Busting the dam of engineering indifference

Senior reporter

British patriotism is an odd thing. Public voices constantly do down the UK’s engineering capabilities but announce a royal wedding and out comes the bunting.

And if there’s one thing still guaranteed to get people fired up it’s the Second World War. So perhaps a new documentary recreating the Dam Busters’ bouncing bomb will be just the thing to help turn more people on to engineering.

Barnes Wallis’s invention of a bomb that would bounce on water and explode at exactly the right depth to blow up German dams was a feat of ingenuity, immortalised in the famous film. But we know little of how he actually did it as few of his calculations and designs have survived.

Windfall Films and Cambridge University lecturer Dr Hugh Hunt set out to follow in Wallis’s footsteps, building a scale version of the Möhne Dam — one of the dams destroyed in the famous raid — in Canada, and devising their own bomb replica in a matter of months before using a vintage DC4 airliner to deliver the payload with incredible accuracy.

The replica bouncing bomb takes shape in the team’s workshop

‘We had to work out the exact size of the bomb then design it so it was strong enough to bounce on water,’ says Hunt, whose usual research focuses more on vibrations in wind turbines and devising geoengineering solutions.

‘Then we had to design a rig to carry the bomb and allow it to spin a balanced way to stop it vibrating. We had the same problems as Barnes Wallis in that at first the bomb kept cracking on impact.’

Bombs away!

It wasn’t an exact recreation: the 30ft-high dam section was built at one third the scale of the original and the Canadian aviation authorities wouldn’t allow the team to carry an actual bomb in the air so explosives had to be pre-placed under the water.

But watching the drop sequence is thrilling and conveys a sense of what an enormous challenge it must have been to manually perform the kind of calculations that today are done automatically by computerised guided missile systems.

Success! The replica Mohne Dam ruptures as the bomb triggers the pre-placed explosives

Hunt hopes the programme will help more people to see the fun and the real applications behind science and engineering, that maths isn’t just about what you learn in the classroom but that you also need practical skills to bring it to life.

‘We’ve got a big job in the UK to build-up a technical curiosity in our kids and adults,’ he says. ‘Television these days is pretty non-technical and the idea that you might start to even put equations on TV is miles off.

‘But the idea that behind the scenes there are calculations is the subliminal message that comes across clearly in this programme.’

The show also highlights that Wallis had the courage of his convictions to scale up his models and be confident that they would work in real life, adds Hunt.

‘These days we wouldn’t have that kind of confidence. Certainly in the civilian world we’d build up to it very gently and do lots of testing. He didn’t have the luxury of doing that but he believed in it, and it’s absolutely extraordinary that he did and he was right.’

As The Engineer has said before on this blog, the profile of UK engineering would benefit hugely from some well-placed, exciting and intelligent TV coverage. And according to the Windfall producer, Tom Cook, mainstream broadcasters are showing more of an interest.

‘I wouldn’t say it’s that difficult selling engineering programmes, it’s definitely something people want,’ he says. ‘It just depends on getting the right approach and this one sold because it’s someone actually doing something as approached to just talking about it.’

If we’re lucky, more programme makers will bring that formula to the screen (although we’ll probably still be stuck with royal wedding repeats for the next few months at least).

Dambusters: Building the Bouncing Bomb will be shown on Channel 4 on Monday 2 May at 8pm.