- 28 minutes ago
A downed American bomber helped reveal why Germany could not build one of the war’s most important engine parts in real numbers. When a B-17 called Wulf Hound landed in German hands, Luftwaffe engineers studied the exhaust-driven turbo-superchargers under its wings and discovered a problem that went far beyond copying a design.
This military history documentary follows the story from the captured Fortress at Rechlin to the German test pilot Hans von Lesecke, the cancelled Focke-Wulf turbocharged fighter, and the material shortages that crippled German production. It also traces how American industry solved the same heat and alloy problems at scale, using precision casting, dental alloy know-how, and mass production to keep B-17 bombers flying at high altitude over Europe.
The result is a fascinating World War II engineering story about turbo-superchargers, high-altitude bomber performance, Luftwaffe test flights, and the hidden industrial battle behind the air war. It is ideal for listeners interested in WW2 stories, military aviation history, aircraft engines, and the technology that shaped bomber warfare.
SEO: WW2 history documentary, military history narration, B-17 bomber story, turbo-supercharger explained, Luftwaffe engineering, American bomber crews, high-altitude aircraft engines, World War II aviation history, wartime technology, and forgotten WW2 stories for history listeners.
This military history documentary follows the story from the captured Fortress at Rechlin to the German test pilot Hans von Lesecke, the cancelled Focke-Wulf turbocharged fighter, and the material shortages that crippled German production. It also traces how American industry solved the same heat and alloy problems at scale, using precision casting, dental alloy know-how, and mass production to keep B-17 bombers flying at high altitude over Europe.
The result is a fascinating World War II engineering story about turbo-superchargers, high-altitude bomber performance, Luftwaffe test flights, and the hidden industrial battle behind the air war. It is ideal for listeners interested in WW2 stories, military aviation history, aircraft engines, and the technology that shaped bomber warfare.
SEO: WW2 history documentary, military history narration, B-17 bomber story, turbo-supercharger explained, Luftwaffe engineering, American bomber crews, high-altitude aircraft engines, World War II aviation history, wartime technology, and forgotten WW2 stories for history listeners.
Category
📚
LearningTranscript
00:00October 17, 1943.
00:03Wechlin, at the southern end of Lake Muritz, about 60 miles north of Berlin.
00:08A Boeing B-17 flying fortress rolls to a stop at the Luftwaffe's main flight test center.
00:15Until recently, it belonged to the United States Army Air Forces.
00:20It came down in Denmark, near the port of Esbjag.
00:23Yesterday, a German test pilot named Hans-Werner Lerke climbed into the left seat,
00:29flew it south, stopped overnight at Schwerin, and this morning brought it the rest of the way.
00:35The people at Wechlin who want this airplane most are not fighter pilots,
00:39and they are not hunting for blind spots in its gun positions.
00:43Lerke later wrote that the fortress went primarily to the power plant experts, engine men.
00:49What they care about sits underneath the four engine nacelles,
00:53a round, heavy, unremarkable-looking piece of machinery tucked behind each engine.
00:59Lerke's words about it are worth hearing exactly.
01:02The B-17 interested us, he wrote, not so much because of its flying characteristics,
01:07but more because of its supercharged engines, which gave excellent performance at higher altitudes.
01:14Think about what that sentence admits.
01:17This is the country of Daimler-Benz, of BMW, of Junkers.
01:22The country that would soon put the world's first jet fighter into combat.
01:27And its specialists are lining up to study something bolted under the wings of an American bomber.
01:33Here is what makes it stranger.
01:35The thing they are studying is not a secret.
01:39It is an exhaust-driven turbo supercharger.
01:42A Swiss engineer patented the basic idea in 1905.
01:46An American engineer named Sanford Moss hauled a working one to the summit of Pikes Peak in 1918
01:53and proved it could give an engine back the power that thin air steals.
01:58None of this was hidden from German engineers.
02:01They understood the principle perfectly well.
02:04So the question in front of these men is not what it is.
02:07The question is the one in the title of this story.
02:11Why could American factories turn this part out by the tens of thousands
02:14while Germany, with all its engineering talent, could not?
02:19Hold on to that question.
02:21The answer is not the one most people would guess.
02:24And one of the men at Recklin would eventually put it in writing.
02:28If you want to see what the American bomber crews carried up into the thin air over Germany
02:33and what it cost to build, hit like and subscribe.
02:37It helps this investigation reach more people.
02:40To understand why those engine men were so eager, go back ten months
02:44to the first time Germany got its hands on one of these bombers almost in one piece.
02:49December 12th, 1942.
02:52Molesworth, England.
02:54The 303rd Bomb Group is flying only its sixth mission.
02:58One of its B-17s, serial number 4124585, carries the name Wolfhound.
03:06Her pilot is 1st Lieutenant Paul Flickinger, 24 years old.
03:11Four of the gunners aboard that day are substitutes, filling in for the regular men.
03:15The group is sent toward the German-held airfield at Romilly-sur-Seine, southeast of Paris,
03:21and ends up striking the rail yards at Rouen instead.
03:25Somewhere along the way, German fighters find Wolfhound.
03:28Number 4 engine goes first.
03:31Then number 3.
03:33Flickinger dives into cloud, turns for England on two engines, and salvos the bombs.
03:39Then the fighters find him again.
03:41And number 2 quits.
03:43One engine.
03:45Ten men.
03:46Occupied France below them.
03:49At about half past twelve, Flickinger puts Wolfhound down on her belly in a muddy field southeast of Paris.
03:55The records call it a perfect wheels-up landing.
03:59All ten men climb out unhurt.
04:02What they do next is exactly what they were trained to do.
04:05They smash the radio.
04:07They smash the IFF set, the box that tells Friendly Radar who they are.
04:12They destroy the films, the maps, the flimsies with the day's signals.
04:17Then they stand in that field and talk about how to destroy the airplane itself.
04:22And they cannot find a way to do it.
04:24Then they head for the woods.
04:26Six of those ten men will eventually make it over the Pyrenees into Spain.
04:30The other four will be captured.
04:33One of them is the ball turret gunner, George Dillard.
04:37He is twenty years old, and on Christmas Day, he will be standing in a railway station in Dijon when
04:43the Gestapo finds him.
04:44Keep his name in mind.
04:46We will come back to him.
04:48Now look at what that crew could destroy, and what they could not.
04:53A radio breaks under a boot heel.
04:56A map burns.
04:58But under each of Wolfhound's four engine nacelles sits a turbo supercharger.
05:03A heavy housing with a small turbine wheel inside, spun by the engine's own exhaust.
05:10Nobody on that crew had a reason to smash it.
05:13It was no secret.
05:14Any trained engine men in Germany would recognize it on sight.
05:19And here is the detail that turns this from a story about a captured airplane into something much stranger.
05:25Eight days after Wolfhound slid into that field, on December 20th, 1942, a German fighter took off with a German
05:32turbo supercharger of its own.
05:35It flew.
05:36It was fast.
05:38And what happened to it in the air is the first clue to why the engine men at Recklin were
05:43still crowding around an American bomber ten months later.
05:46December 20th, 1942.
05:49Most of Wolfhound's crew are still on the run somewhere in France.
05:52In Germany, a Focke-Wulf 190 prototype, the V-18, takes off with something no ordinary 190 carries.
06:01Under its belly hangs a long fairing.
06:04Inside it is a hearth exhaust turbo supercharger, the TK-11, feeding a big Daimler-Benz 603 engine.
06:12That pouch under the fuselage gives the airplane its nickname, Kangaroo, the Kangaroo.
06:19It is Germany's own answer to the thin air above 30,000 feet, and the engine is expected to make
06:26around 2,000 horsepower.
06:28In the air, the engine overheats.
06:31The flights have to be kept short.
06:33Now listen to this next number, because it tells you the problem was never talent.
06:38By May of 1943, that same airplane reaches 416 miles an hour at 36,100 feet.
06:47For a piston fighter in 1943, that is a spectacular figure.
06:52The German turbo worked.
06:54What it could not do was keep working.
06:57It could not be run for long without overheating.
07:00Then comes the decision.
07:02In December 1942, the Luftwaffe had ordered 727 of these turbocharged fighters.
07:09On February 26, 1943, the order is cancelled.
07:15Focke-Wulf turns instead to fighters built around the Junkers Jumo 213, an engine with no exhaust turbine at all.
07:23Germany has tested its own turbo against the sky, and it has stepped back.
07:28Now, to feel what that cancellation really means.
07:32Step into the cockpit of an American bomber, and look at what its pilots ask of the same device.
07:37Not minutes.
07:39Hours.
07:41A fortress bound for Germany climbs out of England, assembles with the rest of its group, crosses the water, and
07:48then lives for hours at 22, 25, 27,000 feet.
07:53Up there, the air is so thin that an unaided engine starves.
07:58The right cyclones on a B-17 are rated at 1,000 horsepower at 25,000 feet, and that rating
08:04exists only because of the turbo underneath each one.
08:08Inside that turbo, the wheel turns at 21,300 revolutions a minute.
08:15Do the arithmetic, and that is 355 turns every second, inside a stream of exhaust hot enough to glow.
08:24Hour after hour, mission after mission.
08:28And this is not a handful of hand-built prototypes.
08:31By 1943, according to General Electric, more than 100,000 of its turbo superchargers were in service.
08:39100,000 on the American side.
08:42On the German side, a canceled order and a fighter nicknamed after a kangaroo.
08:48The pilots manage all of it by hand.
08:51On the early fortresses, the turbos answer to regulators that run on engine oil.
08:56Keeping four engines matched at altitude is constant work for the two men up front.
09:02December 30, 1943.
09:05A B-17G of the 384th Bomb Group, named Lazy Daisy, is at 22,000 feet with Austin Rinna's crew
09:13aboard.
09:15Number 3 turbo will not deliver.
09:17The gauge for that engine shows only 22 inches of manifold pressure.
09:22At that height, it is an engine running out of breath, and the defect goes into the mission report.
09:29Why does that matter so much?
09:31Because in a bomber formation, every fortress covers its neighbors with its guns.
09:37A ship that cannot hold its place drifts back,
09:39and a lone bomber behind the formation is exactly what German fighter pilots hunt for.
09:46Now notice what that report really tells you.
09:49For an American crew, one turbo that fell short for one mission was a defect worth writing up.
09:56A turbo that ran for hours, day after day, at 355 turns a second, was simply normal.
10:04The German turbo could not do, even on a prototype, what American crews treated as routine.
10:11March 17, 1943.
10:14Recklen.
10:16Less than three weeks after that cancellation, Wolfhound flies again.
10:20She wears German crosses now, yellow undersides, and the code D-L-X-C.
10:28Nobody bothers to replace her damaged ball turret.
10:32Hans van Ilerke will get his first instruction flight in her, then move over to the left seat.
10:37And now the engine men can do what no photograph allows.
10:41They can open a nacelle and take an American turbo apart.
10:46Inside is a turbine wheel ringed with small blades the Americans call buckets.
10:52Exhaust pours across the buckets and spins the wheel.
10:55The wheel drives a compressor that crams dense air into the engine.
11:01There is nothing in that layout a German engineer could not draw.
11:05Their own Hirth unit runs on the very same idea.
11:09So put yourself in their place and ask the obvious question.
11:13Same principle, same red-hot exhaust.
11:17Why does the German wheel cook itself in minutes,
11:20while the American one runs straight through a mission into Germany and back?
11:25Here is something almost nobody at Rechlin would have expected.
11:30A few years earlier, the American turbo had suffered from the very same disease.
11:36Writing in Air Force magazine in June 1945,
11:40Major Robert Gielisch remembered how, time after time,
11:44the turbo supercharger would overheat and throw its buckets out of the turbo wheel.
11:49The Americans had stood exactly where the Germans were standing now.
11:53And the cure, when it came, did not come out of an aircraft plant.
11:58It came out of a business that made false teeth.
12:02March 1939.
12:04A single Boeing bomber is climbing toward 25,000 feet.
12:08It is the Y-1B-17A, serial number 37369,
12:14the one fortress the Army has been using to test General Electric turbos.
12:19At the controls is Lieutenant Pearl Roby.
12:23Here is why this one flight matters more than it looks.
12:27Major Robert Gielisch, the same officer who described those thrown buckets,
12:31wrote that if this test had failed,
12:34all orders for turbo superchargers on B-17s would have been cancelled.
12:39Think about that.
12:41Four years before the Luftwaffe cancelled its turbocharged fighter,
12:45the American program stood at the very same fork in the road.
12:49One bad flight, and the B-17 goes to war without them.
12:54Roby levels off at 25,000 feet,
12:57and the airspeed settles at 311 miles an hour, by Gielich's account.
13:02The turbos become standard on every fortress that follows.
13:05Five months later, on August 1, 1939,
13:09Roby and Captain Clarence Irvine take the same airplane to 34,026 feet,
13:15carrying more than 11,000 pounds.
13:18A world record.
13:20Five and a half tons of payload, nearly six and a half miles up.
13:26Sanford Moss, the man who had dragged a turbo up Pikes Peak back in 1918,
13:31had retired from General Electric in 1938.
13:35When the war came, he went back.
13:37He once said his machine kitted the piston engine
13:40into thinking it was at sea level.
13:43Roby's flight proved the kitting worked at 25,000 feet.
13:47It did not prove the machine would survive a war.
13:51What was not solved was the wheel.
13:54For 20 years, the bucket makers had gone from one alloy to another,
13:59forging each bucket and machining it,
14:01and each new alloy bought a little more heat before the metal gave up.
14:06A bucket that lets go at 20,000 revolutions a minute does not fall off.
14:11It leaves.
14:12Now the war was coming, and the army would want turbos not by the hundred,
14:17but by the tens of thousands.
14:20Forging that many buckets, one by one, was simply not practical.
14:24This is where a man named Sam Herron walks into the story.
14:29Born in Newcastle, England, he had come to America in 1921
14:33after falling out with his employer.
14:35And at the army's McCook Field,
14:38he had figured out how to cool red-hot exhaust valves with sodium.
14:43During the war, he was on loan to the government from the Ethyl Corporation.
14:47And Sam Herron wore false teeth.
14:51Here is the problem he was looking at.
14:53There was a cobalt-based alloy whose characteristics obviously suited turbo buckets.
14:59It held its strength in heat that would soften ordinary steel.
15:03But the experts said it could not be cast to the precision a turbine wheel demands.
15:10Herron's answer, as the engine historian L.J.K. Setright told it,
15:14was to take out his dentures.
15:16They were cast from a cobalt alloy called Vitalium by a dental laboratory
15:21to fit the inside of a human mouth,
15:23which is about as unforgiving a fit as any machinist will ever face.
15:28The question was no longer whether this alloy could be cast with precision.
15:32The proof was sitting in his hand.
15:35The alloy belonged to a dental company called Austinol Laboratories in New York.
15:40Its technicians worked with a method thousands of years old.
15:43Carve the part in wax.
15:46Coat the wax in ceramic.
15:48Melt the wax out.
15:49Pour molten metal into the hollow it leaves behind.
15:53Lost wax casting.
15:55They used it to make dentures.
15:57General Electric's engineers in Schenectady wanted to use it to make turbine buckets.
16:02A tooth and a turbine blade.
16:05The same craft, the same patience.
16:08A very different fire.
16:11And here is the detail I want you to remember.
16:14When the candidates were tested,
16:16it was not one of General Electric's own experimental heat-resistant alloys that came out best.
16:21It was the dental alloy.
16:23With its carbon content lowered,
16:25it became the turbo bucket material.
16:26And from late 1941,
16:29its close cousin, Stellite 21,
16:31was the standard.
16:33A metallurgist, writing in 2010,
16:35put a picture of one of those buckets in his paper,
16:38with a caption calling it
16:40The First Successful Investment Casting.
16:43Think about that for a second.
16:45The metal and the method behind the part
16:47that let the B-17 fight at 25,000 feet
16:50came out of a company that made false teeth.
16:54Now go back to Recklin
16:56and to Wolfhound's opened nacelles.
16:58Every one of those buckets
17:00was a small cobalt casting.
17:03Put one on a German laboratory bench,
17:05and a competent metallurgist could tell you what was in it.
17:08Cobalt.
17:09A lot of chromium.
17:11Some molybdenum.
17:12The recipe was no more a secret than the turbo itself.
17:16Think about what that means for the engine men at Recklin.
17:20They are not looking at a mystery.
17:22They are looking at a shopping list.
17:25So why didn't Germany simply copy it?
17:28That question has two halves.
17:29The first is how many of these little castings
17:32America was about to make.
17:33A number so large, it sounds like a misprint.
17:36The second is what was inside them.
17:39Because one of those ingredients
17:41was the metal Germany's own armaments minister
17:44would soon single out in a memo to Hitler
17:46as the one in shortest supply.
17:48February 3, 1944.
17:52Lazy Daisy, the B-17G of the 384th bomb group
17:56we met earlier,
17:57comes back from a mission
17:58with Lt. Sidney Paul Taylor at the controls.
18:01Only now, on the ground,
18:04does anyone notice what happened to number one.
18:07The number one turbo threw a bucket.
18:10Remember what that means.
18:11A piece of the turbine wheel,
18:13spinning hundreds of times a second in red-hot exhaust,
18:16tore loose somewhere along the way.
18:18And the engine kept running well enough
18:21that the crew never knew.
18:23Taylor knew these machines by feel.
18:26Back on December 13, 1943,
18:28when his manifold pressure dropped,
18:30his crew's report describes the fix
18:32as manipulation of the supercharger control.
18:36No manual can teach that touch.
18:39It comes from hours at altitude
18:40with a hand on the turbo controls.
18:43Seventeen days after that thrown bucket,
18:45on February 20th,
18:47the first day of the air offensive
18:48remembered as Big Week,
18:50Taylor takes Lazy Daisy up
18:52for his 25th mission,
18:54the last one of his tour.
18:56Number one turbo throws a bucket again.
18:59Its regulator goes out.
19:01Number two propeller acts up.
19:03And Taylor brings her home.
19:0625 missions.
19:07His tour is done.
19:10Now listen to what those two reports
19:12are really saying.
19:14In Germany,
19:15the turbo was a part that failed
19:17and ended a fighter program.
19:19In an American bomber,
19:21the turbo was a part that could fail,
19:23partly,
19:24in the middle of a mission,
19:26and the airplane still came home.
19:28That is not just a better part.
19:31That is a part built with margin to spare
19:33and a system that could afford to replace it.
19:37Over her career,
19:39the records list nine separate
19:40supercharger problems
19:41on Lazy Daisy alone.
19:44Nine.
19:45And every time,
19:46she went back up.
19:48Which brings us to the number
19:50I promised you.
19:51Get ready for it,
19:52because it sounds like a misprint.
19:54Haynes Stellite,
19:55the company behind the alloy,
19:57says more than 25 million
19:58of its cast buckets
20:00went into aircraft superchargers
20:02during the war.
20:03One metallurgical history
20:05puts the total at 35 million.
20:0825 million.
20:10Spread that over four years of war,
20:12and it comes to roughly
20:1317,000 precision castings
20:16every single day.
20:18Each one shaped first in wax,
20:21coated,
20:22baked,
20:23poured,
20:24finished,
20:24and inspected.
20:26The same patient craft
20:27as a dental crown,
20:29done at the scale
20:30of an ammunition plant.
20:32And the buckets
20:33were only the beginning.
20:35The turbos themselves
20:36came off lines
20:37run by General Electric,
20:38by Ford,
20:39and by Alice Chalmers,
20:41whose supercharger works
20:42in Milwaukee
20:43built General Electric
20:44designs under license,
20:45and won the Army-Navy
20:47E Award
20:48four times.
20:49Here is a figure
20:51worth sitting with.
20:52Not counting spares,
20:54B-17 production alone
20:56needed 50,768 turbo superchargers.
21:01One bomber type.
21:03Four turbos each.
21:05More than 50,000 units.
21:08Now set that beside
21:09the Luftwaffe's cancelled order
21:11for 727 kangaroo fighters.
21:14And here is the part
21:15that truly separates
21:16the two countries.
21:18The Americans
21:19were not just building
21:20the turbo,
21:21they were improving it
21:22in the middle of the war.
21:24Later fortresses
21:25got a new turbo,
21:26the B-22,
21:28built to run
21:28at 24,000 revolutions a minute,
21:31and the rated altitude
21:32climbed from 25,000 feet
21:34to 30,000.
21:35The old oil-driven regulators
21:38gave way
21:38to an electronic system
21:39from Minneapolis-Honeywell
21:41with an overspeed governor
21:42built in.
21:43For the pilots,
21:45that meant less time
21:46wrestling four turbos
21:47into agreement
21:48and more attention left
21:49for the formation.
21:52May 29, 1944.
21:55Lazy-dazy again.
21:57This time,
21:58the pilot is David Rucker,
21:59and his report
22:00contains a request
22:01worth reading twice.
22:03He asks that the airplane
22:04be taken out of combat.
22:06Not because her turbos
22:08have failed,
22:09because they still use
22:10the old oil regulators.
22:12In his words,
22:14you cannot stay in formation
22:15with the electronic type.
22:18Read that once more
22:19and think about
22:20where Germany stood
22:20at that moment.
22:22An American pilot
22:23wants a turbocharged bomber
22:25pulled from the line
22:26because its turbo controls
22:28are one generation old.
22:30On the other side of the front,
22:31Germany's turbos
22:33were still prototypes
22:34and test stand units.
22:36Hold that picture
22:37next to the one at Wechlin.
22:39German engine men
22:40crowded around
22:41an American nacelle,
22:42studying a part
22:43their own country
22:44could not field.
22:46The Americans
22:47were already asking
22:48to retire
22:49the older version of it.
22:51So the first half
22:52of our answer
22:53is now on the table.
22:55America did not make
22:56one good turbo.
22:57It made a turbo industry.
23:00Buckets by the million,
23:02turbos by the tens of thousands,
23:04new models rolled in mid-war,
23:06and crews who expected
23:08all of it
23:08to simply work.
23:11But scale alone
23:12still does not explain
23:13the engine men at Wechlin.
23:14Germany could build
23:16at scale, too.
23:17It turned out,
23:18tanks and fighters
23:19by the thousands.
23:21So why not this?
23:22The answer sits
23:23in a memorandum
23:24Albert Speer handed Hitler
23:26in November 1943.
23:28Speer had done
23:29the arithmetic
23:30on the alloy metals
23:31Germany's war industry
23:32could not live without,
23:33and the number he reached
23:34was not measured in tons.
23:36It was measured in months.
23:38Months until the armaments industry
23:40would simply stop.
23:43Remember that word,
23:44months.
23:46Because a few weeks later,
23:47the man who wrote it
23:48traveled north of the Arctic Circle
23:50to inspect a single nickel mine.
23:52November 11, 1943.
23:55Albert Speer,
23:56Hitler's Minister of Armaments,
23:58sends a teletype
23:59about manganese to Hitler
24:00and to the Army's chief of staff,
24:02General Kurt Zeitzler.
24:04The news is tolerable.
24:0611 to 12 months of stock.
24:08Then comes a second memorandum.
24:10This one inventories
24:11every alloy metal in the Reich
24:13and deliberately leaves out
24:15the imports from the Balkans,
24:16from Turkey,
24:18from Finland,
24:18from northern Norway.
24:20The question behind it is simple.
24:22If the imports stop,
24:24how long can Germany
24:25keep making weapons?
24:27Here is his answer,
24:28in his own words.
24:29The element in shortest supply
24:31is chromium.
24:32This is especially grave
24:34since chromium is indispensable
24:35to a highly developed
24:37armaments industry.
24:38Should supplies from Turkey
24:40be cut off,
24:41he wrote,
24:41the stockpile of chromium
24:43is sufficient only
24:44for 5.6 months.
24:46After that,
24:47he calculated,
24:48production would have to cease
24:49within one to three months.
24:51Speer's own conclusion?
24:53The war would be over
24:54approximately 10 months
24:56after the loss
24:57of the Balkans.
24:59Hitler's reaction
25:00is on record, too.
25:01He snarled
25:02that Speer was to give
25:03the chief of staff
25:04no more memoranda.
25:06I forbid it,
25:07he said,
25:08and turned away
25:09to talk about tank programs.
25:12Now set that memo
25:13beside a turbine bucket
25:14from Wolfhound.
25:15The alloy in those buckets
25:17is roughly
25:18a quarter chromium.
25:20Every turbo
25:21Germany built that way
25:22would draw
25:23on the same
25:24shrinking pile
25:25that fed
25:26armor plate
25:26and gun steel.
25:28America had its own
25:29allocation boards,
25:31but it could buy
25:31from half the world.
25:33Germany could buy
25:34only from whoever
25:35was still willing
25:36and able to sell.
25:38Which is why,
25:39about six weeks later,
25:41the Armaments Minister
25:42of the Reich
25:42is standing in the snow
25:44of northern Lapland.
25:46Speer spent Christmas
25:47of 1943
25:48in the far north,
25:50near Petsamo.
25:52Close by
25:52lay the nickel mines
25:53of Kolosjoki,
25:55which he called
25:56our sole source of nickel.
25:57He found ore piling up
25:59because the transport
26:00was busy building
26:01a bomb-proof power plant.
26:02He gave the power plant
26:04a lower priority
26:05and the nickel
26:05began to move.
26:07Think about that image
26:08for a moment.
26:09The man running
26:10Germany's entire
26:11war production,
26:13personally clearing
26:13a traffic jam
26:14at one mine
26:15above the Arctic Circle.
26:17That is what scarcity
26:18looks like from the top.
26:20Leave Speer
26:21in that snow
26:22for a moment
26:22and cross to the other
26:23side of the war.
26:25The Americans
26:26were counting, too.
26:27February 26, 1944.
26:30In Washington,
26:31Hugh Cumming,
26:32chief of the State Department's
26:34Division of Northern European Affairs,
26:36summarizes a joint intelligence
26:38staff survey of Finland.
26:40Listen to the figures,
26:41because they read
26:42like the ingredient list
26:43of a turbine bucket.
26:45Germany,
26:46the survey found,
26:47was getting from Finland
26:4860% of the nickel
26:49available to it,
26:5028% of its cobalt,
26:52between 23% and 32%
26:55of its molybdenum.
26:57Cobalt and molybdenum,
26:58two of the metals
27:00in Wolfhound's turbine wheels
27:01in Washington
27:02had Germany's dependence
27:03on them measured
27:04to the percent.
27:06More than one pound
27:07in four of Germany's cobalt
27:09came from one country
27:10in the far north.
27:12Then the Americans
27:13and the British
27:13went after the chromium.
27:15April 14, 1944.
27:19Ankara.
27:20Lawrence Steinhardt,
27:22a New York lawyer
27:23who had been
27:23Roosevelt's ambassador
27:24in Moscow,
27:25and his British counterpart,
27:26present Turkey's foreign minister,
27:29Numan Menemencioglu,
27:31with a joint declaration
27:32on strategic materials
27:33going to Germany.
27:35That night,
27:36Steinhardt cables Washington.
27:38The foreign minister
27:39has agreed to cut
27:40chrome deliveries
27:41to Germany
27:42to 4,200 tons a month,
27:44about half the recent rate.
27:47Steinhardt even advises
27:48that a letter Roosevelt
27:49had planned to send
27:50Turkey's president
27:51would now serve
27:52of no useful purpose.
27:54The declaration
27:55had already done the work.
27:57Germany's ambassador
27:58in Ankara,
27:59Franz von Papen,
28:00had been pressing
28:01Numan over the chrome.
28:03He lost.
28:04Six days later,
28:05it goes further.
28:07On the afternoon
28:08of April 20,
28:09Numan tells
28:10the Grand National Assembly
28:11that Turkey
28:11will halt chrome exports
28:13to Germany
28:14and the other Axis countries,
28:15effective that evening.
28:17It happens to be
28:18Hitler's 55th birthday.
28:20The next morning,
28:22Steinhardt's telegram
28:23is on its way.
28:24Now remember Speer's figure,
28:275.6 months.
28:29By his own arithmetic,
28:31the clock he had shown
28:32Hitler has just started.
28:34In February alone,
28:36Turkish chrome deliveries
28:37to Germany
28:38had run to 6,752 tons.
28:42From that April evening,
28:44the official figure
28:45was zero.
28:47And here is where
28:48the two halves
28:49of our answer meet.
28:51On one side,
28:52an industry pouring
28:5325 million cobalt castings
28:56while its diplomats
28:57closed the enemy's supply lines.
29:00On the other,
29:01a country whose armaments chief
29:03was counting chromium in months
29:05and inspecting nickel mines himself.
29:08The engine men at Recklin
29:10did not just lack a turbo.
29:12They lacked the metal
29:13to spend on one.
29:14But German engineers
29:15did not give up easily.
29:17If the metal could not
29:18survive the heat,
29:20perhaps the heat could be kept
29:21away from the metal.
29:23At BMW,
29:24an engineer had been working
29:26on exactly that idea
29:27since 1941.
29:29And by January 1944,
29:31he had a turbo
29:32that worked.
29:34What it cost to build,
29:36and how many ever flew,
29:37is where the engine men's question
29:40finally gets its answer.
29:42And the man who writes
29:43that answer down
29:44is the test pilot
29:45who flew Wolfhound,
29:47January 1944.
29:49At BMW,
29:51an engineer named Dr. A. Mueller
29:53finishes a turbo supercharger
29:55for the BMW 801J,
29:57and a modern historian
29:58of German jet engines
30:00calls it excellent.
30:02Mueller had written
30:03his doctoral thesis
30:04in 1941 on one idea,
30:06cooling a turbine blade
30:08from the inside.
30:09Here is how it works,
30:11and it is genuinely clever.
30:13If you cannot get a metal
30:14that survives the heat,
30:16make the blade hollow
30:17and blow cooler air
30:18through it
30:19so the metal never gets
30:20as hot as the gas around it.
30:22German engineers
30:23were doing this years
30:24before it became
30:25standard practice
30:26in jet engines everywhere.
30:27Give them their due.
30:28This was not
30:30a nation short of ideas.
30:32But look at what
30:33the clever solution costs.
30:35A solid American bucket
30:37is poured into a ceramic mold
30:39like a dental crown.
30:40A hollow,
30:42internally cooled blade
30:43has to be built
30:44with passages inside it.
30:45It is harder to make,
30:47slower to make,
30:48and dearer to make.
30:50And the airplane
30:50those turbo engines
30:51were meant for,
30:52the Junkers 388,
30:54was built only in tiny numbers
30:56before its program
30:57was canceled.
30:57Put the two numbers
30:59side by side.
31:00B-17 production alone,
31:03more than 50,000 turbos.
31:05The Junkers 388,
31:07a handful of airframes.
31:09One of them survives today
31:11in the Smithsonian's collection,
31:13still carrying its
31:14two turbocharged BMW engines.
31:17The German answer
31:18to Wolfhound's turbos
31:19ended up in the country
31:21that built the original.
31:23Now go back to the day
31:24that put a second fortress
31:26into Lerke's hands.
31:27October 9th, 1943.
31:30The 8th Air Force
31:32sends its bombers
31:32far to the east,
31:34out over the Baltic.
31:35At Marienburg
31:36in East Prussia,
31:37a plant the Germans
31:39had believed
31:39was beyond the bomber's range,
31:4196 B-17s arrive
31:43over the Focke-Wulf factory
31:45that builds the 190.
31:47They drop nearly 218 tons
31:50of bombs.
31:51Britain's chief
31:51chief of the air staff,
31:53Sir Charles Portal,
31:54called it the most perfect example
31:56of accurate distribution
31:57of bombs.
31:59One of the fortresses
32:00sent east that day
32:01never makes it home.
32:02With engine trouble,
32:04its crew bails out
32:05over Denmark,
32:06and the pilot
32:07puts the bomber down
32:08in a field near Varde.
32:10That is the airplane
32:11Lerke flies
32:12to Rechlin
32:13a week later,
32:14and the power plant experts
32:15fit it with measuring instruments
32:17to watch its engines climb.
32:19Lerke had been here before.
32:21In the summer of 1943,
32:23he tested a captured
32:24B-24 Liberator
32:26at Rechlin,
32:27climbing it to 27,900 feet
32:29for speedruns.
32:31He admitted he worried
32:33that the pressure changes
32:34might overload
32:35the turbocharged engines,
32:36and he wrote down
32:37what he found.
32:39The rightly admired speed
32:40of these American bombers,
32:42he said,
32:43came only at 7,500 to 9,000 meters,
32:47roughly 25 to 30,000 feet,
32:50exactly where the turbos
32:52did their work.
32:52And the B-17,
32:53he judged,
32:55could operate higher still,
32:56by another 5 to 6,500 feet.
32:59He was no flatterer.
33:01He noted that the American turbos
33:03had to be controlled by hand,
33:05while the BMW engine
33:06in the Focke-Wulf 190
33:08used an automatic
33:09single-lever control.
33:11When German engineering
33:13was better,
33:14Lerke said so,
33:15which is exactly why
33:16what he wrote next
33:17carries so much weight.
33:19On one of those
33:20instrumented climbs,
33:21the fortress from Denmark
33:22caught fire in No. 4 engine
33:24at about 9,000 feet,
33:26and Lerke brought her
33:27into Rechlin on 3.
33:29And at the end
33:30of his account
33:31of the B-17,
33:32the man who flew Wolfhound
33:34wrote the sentence
33:35this whole story
33:36has been building toward.
33:38It must be stressed
33:39that the respectable speed
33:40of the B-17
33:41at higher altitudes
33:43was due solely
33:44to its excellent
33:45exhaust-driven
33:46turbo superchargers.
33:47But for the production
33:48of these devices,
33:50one required not only
33:51the know-how,
33:52but also large quantities
33:53of heat-resisting materials,
33:55which we were lacking
33:56in Germany.
33:57Stop for a moment
33:59and consider who is saying this.
34:01Not an American publicist.
34:03A Luftwaffe test pilot
34:05writing about the enemy's bomber
34:07decades after the war,
34:08with nothing left to prove.
34:11Read it slowly,
34:12because every phrase in it
34:14is a piece of this story.
34:16Due solely to its
34:17turbo superchargers.
34:19That is Roby's climb
34:21in 1939,
34:22and Rucker asking
34:23to retire an airplane
34:24with the old regulators.
34:26The know-how.
34:28That is Sam Herron's
34:29false teeth,
34:30a dental laboratory
34:31in New York,
34:32and 25 million buckets
34:34poured in wax and ceramic.
34:36Large quantities
34:37of heat-resisting materials.
34:39That is Speer
34:41counting chromium in months,
34:42and Lawrence Steinhardt's
34:44cable from Ankara.
34:46Which we were lacking
34:47in Germany.
34:49Six words,
34:50and the whole answer
34:51is inside them.
34:52So that is why
34:53a downed American bomber
34:54carried a part
34:55Germany could not make
34:57in any real numbers.
34:58Not because the Germans
35:00could not understand it,
35:01because building it
35:02took a casting craft
35:04borrowed from dentists
35:05and scaled up
35:06like a munitions line.
35:08And metal
35:09that America could pour
35:10by the ton,
35:11while Germany counted it
35:13by the month.
35:14But Lerker's sentence
35:16has a second meaning,
35:17one that reaches
35:18far beyond bombers.
35:20Those same
35:21heat-resisting materials
35:22were exactly what
35:24Germany needed
35:24for the engine
35:25it was betting
35:26its air war on.
35:28And when America
35:29chose a company
35:30to build its first jet engine,
35:32the reason for that choice
35:33was sitting in
35:34Wolfhound's nacelle
35:35cells all along.
35:36April 18th, 1942.
35:39Lynn, Massachusetts,
35:40north of Boston.
35:42Inside a concrete test cell
35:44the men call
35:44Fort Knox,
35:45a team at General Electric
35:47starts an engine
35:48that has no pistons
35:49and no propeller.
35:51It is the IA,
35:52the first jet engine
35:54built in the United States.
35:55And the department
35:56that built it
35:57has a name you will recognize,
35:59the Supercharger Department.
36:01Notice the date.
36:02This is eight months
36:04before Wolfhound
36:05slid into that French field.
36:07The engine men
36:08at Recklin,
36:09studying a captured turbo
36:11in 1943,
36:12could not know
36:13that the people
36:14who built it
36:14had already used
36:15the same know-how
36:16to build something else
36:17entirely.
36:19Here is how the jet
36:20ended up there.
36:21In May 1941,
36:24General Hap Arnold
36:25reviewed what the British
36:26were doing
36:26with Frank Whittle's
36:27jet engine
36:28and started
36:29an American program.
36:30That October,
36:32a Whittle engine
36:33crossed the Atlantic
36:34in the bomb bay
36:35of a B-24,
36:36along with drawings
36:37for an improved version.
36:39It did not go
36:40to an aircraft engine company.
36:42It went to
36:42General Electric's
36:43Turbomen in Lynn.
36:45The Smithsonian
36:46puts the reason plainly.
36:48Arnold chose
36:49General Electric
36:50because of its experience
36:51with turbo superchargers.
36:53It makes sense
36:54once you see it.
36:55A turbo is a wheel
36:56spun by hot gas
36:58driving a compressor.
36:59So, in essence,
37:01is a jet engine.
37:02The IA's compressor design
37:04closely resembled
37:05the one in GE's turbo.
37:07And the hard part of a jet
37:09is the same hard part
37:10as a turbo.
37:11A ring of blades
37:13living in fire.
37:14The team building it
37:16was hand-picked,
37:17and its nickname
37:18tells you how secret
37:19the work was.
37:20The Hush-Hush Boys.
37:22Their leader was
37:23Donald Warner,
37:24a top Lynn engineer
37:25known as Truly.
37:27In June 1942,
37:29Frank Whittle himself
37:30came over to help,
37:32checking into Boston's
37:33Hotel Statler
37:34under the name
37:35Mr. Whiteley.
37:36The problem he came
37:38to help with
37:38was exhaust gas
37:39running too hot.
37:41Heat, again.
37:43October 1st, 1942.
37:46Muroc Dry Lake, California.
37:48A Bell XP-59A
37:50flies on two
37:51General Electric 1A engines
37:53with Bell test pilot
37:54Bob Stanley
37:55at the controls.
37:56And an Army officer,
37:58Colonel Lawrence Craigie,
37:59takes his turn
38:00after him.
38:02Craigie becomes the first
38:03American military pilot
38:05ever to fly a jet.
38:06America has a jet in the air.
38:09Ten weeks later,
38:11Wolfhound comes down
38:12in France carrying
38:13four turbos
38:14of the same
38:14General Electric lineage.
38:16Now, be fair
38:17to the other side.
38:18Germany got there first.
38:20A Messerschmitt 262
38:22had flown on jet power
38:23alone that July.
38:25And in 1944,
38:27Germany put the world's
38:28first operational jet fighter
38:29into combat.
38:31Junkers built thousands
38:33of its YUMO 004 engines.
38:35On paper,
38:37Germany won the jet race.
38:39But open one of those
38:40engines and look at the turbine.
38:42The blades are not
38:43cast cobalt.
38:44They are hollow,
38:45folded from a sheet
38:46of a steel alloy
38:47called chromadour,
38:49welded,
38:50and cooled by air
38:51bled from the compressor.
38:53Clever, again.
38:55Now, here is the number
38:56to listen for.
38:57According to historian
38:58John Christopher,
38:59the service life
39:00of the JUMO 004
39:01was only 10 to 25 hours.
39:0410 to 25 hours.
39:07Think back to Sidney Taylor
39:09finishing his tour
39:10in Lazy Daisy.
39:1125 missions,
39:13most of them
39:14many hours long.
39:16One American bomber crew
39:17could spend more time
39:19in the air
39:19on a single tour
39:20than a German jet engine
39:22was expected to survive.
39:24Remember Larrake's
39:25six words,
39:27which we were lacking
39:28in Germany.
39:29Here they are again,
39:31inside the most advanced
39:32fighter of the war.
39:34Major Gulick saw the connection
39:35in June 1945.
39:37Writing about the growing pains
39:39of jets,
39:40he noted that America's search
39:42for high-temperature alloys
39:43had been stimulated primarily
39:44by the Army Air Force's
39:46turbo-supercharger program.
39:48The turbo was not a side road.
39:50It was the road.
39:53Remember the dental alloy?
39:54The craft of casting
39:56heat-resistant blades
39:57in wax and ceramic,
39:59which began with turbo buckets,
40:01would become the standard way
40:02jet turbine blades are made
40:04to this day.
40:05And look where that road led.
40:06In 1946,
40:09General Electric's
40:10Linn team proposed
40:11a new jet engine,
40:12the J-47.
40:14It went on to power
40:15the F-86 Sabre
40:16over Korea
40:17and the B-47 bomber,
40:19and more than 30,000
40:21were built.
40:22Packard and Studebaker,
40:24two American car makers,
40:26built it under license.
40:27It is generally counted
40:29as the most produced
40:30jet engine in history.
40:32From a turbo-hauled-up
40:34Pike's Peak
40:34to a dental casting
40:36in a fortress nacelle
40:37to the engine
40:38of the Cold War.
40:40So hear Lerke's sentence
40:42once more,
40:42and notice how much bigger
40:44it has become.
40:45When he wrote that Germany
40:47lacked the know-how
40:48and the heat-resisting materials,
40:50he was explaining
40:51a bomber's speed at altitude.
40:53Without meaning to,
40:55he was also describing
40:56who would lead the jet age.
40:58The engine men at Recklin
41:00were not only looking
41:01at a part Germany
41:02could not make.
41:03They were looking at the future.
41:05And it had been built
41:06in Linn, Massachusetts.
41:08And Wolfhound herself?
41:10In the last spring of the war,
41:11she was sitting at Oranienburg,
41:13an airfield just north of Berlin,
41:15when American bombers came over,
41:17carrying the very kind of turbos
41:19the Germans had once studied
41:20inside her.
41:22What that raid most likely
41:23did to her,
41:24and what became
41:25of the 20-year-old
41:26ball-turret gunner
41:27I asked you to remember,
41:29is where this story ends.
41:31April 10, 1945.
41:34Oranienburg,
41:35just north of Berlin.
41:36The war in Europe
41:38has less than a month to run.
41:39The 8th Air Force
41:41sends more than 1,300 bombers
41:43and 900 fighters
41:44against airfields
41:45used by Germany's jets.
41:48442 B-17s
41:50are sent to Oranienburg alone,
41:52to its munitions depot
41:54and its airfield.
41:55Among them,
41:5639 fortresses
41:58of the 303rd bomb group.
42:01Wolfhound's own group
42:02has come back,
42:03though no one
42:04in those formations
42:04is likely to know
42:05she is down there.
42:07Just after the target,
42:09six to eight
42:09Messerschmitt 262s
42:11come at the 303rd.
42:13For about 20 minutes,
42:15the two answers
42:16to Lerke's sentence
42:17meet in the same sky.
42:19German jets
42:20on hollow sheet metal blades
42:22built to last
42:2310 to 25 hours.
42:25American bombers
42:26on cast cobalt turbos
42:27built by the tens of thousands.
42:31Wolfhound flew
42:32on the group's
42:32sixth mission.
42:33This is its 357th.
42:36It is not free.
42:38One fortress,
42:40Hinn's Revenge,
42:41goes down at Oranienburg.
42:43Eight of her crew
42:44are killed,
42:45among them the pilot,
42:472nd Lieutenant Robert Murray.
42:49One man,
42:50Staff Sergeant Vito Brunale,
42:52survives as a prisoner.
42:54The price of this story
42:56was paid at altitude
42:57by crews like theirs.
42:59That same day,
43:0111 B-17s
43:02bombed a secondary target.
43:04Its name
43:05was Recklin.
43:07The test center
43:08that once studied
43:09a captured fortress
43:10now had free ones overhead.
43:12And down on the airfield
43:14at Oranienburg
43:15sits Wolfhound.
43:17Mario Schulze,
43:18a German researcher
43:19who spent years tracing her,
43:21believes she was damaged
43:23in that raid.
43:24Reconnaissance photographs
43:25from April 14th
43:27and April 20th
43:28show her in the same spot.
43:30She would never fly again.
43:33In August 2008,
43:35workers clearing
43:36old ammunition
43:37at the site
43:37found a service hatch
43:39bearing her serial number.
43:41Schulze's reaction?
43:43Jackpot.
43:44It's the Wolfhound.
43:46Her remains
43:47are kept today
43:48at the
43:48Sachsenhausen Memorial,
43:50the memorial
43:51to the concentration camp
43:52that stood
43:53in that same town.
43:55And her crew?
43:57All ten survived the war.
43:59Six got out
44:00through Spain.
44:01Co-pilot Jack Williams
44:02and navigator
44:03Gilbert Showalter
44:04were the 84th
44:06and 85th evaders
44:07brought out
44:08by the Comet Line,
44:09the Belgian
44:10and French escape network.
44:12Radio operator
44:13Eva Faget,
44:14another of the evaders,
44:16went on,
44:17by the group's records,
44:18to fly 26 more missions
44:20and completed his tour
44:21on April 14, 1945,
44:24four days
44:25after the
44:26Oranienberg raid.
44:28Pilot Paul Flickinger
44:29spent the war
44:30as a prisoner
44:31in Bavaria
44:32and George Dillard,
44:34the 20-year-old
44:34ball turret gunner
44:35I asked you to remember.
44:37On Christmas Day,
44:391942,
44:40the Gestapo
44:41took him
44:41at the Dijon railway station
44:43together with
44:44the tail gunner
44:44Kenneth Kurtenbach,
44:4621.
44:47Both ended up
44:48in Stalag 17b
44:50near Krems
44:51in Austria.
44:52There,
44:52Kurtenbach became
44:53the camp leader,
44:54the man of confidence,
44:56speaking for more
44:57than 4,000
44:58American airmen
44:58behind the wire.
45:00The war department
45:01awarded him
45:02the Legion of Merit.
45:03George Dillard
45:04came home.
45:06Think about
45:07where those two were
45:08on the morning
45:09this story began.
45:10When the engine men
45:12at Rechlin
45:12opened that fortress
45:13in October 1943,
45:16Dillard and Kurtenbach
45:17had been prisoners
45:18for almost 10 months.
45:20The bomber
45:21they had flown in
45:22was in German hands
45:23and Germany
45:23still could not
45:24copy what was
45:25under its wings.
45:27Sanford Moss
45:28lived long enough
45:29to see it all.
45:30He died on
45:31November 10, 1946,
45:33in Lynn, Massachusetts,
45:35the city
45:35where the turbomen
45:36had built
45:37America's first
45:38jet engine.
45:39He was 74.
45:42Sam Herron,
45:43the man with
45:43the false teeth,
45:44died in Detroit
45:46in 1963.
45:48Alloys of that
45:49same cobalt-chromium
45:50family are still
45:52used today in
45:53dentistry and
45:54in artificial joints.
45:55Now go back
45:56one last time
45:57to Rechlin,
45:57to that October
45:58morning in 1943,
46:00and to the
46:01engine men
46:02who cared less
46:03about the guns
46:03than about what
46:04sat under the
46:05nacelles.
46:07They were right.
46:08They were looking
46:09at the most important
46:10thing on that airplane.
46:11And Lecher,
46:13to his credit,
46:14wrote down honestly
46:15what it meant.
46:17He needed only
46:18six words
46:19for the heart of it,
46:21which we were
46:22lacking in Germany.
46:24Germany could take
46:24that part apart,
46:26analyze its metal,
46:27and understand
46:27every line of it.
46:29What it could not do
46:30was build the country
46:32that made it.
46:33A country where
46:34a dental craft
46:35became 25 million
46:36castings,
46:37where diplomats
46:38cut the enemy's
46:39supply of metal
46:40while the factories
46:41kept pouring,
46:42and where ten
46:43young Americans
46:44could climb into
46:45a fortress,
46:46trust four small
46:47wheels spinning
46:48in fire,
46:49and fly to
46:5025,000 feet.
46:52Day after day,
46:54until the job
46:55was done.
46:58Thank you for staying
46:59with this story
47:00to the end.
47:00If it showed you
47:01something new
47:02about the American
47:03bomber crews
47:04and the people
47:05who built their engines,
47:06please give the video
47:07a like.
47:07It genuinely helps
47:09this kind of history
47:10reach more viewers.
47:12Subscribe and turn
47:13on the notification bell
47:14so you don't miss
47:15the next investigation.
47:16And tell us in the comments
47:18where you are watching from.
47:20If your father,
47:21grandfather,
47:22or uncle served
47:23in the Second World War
47:24with the American
47:25or Allied forces,
47:26write his name
47:27and his unit.
47:29We would be honored
47:30to remember him here.