Dam Busters: The Race to Smash the German Dams Timewatch

'This is Chesil Beach in Dorset.

'In January 1943, a British engineer called Barnes Wallis

'came here to carry out full-scale trials of his latest invention.

'A bomb that could bounce on water.'

A bomb that could smash the dams so critical to Germany's industrial heartland.

By the end of the month, the trials had show that the weapon could work

and Wallis was now armed with the film footage to prove it.

'Despite the positive reaction, there were many who still believed

'this would be an impossible mission to mount

'and a wasteful diversion of resources.'

When word reached him that the project was likely to be scrapped,

Wallis realised he had just one card left to play.

'On 12th February 1943,

'Wallis wrote to an old friend in Air Intelligence, a spook,

'appealing to him for his support.'

On the face of it, he's reporting on the latest trial down here

and he reports that the bomb managed to bounce exactly three quarters of a mile.

But at the end of the note, he gets to the crux of it.

This is a plea, a cri de coeur, and he writes three words in pen.

"Help, oh, help."

Wallis had done all he could.

The fate of the project was now out of his hands.

'It's one of the great legends of the Second World War.

'A radical new weapon, a raid of daring and courage.

'19 Lancasters fly deep into the heart of the Third Reich

'at night at just 100 feet.

'History knows them as the Dam Busters.

'But I think there is so much more to this story.

'I want to shake off the dust of a legend that has remained unchallenged for too long.

'This is a raid that nearly didn't get off the ground.

'A weapon that almost never worked.

'A frantic race against the clock to master almost impossible feats of low-level flying and navigation.

'Its commander, a flawed hero leading hastily-scrambled crews.

'Some with little experience.

'And its impact was more than just a few broken dams.

'The damage was far-reaching and came at a critical moment in the Second World War.

'By 1943, the tide was beginning to turn against the Third Reich.

'In Russia, Germany had suffered a humiliating surrender at Stalingrad.

'In North Africa, a crushing defeat now seemed certain.

'And on a third front, over Germany's skies,

'the allies were about to launch a concentrated aerial bomber campaign.'

When the storm bursts over Germany, they will...

'Air Marshal Sir Arthur Harris was Commander-in-Chief of Bomber Command.

'For a year, he had been building to this moment,

'his bomber force slowly growing, technology improving.

'The task given to him - to pursue a strategy of area bombing,

'dropping huge numbers of bombs from on high to pulverise German cities.

'But others were not convinced this strategy was the way to win the war.

'Among them, engineers like Barnes Neville Wallis.

'Wallis was assistant chief designer at Vickers Aviation

'and was best known for the R100 airship and his work on the Wellington Bomber.

'I'm taking his daughters back to their childhood home in Effingham, Surrey

'for the first time since the house was sold over 30 years ago.'

-That was the garage. No!

-That was my bedroom.

-That was the garage.

-It's the same.

-Oh, heavens!

-This was made with pram wheels, is that right?

-The pram wheels were at the top.

-They still are, look.

-Mind your head.

When I heard about the Dam Busters raid success,

there was a door and it had a green curtain

-and the large speaker of the radio.

-Yes.

And I stood up on a kitchen chair which I have in my house to this day

-and listened to them saying about the success of the raid.

-Golly.

-The thing about our father was that he was very practical indeed.

-Yes.

-He was not a silly man.

-No drifting. Never talked in a vague sort of way.

-He was certainly strict with me.

-With all of us.

-He looked over the top of his spectacles.

-My dear boy.

My dear child. My dear girl.

-But you also said he was a lot of fun, as well.

-Oh, he was lovely.

'As number two designer at Vickers, Wallis was given latitude to work on other ideas.

'Early in the war, he circulated a paper about his own ideas for defeating the Axis powers.

'He believed single, large, earthquake bombs dropped with precision

'could be more destructive than area bombing.

'His target - the enemy's power sources.

'It was an engineer's way of stopping the war.'

With no power, there could be no war industry.

Take the key out of the ignition and the car won't work.

This meant not destroying cities,

but coal mines, oil plants,

and of course white coal, water.

In other words, dams.

'In particular, Wallis picked out the Mohne and Sorpe in the Ruhr,

'and the Eder, Germany's largest dam.

'These were sources of power and pride.'

TRANSLATOR: People were proud that the dam had been built here

-TRANSLATOR: It was something special we had.

-Many visitors came.

It was the biggest dam in Germany.

The Kaiser was also here during construction

to see the progress of the building, to see how it was growing.

'Professor Jeremy Black believes these dams had a particular significance in Germany.'

These were iconic dams. I mean, dams as a whole were iconic in the mid 20th century.

But also, we're not on some beach in Pomerania,

we're not on some place in Mecklenburg,

you are in the central area of concern.

You are affecting the absolute focus of the military industrial complex in Germany.

'Dams may have been an ideal target, but early in the war,

'the precision bombing needed to smash them was unachievable.

'In April 1942, a low-level raid on Augsburg had ended in disaster

'with more than half the force shot down.

'But technology did not stand still.

'Undeterred, Wallis now thought of a new weapon.

'A bomb that could bounce on water.

'And his inspiration came from an unlikely source.

'This image of Barnes Wallis experimenting with his daughter's marbles is a famous one.

'But who actually thought to skip the marbles in the first place is still hotly debated.

-They were my marbles that I collected.

-Yes, but you didn't have the water tub.

It was me that had the tub and I shot them into it. It was my game.

It was. There were good marbles that went into the water

and naughty marbles that went onto the crazy paving.

-In that case, darling, it would've been after he'd done that test.

-No.

-This is her all over.

-We're not going to get it straight.

-This is her all over.

-And that's her all over. THEY LAUGH

Rotter!

'When Wallis first thought of the bouncing bomb, the target in mind wasn't dams,

'it was ships.

'Capital ships like the mighty Tirpitz,

'lying in a Norwegian fjord, protected by anti-torpedo nets

'and a threat to allied convoys.

'With a bouncing bomb, Wallis realised he could get over the nets.

'For the Navy, the appeal was obvious.'

Admiralty interest certainly was the catalyst

which actually took the golf mine, as it was known at that stage,

from being a concept, a set of mathematical formula and small-scale trials films,

it was the catalyst which brought it forward to producing the first prototypes dropped off Chesil Beach.

'In fact, without the support of Admiralty,

'it's likely that the bouncing bomb would never have seen the light of day.

'At this point, Wallis still thought of his new bomb as a naval weapon.

'Not only were the German dams also protected by anti-torpedo nets,

'the size of any working bomb that could destroy such huge structures

'would be too big for existing planes to carry.

'Just five miles from Chesil Beach, you can still find one of the early versions of the bouncing bomb.

'I've come to Abbotsbury to have a look.'

Ah, here it is.

This is the prototype. The prototype bouncing bomb that was used during the trials at Chesil Beach.

But as you can see, it's got these little dimples on it, so it was known as the golf mine.

During the trials, they were constantly experimenting with different types of aerodynamics,

so some had smooth casing, some were wood, some were steel, some had these dimples.

'But Wallis wasn't the only one urgently researching new types of weapons.

'At the Road Research Laboratory, scientists hadn't give up

'seeking ways to destroy dams.

'They were experimenting on scale models,

'trying to establish how much explosive would be needed to cause a breach.

'In May 1942 came a breakthrough.'

The discovery came almost by accident when a scale model was deliberately broken up

by placing a charge against the dam wall.

What was significant was not where the charge was placed. That was basic physics.

The breakthrough came through the combination of using a small amount of charge

against the dam wall and underwater.

'Crucially, the model had been destroyed using much less explosive than expected.

'For Wallis, there was new hope that a dam-busting bouncing bomb

'could be carried on existing aircraft.

'His theory gained weight on 24th July 1942

'when the test was scaled up on a real dam at Nantgarw in Wales.

'The result was spectacular.'

What this meant for Wallis was that it should now be possible

to deliver a bouncing bomb capable of destroying the German dams

using existing aircraft, namely Lancasters,

which were built by Vickers rival AV Roe.

'By the end of January 1943,

'trials on the prototype confirmed the bouncing bomb could work

'against ships and dams.

'Those who saw Wallis's film were impressed.

'But to many, getting the weapon to its target still seemed a fantastical proposition.

'Air Vice-Marshal Linnell at the Ministry of Aircraft Production was a sceptic.

'He believed the weapon was unworkable and distracting from Wallis's first priority,

'crucial development of the new heavy bomber, the Vickers Windsor.'

If you look at a lot of the documentation,

there's always this great caveat saying,

"We mustn't interfere with the development work on the Windsor."

That was something that Vickers were very concerned with,

that Wallis shouldn't be deflected off on a project

which, up until the last minute, in many respects,

I think a lot of people felt was a project doomed to failure.

'But still trials continues.

'Then, on 12th February 1943,

'Wallis learned that Linnell was moving quickly to get the bomb rejected.

'Fearing for his project, Wallis now wrote his fateful letter to the spy,

'Group Captain Fred Winterbotham,

'a last-ditch appeal to his only friend on the inside with the influence to make an impact.

'Help, oh, help.'

Winterbotham didn't reply directly to Wallis,

but his response, the next letter in the chain,

was a masterpiece of cunning and suggestion which took matters to the very top.

He chose to write his letter to Air Vice-Marshal Inglis,

one of the assistant chiefs of the air staff, and in just a few short paragraphs,

managed to imply that the prime minister's office were interested, which they weren't,

and that the Navy was about to steal a march over the RAF in the use of this weapon.

But for me, the killer line was when he implies that the chief of the air staff hadn't been fully briefed.

This letter might have been to Inglis, but it was for one person and one person only,

and that was the most senior Air Force officer in the land,

Air Chief Marshal Sir Charles Portal.

'It was a long shot because Portal had set the current strategy of area bombing.

'Even worse, other influential forces were gathering against Wallis's bigger bomb,

'now called Upkeep. Linnell was an old friend and colleague of Arthur Harris

'and warned him of what was being conspired.

'Harris was having none of it.'

Harris was never known to mince his words, but in this letter to Portal on 18th February 1943,

he really lets rip with all guns blazing.

He talks about panacea-mongers running amok in the Ministry of Aircraft Production

and points out that the weapon itself exists so far only in the mind of those who invented it.

He says this is "just about the maddest proposition as a weapon that we've yet come across

"and that's saying something!"

He then says he's prepared to bet his shirt that nothing will ever come of it.

It's pure Harris. But you know what? I think he's got a point.

I think if I was Harris and I'd learnt there was talk of 30 of my front-line Lancasters

being taken away to carry a weapon that still only existed in the mind of Wallis,

I think I'd have been every bit as furious.

'Harris immediately assured Linnell he would put a stop to Upkeep.

'Linnell in turn warned Vickers chairman Charles Craven

'that Wallis was damaging his business interests.

'Wallis, berated by his boss, resigned.

'But his earlier plea to Winterbotham had already lit a fuse.

'As Harris and Linnell moved to shut the project down,

'Winterbotham's letter to Inglis had reached the man at the top.'

When Harris had written his rather outraged letter to Portal on 18th February,

he'd have fully expected the chief of the air staff to support him in his views.

But he was in for something of a shock. It seems that Winterbotham's letter had done the trick

because by the following day, 19th February,

Portal had not only been fully briefed, he'd also seen Wallis's film.

And so he writes to Harris and says, from what he's seen,

he feels this project is worth supporting and then he adds, "unless the cinema lies".

He does assure Harris that he's only going to take away three of his precious Lancasters,

but by a week later, on 26th February, three has become 30.

One can only speculate as to how this came about,

but I think it was a combination of momentum, the shortness of time

and possibly even the RAF wanting to get one over the Royal Navy.

What is does go to show is that this was always about politics and personalities

as much as it was about the science.

And I think in this extraordinary chain of letters, we have the proof of this.

'Incredibly, Portal ordered Linnell to green-light the project,

'even though Wallis's larger Upkeep had yet to be designed.

'On Friday 26th February, Wallis was summoned up to London by Linnell

'to discuss a major strike against the German dams.

'The bouncing bomb was back on.

'Any attack would have to happen by the full moon in May

'and Wallis's weapon would have to be ready in just two months.

'"Could this be done?" he was asked bluntly.

'"Yes," Wallis replied, "it could."

I've often wondered whether Barnes Wallis ever truly believed he could deliver what he'd promised.

The weapon he was proposing still only existed in his mind

and he didn't yet know what it would take to modify the Lancaster

so that it could carry and deliver the Upkeep to the target.

As he stepped out of the Ministry of Aircraft Production here on Millbank,

one can only imagine what must have been going through his mind.

Somehow he had to make good his words and in just eight weeks.

'Barnes Wallis faced a race against the clock to produce a working bomb from a primitive prototype.

'He was confident in his calculations

'but no weapon of scale had ever been developed in so short a time.

'The clock was also ticking for Bomber Command.

'A new special squadron had to be formed at RAF Scampton

'and in record quick time.

'They were to train for a mission, but would not be told the target,

'delivering a weapon that didn't yet exist.

'The plan was to fly from Lincolnshire across the North Sea

'below the German radar at just 100 feet.

'The target was the dams at the head of the Ruhr Valley,

'the industrial heart of Germany.

'The primary targets were the Mohne, the Sorpe,

'and Germany's largest dam, the Eder.

'These were the pride of the Reich.

'Wind Commander Guy Gibson was the man chosen to lead the mission.

'He alone was told the targets.'

Guy Gibson was a hugely experienced bomber and night-fighter pilot.

A man who always led from the front and who exuded confidence and determination.

He was also a more complex character than has often been portrayed.

When he took over 617, he had just finished an 11-month stint commanding 106 Squadron

and was exhausted both physically and mentally.

The pressures of command were absolutely immense.

It's easy to forget that Gibson was still only 24.

'Operational planning often took Gibson away from Scampton

'and he still had his own training to fit around the demands of his new command.

'This combination of absence and strict discipline

'earned him a reputation for being distant and aloof.'

I don't think Gibson was actually bothered with non-commissioned ranks.

He did draw that line of distinction between officers and NCOs and other ranks.

'Sergeant Johnny Johnson joined the Dam Busters Squadron as a bomb aimer.

'He was one of the first to arrive in late March.

'I'm taking him back to number two hangar

'where Gibson and his staff ran the squadron.'

Well done, Johnny. Well done.

So this is the old place.

-Yeah.

-My God.

'It's often thought that Gibson handpicked every pilot and crew.

'It's not true.

'Johnny Johnson's pilot was Joe McCarthy.

'An American, he was one of only four pilots known personally to Guy Gibson.'

Dad said he received a phone call from Gibson

and he asked him if he would come for a new squadron for one mission

and told him to bring as much of his crew as possible.

McCarthy's crew had just finished a tour of 30 operations and were due leave.

Johnny Johnson had planned his wedding for the break,

but Gibson had cancelled all leave.

Johnson's wedding plans were in ruins.

'Outraged, Joe McCarthy went to see Gibson with Johnny and crew in tow.'

So the last time you were here was in March 1943?

-That's right, yeah.

-Amazing.

And if you can imagine, apart from Gibson at his desk over there,

-seven of us in here, as well.

-All lined up along here?

-A bit crowded.

And Gibson said, "What? What's this all about?"

From my point of view, there was going to be bloody murder if we didn't get any leave.

So then Joe said to the wing commander,

I suppose in his typical American style,

"We've just finished our first tour.

"We're entitled to a week's leave. My bomb aimer's

"supposed to be getting married on 3rd April and he's going to get married on 3rd April!"

We got four days, so that was it.

'Johnny's honeymoon would have to wait.'

That was my only personal association with Gibson.

He seemed to have great difficulty in getting down to talking to people below his rank.

So we didn't see much of him as NCOs at all.

But he was, at that stage,

one of the most, if not the most, experienced bomber pilots in the Air Force.

I think his real leadership came to the fore

when he took over this new squadron,

because he got everything that he wanted for that squadron.

'And it wasn't just airmen Gibson needed.'

The seven crew, they're the cutting edge of the weapon, but behind it all

is a vast support team. You can liken it to a Formula One team

where no matter how good the driver,

he's basically only as good as his pit crew.

'To keep one Lancaster flying, as well as air crew,

'there's the parachute packer, the meteorologist

'and the flight controller.

'The bomb train, the flight maintenance crew,

'the aircraft mechanics, the mobile workshop and the petrol bowser.

-'That's 500 people thrown together to form a brand new squadron.'

-OK, sir!

'Incredibly, it was managed, just about, in one week. An unprecedented effort.

'But that was only the start. Operation Chastise, as the raid would be known,

'demanded a completely new approach to flying.

'Low level, at night, over water and dropping a bomb with extreme precision.

'They had just six weeks to perfect this.'

Starting out with practice missions at 500 feet

and then after a day or two, they'd lower it down to 200 feet

and then 100 feet as they became more comfortable flying the aircraft.

And doing all these navigation exercises and ending up

at a reservoir some place where they could drop a practice bomb.

'Joe's wife Shere is also the child of a Dam Buster.

'Her father, John Fraser, was a bomb aimer.'

Dad was called up when he'd just finished his 30 trips.

He was supposed to have a break.

And he got called up to go to 617 Squadron.

He wrote home a lot to Canada to his mom.

He'd be flying over Berlin and he'd be describing this to his mother.

It sounded like a boy.

He was 20 on the dams raid.

'The last surviving Dam Buster pilot is Les Munro.

'He recalls his training well.'

In the early stages, some pilots were not quite adept

at judging how quickly they were approaching objects ahead of them.

There were a number of cases where pilots had clipped the tops of trees

and planes returned with leaves and twigs in their air intake.

'And the crews still didn't know their targets,

'only that they had to fly insanely low.'

There's a place in Lincolnshire called Sutton Bridge.

But before you get to the bridge, the electric cables go across the canal, as well.

-And the practice, when we got round there, was to fly under the cables and up over the bridge.

-No.

-It was great.

-So how high are the cables?

-A bit higher than the bridge.

-THEY LAUGH

It was part of the thrill of being part of 617 Squadron.

'It was a steep learning curve for all,

'but for some more than others.

'Rear gunner Grant McDonald had flown just seven missions.'

What do you remember of the low flying?

-It must have been quite fun, wasn't it?

-Ooh, yeah, yeah.

It was something all right.

It, er...

..comes very, very quickly on you, the ground comes very, very quickly.

'Grant McDonald was Canadian. In fact, nearly a third of the Dam Busters came from the empire.'

-Hi, Gavin.

-Hi.

-How are you?

-Nice to meet you.

-And you.

'I've come to Brisbane to uncover the letters of Australian wireless operator Charlie Williams.

'When he reported to Scampton in early April, he was horrified by the chaos he found.

'His letters to his English fiancee, Bobbie, offer a rare insight

'and sense of immediacy into conditions on the ground.'

This first letter in the collection is written on the day he arrives.

He's anything but cheerful about being there. Nor is he impressed by what he discovered at Scampton.

He says, "Things are in a bit of a mess here.

"The mess is full to overflowing. All I can get is a room for the night with a bed and nothing else."

But what's really interesting about this, of course, is the date, 7th April,

which is two whole weeks after Gibson and some of the first members of the squadron

have started to form at Scampton. Which means, in total, just five weeks to prepare for

what is undoubtedly going to be an extremely arduous and difficult operation.

'The planned 30 Lancasters had been reduced to 20

'and each was now modified to carry a giant bouncing bomb.

'I've asked a current pilot along to look at one of these legendary aircraft.

'As an instructor on Apache gunships, Nick Wharmby spends his time flying at low level

'often at night and at similar speeds to the Lancaster.'

Nick, you've got to see this to believe it.

That is fantastic.

It's unbelievable. I cannot get over how claustrophobic this is.

You can imagine the nerves, can't you, climbing in,

But this is an aircraft stripped down to its bare bones.

This is built for one purpose. Bombing.

It has a smell, hasn't it? It reminds me a little bit of my car,

but it's kind of all metal and rubber and a bit of mustiness, too.

You can imagine what it must have been like after five and a half hours in the air.

-Let's go and have a look at the cockpit.

-Yeah, definitely.

Climbing through this has got more similarities with a submarine than a modern aircraft, hasn't it?

Yeah, you're not wrong. This is not easy to clamber over at all, not when you're as unsupple as I am.

Now try doing that in the dark and when the aircraft's manoeuvring and rolling.

-Lancaster.

-OK, Nick, you're the pilot,

you've just sat down in this for the first time, tell me your thoughts.

I'm quite impressed with the field of view, particularly over the shoulders.

But those long wings, if you think they were going over the dams, targeting 60 feet

and, from what we hear, slightly lower in some cases...

From here to the end of that wing tip is kind of 50 foot, isn't it?

So that puts it into some kind of perspective.

-But in terms of the cockpit layout?

-The rest of the layout, some of this has not changed.

We've got a standard T with an altitude indicator,

air speed, rate of climb.

And then the all-important altitude didn't work below 100 feet.

-HE LAUGHS

-There's a snag.

'And height was an issue.

'Weapon trials continued, and while the Upkeep was spinning OK,

'it was shattering on impact.

'The only solution - to lower the height of release to well below 100 feet.

'Introducing new danger to an unperfected process, time was fast running out.

'With the release height now set at 60 feet,

'the crews had to take their planes even lower.

'Most relished the challenge.'

An exhilarating experience,

flying at 230 miles per hour in a Lancaster at low level.

There was an occasion when we were flying back at 30 feet

-and Les Munro flew underneath us.

-Underneath?

-Underneath us.

But 30 foot is the height of this building behind us.

There wasn't an awful lot of room.

Joe wasn't very pleased with that.

-You must have had the shock of your life.

-We suddenly saw this aeroplane disappear in front of us.

'Crews now had to step up their training.

'Low-level flying continued, but now at night.

'A potentially lethal combination.

'The 30-tonne Lancaster was designed for flying at altitude.

'Operating such a heavy beast at low level was extremely challenging.'

If you think, you're manoeuvring this aircraft, turning it, banking it,

low level, so I'm concentrating hard on the wing, over the water,

in the dark, but possibly, particularly in a left-hand turn,

I'm now belly-up to some of those spurs and pieces of ground

which are as much a threat as the water, so I can't see those,

and the aircraft, when you roll on an angle and bank, wants to slip out of the turn.

If an aircraft's going that way and I want it to go that way, you've got to pull some G,

-but you can only pull 1.8 G in these aircraft.

-Is that not a lot?

That's not a lot at all. So you're working very hard,

you've got to anticipate those turns, basically.

Whereas the medium-level bombing, not an issue.

-Cos you've got lots of free air.

-You can hit air as fast as you like, doesn't hurt a bit.

So very new skills for these crews to learn.

'As the crews pressed on with mastering and taming these great machines in new flying conditions,

'Barnes Wallis had at last made a breakthrough with the bomb's shape.

'On 18th April 1943, the bomb casing again shattered

'and the cylindrical core holding the charge had continued to bounce.

'The Upkeep had now found its final form. And in the nick of time.

'It was also smaller and easier to hoist into the 20 modified Lancasters

'now arriving at Scampton.'

That created a certain amount of curiosity

as far as what were these planes, what were we going to do with these?

And eventually that curiosity was solved with the arrival of the Upkeeps themselves.

Certainly, when the Upkeeps were spun in the trial drop down there,

I think out of 12 aircraft, six were damaged

by splash from the water through the pilots flying either too low

or too slow, and I was one of the culprits.

'Training was nearly over, the raid just days away.

'For wireless operator Charlie Williams,

'the demands of training meant a further strain,

'with fewer opportunities to see his fiancee, Bobbie.'

Charlie Williams really is just an ordinary bloke. He's already tired.

There's lots of references to how exhausted he's feeling, he's flown 28 combat operations already

and he wants out.

"I'm very glad, darling, that you were there

'for the take-off and return. Now you will realise

"what a strain we're under the whole time

"and will not now wonder why our nerves are bad at times.

"You will have an idea what we feel like every time one of our pals fails to return."

'During the raid, each of the seven-man crew knew they would have a crucial role to play.'

All the time the pilot's concentrating on this,

he's got a navigator speaking to him, the bomb aimer calling, "Dummy run, yes or no?"

he's got the two gunners talking about possible threats.

And they've got to be at a specific speed, at a specific height, on a specific heading,

centred on the dam, everything's got to add up.

Ultimately, it comes down to the bomb aimer to make that final decision and the crew have to go with him.

'Training was now over.'

By Sunday 16th May, everything was in place.

The chiefs of staff had given the go ahead.

The crews were trained, the Upkeep was ready

and even the weather conditions looked to be ideal.

It was finally time for the crews to find out what their targets were.

'There were briefings all day.'

About three o'clock, Tannoy message, "All 617 Squadron to the operations room".

And then we discovered for the first time what we were going to do.

We were all briefed together.

It was quite surprising when you found out what you were actually going to be doing.

My God, that was a briefing. Of course, Gibson was there.

And the various other specialists.

The weatherman, the signals man and, of course, Barnes Wallis. He was there, too.

We walked in and the first thing we looked at was the operations map up on the wall

and saw that it led to this area east of the Ruhr.

'There were to be three waves of bombers on two separate routes,

'selected so they crossed at undefended parts of the enemy coast.

'The first two waves were staggered so they arrived at the primary targets at the same time.

'A third reserve wave would follow on a few hours later.

'With the mission revealed at last,

'the crews had just a few hours to make their final preparations.

'All recognised the dangers ahead.'

I've always been struck by that incredibly statistic that out of the 110,000 people

who flew for Bomber Command, a staggering 55,500 never made it home again.

I think there's a danger of us thinking of 617 Squadron

as being somehow the top gun of Bomber Command,

of being some super-elite.

They weren't. They were just ordinary guys,

made up of people like Charlie Williams.

'Charlie now knew his target. Not that he could reveal it.'

7:30pm, that's just a couple of hours before they take off for the dams raid.

He obviously knows what he's about to do.

"I will have a lot to tell you when I do see you, darling.

"And I can only hope it will be very soon.

"This letter will have to be short, dear, as I have very little time and have work to do."

It was a very pleasant day. The weather was very good. We didn't leave till after midnight,

so we were able to see the others go.

They left a couple of hours earlier, around ten.

Even before they boarded the aircraft,

there was this eerie feeling.

A comment made by Ken Earnshaw, who was very close to my dad,

and he told my dad, he said, "I don't think we're coming home".

'Even flying below the radar at 100 feet, the Lancasters could still be seen and heard.

'When they were spotted, the Germans put up a wall of flack.'

The low-flying part of it was the most dangerous part, I felt.

Flying that low, you can't go down and you can't go up.

On account of the anti-aircraft fire, you can't go up.

Once you went up, you were a goner.

And, of course, you've got no room to go down.

So you just had to plough through it.

'When the second wave reached Holland, they ran into trouble.

'Les Munro saw Vernon Byers's plane way off target.'

I saw Byers's plane. He was off course and he flew over the island of Texel.

And I saw his plane shot down, explode in a burst of flames.

I can remember seeing the waves ahead of me on the shore

and I gained a certain amount of height to clear the sand dunes behind the sea shore

and I was losing height on the other side when I was hit by light flak.

And one shell, just one shell hit me midships

and blew a hole about 30 inches diameter in the side of the aircraft.

And cut the intercom communication and severed the electrical systems and that sort of thing.

And everything went blank.

And I circled while I asked the wireless operator to check

whether it was possible to restore inter-communications.

He came back and said, "No, not possible." So I made that decision there and then to return to base.

I had the dubious honour of being the first to land with a live Upkeep on board.

'Former jet pilot and Vietnam veteran Joe McCarthy Jr

'can imagine what it was like for his father.'

You're not flying on autopilot or anything like this.

You're flying the airplane, having to lug it around, you're dodging pylons,

worried about flak, trying to stay on the route, you're making turns

and you're so keyed up, the adrenalin is flowing through your veins.

To me, I think it would be physically, physically tiring.

'In order to appreciate the difficulties of flying a Lancaster attacking these dams,

'I've asked pilot Carlo Ferrari to fly over each one following the exact course taken on the raid.

'Carlo is flying a Beech 18,

'a contemporary plane which, like the Lancaster, lacks modern hydraulics and navigational aids.

'Just like the pilots on the raid, this is the first time Carlo has flown over the dams.

'First the Mohne.'

If you follow the rivers then you are sure that you will arrive on the dam.

This one, it's visible from around ten miles.

But the river by night, this is not the easiest thing to see.

'As leader, Guy Gibson dropped the first Upkeep on the Mohne.

'It failed to breach the dam.

'Each of the dams provided a unique challenge. At the Mohne, the approach may look straightforward

'but it was the only one that was defended by flak-gunners.

'The element of surprise now gone, next up was John Hopgood.

'His bomb aimer was John Fraser.'

When my father took that final step, you know, to set up the bomb

to attack the Mohne Dam, when he finally took command of the aircraft

at that moment he told Hopgood to go around, because they weren't quite ready.

But then that was when they got attacked and they had to drop the bomb, let it go.

He tried to take the aircraft up to a height where they could bail out and get out.

And when Dad bailed, he said the trees looked awfully damn close.

'As well as coordinating the strikes, Gibson flew alongside the next two aircraft to attack

'in an effort to draw the flak.

'The Mohne Dam was finally breached by Dinghy Young in the forth Lancaster to drop its Upkeep.

'The rest of the planes which had been attacking the Mohne were now switched to the Eder.

'Meanwhile, Joe McCarthy and Johnny Johnson had reached the Sorpe.'

This is the actual wall of the Sorpe dam,

and its sloping earthen construction is the same the other side, which makes it really thick.

This is why Barnes Wallis reckoned it was going to take at least six accurate hits to destroy it.

But achieving that kind of accuracy was always going to be difficult.

The crews had to swoop right down from the village over there. Then with just 7.5 seconds over the dam,

had to rapidly climb and clear that tree line.

And in moonlight and with the dam shrouded in mist.

The next dam, it flowed from east to west.

'For the aircraft, the challenge was flying along the dam wall.'

Parallel? OK.

That's amazing!

'Bomb aimer Johnny Johnson had the task of dropping the Upkeep.'

On our actual attack, when I wasn't satisfied, I called dummy run.

If Joe wasn't satisfied, he just pulled away

and left me to call dummy run.

And our humorist, who was Dave Roger in the rear turret,

after about the sixth or seventh dummy run,

a voice from the rear turret, "Won't someone get that bomb out of here?"

I know when they dropped the bomb, they estimated it was from 30 feet.

And the wingspan is a little over 100 feet on a Lancaster.

And here you are, at night, in some place you've never been before with hills

and having to lug this airplane around, get it down, and drop it.

I guess that's why they took ten tries before they were able to have everything right.

Bomb aimer Johnny Johnson then let it go.

When I said, "Bomb's gone", "Thank Christ!" came from the rear turret.

But then, of course, it was nose up, straight away,

because of hitting hills on the other side.

'Throughout the raid, the successes and the losses were signalled back to base

-'by the wireless operators like Charlie Williams.

-MORSE CODE BEEPS

'At the five group operations room in Grantham, Harris and Wallis were following events as they unfolded.'

The success of the operation still hung in the balance.

Two crews had already returned home early, five more had been shot down.

The Mohne had been breached but just one Upkeep had been dropped on the Sorpe.

And the toughest challenge still lay ahead.

'For me, the most daunting target of all was the Eder Dam

'because of its steep hills and closed approach.

'Will Carlo Ferrari agree?'

Uh-uh. The first approach, I had to find out where the schloss is

and then you can see it from a distance.

I'm standing here on the wall of the Eder Dam.

'Above me, Carlo is targeting the spot where I'm standing.'

The problem is, this is really difficult terrain.

They've got to get around that spit of land before they can turn in straight towards the dam.

Heading around. You have to turn very steep.

Our plane is pulling a pretty tight turn,

but remember, the Lancaster is four times the size, 30 tonnes,

and has a 9,000 pound bomb underneath it.

'On the night, on his sixth run, David Shannon was the first to drop his bomb.

'There was no breach.'

Our plane is flying at 500 feet, but on the raid itself they were operating at just 60 foot.

'Second up, Henry Maudslay. Three runs, bomb gone, still no breach.'

By the time they reached the dam wall, they were flying no higher than that lamppost.

Having passed the dam wall, they then had to clear that ridge of hills over there.

-'So what's Carlo's verdict?'

-I was surprised by the shape of this lake.

That you have to turn quite steep to the left to arrive at the dam.

The last two dams, I wouldn't be able to do it by night.

But this one, this is something for high-class pilots.

'Last up was Les Knight.

'Last plane, last bomb, last chance.

'Three bounces, an explosion and then the dam finally gave way.

'This footage from later that day was covertly shot by a German soldier on leave

'and has only recently come to light.

'A single Upkeep, detonated in the prescribed place against the dam wall, 30 foot underwater,

'had vindicated Barnes Wallis and all those who had believed

'in the possibilities of this extraordinary weapon.

'Karl-Heinz Bremmer and Karl Schafer were both young boys when the dams were attacked.'

TRANSLATOR: We were in the cellar, my parents, me and eight siblings.

There was no bang or anything like that.

There was a dull tremor, and when the planes were gone,

my father went outside and said, "The water is coming."

And we saw how, on the other side, in the forest,

a wall of water of nine to ten metres came rolling through the forest.

TRANSLATOR: And then I went up the hill.

And then, at the end, we overtook some other people,

and we only just made it up the hill.

How we got through the water, I don't know.

The people we had overtaken were all washed away.

'In total, six of the Upkeeps had hit their target and two of the dams had been breached.

'But there was a toll to be paid.

'Eight of the 19 Lancasters were to be lost,

'some before they had even reached the dams.'

Two of the Lancasters that crashed en route hit power lines.

This is where Barlow's came down, just a few miles inside Germany.

We're pretty sure they were following the line of the railway

which is just over there beyond the trees.

But looking at those power cables really underlines just how low they were flying.

Who knows why he struck them? Perhaps he looked down for a moment.

But suddenly the Lancaster was engulfed in flames and ploughed into the ground.

It came to a halt here, killing all on board. The wireless operator was Charlie Williams.

'He'd been due to marry Bobbie the following week.

'Charlie Williams was one of 53 airmen killed on the raid.

'Three more, including John Fraser, were taken prisoner.

'For the returning crews, exhaustion outweighed euphoria.'

You didn't know that evening. You didn't know.

You just ate and went to bed.

It really wasn't until next morning that it hit you.

That there were 53 people missing.

The only thing that bothered you the next day was the lorry coming round

to pick up the effects of the crews that didn't come back.

That was not a good sight at all.

'Analysis began immediately.

'Les Munro, who had been forced to turn back early, remembers his run in with Gibson.'

After the bulk of the crew had returned, Gibson came up to me and said, "What happened, Les?"

I said, "Oh, I was hit by flak."

He said, "You were too high", and turned round and walked away.

He wasn't prepared to discuss my side of it with him.

His view was the only one. And he indicated that that night.

'For Gibson, there was nothing but praise.

'Awarded the Victoria Cross by the King, he became a national hero.

'And the accolades were entirely justified.

'Just before the raid, Gibson had been so exhausted, his doctor had tried to ground him.

'The following year he was killed in action.

'In the days after, the raid was seen as a huge success,

'and instantly caught the public's imagination.

'Since then, it has been repeatedly re-appraised, not least by those who took part.

'Joe McCarthy Jr remembers visiting the Sorpe Dam with his father,

'the first time either of them had seen it from the ground.'

He had his hands on his hips and he was looking and with a quizzical look on his face.

And I said, "What's going on?"

He said, "You know, if I'd seen this view, this dam and the hills from this angle

"before the raid, I would have said it couldn't be done."

'The Sorpe Dam was only damaged, not breached.

'Barnes Wallis had predicted six bombs would be needed to smash the Sorpe.

'But most of the second and third waves hadn't made it.

'So why had so many planes not reached the target?

'What had gone wrong?

'I've come to the Met Office archives in Exeter,

'to see someone who may be able to throw some light on the matter.'

Simon, I particularly want to talk to you because I've got a theory that the second wave,

which was supposed to attack the Sorpe dam, crossed further south than everyone thinks they did.

They were supposed to cross over at Vlieland,

a little island off the north coast. I think they crossed at Texel.

The first thing to look at is the navigation logs as they give us

what the pilots were told during their briefing

as to what they expected the weather to be.

It clearly says here in the navigation logs

that at 1,000 feet, the winds were expected to be calm, to the west of three degrees east.

At that time, they didn't know anything about nocturnal jet streams.

-Which is?

-The nocturnal jet stream. It's where we have a very warm day,

and typically occurs in the spring, very warm dry air at the surface,

and at night, the sky's clear, all of that heat radiates out into space.

We get a block of very cold air at the surface at very low levels, and above that, the warm air of the day.

Now, where those two meet, you get a narrow channel of strong moving winds.

-And they occur at low levels.

-At 100-foot level?

-Absolutely, at the 100-foot level.

But back then, it wouldn't really be known about.

If we look through the charts for Europe for the afternoon,

there are observations from the Dutch coast, the Belgian coast, even on the French coast,

that were telling us the surface wind was already north-easterly at 20, possibly even 30 knots.

-And that's down at that 100-foot level?

-That's actually down at the surface, 20 to 30 knots.

And if you do hit a sufficient wind coming into the coast,

it won't take a great deal to blow you two, three, four miles off course in a short period of time.

So, if I get this right, you're saying that would have been sufficient to knock them

-from Vlieland, where they're supposed to cross, to Texel here.

-Yep.

-Which is a matter of ten or 15 miles.

-Absolutely.

That's good enough for me.

'So an undetected wind could have sent them over the flak batteries of Texel

'rather than the undefended Vlieland and affected the raid's chance of a clean sweep.

'Even so, the damaged caused should not be underestimated.

'The raid had left a huge scar. And not just a physical one.

'There was another impact. One that struck at the heart of German consciousness.'

Of course, it was an enormous catastrophe.

Although at the time, we didn't believe in the final victory anymore.

When the dam was broken, we thought, "Now we have no strength left."

'The timing of the raid was also disastrous for the Germans.

'The strike against the dams could not have come at a worse moment.

'Later that summer, the allies invaded Sicily

'and the Russians pushed the Germans back at Kursk.

'The huge cost and diversion of resources was one Germany could not afford.

'The Mohne and Eder dams needed massive rebuilding.

'And even the Sorpe had to be drained for repair.'

You can understand why the Mohne Dam was one of the best-known buildings in Germany.

It was a massive feat of engineering.

But just imagine having to rebuild that in five months and in the middle of total war.

'It's been argued that the impact of the raid was minimal

'because the targets weren't important and the dams were rebuilt in five months.

'This is total rubbish.

'If the dams weren't important, why was the Nazi high command in such a hurry to rebuild them?'

One needs to move away from the idea it just produced a flood.

Of course it produced a flood and the flood did damage and disruption

and that's important. But actually, what was much more consequential was the damage to industrial plant

and the enormous resources required to both repair the industrial plant,

to repair the breached dams, and then to deal with all the other dams and strengthen them,

both strengthen them against bombing and also to provide proper anti-aircraft defences.

All of that involved hundreds of thousands of man hours of labour.

'In fact, the effects of the raid were lasting and its bigger consequences wide-reaching.'

In recent years, historians have tended to downplay the successes of the dams raid.

But I think that's wrong. Operation Chastise had many far-reaching effects, not all of them immediate.

Just a few weeks after the reopening of the Mohne Dam in the autumn of 1943,

Field Marshall Rommel took command of the Atlantic wall,

a planned series of defences that ran all the way from Denmark down to western France.

When he reached the Channel coast, he discovered there was barely a wall there at all.

And one of the reasons for that was that many of the labourers had been transferred to Germany

to rebuild the dams.

Barely 12 months after the raid, an allied force set forth from ports all along the English coast.

With the German defences still incomplete, the invasion was a success.

Simply put, without the dams raid, D-Day would have been considerably harder.

'And what now for Barnes Wallis?

'This man of vision had shown that precision bombing could play an important role in ending the war.

'Now returning to his original earthquake bomb, he developed the Grand Slam and Tallboy.

'18 months later, it was Tallboys that finally sank the Tirpitz in its Norwegian fjord.

'The mission was carried out by Bomber Command's elite precision force.

'The squadron now known as the Dam Busters.'

Subtitles by Red Bee Media Ltd

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