“DAMBUSTERS” BREACH RUHR DAMS

London, England · May 16, 1943

At least since 1937, two years before the out­break of Euro­pean hosti­lities, British intel­li­gence had looked into devel­oping alter­na­tive ways to de­stroy Ger­man facto­ries in the Ruhr Valley, Ger­many’s indus­trial heart­land. Late on this date in 1943 in Germany, a Brit­ish squad­ron of nine­teen modi­fied Avro Lan­caster bombers, each with a 9,250‑lb pay­load of one externally mounted, specially designed “bounc­ing bomb” (actually a revolving depth charge), flew toward three dams on the Moehne and Eder rivers in the Ruhr Valley.

The “dam­busters” in Opera­tion Chas­tise dropped their bombs into the reser­voirs when spring run­off was at its highest. Released from a height of 60 feet, the barrel-shaped bombs skipped across the water’s sur­face like stones rico­cheting across a lake, to sink and deto­nate against the face of the dam at a pre­de­fined depth. (Fitted with elec­tric motors to set them spinning back­wards to the direc­tion of travel before being released, the bombs needed to skip over the water to avoid being trapped in pro­tec­tive steel netting near the wall; spinning back­wards ensured that the bombs hugged the wall when they hit it and sank.)

The spec­tac­u­lar feat of pre­ci­sion bombing, argu­ably the most auda­cious bombing raid of the Euro­pean war, breached two of the three tar­geted dams. The Moehne dam alone spilled around 330 mil­lion tons of water into the west­ern Ruhr region, devas­tating fac­tories, homes, mines, and farm­land for miles around. Some farm­land remained effec­tively un­us­able until the 1950s. The loss of the two dam power plants and the de­struc­tion of seven others inter­rupted hydro­electric power gene­ration for about two weeks. The greatest im­pact was felt, as intended, on the Ruhr’s muni­tions indus­try. Strangely, the RAF, which lost 8 Lan­casters and 53 crew members in the Chastise raid, did not return to bomb the dams as they underwent repairs.

Bodies of at least 1,579 vic­tims were found along the Moehne and Ruhr rivers, with hun­dreds of people gone missing. The city of Neheim was worst hit: over 800 people perished, among them some 500 female slave laborers from the Soviet Union. The drowning of thou­sands of civil­ians and POWs led to changes in the Geneva Con­ven­tion to pro­hibit simi­lar raids in the future “if such may cause release of dan­gerous forces from the works or instal­la­tions and con­se­quent severe losses on the civilian population.”





Operation Chastise: Busting Dams in Germany’s Industrial Heartland

Moehne dam breach, North Rhine-Westphalia, May 17, 1943 Eder dam breach, North Rhine-Westphalia, May 1943

Left: The Moehne dam breached, photo­graphed by an RAF pilot on May 17, 1943, one day after RAF 617 Squad­ron had attacked the dam with their cylin­dri­cal bombs. Six bar­rage bal­loons can be seen above the dam. The two direct hits on the con­crete-and-steel gra­vity Moehne dam resulted in a breach around 250 ft wide and 292 ft deep. A tor­rent of water around 32‑1/2 ft high and traveling at around 15 mph swept through the valleys of the Moehne and Ruhr rivers in North Rhine-West­phalia, extending for around 50 miles from the source.

Right: The Eder dam, the largest in Europe, was also breached in two places. The wave from the breach was not strong enough to result in sig­nif­i­cant damage by the time it reached Kassel, the largest city in North­ern Hessen. The crest of a third dam, the Sorpe dam, had a por­tion been blown off but was other­wise un­scathed, pro­tected from the Lan­cas­ters by an in­creasingly dense fog that rolled in during the raid.

Dambusters Declassified Documentary: Retracing the 1943 Raid by RAF 617 Squadron

WWII Chronicles book coverHistory buffs, there is good news! The Daily Chronicles of World War II is now avail­able as an ebook for $4.99 on Amazon.com. Con­taining a year’s worth of dated entries from this web­site, the ebook brings the story of this tumul­tu­ous era to life in a com­pelling, author­i­ta­tive, and suc­cinct man­ner. Fea­turing inven­tive naviga­tion aids, the ebook enables readers to instantly move for­ward or back­ward by month and date to dif­fer­ent dated entries. Simple and elegant! Click here to purchase the ebook.