The Dam Busters follows the conception and implementation of a new British weapon during World War II and the true story of ‘Operation Chastise’ – a mission carried out on the night of 16 May 1943 by the Lancaster bombers of RAF 617 Squadron against the Möhne, Eder and Sorpe dams in Germany’s industrial Ruhr valley.
In 1942, aeronautical engineer Dr Barnes Wallis (Michael Redgrave) is possessed with a seemingly absurd idea – the creation of a revolutionary “bouncing” bomb, capable of dodging torpedo nets by skimming over the water’s surface to destroy the Ruhr dams and paralyse Germany’s heartland.
The film describes the development of the bomb – showing Wallis shooting marbles across a bathtub of water as the idea begins to form – through to devising a particularly simple bombsight and an altimeter that had to be developed.
“He spends hours and hours shooting golf balls up and down,” complains the supervisor of an experimental ship tank in Teddington, “and every now and then he breaks a window.”
Wallis meets with Arthur “Bomber” Harris (Basil Sydney), the head of RAF Bomber Command, in order to procure the resources necessary to create his bombs. Hesitant at ﬁrst, Harris eventually approves Wallis’s plans and Prime Minister Winston Churchill (not depicted on screen) authorises the project.
A special Squadron is formed and selected to carry out the attack, led by Wing-Commander Guy Gibson (Richard Todd) – and his unfortunately named black labrador – who is given responsibility for the sortie and intensive training.
Major disappointments accompany the initial trials: the casing of the bomb has to be drastically re-designed and it transpires that the aircraft will need to approach the dam considerably lower and faster than had been predicted.
The climax of the film – the actual attack on the German dams – is rather a disappointment due to some unimpressive special effects.
The bombers ﬂy low and attack the dams as planned. Although eight Lancasters and on-board crew members perish, two dams – the Möhne and Eder – are successfully breached. The Sorpe dam was not breached, and its bombing does not make it to the screen.
The Dam Busters premiered at the Empire Theatre, Leicester Square, London on 16 May 1955 (the 12th anniversary of the raid), with Princess Margaret and 617 Squadron veterans and family members in attendance. The film was the most profitable film in Britain in 1955 and notices on both sides of the Atlantic were uniformly adulatory.
Adapted by R.C. Sherriff from the books Enemy Coast Ahead (1946) by Guy Gibson and The Dam Busters (1951) by Paul Brickhill, the film is a tribute to the genius of Barnes Wallis who fought persistent scepticism and disbelief from Whitehall that such a feat was possible.
The flight sequences in the film were shot using four real Avro Lancaster B.VII bombers that had to be taken out of storage and modified (the mid-upper gun turrets were removed to mimic 617 Squadron’s special-purpose aircraft). The planes, supplied by the RAF, cost £130 per hour to run – a tenth of the film’s production costs.
The long, narrow reservoirs in the Upper Derwent Valley, Derbyshire, a few miles west of Sheffield – the test area for the real raids – stood in for the Ruhr valley for the film.
Coastal scenes were shot between Skegness and King’s Lynn, Norfolk, on the English Channel, and additional aerial footage was shot north of Windermere, in the Lake District.
The film set some scenes at RAF Scampton, where the real raid was launched, but most ground location shooting took place at still-operational RAF Hemswell, just north of Scampton and 55 flight miles due east of the Upper Derwent Valley.
Several obsolete Avro Lincolns mothballed at Hemswell prior to being broken up were used to double for additional 617 Squadron Lancasters on the ground. Active-duty RAF pilots based at Hemswell flew the Lancasters during filming.
Dr Barnes Wallis
Sir David Pye
Stanley Van Beers
Doctor WH Glanville
Official from Ministry of Aircraft
Captain Joseph Summers
RAF Officer at trials
Air Chief Marshal Sir Arthur Harris
Group Captain JNH Whitworth
Wing Commander Guy Gibson
Flight Lieutenant RD Trevor-Roper
Flight Lieutenant REG Hutchison
Flight Officer FM Spafford
Flight Lieutenant AT Taerum
Flight Sergeant Pulford