Bouncing bomb

[arprocter]

They came up with an ingeniously simple way to tell if the plane was at the correct altitude over the water

http://www.thedambusters.org.uk/height.html

[sirwolfgang]

I always thought this was the more nuanced but clever part of the operation.

That said, I would hate to have been one of the test pilots for the barrels. One of them bounced too high, and ripped the plane in half.

[cyberferret]

This is what surprised me about the Wikipedia article - you would think they would have mentioned the simple yet clever way that the crew could ensure that they were at the correct release height over the water using spotlight beams.

[jgw]

I was told that the inventor came up with the idea while at the theatre with his wife. As the spotlights converged on a performer, the idea sprung to mind, and he yelped "I've got it!"

Quite possibly embellished, but plausible that should be the inspiration.

[DanBC]

It's really interesting to read the history of Bomber Command.

Max Hastings has a good book: https://www.amazon.co.uk/Bomber-Command-Pan-Military-Classic...

I mention it because the book talks about the problem they had with targeting, and refinements they made.

It also talks about the change in attitudes about targeting civilians, from being a war crime that must be avoided at the beginning, to being the only thing that could stop the war at the end.

[Tepix]

German Wikipedia has a long, quite dramatic page about the bombing of the Möhnetalsperre using these bombs in May 1943 at https://de.wikipedia.org/wiki/M%C3%B6hnekatastrophe

According to the page, the attack did not achieve its goal of interrupting the arms production in the Ruhrgebiet area, however a lot of people were killed, including many female forced laborers.

[ygra]

Well, killing the workers is also a way of disrupting arms production. In my hometown the allies didn't so much bomb the shipyard or airplane factories, but rather the part of the city where workers lived. Not sure how effective it was, though.

[JackFr]

One of the coolest unit patches of all time: https://en.wikipedia.org/wiki/File:617sqn-600.jpg

'Apres moi le deluge'

[cyberferret]

Which is all very gung-ho and all that, until you consider the thousands [edited - hundreds] of German civilian men, women and children who drowned in the valley after the dam breach. [0]

[0] - http://www.abroadintheyard.com/german-survivors-of-dambuster...

[tpeo]

Which, incidentally, is a quote attributed to Louis XVI of France.

[alanh]

(“After me, the flood.”) Indeed, that is incredibly cool.

Super tangential, but there is a very enjoyable Regina Spektor song titled “Après Moi” with the full phrase as a refrain.

[SixSigma]

Barnes Wallace had previously designed the R100 [1] airship for Vickers - the one that didn't crash. The one that did crash was an RAF project. The govt. was having a competition to see which design would be best.

The R100 flew to Canada and back without incident, setting various records on the way.

The fatal R101 flight to India was insisted on by the Air Ministry in response. A deadly effect of "ship it when we say" rather than "ship it when it's ready"

One interesting fact from the R100 story : the stress calculations of their airframe were obviously done by hand and took 3 months to complete, something one could do in Excel nowadays, even without CAD.

The figures are almost unimaginable :

Wallis finally settled on the use of six reconditioned Rolls-Royce Condor petrol engines for propulsion. [2] Each of which generated 500 hp (373 Kw) and weighed 1,504 lbs (682 kg).

From wikipedia :

Nevil Shute later suggested in Slide Rule: Autobiography of an Engineer that the success of R100's Canadian flight indirectly led to the R101 disaster. Prior to the transatlantic flight, the Cardington team could suggest that neither airship was ready for a performance of such duration. However, when R100 returned in triumph they had to either make the flight to India or admit defeat – which would have meant discredit with the consequent danger of losing their jobs.

[1] https://en.wikipedia.org/wiki/R100

[2] https://en.wikipedia.org/wiki/Rolls-Royce_Condor

[tnorthcutt]

I really enjoyed watching The Dam Busters[0] as a kid. Pretty amazing technical feat, given the circumstances.

[0]: http://www.imdb.com/title/tt0046889/

[greedo]

Lucas used a lot of footage from The Dam Busters for storyboarding the Death Star trench run in Star Wars. Some of the dialogue is lifted as well.

[dahart]

I used to have a DOS game by the same name https://en.m.wikipedia.org/wiki/The_Dam_Busters_(video_game)

High probability the game was inspired by the show, I'd guess.

[unicornporn]

Here's a fantastic video showing a bouncing bomb in action: https://www.youtube.com/watch?v=Ik9vCg-xRr4#t=0m47s

[cyberferret]

That's a great video. Extremely low release. The splash from the drop actually smacked into the rear fuselage. I bet in the actual mission the tail gunner would have had wet feet, but a great view of the bomb skipping across the water...

[biofox]

There was a Channel 4 documentary a few years ago where they made and tested one of these. I didn't see it, but there are clips online:

https://www.youtube.com/watch?v=8IeGYkwVIWw

[paulajohnson]

Growing up, Barnes Wallis was my hero. Paul Brickhill's book describes how he had to battle unimaginative Whitehall bureaucrats one day, and cutting edge engineering problems the next, to get the thing built.

[trhway]

Similar technique using regular bombs

https://en.wikipedia.org/wiki/Skip_bombing

[bgentry]

The PBS show Nova attempted to recreate this bomb on an episode called Bombing Hitler's Dams: http://www.pbs.org/wgbh/nova/military/bombing-hitler-dams.ht...

They dug a giant hole to build a test dam for this project. Fun to watch.

[mLuby]

Apparently these were the inspiration for the Death Star trench run (because why else would you fly into that trench?)

[leonix]

This reminds me of an old russian anecdote of the cold war period.

USA dropped a nuclear bomb on the USSR. 5 million people died, panic in the media, outcry from the whole world community, etc.

Couple days later another sensation: USSR dropped a rubber bomb on the USA. 50 million people died, counting: the bomb continues to bounce!

[sndean]

There's a decent video by Veritasium about the Magnus Effect, where the bomb is essentially given lift by its backspin:

https://www.youtube.com/watch?v=2OSrvzNW9FE

[ada1981]

We are going to have such great bouncing bombs. The best.