‘The Dam Busters’ Was Inspired By the Heroics and Heavy Losses of No. 617 Squadron RAF

Photo Credit: Hope72 / MovieStillsDB
Photo Credit: Hope72 / MovieStillsDB

While there are many good war films, few can be considered truly great. The Dam Busters (1955) is one of the few that falls into the latter category. Following the actions of No. 617 Squadron RAF, the British Film Institute (BFI) went so far as to call it one of the greatest British films of the 20th century.

Learn about the real-life World War II-era Dambusters Raid and those involved.

Bouncing bomb

Bouncing bomb attached to the weapons bay of an Avro Lancaster
Practice bouncing bomb attached to the weapons bay of Guy Gibson’s Avro Lancaster, 1943. (Photo Credit: Unknown Author / National Archives / Wikimedia Commons / Public Domain)

Prior to WWII, the British Air Ministry identified the strategic importance of Germany’s industrial Ruhr Valley, which contained hydroelectric dams that provided power, water and transportation resources. Ultimately, they didn’t have a weapon to use against a target of that type, nor was there an aircraft large enough to carry a bomb of that size, so an attack on the region was put on the back burner until the conflict was well underway.

Barnes Wallis, the assistant chief designer at Vickers, began work on a bomb that could be used against a dam, taking into account the difficulty of attacking a heavily-defended location with torpedo nets. His solution was the bouncing bomb. It was designed with a backspin, so that, when it was dropped from a heavy bomber, it would travel across the top of the water before colliding with the target, after which it would sink and explode.

Operation Chastise

Avro Lancaster parked on dirt-packed ground
Avro Lancaster during handling trials with the Aeroplane and Armament Experimental Establishment, 1943. (Photo Credit: Ministry of Aircraft Production / Imperial War Museums / Getty Images)

After a series of successful tests against model dams, it was determined the bouncing bomb could be used in the Ruhr Valley. As the weight was just right for the Avro Lancaster to carry, the aircraft was modified for the evolving mission. This required getting rid of the dorsal gun turret and most of the internal armor. The bomb-bay doors were also taken off, as the bomb was too big to fit with them closed.

With a bomb developed and an aircraft secured, all that was left was to find a team for the mission. The task was given to No. 5 Group RAF in late March 1943, who created what became No. 617 Squadron RAF, codename “X.” Twenty-one different bomber crews were selected, consisting of different nationalities: Australian, New Zealand and Canadian.

They were sent to RAF Scampton for training under the charge of Wing Cmdr. Guy Gibson.

Formulating a plan of attack

Guy Gibson staring into the distance
Wing Cmdr. Guy Gibson, 1943. (Photo Credit: Fg. Off. G Woodbine / Imperial War Museums / Getty Images)

Guy Gibson was an impressive force, having successfully flown over 170 bombing and fighter missions by the time he was just 24 years old. With his involvement, the plan came together. The Möhne and Sorpe Dams, upstream from the Ruhr’s industrial area, were selected as the primary targets, with the Edersee Dam deemed a secondary one.

The crews began a period of intensive training, focused heavily on flying at low altitudes at night.

For Operation Chastise, as it was called, the squadron was divided into three formations. The first contained nine bombers, piloted by Gibson, Flight Lt. John V. Hopgood, Flight Lt. H.B. Martin, Squadron Leader H.M. Young, Flight Lt. David Maltby, Flight Lt. David Shannon, Squadron Leader Henry Maudslay, Flight Lt. Bill Astell and P/O Les Knight. They were tasked with hitting the Möhne Dam and dropping any bombs that remained on the Edersee.

The second contained five bombers, piloted by Flight Lt. Joe McCarthy, P/O Vernon Byers, Flight Lt. Norman Barlow, P/O Geoff Rice and Flight Lt. Les Munro. They were told to only attack the Sorpe Dam. The third formation consisted of five reserve aircraft that would take off hours later than the primary two groups, attacking where needed.

Launching Operation Chastise

Overhead view of the damage sustained to the Edersee Dam
Edersee Dam after being hit during the Dambusters Raid, 1943. (Photo Credit: Bundesarchiv, Bild 183-C0212-0043-012 / Wikimedia Commons CC-BY-SA 3.0 de)

The raid was launched on the evening of May 16, 1943. Guy Gibson and his formation were successful in their assault on the Möhne Dam, with six bombs dropped. The crew then turned their attention to the Edersee, which they were also able to collapse. The second and third formations attacked the Sorpe Dam, but were unable to destroy it.

The bombers began their return to the United Kingdom approximately six hours after their departure, but they didn’t all make it back. Out of the 19 aircraft that set off as part of Operation Chastise, eight were lost. Three were shot down on their way to their target dams, two hit power lines, one was shot down while bombing the Möhne Dam and the final two were shot down on their return to base. Fifty-three of the 133 men were killed, and three became prisoners of war (POWs) in Germany.

Aftermath of Operation Chastise

Guy Gibson walking with members of No. 617 Squadron RAF outside of Buckingham Palace
Wing Cmdr. Guy Gibson and No. 617 Squadron RAF attending an investiture ceremony at Buckingham Palace for him to receive the Victoria Cross, 1944. (Photo Credit: Keystone / Hulton Archive / Getty Images)

While the losses for the Royal Air Force and other Allied airmen were high, the number killed due to the attack was far higher. In the flooding, roughly 1,600 civilians, POWs and female slave laborers drowned. Gibson later commented on this, saying, “The fact that people… might drown had not occurred to us… No one likes mass slaughter and we did not like being the authors of it.”

Even the bouncing bomb creator struggled to reconcile the cost of the attack. His wife wrote, “Poor B. didn’t get home till 5 to 12 last night, only 3 hours sleep Saturday, didn’t take his clothes off Sunday, and was awake till 2.30 this morning telling me all about it. And then, poor dear darling Barnes, he woke at 6 feeling absolutely awful: he’d killed so many people.”

This was of little consequence at the time, however, as the Dambusters Raid filled the British public with a renewed sense of positivity. They viewed the survivors of No. 617 Squadron RAF as heroes, and Gibson was the best of them all. He was awarded the Victoria Cross in 1944 for his actions.

Although their mission was over, the men were retained as a specialist bombing unit. Gibson was tragically killed when he was shot down during a raid in September 1944.

The Dam Busters (1955)

Still from 'The Dam Busters'
The Dam Busters, 1955.(Photo Credit: Hope72 / MovieStillsDB)

The Dam Busters focuses on this heroic event, drawing inspiration from Paul Brickhill’s 1951 namesake book and Guy Gibson’s Enemy Coast Ahead, which he wrote prior to his death. It follows the real events of Operation Chastise, emphasizing the successes and heavy losses of the raid. For example, the film concludes with Gibson saying he can’t go to bed until he’s written letters to the families of all the men he lost.

The Dam Busters is generally considered to be a very accurate movie, something helped by the RAF loaning the producers real Avro Lancasters. The main point of embellishment is the emphasis that the raid was detrimental to the German war effort, which is less accurate and more idealistic.

More from us: Netflix’s Adaptation of ‘All Quiet on the Western Front’ Shows the Brutalities of Trench Warfare

Regardless the actions portrayed in The Dam Busters, the men of No. 617 Squadron RAF in real life were incredibly courageous.

Rosemary Giles

Rosemary Giles is a history content writer with Hive Media. She received both her bachelor of arts degree in history, and her master of arts degree in history from Western University. Her research focused on military, environmental, and Canadian history with a specific focus on the Second World War. As a student, she worked in a variety of research positions, including as an archivist. She also worked as a teaching assistant in the History Department.

Since completing her degrees, she has decided to take a step back from academia to focus her career on writing and sharing history in a more accessible way. With a passion for historical learning and historical education, her writing interests include social history, and war history, especially researching obscure facts about the Second World War. In her spare time, Rosemary enjoys spending time with her partner, her cats, and her horse, or sitting down to read a good book.