 01:13:26.170
the crushing weight of the ocean. But as we conclude

01:13:26.170 --> 01:13:28.289
this deep dive and look to the horizon of naval

01:13:28.289 --> 01:13:30.909
warfare, navies around the world are no longer

01:13:30.909 --> 01:13:33.649
focusing exclusively on human endurance. They

01:13:33.649 --> 01:13:36.270
are aggressively developing massive, AI -driven,

01:13:36.609 --> 01:13:39.710
entirely uncrewed, autonomous submarines. And

01:13:39.710 --> 01:13:42.529
that reality leaves us with a lingering, somewhat

01:13:42.529 --> 01:13:45.210
unsettling thought to mull over as we wrap up

01:13:45.210 --> 01:13:48.630
today's deep dive. For over a century, the size,

01:13:48.789 --> 01:13:50.649
the shape, and the operational limits of every

01:13:50.649 --> 01:13:53.090
single submarine ever built have been fundamentally

01:13:53.090 --> 01:13:55.750
constrained by the squishy, fragile human element.

01:13:55.930 --> 01:13:59.409
You have to design massive heavy steel pressure

01:13:59.409 --> 01:14:02.329
hulls solely to protect human lungs from the

01:14:02.329 --> 01:14:04.529
ocean's weight. You have to dedicate huge amounts

01:14:04.529 --> 01:14:07.489
of interior space to galleys for cooking food,

01:14:07.750 --> 01:14:10.430
bunks for sleeping, complex chemical scrubbers

01:14:10.430 --> 01:14:13.130
to manufacture oxygen, and you have to design

01:14:13.130 --> 01:14:15.909
tactical limits to manage the profound psychological

01:14:15.909 --> 01:14:18.529
toll of the dark and the deep on the human mind.

01:14:18.720 --> 01:14:21.699
But when we look to the future, when we completely

01:14:21.699 --> 01:14:24.300
remove that fragile human element from the depths,

01:14:24.840 --> 01:14:27.079
when a submarine is no longer a life support

01:14:27.079 --> 01:14:30.500
system, but simply a cold calculating artificial

01:14:30.500 --> 01:14:33.390
intelligence housed inside. a pressure -proof

01:14:33.390 --> 01:14:35.850
titanium casing that never needs to breathe,

01:14:36.369 --> 01:14:38.789
never needs to eat, and never needs to sleep.

01:14:38.829 --> 01:14:41.590
What unimaginable shapes, what crushing depths,

01:14:41.729 --> 01:14:44.550
and what terrifying new tactical realities will

01:14:44.550 --> 01:14:46.550
the U -boats of the 21st century take? That's

01:14:46.550 --> 01:14:48.550
a chilling thought. It really is. Thank you for

01:14:48.550 --> 01:14:50.369
joining us on this immersive journey into the

01:14:50.369 --> 01:14:53.069
history and the future of the deep today. Keep

01:14:53.069 --> 01:14:54.930
questioning the history you think you know, keep

01:14:54.930 --> 01:14:57.090
looking below the surface of the narrative, and

01:14:57.090 --> 01:14:59.149
keep diving deep into the things that make you

01:14:59.149 --> 01:15:00.710
curious. Farewell.