Operation Chastise was the official name for the attacks on German dams on May 17, 1943 in World War II using a specially developed "bouncing bomb". The attack was carried out by Royal Air Force No. 617 Squadron, subsequently known as the Dam Busters. Scrivener Dam, Canberra Australia, was engineered to withstand a once-in-5000-years flood event A dam (a common Teutonic word, compare to Dutch dam, Swedish and German damm, and the Gothic verb faurdammjan, to block up) is a barrier across flowing water that obstructs, directs or retards the flow... May 17 is the 137th day of the year in the Gregorian Calendar (138th in leap years). ... 1943 is a common year starting on Friday. ... Mushroom cloud from the nuclear explosion over Nagasaki rising 18 km (over 11 miles) into the air. ... The bouncing bomb was a kind of bomb designed by Barnes Wallis of Vickers-Armstrong at Brooklands, Surrey. ... The Royal Air Force (often abbreviated to RAF) is the air force branch of the UK Armed Forces. ... No. ...

The Eder dam, one of the targets of Operation Chastise. Note the missing porthole on the left, which was not replaced after the attacks.

A view of the eder dam, Germany. ... A view of the eder dam, Germany. ...

Development of the plan

The mission developed out of a bomb designed by Barnes Wallis and developed into a working device by a team at Vickers. Wallis was an aircraft designer and had the successful Wellesley and Wellington to his credit. While working on the Warwick, he also began work on bomb design with dams specifically in mind. Sir Barnes Neville Wallis, FRS, commonly known as Barnes Wallis, (September 26, 1887 – October 30, 1979) was a British scientist, engineer and inventor. ... The Vickers corporation, founded as the Vickers company in 1828, was a British manufacturer, primarily of military equipment. ... The Vickers Wellesley was a 1930s light bomber built by Vickers for the Royal Air Force. ... The Vickers Wellington was a twin-engine, medium bomber designed in the mid-1930s at Brooklands in Weybridge, Surrey, by Vickers-Armstrongs Chief Designer, R.K. Pierson. ... The Vickers Warwick was a transport, anti-submarine patrol and air-sea rescue aircraft of the RAF during World War II. Vickers Warwick The Warwick was designed in response to Air Ministry specification B.1/35 for a two-engined heavy (by the standards of the day) bomber to replace...

His initial idea was for a 10-ton bomb to be dropped from 40,000 feet (12,200 m). However, research showed that a bomb sufficient to breach dam without a direct hit would be too heavy for any available bomber to carry. A much smaller charge would suffice if it could be exploded directly against the dam wall below the surface of the water. The major German dams were protected by heavy torpedo netting to prevent such an attack, and Wallis's breakthrough was to overcome this. A drum-shaped bomb, spinning rapidly backwards and dropped from a sufficiently low altitude at the right speed, would skip for the required distance over the surface of the water in a series of bounces before reaching the dam wall and using its residual spin to run down the wet side to the dam's base. An accurate drop could bypass the dam protection and let the bomb be detonated against the dam with a hydrostatic fuse. After testing, and many meetings, the idea was adopted on February 26, 1943. The bomb was codenamed 'Upkeep'. The dams were to be bombed in May of that year, when water levels would be highest. February 26 is the 57th day of the year in the Gregorian Calendar. ... 1943 is a common year starting on Friday. ...

The operation was given to 5 Group which formed a new squadron to undertake the mission. Initially called Squadron 'X', it was led by Wing Commander Guy Gibson, a veteran of over 170 missions. A further 21 crews were chosen from 5 Group to join the new squadron based at RAF Scampton, 5 miles north of Lincoln. Wing Commander (rank) is a rank in the Royal Air Force, equivalent to a Lieutenant Colonel in most Armies, the Royal Marines and the United States Marine Corps. ... Photo from 617 Squadron The dambusters Photo submitted by Roger Shenton - (taken by John Kramer) Photo of the Dambusters Memorial at Woodhall Spa. ... RAF Scampton is a Royal Air Force station situated north of Lincoln in England. ... Lincoln (pronounced Ling-kun) is a cathedral city and county town of Lincolnshire, England, a bridging point over the River Witham, which flows to Boston. ...

The targets were the three key dams in the Ruhr area, the Möhne and the Sorpe on the Ruhr River and the Eder Dam on the Eder River. The loss of hydroelectric power was important but the loss of water to industry, cities and canals would have greater effect. Map of the Ruhr Area The Ruhr Area (German Ruhrgebiet or, colloquially, Ruhrpott) is a metropolitan area in North Rhine-Westphalia, Germany, consisting of a number of large industrial cities bordered by the rivers Ruhr to the south, Rhine to the west, and Lippe to the north. ... The Möhne Reservoir is an artificial lake in Northrhein-Westphalia, some 45 km east of Dortmund. ... The Ruhr in Essen-Kettwig The Ruhr is a large river in western Germany (North Rhine-Westphalia) starting near the town of Winterberg in Sauerland and ending in the Rhine in the city of Duisburg. ... The Eder barrier, which creates the Edersee. ... The Eder is a river in Germany (ca. ...

The aircraft were adapted Avro Lancaster Mk IIIs, dubbed Type 464 (Provisioning). To reduce weight, much of the armour was removed, as was the mid-upper turret. The substantial bomb and its unusual shape meant that the bomb doors were removed and the bomb itself hung, in part, below the body of the aircraft. It was mounted in two crutches and before dropping, it was spun up to speed by an auxiliary motor. The Avro Lancaster was a four-engined World War II bomber aircraft made initially by Avro for the Royal Air Force. ...

Bombing from 60 feet (18 m) at 240 mph (390 km/h), at a very precise distance from the target, required expert crews, intensive night and low-altitude flying training, and the solutions to two technical problems. The first was to know when the airplane was the correct distance from the target. The two key dams at Moehne and Eder had a tower at each end. A special aiming device (a device with two prongs making the same angle as the two towers at the correct distance from the dam) showed when to release the bomb. The second problem was to measure the airplane's altitude (the usual barometric altimeters were insufficiently accurate). Two spotlights were mounted under the nose and under the fuselage such that their beams would intersect 60 feet (18 m) from the underside of the plane. At the correct height, the two spots of light would merge into one on the surface of the water. The crews practised over the Eyebrook reservoir in Leicestershire (built in 1940 to supply Corby steelworks), and the Derwent Reservoir, Derbyshire. See also: British reservoirs. Several equivalence relations in mathematics are called similarity. ... In an aircraft, the fuselage is the main body section that holds crew and passengers or cargo. ... Leicestershire (abbreviated Leics) is a landlocked county in central England. ... Corby is an industrial town and a local government district located in Northamptonshire, England. ... Derwent Reservoir is one of three reservoirs in the Upper Derwent Valley in the north east of Derbyshire, England. ... Reservoirs and dams in the United Kingdom is a link page for any reservoir or dam in the United Kingdom. ...

The bombs were delivered to the squadron on 13 May, after the final tests on 29 April. With promising weather reports the pilots, navigators and bomb aimers were informed of the targets on 15 May, the rest of the crews on the following day. May 13 is the 133rd day of the year in the Gregorian Calendar (134th in leap years). ... April 29 is the 119th day of the year in the Gregorian calendar (120th in leap years). ... May 15 is the 135th day of the year in the Gregorian Calendar (136th in leap years). ...

The attacks

Organisation

The Lancasters were organised into three groups. Formation 1 was to attack the Moehne and after that, aircraft still with bombs would attack the Eder. Formation 2 was to attack the Sorpe. The third group was a mobile reserve, it would take off two hours later and bomb as directed, either attacking the main dams or bombing smaller dams at Schwelm, Ennepe and Diemel.

The operations room for the mission was at 5 Group headquarters in Grantham. The codes, transmitted in morse, for the mission were agreed on as Goner for bomb dropped, Nigger for the Moehne breached, Dinghy for the Eder breached and ?? for the Sorpe breached. The Nigger code was after Gibson's black dog that had been run-over and killed on the morning of the 17th. Location within the British Isles. ... Morse code is a system of representing letters, numbers and punctuation marks by means of a code signal sent intermittently. ...

The Outbound Flights

The outbound flights were flown at treetop level (between 75 and 120 feet) to avoid detection by the German air defence radar. The aircraft flew two routes, carefully skirting known flak hot spots.

Formation 1 entered continental Europe between Walcheren and Schouwen, crossed the Netherlands, skirting the airbases at Eindhoven and Gilze-Rijen, curved round the Ruhr defences and turned north to avoid Hamm before turning to head south to the Moehne. Formation 2 flew further northwards, cutting over Vlieland and crossing the Zuider Zee before joining the first route near Wesel and then flying south beyond the Moehne to the Sorpe. Satellite image of the Scheldt estuary Walcheren is a former island in the province of Zeeland in the Netherlands at the mouth of the Scheldt estuary. ... Schouwen-Duiveland is a municipality and an island in the southwestern Netherlands. ... Eindhoven is a municipality and a city located in the province of Noord-Brabant in the south of the Netherlands, originally at the confluence of the Dommel and Gender brooks. ... Gilze en Rijen is a municipality in the southern Netherlands. ... Map of Germany showing Hamm Hamm is a city in North Rhine-Westphalia, Germany. ... Vlieland (Frisian: Flylân) is a municipality in the northern Netherlands. ... Landsat photo The Zuider Zee (Dutch: Zuiderzee, pronounced ZIGH-der-zee) was a former shallow inlet of the North Sea in the northwest of the Netherlands, extending about 100 km inland and at most 50 km wide, with an overall depth of about 4 to 5 meters and a coastline... Wesel is a city (population about 64,300 in 2003) in Germany, located at the point where the Lippe River empties into the Rhine. ...

Formation 1 was of nine aircraft in three groups — Gibson, Hopgood, Martin; Young, Astell, Maltby; and Maudslay, Knight, Shannon. Formation 2 was of five aircraft, those of McCarthy, Byers, Barlow, Rice and Munro. Formation 3 consisted of the aircraft of Townsend, Brown, Ottley and Burpee. Two crews were unable to make the mission because of illness.

The first aircraft, those of Formation 2 and heading for the longer northern route, took off at 21h10. McCarthy's aircraft had a hydraulics fault and he took off in a reserve craft twenty minutes late. Formation 1 took off from 21h25.

The first casualties were taken soon after the craft reached the Dutch coast. Formation 2 did not fare well: Munro's aircraft lost his radio to flak and turned back over the Zuider Zee while Rice flew too low and lost his bomb in the water but recovered the aircraft to return to base. The aircraft of both Barlow and Byers crossed over the coast around Harderwijk and were shot down shortly thereafter. Only the tardy aircraft of McCarthy survived across the Netherlands. Formation 1 lost only Astell, somewhere over Rosendaal. American troops man an anti-aircraft gun near the Algerian coastline in 1943 Anti-aircraft, or air defense, is any method of combating military aircraft from the ground. ... Harderwijk is a municipality and a city in the eastern Netherlands. ...

The Moehne dam following the attacks

Download high resolution version (2304x1728, 1666 KB)The Moehne Dam following Operation Chastise. ... Download high resolution version (2304x1728, 1666 KB)The Moehne Dam following Operation Chastise. ...

The attack on the Mohne dam

Formation 1 arrived over Moehne Lake and Gibson's aircraft (G for George) bombed first. Hopgood (M for Mother) attacked second. Hopgood's aircraft was hit by flak as it made its low-level run and was then caught in the blast of its own bomb and destroyed. Martin (P for Peter) bombed third; his aircraft was hit but made a successful attack. Then Young (A for Apple) made a successful run and after him Maltby (J for Johnny) and then, finally, the dam was breached. Gibson then led Young, Shannon, Maudslay and Knight to the Eder.

The attack on the Edder dam

The Eder valley was heavily fogged but not defended. The tricky topography of the surrounding hills made the approach difficult and the first aircraft, Shannon's, made six runs before taking a break. Maudslay (Z for Zebra) then attempted a run but the bomb struck the top of the dam and the aircraft was caught in the blast. Shannon made another run and successfully dropped his bomb and the final bomb of the formation, from Knight's aircraft, breached the dam.

The attacks on the Sorpe and Ennepe dams

McCarthy (T for Tom) reached the Sorpe alone. It was the least likely to be breached — a vast earth dam rather than the two concrete structures successfully attacked. Despite the mist and ill-placed hills, McCarthy's aircraft successfully dropped its bomb but did not breach the dam. Three of the reserve aircraft were directed to the Sorpe. Burpee (S for Sugar) never reached the dam. Brown (F for Freddy) reached the dam and in increasingly dense mist finally dropped his bomb without breaking the dam. Anderson (Y for Yorker) arrived last and the mist was too dense for him to even attempt the run. The remaining two aircraft were sent to subsidiary targets, Ottley (C for Charlie) was shot down en route while Townsend (O for Orange) successfully dropped his bomb on the Ennepe.

The return flights

On the way back, flying again at treetop level, one further aircraft was lost, that of Young which was hit by flak and crashed into the sea just off the coast of Holland.

Complete list of the aircraft involved

After the Raid

In all, 53 of the 133 aircrew were killed and three bailed out to be made POWs. Of the surviving aircrew thirty-three were decorated at Buckingham Palace on 22 June, with Gibson awarded the Victoria Cross. There were five DSOs, ten DFCs and four bars, twelve DFMs and two CGMs. Geneva Convention definition A prisoner of war (POW) is a soldier, sailor, airman, or marine who is imprisoned by an enemy power during or immediately after an armed conflict. ... Buckingham Palace and the Victoria memorial. ... June 22 is the 173rd day of the year (174th in leap years) in the Gregorian Calendar, with 192 days remaining. ... Victoria Cross, Source: Veterans Affairs Canada The Victoria Cross (official post-nominal letters VC) is the highest award for valour that can be awarded to members of the British and Commonwealth armed forces of any rank in any service and civilians under military command. ...

After a public relations tour of America, Gibson returned to operations and was killed on a mission in 1944.

Following the dams raid, 617 squadron was kept together as a specialist unit. The squadron badge ("on a roundel, a wall in fesse, fracted by three flashes of lightening in pile and issuant from the breach, water proper") was chosen and a motto "Après moi le déluge". The squadron went on to drop Wallis' massive Tallboy bomb and Grand Slam bomb, using an advanced bomb sight which enabled the bombing of small targets with far greater accuracy than was routinely obtained with conventional bomb aiming techniques. The squadron is still active today. The Tallboy was a bomb developed by Barnes Wallis in 1944. ... The Grand Slam (Earthquake) bomb was developed by Barnes Wallis in late 1944. ...

Effect on the war

The tactical view

The Moehne and Eder lakes poured around 330 million tons of water into the western Ruhr region. Mines were flooded and houses, factories, roads, railways and bridges destroyed as the flood waters spread for around 50 miles (80 km) from the source. Estimates show that before 15 May 1943 water production on the Ruhr was 1 million tonnes, which dropped to a quarter of that level after the raid. In terms of deaths: 1,294 people were killed, 749 of them Ukrainian POWs from a camp just below the Eder Dam. After the operation Barnes Wallis wrote, "I feel a blow has been struck at Germany from which she cannot recover for several years". May 15 is the 135th day of the year in the Gregorian Calendar (136th in leap years). ... 1943 is a common year starting on Friday. ...

However, on closer inspection, Operation Chastise did not have the military effect that was at the time believed. By 27 June, full water output was restored, thanks to an emergency pumping scheme inaugurated only the previous year, and the electricity grid was again producing power at full capacity. The raid proved to be costly in lives (more than half the lives lost belonging to allied POWs), but in fact no more than a minor inconvenience to the Ruhr's industrial output. However, the pictures of the broken dams proved to be an immense morale boost to the Allies, especially to the British, still suffering under German bombing. June 27 is the 178th day of the year (179th in leap years) in the Gregorian calendar, with 187 days remaining. ...

The diplomatic view

An important reason for planning the raid was to persuade Stalin that Britain was capable of being an effective ally and that as a consequence, the Soviet Union should continue to resist the German invasion of its territory. Iosif (usually anglicized as Joseph) Vissarionovich Stalin (Russian: Иосиф Виссарионович Сталин), original name Ioseb Jughashvili (Georgian: იოსებ ჯუღაშვილი; see Other names section) (December 21, 1879[1] – March 5, 1953) was a Bolshevik revolutionary and leader of the Soviet Union. ... Original German plan Operation Barbarossa (Unternehmen Barbarossa) was the German codename for Nazi Germanys invasion of the Soviet Union during World War II, which commenced on June 22, 1941. ...

This was the middle period of the war when the Japanese had relatively recently brought the United States into it on Britain's side (see Attack on Pearl Harbor). Germany had a little earlier done the same with the Soviet Union (see Operation Barbarossa). However, the Soviet Union was in a very serious position, although by the time the preparations for the raid were complete the USSR had found the capacity to begin its counter-offensive on the Don and Volga. See Battle of Stalingrad. The Dams Raid enabled Churchill, in negotiations with the leaders of these new allies, to point to an effective strike against the hitherto apparently invincible German state so that he was taken more seriously as an ally than might otherwise have been the case. This was relevant vis-à-vis Stalin but also in the USA. Although Churchill had the sympathetic ear of Roosevelt, many of the US military staff were less persuaded of the value of British experience and capabilities. (See Churchill, W.S. (1951).) The Imperial Japanese Navy made its attack on Pearl Harbor on the morning of December 7, 1941. ... Original German plan Operation Barbarossa (Unternehmen Barbarossa) was the German codename for Nazi Germanys invasion of the Soviet Union during World War II, which commenced on June 22, 1941. ... The eastern front at the time of Operation Uranus. ... This article is about the river in Western Russia. ... Волга Length 3,690 km Elevation of the source 225 m Average discharge 8,000 m³/ s Area watershed 1. ... The Battle of Stalingrad was a major turning point in World War II, and is considered the bloodiest and largest battle in human history and arguably one of the greatest come-backs in military history. ... The Right Honourable Sir Winston Leonard Spencer-Churchill, KG, OM, CH, FRS (30 November 1874–24 January 1965) was a British statesman, best known as Prime Minister of the United Kingdom during the Second World War. ... Franklin Delano Roosevelt (January 30, 1882–April 12, 1945), 32nd President of the United States, the longest-serving holder of the office and the only man to be elected President more than twice, was one of the central figures of 20th century history. ...

The strategic view

The Dams Raid was, like many of the air raids, undertaken with an ongoing view to the need to keep drawing German defensive effort back into Germany and away from actual and potential theatres of ground war, a policy which culminated in the Berlin raids of the winter of 1943–44. In May 1943 this meant keeping the Luftwaffe and anti-aircraft defence forces' effort away from the Soviet Union; in early 1944, it meant clearing the way for the aerial side of the forthcoming Operation Overlord. The Battle of Normandy was fought in 1944 between the German forces occupying Western Europe and the invading Allies. ...

Notes

A 1954 movie, The Dam Busters was made about the raids and was very popular. 1954 was a common year starting on Friday of the Gregorian calendar. ... The Dam Busters is a 1954 British war film, set during World War II, and documenting the true story of the RAFs 617 Squadron, the development of the bouncing bomb, and Operation Chastise - the attack on the Ruhr dams in Germany. ...

Bibliography

• The Dambusters Raid, John Sweetman (Cassell, 1999). Good "warts and all" account.
• The Dam Busters, Paul Brickhill (1952). 'Novelised' style. Covers entire wartime story of 617 Squadron.
• Enemy Coast Ahead, Guy Gibson (1955). Gibson's own account, written before his death on operations in 1944.
• Churchill, W.S. The Second World War (1951) Vol IV Chapetr XXV. [Concerning US military attitudes to involvement in Europe.]

External links

• Site with details of the raids, full crew listing, links to present day 617 Sqn and much more
• Online Dambusters exhibition at the UK National Archives
• Secrets of the Dead: Bombing Nazi Dams and their link page
• BBC Online - Myths and Legends - Home of the Dambusters
• 50th Anniversary BBC News.
• Imdb Archive Information