Operation Chastise

Operation Chastise
Part of The Second World War
The Möhne dam on the day after the attacks.
Date 16/17 May 1943 Location Eder River, Germany Result British Success
Belligerents
United Kingdom	Nazi Germany
Commanders
Guy Gibson	Josef Kammhuber
Strength
19 bombers	XII. Fliegerkorps
Casualties and losses
Eight aircraft shot down 53 aircrewmen killed, three taken prisoner	Two Dams breached 1 dam heavily damaged 1,294 civilians killed

Operation Chastise was the official name for the attacks on German dams on 16/17 May 1943 in the Second World War using a specially developed "bouncing bomb" invented and developed by Barnes Wallis. The attack was carried out by Royal Air Force No. 617 Squadron, subsequently known as the Dambusters. The Möhne and Eder dams were breached in these attacks, causing a catastrophic flooding of the Ruhr valley, while the Sorpe dam sustained only minor damage.

Background

Prior to the war, the industrial heartland of Germany had been identified by the Air Ministry as an important strategic target and the dams of the area considered as particular targets. Besides providing power they were used to provide water into the canal transport system. The methods to attack the dams had been carefully considered. Calculations indicated that repeated strikes with large bombs would be effective but the necessary accuracy with the standard bombers of Bomber Command in the face of enemy defences was unlikely to be met.

Development of the plan

This bombing mission developed out of a concept to use the bomb that was designed by Barnes Wallis and developed into a working weapon by his team at the Vickers company. Wallis was an aircraft designer, and he had worked on the design and development of the Vickers Wellesley and Vickers Wellington bombers. While working on the Vickers Warwick airplane, Wallis also began work on bomb design with dam-destruction specifically in his mind as a goal.

Wallis's initial notion was for a 10-tonne bomb to be dropped from abouth 40,000 feet in altitude (12,200 meters). This idea was part of the earthquake bomb concept. However, at that time, there was no bomber that was capable of flying to this altitude with such a heavy load.

A much-smaller explosive charge would suffice, if it could be exploded directly against the dam wall but below the surface of the water. The major German reservoir dams were protected by heavy torpedo nets to prevent such an attack, and one of Wallis's breakthroughs was to overcome this. A drum-shaped bomb, spinning rapidly backwards (at over 500 r.p.m.). and dropped from a sufficiently low altitude at the correct speeds, would skip for a significant distance over the surface of the water in a series of bounces - before reaching the dam wall. Then, using its residual spin, the bomb could run down the wet side of the dam to its base. An accurate bomb-drop could bypass the dam's protection and enable the bomb to be detonated against the dam by a hydrostatic fuse. After some testing, and many engineering meetings, this idea was adopted on 26 February 1943. The bomb was codenamed "Upkeep". The dams were to be bombed in May of that year, when water levels would be highest, and thus create the most damage to the German war efforts.

Air Vice-Marshal Ralph Cochrane, Wing Commander Guy Gibson, King George VI and Group Captain John Whitworth discussing the Dambusters Raid in May, 1943

King George VI speaking to Flight Lieutenant Les Munro

This dam-busting operation was given to the No. 5 Group RAF, which formed a new squadron to undertake the mission. Initially called Squadron 'X', its development ran faster than the bureaucracy that named squadrons. It was led by Wing Commander Guy Gibson, a veteran of over 170 bombing missions. 21 bomber crews were chosen from the Group to join the new squadron, which was to be based at RAF Scampton, about five miles north of Lincoln, Lincolnshire.

The targets that were selected were the two key dams upstream from the Ruhr industrial area, the Möhne Dam and the Sorpe Dam. Then, as a secondary target, there were selected the Eder Dam on the Eder River that feeds into the Weser river. The loss of hydroelectric power was important, but the loss of water to industry, cities. and canals would have greater effect. Also, there was the potential for causing devatating flooding when and if the dams were broken.

An original Upkeep bouncing bomb at the Imperial War Museum Duxford

The aircraft were modified Avro Lancaster Mk IIIs, known as B Mark III Special (Type 464 Provisioning).^[1] To reduce weight, much of the internal armor was removed, as was the mid-upper machine gun turret. The substantial bomb with its unusual shape meant that the bombbay 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.^[2]

Bombing from an altitude of 60 feet (18 meters) at 240 mph air speed (390 km/h), at a pre-selected distance from the target, required expert crews. Intensive nighttime and low-altitude flight training was given, and there were technical problems to be solved. The first one was how to know when the aircraft was at the correct distance from its target. The key Möhne Dam and Eder Dam had towers 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 aircraft's altitude (the usual barometric altimeters lacked sufficient accuracy). Two spotlights were mounted, one under the nose and another under the fuselage, such that at the correct height their light beams would converge on the surface of the water. The crews practised at the Eyebrook Reservoir in Leicestershire / Rutland, at the Abberton Reservoir near Colchester, at the Derwent Reservoir, Derbyshire, and at the Fleet Lagoon in Chesil Beach, Dorset. The bomb/mine itself was first tested at the Elan Valley Reservoirs.

The bombs were delivered to the squadron on 13 May, after the final tests on 29 April. Given promising weather reports, the pilots, navigators, and bombardiers were informed of their targets on 15th May, with the rest of the crewmen told on the next day.

The attacks

Using two spotlights to adjust altitude, a modified Lancaster (in this case AJ-J), dropped a backspun drum which skipped over torpedo nets protecting the dam. After impact its bomb would then settle at the dam's base and explode.

Organisation

The Lancasters were organised into three groups. Formation 1 was to attack the Möhne 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 on 17 May and bomb as directed, either attacking the main dams or bombing smaller dams at Schwelm, Ennepe and Diemel.

Formation 1 was of nine aircraft in three groups— piloted by 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 Anderson, Townsend, Brown, Ottley and Burpee. Two crews were unable to make the mission because of illness.

The operations room for the mission was at 5 Group headquarters in Grantham, Lincolnshire. The codes (transmitted in morse) for the mission were agreed on as Goner for bomb dropped, Nigger for the Möhne breached and Dinghy for the Eder breached. The Nigger code was after Gibson's black dog ^[3] that had been run over and killed on the morning of 16 May, the day of the attack. Dinghy was from the nickname of Gibson's friend Young who would be flying A-Apple—Young had had to make forced landings in the sea several times on operations, he and his crew having to resort to the aircraft's inflatable liferaft. Thereafter, he had been known as "Dinghy Young".

The outbound flights

The aircraft flew two routes, carefully avoiding known flak concentrations, and timed to cross the enemy coast simultaneously. The first aircraft, those of Formation 2 and heading for the longer northern route, took off at 21h28.^[4] McCarthy's bomber had a hydraulics problem, and he took off in a reserve craft 20 minutes late. Formation 1 took off from 21h39, 16 May, in groups of three at ten minute intervals.^[4] The reserve formation did not begin its launch until 0009 of 17 May.^[4]

Formation 1 entered continental Europe between Walcheren and Schouwen, flewover the Netherlands, skirted the airbases at Gilze-Rijen and Eindhoven, curved around the Ruhr defences, and turned north to avoid Hamm, before turning to head south to the Möhne River. Formation 2 flew further northwards, cutting over Vlieland and crossing the IJsselmeer before joining the first route near Wesel and then flying south beyond the Möhne to the Sorpe River.

The bombers flew low, at about 100 ft altitude, in order to avoid radar detection. Flight Sergeant George Chalmers, the radio operator on the plane "O for Orange", looking out through the astrodome, was astonished to see that his pilot was flying towards the target along a firebreak in a forest at below treetop level. On the return flight over the Dutch coast, German flak shells were seen bouncing off the top of the sea ^[5].

The first casualties were suffered soon after the bombers reached the Dutch coast. Formation 2 did not fare well: Munro's aircraft lost its radio to flak and turned back over the IJsselmeer, while Rice flew too low, struck the sea and thus lost his bomb in the water. However, he recovered flight to return to his airbase. Both Barlow's and Byers's Lancasters crossed over the coast around the island of Texel. Byers's bomber was shot down by flak shortly afterwards, crashing into the Waddenzee. Only the delayed bomber piloted by McCarthy survived the flight across The Netherlands. In addition, Formation 1 lost Astell's bomber near the hamlet of Marbeck, Germany, when he flew his plane into high tension electrical cables and crashed his Lancaster into a field.^[4]

The attack on the Möhne Dam

The Möhne Dam after the attack.

Formation 1 arrived over Möhne 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 crashed shortly after, when a wing disintegrated. Three crew successfully left the aircraft, but only two survived. Subsequently Gibson flew his aircraft across the dam to draw flak from Martin's run. Martin (P for Popsie) bombed third; his aircraft was damaged but made a successful attack. Next, Young (A for Apple) made a successful run and after him Maltby (J for Johnny) when, finally, the dam was breached. Gibson, with Young accompanying, led Shannon, Maudslay and Knight to the Eder.^[4]. In the attack on the Moehne Dam a running commentary from one of the bombers making the attack was relayed to base by an airborne TR (Transmitter Receiver).1142 manufactured by GEC, the distance being too great for direct VHF.^[6].

The attack on the Eder Dam

A recent photograph of the Eder Dam. Note the missing sluice-gate holes on the left, which were not replaced after the attacks.

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 severely damaged in the blast. Shannon made another run and successfully dropped his bomb. The final bomb of the formation, from Knight's aircraft (N for Nut), breached the dam.

The attacks on the Sorpe and Ennepe Dams

The Sorpe Dam was the one least likely to be breached. It was a huge earthen dam rather than a concrete and steel one, such as the two structures already successfully attacked. Due to various problems, only three Lancasters reached the Sorpe Dam - Joe McCarthy in "T for Tommy" (the delayed aircraft for the second wave) and later Brown in "F for Freddie", and Anderson in "Y for York", both of the third formation. This attack differed from those on the concrete dams in two ways - the "Upkeep" bomb was not spun, and the approach was made along the length of the dam, not at right angles over the reservoir -- because of the topography of the valley.

McCarthy was on his own when he arrived over the Sorpe Dam at 0015 hours, and he realised that the planned approach was even more difficult than the planning model had suggested - as it turned out, the flight path led over a church steeple of in village of Langscheid, which was located on the hillcrest overlooking the dam. With only seconds to go before the bomber had to pull up again to avoid the hillside at the other end of the dam, the bombardier George Johnson had no time to correct his bomber's height and heading.

McCarthy made nine attempted bomb runs before Johnson was satisfied. The 'Upkeep' bomb was dropped on the tenth run. It was just as well that the Germans had thought this dam to be invulnerable to air attack: they had placed no anti-aircraft guns in this area. The bomb from McCarthy's bomber exploded, but when he turned his Lancaster to assess the damage, it turned out that only a section of the crest of the dam had been blown off, while the main body of the dam itself was still functional.

Meanwhile, three of the reserve aircraft had been directed to the Sorpe Dam. Burpee in "S for Sugar" never arrived. (It was later determined that it had been shot down while skirting the Gilze-Rijen airfield). Brown in "F for Freddy" reached the Sorpe Dam, and in the increasingly dense fog hastened to drop his bomb -- but also failed to breach the dam. Anderson in "Y for York" arrived last, but by then, the fog had become too dense for him even to attempt a bombing run. The remaining two bombers were then sent to secondary targets, with Ottley in "C for Charlie" being shot down en route to the Lister Dam. Townsend in "O for Orange" eventually dropped his bomb at the Ennepe Dam without harming it.^[4]

A Possible Attack on the Bever Dam

There is some evidence that Townsend might have attacked the Bever Dam by mistake rather than the Ennepe Dam.^[7] Townsend reported difficulty in finding his dam, and in his post-raid report he complained that the map of the Ennepe Dam was incorrect. The Bever Dam is located only about five miles southwest of the Ennepe Dam, and its reservoir has a similar topography. However, the Bever Dam is located on the southern edge of the reservoir while the Ennepe is located on the northern edge of its reservoir. With the foggy mists filling the valleys during the early morning hours, it would be understandable for him to have to mistaken the two lakes. The War Diary of the German Naval Staff reported that the Bever Dam had been attacked at nearly the same time that the Sorpe Dam was. In addition, the Wupperverband authority responsible for the Bever Dam is said to have recovered the remains of a "mine". Paul Keiser, a 19-year-old soldier on leave at his home close to the Bever Dam, also reported a bomber's making several approaches to the dam and then dropping a bomb that caused a large explosion and a great pillar of flame.

The author of the book, The Dambusters' Raid, John Sweetman, suggests that Townsend's report of the Moon's reflecting on the mist and water is consistent with an attack that was heading to the Bever Dam rather than to the Ennepe Dam, given the Moon's azimuth and altitude during the bombing attacks. Sweetman also points out that the Ennepe-Wasserverband authority was adamant that only a single bomb was dropped near the Ennepe Dam during the entire war, and that this bomb fell into the woods by the side of the dam, not in the water, as in Townsend's report. Finally, members of Townsend's crew independently reported seeing a manor house and attacking an earthen dam, which is consistent with the Bever Dam rather than the Ennepe Dam. The main evidence supporting the hypothesis of an attack of the Ennepe Dam is Townsend's post-flight report that he attacked the Ennepe Dam on a heading of 355 degrees magnetic. Assuming that the heading was incorrect, all other evidence points toward an attack on the Bever Dame. ^[7]

The return flights

On the way back, flying again at treetop level, two more Lancasters were lost. The damaged "Z for Zebra" was struck by flak near Netterden, and Young's "A for Apple" was flayed by flak north of IJmuiden. That bomber crashed into the North Sea just off the coast of The Netherlands.^[4]

The nine surviving Lancasters began landing at Scampton at 0311 hours, with Gibson returning at 0415 hours. The last of the survivors, Townsend's bomber, put its wheels on the ground at 0615 hours.^[4]

Complete list of the aircraft involved

Bomb damage assessment

The Bomber Command wanted to conduct a complete bomb damage assessment as soon as possible. Therefore, the Commanding Officer of the Number 542 Squadron of the RAF was informed by Bomber Command Headquarters of the target time of the attacks. A photo-reconnaissance Spitfire fighter of that squadron, piloted by Flying Officer Frank "Jerry" Fray ^[8] took off from RAF Benson at 0730 hours and arrived over the Ruhr River right after first light. Photos were taken of the breached dams and of the huge floods. ^[9] The pilot later described the experience: ^[8]

After the raid

Memorial to Operation Chastise members at Woodhall Spa, Lincolnshire

Three aircrew from Hopgood's aircraft baled out successfully, but one later died from wounds while the others were captured. One of the crew in Ottley's aircraft survived its crash. In total, therefore, 53 of the 133 aircrew who participated in the attack were killed, a casualty rate of almost 40%. Of the survivors, 34 were decorated at Buckingham Palace on 22 June, with Gibson awarded the Victoria Cross. There were 5 Distinguished Service Orders, 10 Distinguished Flying Crosses and four bars, 2 Conspicuous Gallantry Medals, and 11 Distinguished Flying Medals and one bar.^[10]

Memorial to the German dead in Neheim, 7 kilometres (4 mi) from the Möhne dam

Initial German casualty estimates were about 1,300 killed, including 749 French, Belgian, Dutch, Ukrainian prisoners of war and labourers.^[11][12]

After a public relations tour of America and time spent working in the Air Ministry in London writing the book which would later be published as Enemy Coast Ahead, Gibson returned to operations and was killed on a Mosquito operation 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 lightning in pile and issuant from the breach, water proper") was chosen and a motto "Après moi le déluge" (After me the flood). According to Brickhill there was some controversy over the motto, with the original version Après nous le déluge (After us the flood) being rejected by the heralds as having inappropriate provenance (having been coined, reportedly, by Madame Pompadour), and après moi le déluge having been used by Louis XV in an "irresponsible" context. The motto having been chosen by the King, the latter was finally deemed acceptable.

The squadron went on to drop Wallis' massive Tallboy and Grand Slam bombs, including an attack on the German battleship Tirpitz, 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.

In 1977 the Protocol I amendment to the Geneva Conventions outlawed attacks on dams if it might cause severe civilian losses.

Effect on the war

The tactical view

The Möhne and Eder lakes poured around 330 million tons of water (equivalent to a cube 687 m on each side) 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. The Eder drains towards the east into the Fulda, flooding farmland and several villages. 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: according to the latest sources,^[13] at least 1,650 people were killed: around 70 in the Eder Valley, and at least 1,579 bodies were found along the Möhne and Ruhr rivers, with hundreds missing. 1,026 of the bodies found downriver of the Möhne Dam were foreign prisoners of war and forced-labourers in different camps, mainly from the Soviet Union. Worst hit was the city of Neheim (now part of Neheim-Hüsten) at the confluence of the Möhne and Ruhr rivers, where over 800 people perished, among them at least 526 female forced-labourers from the Soviet Union. (Some non-German sources erroneously cite an earlier total of 749 for all foreigners in all camps in the Möhne and Ruhr valleys as the casualty count at a camp just below the Eder Dam.^[12])

After the operation Barnes Wallis wrote, "I feel a blow has been struck at Germany from which she cannot recover for several years." 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^{[citation needed]}. The raid proved to be costly in lives (more than half the lives lost belonging to allied POWs and forced-labourers), but in fact no more than a minor inconvenience to the Ruhr's industrial output.^[14]

In his book Inside the Third Reich, Albert Speer expressed puzzlement at the raids; destruction of one of the dams served no purpose at all, he claimed, and the failure to follow up with additional raids represented a major lost opportunity for the Allies.

The value of the bombing can perhaps best be seen as a very real boost to British morale, proving to people of bitterly embattled Britain they had the ability to strike back.^{[citation needed]} In a very real sense it empowered the entire British populace. Its legacy, during the war years, was one of delivering hope, and belief to a people under constant bombing and bombardments.^[15]

The strategic view

The Dams Raid was, like many British air raids, undertaken with a 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 1943–1944. 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.

By far the greatest and most unexpected effect was on German food production. The Ruhr Valley below the dams was a major source of vital food for Germany, and large areas of arable land were rendered unusable and huge numbers of farm animals were killed. This had an immediate negative effect on German morale. In addition, the pictures of the broken dams proved to be a propaganda and morale boost to the Allies, especially to the British, still suffering under German bombing. ^[8]

An associated, but equally major effect was that Barnes Wallis's ideas on earth quake bombing, which had been rejected before, now became accepted by 'Bomber' Harris. Prior to this raid bombing practice had been to 'area bomb' with many light bombs, in the hope that one would hit the target. Work on the earthquake bomb theory resulted in the Tallboy and Grand Slam weapons, which caused unprecedented damage to German infrastructure in the later stages of the war. They rendered the V-2 assembly building unusable, buried the V-3 guns, sank the Tirpitz and destroyed many bridges and other hardened installations. Notable amongst their successes were the U-Boat pens at Brest, where they penetrated 20 ft thick roofs of reinforced concrete, and the Saumur Tunnel.

The diplomatic view

An important reason for planning the raid was to persuade Stalin that Britain was capable of being an effective ally. This was the middle period of the war, when the United States had recently entered the war on Britain's side due to the attack on Pearl Harbor. Germany's invasion of the Soviet Union, Operation Barbarossa, had brought the USSR into the war and it was being hard pressed by the German forces. Due to the seriousness of the situation for the Soviet Union during this period, Stalin often called upon the Western Allies to open a second front: the Dambusters raid provided the British with a valuable opportunity to prove that they were harrying the Germans in every way they could while building up forces for an eventual liberation of Western Europe. However, by the time the preparations for the British raid were complete, the USSR had managed to fight back against German forces; the USSR had also found the capacity to begin its counter-offensive on the Don and Volga. 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. As a result, he was taken more seriously as an ally than might otherwise have been the case. This was most relevant in negotiations with Stalin, but also to a lesser degree in the USA. Although Churchill had the sympathetic ear of Roosevelt, many of the US military staff had until then been less persuaded of the value of British experience and capabilities.^[16]

Popular culture

• A 1955 film, The Dam Busters was made about the raids and was very popular. Its depiction of the raid, along with a similar sequence in the film 633 Squadron, provided the inspiration for the Death Star trench run in Star Wars: A New Hope. The film is also watched on television by the character Pink in the 1982 film, Pink Floyd The Wall.
• In 1984, a Commodore 64 computer combat flight simulator The Dam Busters was made based on this operation.
• A 1989 British commercial for Carling Black Label lager reused footage from the attack sequence of the 1955 film, with a wily German sentry (played by Jon Glentoran, stage name of the artist Jon Dixon) on top of the dam catching the perfectly spherical bombs in the manner of a football (soccer) goalkeeper. The pilot of the attacking Lancaster then delivers the brand slogan: "I bet he drinks Carling Black Label!" The commercial ran for many years, frequently appearing in advert breaks for both the 1955 film and documentaries about Operation Chastise. A subsequent Carling commercial also used bouncing bomb imagery, this time to enable a British holidaymaker to beat the Germans to the sunbeds.
• The PC game Call of Duty features a mission in the British campaign, sometime after Operation Chastise, where the players must suppress the Eder Dam's anti-aircraft defenses and destroy the dam's generators in order to clear the way for the RAF to make an air raid against the dam.
• The console game Secret Weapons Over Normandy features a mission in which the player must destroy a dam and the suggested weapon is the bouncing bomb. However the dam involved is stated to be in Norway and the mission objective is based on the sabotage at Vemork, so the game has conflated this sabotage and the Dambusters mission.
• On 1 September 2006, it was announced that Peter Jackson would produce a remake of the 1955 movie, to be directed by Christian Rivers with production starting in 2008.
• On 16 May 2008, a commemorative event to mark the 65th anniversary was held at Derwent Reservoir, Derbyshire, including a flypast by the Battle of Britain Memorial Flight Lancaster, Spitfire and Hurricane. The event was attended by Les Munro, the only surviving pilot from the original raid, and Richard Todd the actor who played Wing Commander Guy Gibson in the 1955 film.

See also

References

Notes

Bibliography

External links

• Official site of the Royal Air Force about Operation Chastise
• 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
• 60th Anniversary BBC News.
• Video of commemorative fly-by of Lancaster, Spitfire and Hurricane from D. Telegraph website
• Dambuster & Guy Gibson website in Dutch /
• Dam Busters Filmclips
• Gunner Douglas Webb
• German history website about Operation Chastise (German)
• G for George at the Australian War Memorial, Canberra
• History of the air war in the Ederbergland and Waldeck Frankenberg (German)
• Eyebrook municipal website
• Dambusters site with details of Operation Chastise including video footage and more
• Dambusters: A Landmark Oral History by Max Arthur
• German photography archive (German)
• Website about Flt Lt David Maltby and his crew
• Dambusters weblog
• Picture of a 617 Sqn Type 464 (Provisioning) modified Lancaster B.Mk III
• Picture of Gibson (on ladder entering hatch) and his crew immediately prior to taking-off for the dams raid - 'Spam' Spafford is on the right