- 11 minutes ago
Category
📺
TVTranscript
00:02Eighteen months into World War I, the Germans devastate British cities with enormous airship bombers called Zeppelins.
00:13It's an entirely new kind of terror campaign.
00:17There was a policeman running down the road shouting, they're here, they're here, the Germans are here.
00:23In a game-changing strategy, the Germans ruthlessly bomb ordinary civilians from the air.
00:31This is the beginning of modern warfare, red in tooth and claw.
00:35But exactly how these mighty machines worked has been lost to history.
00:40Now, engineer Hugh Hunt will investigate the incredible technology behind these gas-filled monsters.
00:52It's an explosive tale of bombs and bullets, with a mystery at its core.
00:58A big bag full of hydrogen. Why couldn't we shoot them down? They were just there, surely.
01:04Hugh will discover an unexpected personal connection to the events.
01:08What we have here is the bullet your uncle designed.
01:12And he will unravel an amazing story of ingenuity and courage.
01:17Good on you, Uncle Jim.
01:19Zeppelin Terror Attack. Right now, on NOVA.
01:41Major funding for NOVA is provided by the following.
01:46The David H. Koch Fund for Science. Supporting NOVA and promoting public understanding of science.
01:52The David H. Koch Fund for Science.
01:55And the Corporation for Public Broadcasting.
01:58And by PBS viewers like you. Thank you.
02:06As the city of London sleeps, German commanders 500 miles away are planning a deadly attack.
02:20It's 1915, and World War I battles are raging in the trenches of Northern Europe.
02:29But at 11 p.m., May 31st, the Germans open a new battlefront.
02:38They strike at the enemy in their own backyard.
02:42For the first time in history, London is under attack from the air.
02:48But these bombs aren't being dropped from planes.
02:52The Germans have deployed a terrifying new weapon of mass destruction.
02:57The Zeppelin.
03:00For the next two and a half years, these mighty airships rained down death on British streets.
03:06Claiming the lives of hundreds of innocent civilians.
03:10They are the biggest flying vessels ever built.
03:14Able to travel higher and further than any airplanes of the day.
03:20How did the Germans construct these colossal machines?
03:24What was the secret of their lethal success?
03:28And why were they so difficult to destroy?
03:47The Zeppelin NT airship is the last word in sleek aeronautical engineering.
03:56It is the latest in a long line of airships going back 100 years
04:01that have carried passengers on scenic pleasure cruises.
04:07Taking his seat in the gondola is Cambridge University engineer Dr. Hugh Hunt.
04:15But today, he is taking a trip into the past to discover how the Germans built the Zeppelin bombers of
04:22World War I
04:23and how the British strove to bring them down.
04:27Just like that.
04:33We've just taken off and I'm just amazed at how quick that was.
04:38Hugh was expecting the airship to be slow and cumbersome, but this one is full of surprises.
04:45The Zeppelin's noted to talk about manoeuvrability or is it generally airships are manoeuvrable?
04:52The new Zeppelin is definitely very manoeuvrable and far more manoeuvrable than a lot of the others.
04:57Whoa!
04:58Yes, as you can see.
05:01Whoa!
05:03So yes, it turned very rapidly.
05:05That is remarkable.
05:12This machine can reach a top speed of 78 miles per hour and stay in the air for 24 hours.
05:19And its predecessors of a century ago were almost as fast, just as far ranging, and over twice as big.
05:34On July 2nd, 1900, three years before the first airplane flew, a retired German soldier called Count Ferdinand von Zeppelin
05:45unveiled his own revolutionary flying machine.
05:54He produced a fleet of these airships and fitted them out like luxury liners.
06:00They carried well-heeled passengers on grand excursions over the Alps.
06:09To an enthusiastic German public, Zeppelins were shining beacons of the superiority of their nation's engineering.
06:19But with Germany on the brink of war with Britain, the military had other plans for the airships.
06:29They would make perfect long-range bombers to strike at the enemy in their own backyard.
06:38Bombing London would cause panic in the civilian population and force the British government to pull out of the war.
06:49The brains behind the Zeppelin bombing campaign was Navy Commander Peter Strasser.
06:57A confirmed bachelor married only to his job.
07:01He was an inspirational leader who didn't mince his words.
07:05Your holy duty is to destroy London's destruction.
07:09You are ready to bring the highest punishment for your fatherland.
07:12The crowned sword for every humble son of Germany.
07:17In a corner of Commander Strasser's war room, Hugh has assembled a Zeppelin think tank.
07:25Among the experts is military historian Professor Eric Grove.
07:31Strasser was one of that group of officers of the armed forces who actually came into airships and caught the
07:39bug.
07:39He suddenly became a convert.
07:42It was a road to Damascus conversion.
07:44And this new technology was going to win the war.
07:51War had broken out on August 4th, 1914.
07:57The forces of Austria and Germany lined up against those of Russia, France and Britain.
08:06Initially, World War I looked like it might be over by Christmas.
08:14But it degenerated into a long, bloody war of attrition that would claim the lives of over 16 million people.
08:27Strasser believed he could bring a swift end to the carnage on the battlefield by bombing civilian targets like London
08:34into submission.
08:37The weapon that would deliver victory was the new Zeppelin bomber.
08:42The Zeppelin raids demonstrate what 20th century war was going to be all about.
08:47Where the war is carried into the heart of the enemy territory.
08:51And you rationalize it by saying the more frightful you are, the sooner the war will end, the sooner the
08:56enemy will give in.
08:59The technology Strasser pinned his faith on employed the latest lightweight materials.
09:05Unlike a blimp, which relies on the pressure of the gas inside to keep its shape, the Zeppelin had a
09:12rigid aluminum alloy skeleton.
09:17This strong lattice structure meant the engineers could make Strasser's new airship enormous.
09:25At 650 feet, it was more than twice as long as a jumbo jet.
09:33Beneath its canvas skin, it contained 19 bags filled with hydrogen gas.
09:46Hydrogen is lighter than air and provided lift to the airship.
09:54But molecules of hydrogen are so small that they pass easily through the weave of most fabrics.
10:02Stopping the gas from leaking was one of the major challenges facing the Zeppelin engineers.
10:13Leaking hydrogen gas was blamed for the notorious Hindenburg disaster of 1937,
10:19when the highly flammable gas caught fire and destroyed the giant airship at Lakehurst, New Jersey.
10:28Of the 97 people on board, 35 perished.
10:37So this is eight tons, which I can...
10:44God, I'm lifting an airship.
10:46Today, it's non-flammable helium rather than hydrogen that makes the modern Zeppelin lighter than air.
11:11The helium is held in an envelope made of laminated plastic.
11:17But stopping the gas from leaking is still a problem.
11:21Gas will escape.
11:23We average somewhere 10 to 15 cubic metres a day of natural loss.
11:32Is it through sort of pinprick holes in the thing or is it just through the fabric?
11:38Most of the helium could be pinprick holes that occur over a period of time.
11:43Very, very difficult to completely seal it.
11:46You've got a good seal when there's not so much pressure.
11:48When there's pressure and it's stretching, you've got a little bit of a leak.
11:51But here we are in 2012 and we've got pretty fancy materials and the bloody thing still leaks.
11:58What about in the early days?
12:01To make the leak-proof bags that held the hydrogen, the airship pioneers needed a material that was light and
12:08strong and in plentiful supply.
12:12They found it in an unlikely place, inside a cow.
12:22One of the things that I found so fascinating is the story of what these bags are made of.
12:27And they were made of this stuff, which, well, you look at this and you kind of think, well, is
12:35it paper? What is it?
12:37It's the intestinal lining of a cow.
12:40It's extraordinary, isn't it?
12:41I've never actually seen this stuff before.
12:43No, I haven't either.
12:44I haven't read about it.
12:45And it's...
12:46It's tough.
12:49At this processing plant in Middlesborough, England, animal intestines arrive by the barrel load from the slaughterhouse.
12:59Incredibly, this stuff was the raw material for zeppelins.
13:06Hugh investigates, reluctantly.
13:09I'm not sure I should have had a cooked breakfast this morning.
13:13These intestines are used to make sausage skins just as they were in Germany during the First World War.
13:20Today, the guts are processed on an industrial scale, as factory owner John Veschenfelder explains.
13:27First machine's taking grass now.
13:29The second machine?
13:30Grass.
13:31What, grass?
13:32.
13:33Go to the second machine.
13:34Yeah.
13:35The second machine's taking milk itself.
13:37Right?
13:39The final machine is what we call the finishing machine.
13:43Hugh wants to find out how narrow tubes can be turned into enormous balloons.
13:53And then, what we make balloons out of.
14:01Sensibly, the zeppelin builders started with the biggest piece of cowgut they could find.
14:08This is the appendix.
14:10Right, I see.
14:11It's called the blind end of the stomach.
14:14So that's a cow's appendix.
14:16The thin membrane that lines the cow's appendix is made of collagen, the same stuff that forms skin and bones.
14:24It has some very special properties.
14:28See its texture.
14:29Look at that.
14:30It's like a balloon.
14:31It's strong.
14:33If we get some warm water and just dip it in the warm water now.
14:36Somehow, the German zeppelin builders stumbled across the technique for joining the membranes together using nothing more than water.
14:43Like this.
14:44Yeah.
14:45If we get it over the edges, it'll actually hold on the edges.
14:48Right?
14:50If I get another one, just overlap it.
14:53Using this magical process, the Germans were able to piece together their gigantic gas bags from small strips of cowgut.
15:01What we need to do now is leave that to dry.
15:03So we did one, and after two hours, this is what we found.
15:08You see the way it's joined there, it's just melted, blended together, and it's absolutely perfect.
15:14That won't come apart.
15:16Just the moisture has bonded it together.
15:18But I want to understand why.
15:25To find out, Hugh takes the sample back to Cambridge University and asks his colleague, collagen expert Michelle Oya.
15:35They take a close look at the overlapping joint under a scanning electron microscope.
15:42Oh, wow.
15:44Golly.
15:46We've got all of these tiny, tiny, tiny little fibres going across the interface here.
15:53All the fibres.
15:54All the fibres.
15:56But if this is the interface, what's extraordinary is just how much intertangling and intertwining has happened.
16:03This doesn't look like just two sheets of anything.
16:05It looks like something really quite...
16:08Structurally complicated.
16:09Structurally complicated.
16:11The entwined fibers bind the two sheets of collagen together.
16:18When the collagen is wet, the fibers at the interface slide across one another without sticking.
16:24But as they dry out, they become tacky and adhere to one another.
16:32Our ancestors were very crafty and the fact that they figured out how to use this natural polymer for other
16:38uses doesn't surprise me at all.
16:43Cow gut was a zeppelin's secret weapon.
16:51But it took the intestines of more than a quarter of a million animals to make just one airship.
16:58The material was so precious to the war effort that for a time, sausage making in Germany was verboten.
17:10By January 1915, the Germans had assembled a fleet of 13 zeppelin bombers.
17:17At last, Commander Strasser had the firepower to launch his terror campaign.
17:26He chose targets within easy reach of Germany.
17:30One was the seaside resort of Great Yarmouth in Norfolk.
17:36Here is where German bombs first fell on Britain.
17:41And this street is where the first civilians died.
18:03The next morning, sleepy towns along the coast awoke to find the war on their doorstep and bodies among the
18:12rubble.
18:14For the Germans, this was just the start.
18:18Strasser couldn't resist tweaking the lion's tail as well as by bombarding coastal towns, also bombarding British cities.
18:26And he thought that they could inflict so much damage that British morale would crack.
18:33The city Strasser prized above all others was London.
18:41For the next four months, the Germans launched raid after raid, feeling their way towards the capital.
18:52Then, finally, on May 31, 1915, a lone zeppelin made it.
19:03Zeppelin LZ-38 bombed the suburbs of North London before heading south, leaving a trail of destruction.
19:15In 20 minutes, it had dropped 28 bombs and a further 91 incendiary bombs that were designed to set London
19:25ablaze.
19:28The shot was incredible.
19:29There are huge burning fires in the streets, explosions going off.
19:33People are throwing up their windows to look out and see what's going on.
19:37And one man reported that there was a policeman running down the road shouting,
19:40They're here! They're here! The Germans are here!
19:48Two firebombs fell on a house in Hackney.
19:56This couple, Mr. and Mrs. Good, were in their bedroom and they couldn't get out.
20:00And they found Mr. and Mrs. Good, you know, burnt, but kneeling by the side of the bed.
20:05And the husband had his arm around his wife.
20:07And it was almost like they were praying.
20:09The effectiveness of these German incendiary bombs was brutally obvious.
20:16One bomb identical to those that devastated London that night has survived intact.
20:23We have here an original incendiary bomb.
20:27It's a direct descendant of projectiles used in earlier wars, which consisted of burning rags, rope and things like that,
20:36that were loaded into a cage and fired at the enemy positions.
20:39Didn't the Romans do that sort of stuff?
20:40Yes, they did. And it hasn't changed.
20:42It went right the way through the Napoleonic Wars and the Crimean War.
20:46And I think this is a direct successor.
20:49John Starling wants to find out what makes this bomb tick.
20:54So he takes it to an army colleague.
20:58Explosives expert, Major Peter Norton.
21:00John's got the bomb here for us.
21:04They x-rayed the bomb to see what's inside.
21:08Excellent.
21:09This allows them to figure out how it worked.
21:15When the bomb hit its target, the impact would have triggered the fuse and set fire to a substance called
21:22thermite,
21:23a mixture of iron oxide and aluminum that burns with a fierce heat.
21:28This, in turn, would cause a tank of benzene, a form of gasoline, to explode.
21:36Peter wants to show John how the fire bomb worked.
21:39We certainly never made a World War I zeppelin incendiary before.
21:46So it'll be very interesting to see what sort of target effect we get.
21:55While John and Peter build the bomb, Hugh Hunt prepares the target, a typical 1915 bedroom.
22:05One mystery they hope to solve is why the bomb is bound in rope coated in tar.
22:12And another is how the Germans managed to get the tar on in the first place.
22:24With the tar coating applied, the bomb is ready to be loaded with explosives.
22:30Fill this with thermite, that would make a good bedside lap.
22:33Well, you'd certainly be able to read a book for a short period of time.
22:38We're going to fill this with thermite.
22:40It gives off massive amounts of heat.
22:42So, as I say, typically for fish, you'd expect to see two to two and a half thousand degrees centigrade.
22:46We're going to put some benzene in there as well, and then initiate that electrically.
22:51Perfect.
22:52We hope we're going to get a fairly violent conflagration.
22:56Intense localized heat, which will spread, creating secondary fires.
23:01Three, two, one.
23:07As Peter predicted, the raging thermite immediately causes the benzene to explode in a fireball.
23:22But what's surprising is that the bomb is still burning 15 minutes later, thanks to the tarred rope.
23:30We thought the rope would add a burning effect, but it's quite surprising how much time it'll just continue to
23:37burn away and use up the fuel that's provided by the tar.
23:41That rope is actually a critical component to the bomb.
23:44You want to actually sustain the temperature to set fire to wood, the buildings, etc.
23:50If you drop enough of them, you'll overload the emergency services and things like that.
23:55So, incendiary is actually far worse in some ways than high explosives.
23:59You see things burning. It's more of a terror weapon.
24:04The Zeppelin commanders were already planning how to take full advantage of their new terror weapon.
24:11Some questioned the morality of firebombing civilians.
24:16But Strasser was steadfast. He had God on his side.
24:21My men are wise and worthy.
24:24Their task is holy.
24:26So, how can they sinify if they only receive their sins?
24:31If that's what we do is terrible, then let the fear be the salvation of Germany.
24:35Strasser.
24:39As the war ground to a stalemate on the Western Front, Strasser wanted to ramp up his attacks on the
24:46British capital.
24:48But just getting an airship there was an almighty challenge.
24:54At high altitudes, the crew had to contend with unpredictable weather.
24:59Heavy rain soaking into the Zeppelin's canvas outer skin would weigh the airship down.
25:05And high winds could blow it miles off course.
25:10But there was a new problem that hadn't been anticipated.
25:14No one had flown so high before.
25:17And the crews began to suffer from the debilitating effects of altitude sickness.
25:26Hugh wants the full Zeppelin experience, altitude sickness and all.
25:30So, he visits aeronautics engineer Andy Elson, the first man to pilot a hot air balloon over Everest.
25:38The old Zeppelins used to fly at 21,000 feet.
25:41So, what we want you to do is to experience what they would have suffered.
25:46And I won't tell you what the symptoms were. We're distancing afterwards.
25:49Andy will take Hugh up to 21,000 feet, as high as a Zeppelin could go, without them having to
25:56leave the ground.
25:58By pumping out the air of his sealed chamber, Andy can simulate the thin atmosphere and low pressure of high
26:06altitudes.
26:08Usually, he tests the performance of airplane engines inside his chamber.
26:13Today, he's testing Hugh.
26:16We're at 12,300 feet.
26:22To avoid the risk of Hugh passing out during the ascent, he will breathe oxygen until they reach Zeppelin altitude.
26:3121,600 feet.
26:33Andy to Pete, stop pumping.
26:37Now, Hugh will have to quickly adjust to the same thin air as the Zeppelin crews and pass a test
26:45designed for toddlers.
26:48Are you ready?
26:56He starts confidently.
27:02Certainly cold.
27:03Yeah, definitely cold.
27:06So, name, address, dates of birth, and style sign.
27:12After a few minutes, Hugh struggles to spell the word Capricorn.
27:23I feel as if my eyebrows are falling off. My eyebrows are falling off.
27:28Hugh's brain is being starved of oxygen, and it's beginning to show.
27:33I feel as if I'm very heavy.
27:34Be careful.
27:40That's heavy.
27:42So, do I feel heavy because I'm lightheaded, or...?
27:47You haven't got enough oxygen in your muscles to make them work properly.
27:52So, it's not because I've lost buoyancy?
27:54No, no.
27:56Wow, that's...
28:01A few puffs of oxygen brings Hugh back to normal.
28:06The Zeppelin crews realized the restorative effects of oxygen, too, and began carrying cylinders of the gas on high-altitude
28:15flights.
28:19But they hit another problem.
28:22Seeing where they were going when clouds obscured the ground.
28:30One solution seems remarkable today.
28:35They would dangle a tiny capsule, called a sub-cloud car, thousands of feet below the airship, from where a
28:44crewman on a telephone would guide them in.
28:49The Zeppelin would be above the cloud, and the sub-cloud car would be below the cloud.
28:54And he could say left a bit, right a bit, forward a bit, and release the bombs from there.
28:59Horrific, absolutely.
29:00Horrific.
29:01Given the difficulties, it's incredible that any Zeppelins made it to London.
29:10But on September 8, 1915, Strasse launched a raid targeting the business and political center of the British capital.
29:19And one Zeppelin got through.
29:22The airship that made most impact that night was that captured by Heinrich Matti.
29:28And actually he had been to London before as a tourist, so he actually knew what the
29:32landmarks were.
29:35Matti followed the chain of tourist sites right up to his primary target, the heart
29:41of the old city.
29:47This square mile of real estate was the financial hub of the British Empire.
29:55Matti's uncanny skills as a navigator would single him out as the most successful airship
30:01commander of the war.
30:04For his rendezvous with London, he packed a surprise package, weighing some 660 pounds.
30:11He is carrying on board the largest single bomb dropped from the air at that time in
30:18the war.
30:18And he called it his love gift, his gift of love to London.
30:24Matti delivered his gift and much else besides.
30:31His firebombs left the textile warehouses around St. Paul's Cathedral burning out of control.
30:42His explosive bombs destroyed homes and shops, pubs and buses.
30:59In just 10 minutes, 22 civilians, including six children, were killed.
31:11Newspaper headlines reflected the anger felt by the British public, that Germany could indiscriminately
31:17target women and children.
31:21Peter Strasser saw things differently.
31:25Peter Strasser saw things differently.
31:28Peter Strasser saw things differently.
31:49There was no distinction between the front and the rear area.
31:53The munitions worker was just as much a target as the people firing the ammunition at the
31:59front.
32:00And therefore, if it killed children, and that had some terror effect, a morale effect, well
32:05and good.
32:06It's the beginning of modern warfare.
32:07It's the beginning of modern warfare, red in tooth and claw.
32:14By the end of 1915, Londoners had watched German airships rain death down on their city on
32:22five occasions with total impunity.
32:27Public outrage at the lack of civil defense forced the British government into action.
32:40To take out the Zeppelins, they brought in the latest anti-aircraft guns from France and positioned
32:46them around the capital.
32:51But the airships flew at night and were virtually impossible to see in the dark.
32:57Could they try to hear them coming?
33:03At Spurn Point on the Yorkshire coast, where the Zeppelins crossed the North Sea and entered
33:09England, a concrete structure called a sound mirror still stands.
33:19It was designed to detect the sound of the approaching airships.
33:25The sound mirror worked by amplifying the Zeppelin's engine noise.
33:31Sound waves hitting the concrete dish would be reflected and focused by the concave surface
33:37onto a single spot.
33:40This concentration of sound waves would increase the volume.
33:48Using a horn in the end of a pole to pick up the sound, an operator would wait patiently
33:53night after night with his ears peeled.
33:57Once he detected the distinctive drone of Zeppelin engines, he would move the horn around until
34:03the sound was at its loudest.
34:07By tracing back along the line of his pole, he could locate the invisible airship in the
34:13night sky.
34:15With the help of acoustics engineer Dr. David Sharp, Hugh hopes to find out how effective
34:21this early warning system was.
34:24With the stethoscopes on, the listener would listen out, and if they found that the sound
34:30was loudest in about this region here, that would indicate that the aircraft was coming
34:35in from the direction that this is pointing effectively.
34:38Well, why don't we try and experiment?
34:40Yeah, why not?
34:40Yeah, why not?
34:42Hugh arranges for an aircraft to fly towards the concrete mirror.
34:54They set up two microphones.
34:57One picks up the ambient sound at the scene.
35:01The other, operated by Hugh, monitors the sound reflected by the mirror, just as the horn
35:08did during World War I. David monitors the output of each mic. Hugh's is in red. If the
35:17mirror works, Hugh's mic should pick up the plane first.
35:21So by Hugh moving the microphone around, you can see when the pole's actually pointing
35:27towards the sound source, that's when the sound's coming up as its loudest on the microphone.
35:32Although the plane is too far away to see, it's coming within range of the sound mirror.
35:41I'm hearing it directly behind me. Very clear peaks on the red. I can't hear it without the
35:51headphones. Hugh finds the area on the dish where the engine noise is loudest. His microphone
35:58pole points straight to a spot in the sky. Well, I reckon it's out there. That's incredible.
36:09That's fantastic. We found that we were able to get an amplification of 20 decibels, maybe
36:17four times as loud as you would hear normally. But they were hearing aircraft as far as 15,
36:2220 miles away. Getting that sort of advance warning, you could start to prepare for an
36:28imminent air attack. The alert would go out to makeshift airfields that had been set up
36:36around London. Young pilots were trained in the treacherous art of night flying. As soon
36:44as a Zeppelin was detected, they would leap into action. To save weight, they flew alone. Taking
36:53the place of the co-pilot, a Lewis machine gun, pointing straight up so the plane could attack
37:00from below. This is a replica of the BE-2C aircraft that fought the Zeppelins. Pilot Matt Boddington
37:14will take Hugh up for a spin. They had no parachutes either and had to fly the plane from the
37:25backseat.
37:37Matt will give Hugh a taste of what it was like to take on a Zeppelin in a flimsy contraption
37:43made of wood and canvas. But once the pilot located a Zeppelin and needed to man the machine gun,
38:03the BE-2C really came into its own.
38:08They were actually so stable that, as you can see, I could quite have to take my hat off,
38:14pat me on the shoulders, and we'd fly along quite happily. This, of course, made it a really
38:18good, stable gun platform shooting at Zeppelin. The aeroplane would almost fly itself.
38:36But with the Zeppelin in his gun sights, the pilot would soon discover the plane's crippling limitation.
38:43It lacked firepower. Its puny machine gun bullets would make such tiny holes in the envelope,
38:52and the gas would leak out so slowly that the Zeppelin would be able to carry on flying.
38:58What the BE-2C needed now was an armament to enable it to tackle the Zeppelins.
39:04And that's where a lot of work was going on behind the scenes to try and develop a bullet
39:11that was going to be effective against Zeppelins.
39:15One scheme was to use a flaming bullet that was meant to set fire to the Zeppelin's hydrogen gas,
39:23which is highly flammable.
39:25The brains behind the idea was a car manufacturer named James Buckingham.
39:33In the course of investigating the Buckingham bullet, Hugh discovered he has an unexpected connection to the man.
39:42He's my great-uncle Jim.
39:46Here was I thinking that I was just going to be exploring Zeppelins and finding it out.
39:51But it's turned into a family.
39:53Part of the story, yeah.
39:54Just incredible.
39:56Hugh wants to find out how his great-uncle's incendiary bullets worked.
40:02Munitions collector Tony Edwards has some answers.
40:07What we have here is an original factory drawing of the bullet your uncle designed.
40:13Cartridge, small arm, incendiary, Buckingham, 303-inch Mark 7B.
40:19Because he had the Buckingham Motor Company or something?
40:21That's right, the Buckingham Motor Company of Coventry.
40:23And he was one of a number of engineers who, when war broke out, turned their creative mind to the
40:29problem of shooting down Zeppelins and balloons.
40:32It's a bit of a leap, going from designing and building cars to going to bullets.
40:37Absolutely, I agree.
40:37You might have thought he would go into making sort of tanks or engines, aircraft engines or something.
40:43Yeah, yeah.
40:43And what you have is this here is filled with phosphorus.
40:47Phosphorus ignites when it meets the air.
40:50And if you look at this bullet here...
40:51That's one of them, is it?
40:52Yes.
40:52You can see there the hole that's filled with solder.
40:58When the Buckingham round is fired, it spins down the barrel and the friction generates heat.
41:06This melts the solder that plugs the hole.
41:13As the bullet exits the gun, the phosphorus ignites in the air and the spinning motion throws the burning chemical
41:20out through the hole.
41:29These bullets, I mean, these presumably don't work anymore, do they?
41:32Well, we're hoping that they're going to.
41:34This is not a spent bullet?
41:35No, this is not a spent bullet.
41:36This is an unfired bullet, still with the solder in, still with the phosphorus in.
41:43So if I pick away with my pen knife with those little holes...
41:46I wouldn't advise you.
41:47No, okay.
41:48What we're going to do, we're going to try these out, we're going to fire them and to see if
41:52they work.
41:53Oh, God.
41:54They'll fire the precious 100-year-old Buckingham rounds remotely.
42:00Just in case they explode in the rifle.
42:05Tony captures the flying bullet using a slow-motion camera.
42:09Look at that.
42:10And you can see it spinning.
42:12Good on you, Uncle Jim.
42:14As it's being thrown out, it's igniting in the air.
42:17When that hits, some of that phosphorus will start burning, which will, of course, ignite the hydrogen.
42:23Well, that's a theory.
42:25That's it.
42:25We should see.
42:28But for all their promise, when the British pilots fired the Buckingham bullets into a Zeppelin, nothing.
42:38Somehow, they passed straight through the gas bags, without the burning phosphorus igniting the hydrogen.
42:49To try and understand why, Hugh revisits aeronautical engineer Andy Elson, who'd watched over Hugh in the low-pressure chamber.
42:59I see a cylinder which says hydrogen on it.
43:01Yeah.
43:02Andy is bubbling hydrogen through a bucket of soapy water to demonstrate to Hugh the flammability of the gas.
43:10We can ignite the bubbles and they'll burn on your hand without your skin burning.
43:13Uh-huh.
43:15OK.
43:16Righty-o.
43:16Those hydrogen bubbles.
43:18Yeah.
43:18Can you chuck that out of the way?
43:20If I grab hold of that...
43:26Bwah!
43:31Hey, look at that!
43:34Well, I knew I needed a shave, but I didn't want...
43:37The thing that really gets me about this whole Zeppelin thing is that we all know that hydrogen's flammable.
43:43And that was really easy to set fire to those bubbles.
43:47Mm.
43:48And why is it so bloody difficult to set fire to a Zeppelin?
43:52Andy has come up with an experiment to try and solve the mystery.
43:56So we've got a polythene bag which we're going to fill with hydrogen.
43:59And inside is an electric heating element, which is going to glow red-hot, just like the burning phosphorus from
44:07the incendiary bullet.
44:13In this experiment, the heating element, red-hot at over a thousand degrees Fahrenheit, stands in for the flaming bullet.
44:22But surrounded by only hydrogen inside the bag, and no oxygen, it doesn't start a fire.
44:30So that Zepp's only full of hydrogen.
44:33Mm.
44:33And I can feel the heat radiating from here.
44:36Mm-hm.
44:37The heating element is glowing red-hot.
44:39If there was oxygen in there, that would have exploded by now.
44:42Hydrogen, like most things, simply cannot burn in the absence of oxygen.
44:48So what will happen if some is allowed into the balloon?
44:52Andy will find out by blasting big holes in it to let the air in.
45:02Oh, there we go.
45:07This is a difficult process to try and light this hydrogen.
45:11That handful of bubbles, easy.
45:13That was easy.
45:14Because the oxygen is close to the hydrogen, everything's nice and easy.
45:18Here, lots of hydrogen, no oxygen in sight, except on the other side of this piece of plastic.
45:25Nothing was ever going to happen.
45:27You then put holes in.
45:29Whoa, here we go.
45:31You've got to get the hydrogen and oxygen mixture in the right place,
45:34and you've got to get your ignition source in the right place.
45:41Fortunately for the British, engineers were already working on another innovation,
45:46an explosive bullet that would rip holes in the gas bag wide enough to allow plenty of oxygen to rush
45:53in.
45:57This bullet would contain nitroglycerin, an explosive chemical sensitive to shock.
46:07When the bullet hit the canvas skin of the Zeppelin, it would slow down, but a steel ball inside would
46:15keep moving forward,
46:17compressing the nitroglycerin until it exploded, blowing a big hole in the gas bag.
46:24The air would rush in and the oxygen would mix with the hydrogen to create an explosive cocktail of gases.
46:34If the flaming bullet entered the Zeppelin at this moment, it would have a good chance of sparking a fire.
46:45The British airmen were told to alternate the bullets when they loaded their machine gun magazines.
46:51It would take both rounds to bring down a Zeppelin.
46:55They've now got the incendiary and the explosive bullet.
46:59And the pilots were instructed to mix their rounds and fire them alternately.
47:04And they'd alternate between incendiary and explosive.
47:09And the theory was if he fired enough of them into the aircraft, eventually he'll start a fire.
47:15The first opportunity to try out the new ammunition was September 2, 1916, when the Germans launched the biggest raid
47:25of the war.
47:29A fleet of 16 airships set a course for London.
47:36British fighters were scrambled at 11 p.m.
47:39The first pilot into the air was 21-year-old William Leif Robinson.
47:47At 2.15 in the morning, one of the airships was caught in searchlights 12,000 feet above North London.
47:57Anti-aircraft guns opened fire.
48:00The noise had been so intense that people started coming out of their houses.
48:05And up in the sky, they see this glowing monster.
48:09Shells bursting all around it.
48:11They describe it as like stars twinkling in the sky.
48:14But it's the shrapnel shells exploding.
48:18Leif Robinson saw the cornered Zeppelin too, and headed towards it.
48:24He had the airship at his mercy.
48:29He flew along the underside and fired a drum of his special bullets into it.
48:36To his dismay, they had no effect.
48:44Undeterred, he reloaded and went back in.
48:47But again, to no effect.
48:51In desperation and with just one drum of ammo left, he was forced to improvise.
48:58He concentrated his fire onto one spot, emptying the whole drum of bullets into the stern.
49:06By clustering the rounds into one area, the young pilot managed to open up a big enough hole for the
49:13oxygen to rush in.
49:17And the alternating bullets finally set the airship alight.
49:23And the alternating bullets finally set the airship alight.
49:36The cheers of the crowd were hard, merciless cheers.
49:40This was relief.
49:41The people were enjoying this moment.
49:44We were fighting back.
49:48As it hit the ground, railway engines were blowing into the hooters.
49:52People started singing the national anthem.
49:54People were dancing and singing in the streets.
49:55The newspapers the next day described it as the greatest free show London has ever seen.
50:03On the day that came to be known as Zep Sunday, tens of thousands of relieved Londoners picked over the
50:11wreckage for souvenirs.
50:15Overnight, pilot William Leif Robinson became the most famous man in Britain.
50:21Babies, flowers and hats were named after him.
50:26And he was mobbed wherever he went.
50:30Within a month, the technique he perfected for taking out airships had brought down two more.
50:36It was the beginning of the end for the Zeppelin.
50:46Peter Strasser stubbornly refused to accept defeat.
50:53On August 5th, 1918, with the war effectively lost for Germany, he sent his airships out on one last raid.
51:05This time, he would lead the attack himself.
51:09Believe me, I don't want to die more than other men.
51:12But being there is the highest for me above.
51:21Strasser didn't live to see England.
51:24A British fighter spotted his Zeppelin over the North Sea.
51:29And Peter Strasser himself fell victim to the deadly alternating bullets.
51:37His master plan, to break an enemy's morale by deliberately targeting civilians, had failed.
51:53But the terror it inflicted on the people of Britain would find its full expression in the next war.
52:02The great airships would be overtaken by other technology, as engineers would find more efficient ways to deliver death from
52:13the sky.
52:42The Great Airship
52:43is available on DVD.
52:45To order, visit shoppbs.org or call 1-800-PLAY-PBS.
52:50NOVA is also available for download on iTunes.