Chastise. Max Hastings

in his study with an assistant. (Cambridge University Library/MS Vickers)

      1940 cartoon showing the Wallis-designed Wellington bomber.

      The scaled-down model of the Möhne at Nant-y-Gro in Powys, eight minutes after a test explosion in 1942. (The National Archives/AVIA 10/369)

      Recording apparatus attached to scale-model dam at Watford. (The National Archives/DSIR 27/43)

      Test explosion at Nant-y-Gro. (The National Archives/AVIA 10/369)

      Cherwell, Portal, Pound and Churchill watching a display of anti-aircraft gunnery, June 1941. (Imperial War Museum/H 10306)

Air Vice Marshal the Hon. R.A. Cochrane. (Imperial War Museum/CH 14564); Sir Charles Craven. (Cambridge University Library/MS Vickers); Sir Norman Bottomley. (National Portrait Gallery, London/Howard Coster); Arthur Collins; Air Marshal Sir John Linnell. (Imperial War Museum/CM 5259); Gp. Capt. F. W. Winterbotham. (Barry James Gilmore/Fairfax Media/Getty Images)

      Air Chief Marshal Sir Arthur Harris. (Imperial War Museum/CH 13020)

      Harris with his wife Jill and daughter Jackie. (Leonard McCombe/Picture Post/Getty Images)

      Avro Lancaster ED932 (G-George) being flown by Guy Gibson during tests at Reculver. (Imperial War Museum/FLM 2343)

      An Upkeep bounces onto the seafront during tests at Reculver. (Imperial War Museum/FLM 2343)

      Tests at Reculver. (Imperial War Museum/FLM 2360; FLM 2362; FLM 2363)

      Melvin Young in the victorious 1938 Oxford Boat Race crew. (The Times/News Licensing)

      Young’s miraculous October 1940 Atlantic rescue. (Trinity College Oxford, with help from Arthur G. Thorning)

      Young with his rescuer’s captain. (Trinity College Oxford, with help from Arthur G. Thorning)

      Melvin and Priscilla Young. (Trinity College Oxford, with help from Arthur G. Thorning)

      John ‘Hoppy’ Hopgood. (Hopgood family)

      Hopgood with his sister Betty and his mother. (Hopgood family)

      Hopgood with his siter Marna. (Hopgood family)

      Aircrew of 106 Squadron. (Imperial War Museum/HU 91941)

      Henry Maudslay at Eton. (Maudslay family)

      Maudslay as squadron leader. (Lincolnshire County Council Archives)

Guy Gibson and his wife Eve. (Trinity Mirror/Mirrorpix/Alamy)

      Gibson in 1944. (Imperial War Museum/CH 13618)

      Gibson with Nigger. (Associated Newspapers/Rota/Shutterstock)

      Gibson, Spafford, Hutchison, Deering and Taetum at Scampton. (CNP Collection/Alamy)

      Bill Astell and his family on a pre-war outing in Derbyshire. (Ray Hepner)

      Gibson with Dave Maltby. (CNP Collection/Alamy)

      Australian crew members on leave in London after the raid. (Imperial War Museum/CH 9942)

      F/Lt. Bill Astell. (Lincolnshire County Council Archives)

      F/Lt. Joe McCarthy and his crew. (CNP Collection/Alamy)

      P/O John Fraser at his wedding, a week before Chastise. (Cavendish Press)

      F/Lt. David Shannon. (Central Press/Hulton Archive/Getty)

      F/Lt. Les Munro.

      The aircrew who took part in Operation Chastise. (Imperial War Museum/CH 11049)

      Lancaster taking off from Scampton for Chastise. (Imperial War Museum/CH 18006)

      Wreck of a 617 Squadron Lancaster on a Dutch beach. (The National Archives/AIR 20/4367)

      Harris and Cochrane at the debriefing of Gibson’s crew. (CNP Collection/Alamy)

      WAAF intelligence officer Fay Gillon with survivors of the raid, including Maltby, Munro, Trevor-Roper and Shannon. (Fay Gillon)

      King George VI at Scampton, with Gibson and Whitworth. (CNP Collection/Alamy)

Some of the survivors of the raid: Sutherland, Kellow, O’Brien, Hobday, Johnson, Knight, Grayston.

      Fred Tees, sole survivor of C-Charlie’s crash. (Tees family)

      Letter from Gibson to Tees’s mother, informing her that her son is missing in action. (Tees family)

      Flooding in Neheim after the raid. (Werner Buehner)

      Victims of the flood in Fröndenberg.

      Women attempting to salvage household goods after the Möhnekatastrophe.

      Albert Speer assessing the damage at the Möhne. (akg-images/Alamy)

      Reconstruction work on the Möhne. (Werner Buehner)

      Harris with his wife and daughter after the war. (Imperial War Museum)

      Barnes Wallis at Teddington during the filming of The Dam Busters. (SWNS)

      Wallis with Michael Redgrave, who played him in The Dam Busters. (Pictorial Press Ltd/Alamy)

Epigraph

      Boffin/bofin/n.chiefly Br. informal, a scientific expert; esp. one involved in technological research [origin unknown]

       Longman’s Dictionary of the English Language

      ‘It is proposed to use this weapon … against a large dam in Germany which, if breached, will have serious consequences in the neighbouring industrial area … The operation … will not, it is thought, prove particularly dangerous, but it will undoubtedly require skilled crews … Some training will no doubt be necessary.’

      Air Vice-Marshal Robert Oxland, Bomber Command HQ, to Air Vice-Marshal Ralph Cochrane, AOC 5 Group, on 17 March 1943

      ‘One thing,’ said Dim, ‘if we do go and attack … one of us might possibly get a posthumous VC.’

      ‘Who wants that?’ said Taffy.

      ‘Not me,’ said one of the boys. ‘All I want is a Peace and Victory Medal.’

      Most of us agreed.

      Guy Gibson, Enemy Coast Ahead

      After Hollywood mogul Daryl Zanuck was shown the movie The Dam Busters in 1955, he demanded disbelievingly, ‘Is that a true story?’ Yes, he was told. ‘Then why doesn’t it say so?’

RAF Ranks and Army Equivalents

      Marshal of the RAF – Field-Marshal

      Air Chief Marshal (ACM) – General

      Air Marshal (AM) – Lieutenant-General

      Air Vice-Marshal (AVM) – Major-General

      Air Commodore (A/C) – Brigadier

      Group-Captain (Gp. Capt.) – Colonel

      Wing-Commander (W/Cdr.) – Lieutenant-Colonel

      Squadron-Leader (S/Ldr.) – Major

      Flight-Lieutenant (F/Lt.) – Captain

      Flying Officer (F/O) – Lieutenant

      Pilot Officer (P/O) – Subaltern

      Flight-Sergeant (F/Sgt.) – Warrant Officer

      Sergeant (Sgt.) – Sergeant

      Corporal (Cpl.) – Corporal

      Leading Aircraftman (LAC) – Lance-Corporal

      Aircraftman