The Möhne Dam, at the time of its completion in 1913, was the largest dam in Europe. The Möhne Reservoir, which the dam created by restricting the flow of the Ruhr River, was by far the continent’s largest Reservoir. At 650 metres long and 40 metres high, the dam created a reservoir with a storage capacity of 134.5 million cubic metres of water. It was vast!
It was conceived and then built for several reasons. Firstly, the region to the west of the Möhne, the Ruhr Region, had gone about a period of vast industrialisation in the preceding decades, with water intensive industries such as coal mining and steel production forming a colossal cluster of heavy industry in the area. Secondly, the Ruhr River itself was prone to flooding, which had proved particularly disruptive and costly for the coal mines. A dam would have to be built, one that could regulate water levels on the Ruhr River downstream and prevent flooding, while also readily providing the thirsty Ruhr Region with all the water that it required.
26 years after the Möhne Dam opened, World War Two broke out and Germany became a target of Allied bombing attacks. The Möhne Dam was vulnerable and the Germans knew it. Duly, they covered the reservoir in torpedo nets, netting that was designed to catch bombs and therefore prevent the Möhne Dam from being destroyed by conventional air raid bombings.
Despite the torpedo netting, the British were determined to destroy the dam. By doing so, they believed, they could flood the Ruhr Region and reduce Nazi Germany’s ability to produce steel. Steel was vital to the war effort and a damaged Ruhr Region would pull resources away from the Western Front. But they could no longer destroy the dams using conventional bombs; they wold have to come up with something unique, something capable of travelling under the torpedo netting.
Operation Chastise began, with the engineer Barnes Wallis tasked with the job of creating a bomb capable of breaching the dam. What he came up with was a bomb, that which, when dropped at the correct angle, would bounce across the water’s surface, passing under the torpedo netting, making contact with the dam wall and then sinking before exploding. It was called the bouncing bomb.
And so, on the nights of the 16th and 17th of May, 1943, the mission to destroy the Möhne Dam – along with nearby Edersee Dam – was launched. It was squadron number 617 of the Royal Air Force that undertook the attacks, but they would become better known as the Dam Busters. Flaying low to avoid enemy radar detection, the squadron made their way to the dams via Holland, and the attack was launched. The mission was executed successfully and both dams were breached, causing over 1,600 fatalities and catastrophic flooding as far as 150 miles downstream from the dams. The British, too, suffered losses; eight aircraft were shot down, with 53 aircrew dying as a result and three others taken as prisoners.
Following the destruction of the Möhne Dam, the Nazi authorities quickly diverted resources towards its rebuilding. For propaganda reasons, they wanted it rebuilt as quickly as possible. They wanted to demonstrate to the Allies that the war effort was not stretching German resources, that they were coping just fine. Several thousand forced labourers, working around the clock and under strict supervision, worked to rebuild the dam. It became operational again on the 3rd of October, 1943, six months after its original destruction.
Today, In the UK, the impact that the Operation Chastise, bouncing bomb raids had on Nazi Germany is still a debated topic. In Germany, the Möhne Reservoir and Dam continue to provide water and hydroelectricity to the Ruhr Region. The lake itself is a popular tourist attraction for leisure boaters and motor bike tourers. A small memorial next to the dam serves to commemorate those that lost their lives in the original attack, as well as those that died during its rebuilding.