In the early hours of the 17th of May, 1943, Avro Lancaster callsign M Mother was hit by anti-aircraft fire over the Möhne Dam, and crashed. Two of the bomber's crew survived the impact, and upon their discovery by a German ground patrol, were treated with all dignity due to prisoners of war, and were asked if anything could be provided to them. One of the Pilot Officers replied that he would quite like a glass of water. The patrol leader was taken aback, and asked if the officer was being serious, and explained that the water supply had just been destroyed by the raid in which their aircraft took part. This was the first indication received that the Dam had been breached, and that Operation Chastise had succeeded.

The operation that took place 75 years ago is perhaps best known for the first and only practical application of a 'bouncing bomb', a concept thought up by British scientist Barnes Wallis, which was designed to attack the reservoir dams of the industrial Ruhr valley, by so doing British High Command hoped that the industrial heartland of the German Reich would be crippled. Shaped as a cylinder and equipped with a depth charge, the bouncing bomb was designed to be dropped from low altitude while spinning at high velocity, so that the bomb would skim over the water rather than sink into it. This would allow the bomb to nestle itself close to the dams, and sink to a depth at which the depth charge would explode. It was hoped that the force of the explosion, as well as the constant force of the water pushing against the dam, would be enough to cause the dams to breach, and flood the factories and transport infrastructure below.

The operation was a success for the Royal Air Force; two of the dams were breached (Möhne and Eder), and one damaged (Sorpe). Water production int he Ruhr valley dropped to a quarter of its peak on the 15th of May, coal production dropped by 400,000 tonnes, and nine power stations were damaged severely or destroyed by the waters. However, juts over a month after the raid, the dams had been repaired, and full productivity in the Ruhr valley had resumed. However, the greatest cost came in lines; it is estimated that 1,650 were killed by the raid as a result of the flood, while 53 airmen were killed while taking part in the raid. As such, today, we not only remember the scientific achievements of Operation Chastise, but also the cost in human lives on both sides, in an RAF operation that represents a small, yet hugely significant part, of the air force's contribution to the war effort.