How did the Dambusters' bouncing bomb add up?

A unique spinning five-ton bomb bounced across the surface of water like a giant skimming stone - destroying two dams in Germany's Ruhr valley, crippling Hitler's arms factories and changing the course of the war.

Planned in Grantham, the Dambusters' raid on key dams in 1943 passed into military history - and film folklore with a 1950's feature film starring local legend Richard Todd.

But the bouncing bomb as designed by Barnes Wallace for 617 Squadron was actually a triumph of science and mathematical planning.

A special Gravity Fields presentation at KGGS - The Engineering of the Bouncing Bomb - revisits the Channel 4 documentary which re-created the audacious Dambusters' raid for the first time since the war.

Hilary Costello, who collaborated with Cambridge engineer Dr Hugh Hunt on the documentary, will show excerpts from the documentary. She will relate how a team of infectiously enthusiastic scientists, assisted by dam engineers, explosives experts, mechanics and pilots, recreated the iconic Dambusters' bombing raid.

With many original records lost, Dr Hunt first had to do his own scientific calculations on how to make a bomb bounce across water.

The team modified a vintage Second World War aircraft to carry a bomb the size of an oil drum, flew it dangerously low over a Canadian lake and tried to release the bomb at the perfect point so that it bounced across the water onto a specially-constructed 130-foot-wide dam.

Gravity Fields is supported by SKDC and has received Arts Council England funding

Dambusters: The Engineering of the Bouncing Bomb. Hilary Costello
Grantham and Kesteven Girls' School. Wednesday 26 September, 4.30pm