Few airborne missions in the history of the Second World War have taken on such an iconic status as that of Operation Chastise, otherwise known as the Dambusters Raid. On the night of 16 May 1943, Royal Air Force Squadron 617 launched a surprise attack on a number of strategic German sites, featuring the pioneering use of new ‘bouncing bombs’, codenamed ‘Upkeeps’. This surprise attack successfully targeted German industrial sites with a high degree of precision, resulting in the breaching of two major dams in the Ruhr industrial valley, and severely damaging a third. The raid caused extensive damage to German infrastructure, power and water supplies, and resulted in a very high civilian death toll. Only half of the squadron survived the mission, which was immortalised in the 1955 epic war film The Dambusters. Although the significance of the raid in the overall war effort is debated, it is clear that Operation Chastise functioned as a significant blow to German morale in this critical stage of the Second World War. The raids live on in the collective British memory as a shining example of British ingenuity and daring-do.
- March 1942 – Wallis designs the new ‘bouncing bomb’ to target German dams
- 26 February 1943 – Operation Chastise is given the go-ahead; testing begins
- 29 April 1943 – Final tests of the new bouncing bombs
- 16 May 1943 – Operation Chastise is launched
- Barnes Wallis – Inventor of the ‘bouncing bombs’ used in Operation Chastise
- Sir Arthur Harris – Chief of Bomber Command
- Guy Gibson – Wing Commander of No.617 Squadron
- Building the Bouncing Bomb
During the early 1940s, at the height of the Second World War, Allied policymakers had identified a number of strategic sites in the German heartlands that were thought to provide opportunities to limit the capacity of the Germans to operate potentially. In particular, the heavily industrialised Ruhr Valley was singled out as an important target. The valley contained a number of important dams that provided crucial hydroelectric power and ensured a clean supply of water for civilians, military personnel, and for industrial use in steel making. If these dams could be breached, it was suggested, it would strike a keen blow to the German war effort.
However, devising a way to attack these important and well-defended sites was no easy feat. The targeted dams, particularly the Mohne, were well defended by German flak (anti-aircraft guns), and the mission would require a surprise attack, capable of dropping a significant load on the site with hitherto unprecedented accuracy. The bombs needed to be large enough to cause sufficient damage to breach the concrete dam, but the planes also needed an extremely accurate targeting system, flown with sufficient dexterity in order to avoid detection. Such a raid had never been attempted before, and to all intents and purposes, in the early 1940s, it seemed to be impossible.
A number of wartime engineers were set the task of creating new technology that would facilitate the mission. Barnes Wallis, an engineer at Vickers, applied himself and developed an innovative and intelligent solution to the problem. The initial idea was to construct a 10-tonne bomb that could be dropped from around 40,000 feet in the air. This bomb would have the capacity to cause serious damage to the dam wall but was likely to have limited success on account of the torpedo nets that were intended to prevent such attacks. Wallis needed to find a way to circumvent the torpedo nets and to land the bombs at the base of the dam wall. In order to achieve this, he devised an ingenious solution. The bomb he designed was drum-shaped and small and was designed to spin backwards. This meant that it could be dropped from a low altitude on to the water, where the spinning momentum would lead it to bounce along the surface, in much the same way as a spinning stone bounces off the surface of a lake. In this way, the bomb could avoid the torpedo nets altogether and be detonated once it landed next to the dam by means of a hydrostatic fuse.
Wallis’s designs were initially met with ridicule, and Sir Arthur Harris, Chief of Bomber Command, is said to have referred to them as ‘tripe’ and the ‘maddest proposition’. However, Wallis persevered with his tests. The second challenge was to find a vessel suitable for carrying the bombs to their destination. The planes needed to be capable of carrying a four-tonne bomb, modified to allow for the spinning mechanism to be fitted, and needed to be flown extremely low to the ground in order to ensure that they hit the water at the correct angle. A series of trials were carried out in late 1942, first on a scaled prototype and later on a full-sized prototype on Chesil Beach in January of 1943. Following this, it was decided that a modified version of the Arvo Lancaster bomber would be sufficient to carry the bombs, thus considerably accelerating the process of development. Finally, on 26 February 1943, the mission was given the go-ahead.
Planning and Preparations
The operation was assigned to a new squadron taken from No. 5 Group RAF, led by Wing Commander Guy Gibson. Gibson was an experienced and capable flyer and was given the task of putting together the dedicated 617 Squadron and running tests with the new bombs and modified planes. Gibson was the only one to be given full information about the details of the raid, and he began to intensively drill his crews in order to give the mission the best possible chance of success. The squadron consisted of personnel from the Royal Air Force, in addition to those from the Royal Canadian Air Force, the Royal Australian Air Force and the Royal New Zealand Air Force.
The key targets for the mission were identified as the Mohne Dam and the Sorpe Dam, both upstream from the Ruhr industrial complex. The Eder Dam, on the nearby Eder River, was chosen as a secondary target, but there were limited hopes that this would be destroyed, due to the steep hills surrounding the reservoir, which would make the approach more difficult. The days leading up to the raid were tense and uncertain, as the final preparations for the mission were made. At midday on 16 May, the crews were finally briefed on the substance of the plan and given their orders for the raid. Operation Chastise would take place that very night.
Operation Chastise: The Launch
From 9.28pm on 16 May, 19 Lancaster bombers, carrying 133 crew, departed Lincolnshire in waves, organised into two main groups and taking different routes into enemy territory. The bombers flew low in order to avoid radar detection and this created problems from the very outset. One fighter, flying too low, actually struck the sea, and lost the bomb in the water. Another ran into electricity pylons and crashed; others were shot down by anti-aircraft fire as they hit the Dutch coast.
Gibson headed the first formation, bound for the Mohne Dam. One by one, the bombers went in and dropped their payload, but it took five attempts before the dam was breached. The planes with the remaining bombs then went on to attack the Eder, which was also successfully breached just half an hour later. Repeated bombardment of the Sorpe yielded limited results: the dam was damaged but remained intact.
The last bomber arrived back at base at 6.15am on 17 May. Of the 133 crewmen who had set out as part of Operation Chastise, 53 were killed, and three were captured, becoming prisoners of war. However, the operation had been a surprising success. The breaching of the Mohne and Eder Dams had caused a huge flood to surge down the valley, destroying factories, military infrastructure and putting a major hydroelectric power station out of commission. In addition to this, the operation killed approximately 1600 people, most of whom were factory workers and foreign prisoners of war. The surprise hit on German infrastructure was a huge blow to morale, and created a corresponding surge of hope among the British and Allied forces.
The impact of Operation Chastise as part of the overall war effort has been the subject of extensive debate, even from the moment the last planes flew back on 17 May 1943. Privately, Arthur Harris continued to disparage the entire mission and believed it to have no strategic worth. However, publicly, the raid was immediately announced as a major victory and was said to have caused catastrophic damage to the German war effort. In particular, the flood based by the breaching of the Mohne Dam had an extremely significant effect on local infrastructure, washing away roads, bridges and railway lines within a 50-mile radius. In addition to this, the dam’s principal utility, which was the production of hydroelectric power, was destroyed, meaning that factories and households across the region were left without power for weeks after the mission. Coal production across Germany dropped significantly in the month following the raid, which appears to have been a direct consequence of the damage done in the Ruhr Valley. In addition to this, local agriculture was devastated; the flood washed away significant tracts of arable land and livestock, leaving the area impossible to cultivate for almost a decade after the raid. Operation Chastise was lauded in Britain as an enormous strategic and military victory.
However, with the benefit of hindsight, it appears that the raid did not have as decisive an impact in the war that has been assumed. Although the Ruhr Valley suffered a huge shock, in practical terms, water and electricity output was restored to their pre-raid levels within six weeks of the operation. Although the loss of life had been considerable, the fact that the majority of these casualties were foreign workers and prisoners of war meant that the effect of the deaths was muted in German society. Although the raid was a profound shock and temporarily damaged domestic morale, its impact was relatively short-lived. Significantly, the British failed to target the site again during the reconstruction effort, when it would have been at its most vulnerable, and so any strategic impact on the overall German war effort was fairly limited.
Perhaps the most significant implication of Operation Chastise was its boost to Allied (and especially British) morale. The British, who had been subjected to the incessant onslaught of German bombs throughout the Blitz, had scored a huge victory with just a handful of daring airmen. The operation showcased British ingenuity, bravery and tactical superiority, which raised the hopes that were beginning to fade after four long years of war. It is for this reason that the Dambusters raid has endured in British memory: it provided a real sense of victory at a time when it was most needed in British society.
Sites to Visit
- The Dambusters Memorial, Woodhall Spa, England. This memorial is near to RAF Coningsby in Lincolnshire and is the site from which the Dambusters Raid was launched. Annual events to commemorate the raid and other Second World War battles are held around the site.
- RAF Coningsby, Lincolnshire, England. The fighter base at Coningsby is host to an excellent exhibition on the Battle of Britain, and has a number of British fighter planes on display, including Spitfires, Hurricanes, and an Avro Lancaster used in the Dambusters Raid.
- RAF Museum, London, England. This excellent, comprehensive London museum contains a range of exhibits pertaining to the role of the Air Force in wars throughout the 20th and 21st centuries, particularly the Second World War.
Film, Literature and TV
- The Dambusters, a 1955 epic war film based on the events of Operation Chastise. One of the most successful and iconic World War II films ever made, the Dambusters recreates the events of Operation Chastise, focusing on the lives of those who fought and died during the raid.
- Dambusters Declassified. 2010 TV movie taking a fresh look at the Dambusters raid, by the actor/pilot Martin Shaw, focusing on newly declassified information and sources.
- Max Arthur, Dambusters: A Landmark Oral History, (Virgin: 2009). This fascinating history of the raid, introduced in a foreword by Stephen Fry, places the voices of those who took part in the operation at the forefront, offering a unique and visceral insight into the events.
- Chris Ward, Dambusters: The Forging of a Legend: 617 Squadron, (Casemate Publishers, 2009). This book offers a good introduction to the 617 Squadron and the events of Operation Chastise, including a useful discussion of its aftermath and significance as part of the war effort.
- John Sweetman, The Dambusters Raid: The Most Audacious Bombing Raid of the Second World War (Cassell, 1999). This classic history of the raid offers a detailed and fresh look at the genesis of Operation Chastise, the events of the raid, and the implications for British military history.