The attack on three German dams the Mohne, the Sorpe, and the Eder on the night of May 16, 1943 has been a source of controversy for many years. The main question among historians has been, "was the temporary damage worth the hundreds of lives lost?" The intent of this investigation is to present the evidence and reach a conclusion on this issue. The success of the operation will be determined by weighing the negative results of the raid against the positive ones. The majority of the research for this investigation will come from books previously belonging to F/Sgt K.W. Brown, Dambusters pilot. Other information will come from newspaper clippings, video documentaries, Brown's personal account of the raid and his log books. The paper will include the formation of Squadron 617, the raid itself and the effects had upon the German war effort as a result.
Barnes Wallis is the British inventor of the unique bomb used in the raid. Wallis was an eccentric aeronautical engineer who had set his mind to finding a way to deter the Germans. Norman Boorer, who was an assistant of Wallis's, said that, "Wallis would do anything to help his country."1 As WWII was a total war, much of the war effort relied on industrial production. The dams had been targeted by the RAF from the beginning of the war2 but they did not have a weapon with which they could attack the massive dams. So Wallis set to work to create a bomb that would be able to do such a task. After many experiments, and over a year of testing, Wallis had created the 'bouncing bomb', the basic design of which was a cylindrical shaped bomb of 9500lb that would be spun backwards at a rate of 500 rpm,3 and dropped at a very low level. The bomb would skip over the water with a reverse spin and upon hitting the dam wall would sink and detonate half way down.4 This was the process used for the attack on the Mohne and Eder dams. The bomb used on the Sorpe, which was an earthen dam, had to be dropped directly on top of the dam and with no backspin.5 The bombs would have to be carried by the only aircraft capable of carrying a bomb this large at this point in time; it was the Lancaster bomber which had just recently come out on the market. Now the only thing that Barnes Wallis needed was a squadron capable of flying one of the largest planes in the world at extremely low levels.
Having been persuaded by Air Chief Marshal Portal of the validity of an attack on the dams, Air Marshall Sir Arthur Harris informed Air Vice Marshall Cochrane on 15 March 1943 of his intention to form a special squadron of Lancaster's for the purpose of bombing the three major dams of the Ruhr Valley.6 This special squadron would be made up of only the best crew and ground crew. The 147 hand picked men were ordered to report to the Scampton Air Force base on the east coast of England.7 All information was top secret; all men arrived at Scampton knowing nothing about why they were there. By 31 March they were already doing X-Country and Bombing practice.8 The squadron number assigned to the group was 617, but they soon became better known as The Dambusters. The man chosen to lead the squadron was Wg Cdr Guy Gibson, who was an experienced pilot, having flown 170 operations9 and highly decorated at only twenty-five years of age. The date chosen for the attack was May 16-17, 1943. Squadron 617 now had only six weeks10 to become experts at flying Lancaster's with a 100 foot wing span at levels of 60 feet at night.11 This date was chosen because it was when the water level of the dams would be at its highest, and there was a full moon on the night of May 16, meaning that the chances of success were greatly increased.
May 16, 194312 was the night the raid, which would soon become known as Operation Chastise took place. The operation would be one of "great difficulty and hazard, demanding a high degree of skill and courage and close co-operation between he crews of the aircraft engaged."13 The crews were briefed on May 15 where they found out for the first time that their targets would be the dams.14 Crews would be sent to attack the Mohne, the Eder and the Sorpe dams. There was also a mobile reserve which would be sent to wherever they were needed.15 At 9:28 pm on May 16 the first wave left to cross the English Channel.16 The planes together with the bombs weighed 55 000lbs, the runway was grass and there was a lack of wind, making take-off a challenge.17 Before getting to the dams the crews experienced many obstacles, at one point F/Sgt Brown was flying his craft, with the bomb spinning at 500rpm, along a road and below the tree level to avoid flak.18 Of the group that breeched the Mohne, five crews were sent on to the Eder.19 The breeching of the Mohne sent 134 million tons of water in a river 25 feet high and moving 20 feet per second slamming into the Ruhr Valley.20 The Eder dam was also breeched and 200 million tons of water was sent hurtling towards the Eder Valley. Two bombs were dropped on the Sorpe. The result of both mines was crumbling of the crest of the dam and slight cracking of the dam wall, it was not breeched.21 Of the nineteen planes sent out that night, only nine would return the following morning.22 Fifty-six out of one-hundred thirty-three men were killed from one squadron in one night.
The effects felt upon Germany as a result of the Dams Raid were minimal compared to what had been expected by Barnes Wallis, Guy Gibson and Arthur Harris. It was not due to miscalculation however. The construction of the bomb was carefully calculated and set to detonate at the optimum depth. It was determined that the three dams held back a total of 410 million tons of water.23 The Mohne and the Sorpe fed the industrial region of the Ruhr Valley and between them held back 76% of the water available to the valley.24 It required 100-200tons of water to produce one ton of steel, and steel was essential to Hitler's war effort.25 Damage to these important structures should theoretically cripple German industry and consequently have a great impact on the war. However the damage done to the dams was hardly significant and the Germans had water production to the Ruhr restored within six weeks.26 They were able to immediately resort to other sources of power and had the dams rebuilt within eleven weeks.27 And yet the mission was deemed a success.
There are many results which led to the raid being considered a success. The most impacting and immediate result was the flooding of the Ruhr and Eder valleys. Factories were crippled, hundreds of houses were wiped out, and over one thousand German lives were lost.28 These results as well as communication disruption and the destruction of many bridges did prove to be a blow that Germany was not expecting. It meant that time and resources had to be put into the rebuilding of the dams. Workers were transferred from other regions to rebuild the dams and it took 10 000 regular troops to defend them after this.29 Men and anti-aircraft units which had previously been attacking forces were now ordered to sit idly by and defend the dams.30 The now obvious vulnerability of Germany did wonders for the moral of the Allied nations, who had not celebrated a victory in many months. The indestructible Germans had been hit, victory suddenly became a possibility. It was also a boost in morale for other crews of Bomber Command,31 as these men had become disheartened by their lack of successful operations. The moral of Britain was also lifted and the raid became the turning point from a nation on the defense to one that was on the attack.32
Another success of the raid was the newfound technology and capability to bomb targets at a precise point. Barnes Wallis's ideas were now given special attention and more of his bombs were used throughout the war such as the attack on the Dortmund-Ems Canal and the Tirpitz Raids.33 Wallis's deep penetrating bombs were also used with great effectiveness against concrete bunkers of V-rocket sites.34 A very beneficial effect that the raid had for the Allies was that upon the Americans. At the time of the raid the Americans were questioning the value of continued aid to the bombing sector because of recent losses to their 8th Air Force. The success of precise, low level, night bombing convinced them of the value to be had in Bomber Command, which they continued to support.35 The raid was also pleasing to Stalin who, at the time was demanding more effort from the Western Allies. The Russians at this time were being slaughtered and Stalin felt that the west was not contributing enough.36 The raid proved him wrong.
It is however impossible to ignore the extremely high number of lives lost and the risk taken by the pilots and crew, all of which resulted in little damage. As well, most of the Germans who lost their lives were civilians including women and children who lived in the valleys. The controversy around the issue of the raid's success becomes immediately obvious upon examination of the evidence.
The Allied air attack on German hydroelectric dams in the Ruhr Valley on the night of May 16, 1943 was a success. Despite the tragic number of losses, the failure to breech the Sorpe dam, and the insignificant affect had upon the German industries contribution to the war effort, the mission was successful. This is because there were political benefits which include the commitment of the Americans to the bombing sector of the Air Force and technological benefits, which include the use of aiming devices to allow low level bombing, as well as the future invention of new bombs by Barnes Wallis. There was also a boost to Allied moral that had not been experienced in months. Even though the material damage done was not as great as initially expected the unexpected benefits proved to be high in numbers. These results are what lead to the raid later becoming known as 'one of the most celebrated attacks of the Second World War'.37