On the night of May 16-17, 1943, 19 Lancaster bombers of the RAF's 617 Squadron, led by Wing Commander Guy Gibson, took off from RAF Scampton to attack the dams of the Ruhr Valley. The mission, Operation Chastise, required them to fly at exactly 60 feet above the water, at 220 miles per hour, in moonlight, dropping a 9,000-pound bouncing bomb designed by Barnes Wallis that would skip across the water and detonates against the dam wall.
Of the 19 crews that departed, 8 were shot down. 53 of the 133 airmen never returned. Three more were captured. Gibson was awarded the Victoria Cross. The Mohne Dam was breached, as was the Eder Dam. The Sorpe Dam was damaged but not destroyed. The flooding downstream destroyed factories, power stations, and bridges, killing an estimated 1,600 people — including over 1,000 Soviet and Polish forced laborers in camps below the dams.
What is less well known is that the raid required crews to practice the low-level bombing technique over the Derwent Reservoir in England for weeks. They flew at 60 feet — the height of a church steeple — at night, in some cases with their wings clipping the water. The bouncing bomb had to hit the water at exactly 220 mph, skip at least three times, and detonate at exactly 30 feet depth. The margin for error was measured in feet.
The loss of 8 crews from a total of 19 was devastating. 617 Squadron, which became known permanently as the Dambusters, went on to become the RAF's most elite precision bombing unit. They were later called in for the most dangerous missions of the remaining two years of the war, including sinking the battleship Tirpitz with 12,000-pound Tallboy bombs in November 1944.
Gibson was killed in a Mosquito aircraft crash on September 19, 1944, just 16 months after the Dambusters raid. He was 26 years old. His legacy lives on, but the full list of the 53 men who died on the night of May 16-17 is still preserved at the RAF Museum Cosford.