The Story of Barnes Wallis and the Bouncing Bomb.
A key principle of lateral thinking is to consider the opposite. If everyone is heading west think about going east. If the fashion is fast then consider slow. If the crowd is selling then contemplate buying. Which brings us to this question, what is the opposite of vertical?
Barnes Wallis was born in Derbyshire, England in 1887. He went to grammar school and left at the age of seventeen. He became an apprentice at a shipbuilder and in his spare time he studied for an external degree in Engineering at London University.
The big new thing at the time was powered flight and in 1913 Wallis became an aircraft designer at Vickers. He worked on many innovations in the design of airships and aeroplanes. In 1930 he created a revolutionary geodetic design for the R100 airship. It used light alloys in a space frame formed from a spirally crossing basket-weave of load-bearing members. It was stronger and lighter than conventional approaches and this design was later used with great success in the Wellington bomber.
During WWII Vickers was heavily involved in the war effort and Wallis turned his attention to increasing the effectiveness of bombing. All bombs were dropped vertically which meant that aiming them for a precise target was very difficult. In 1942 Barnes Wallis had a brainwave. Was it possible to develop a bomb which could be delivered horizontally? He experimented by skimming stones over water. He wrote a paper entitled “Spherical Bomb – Surface Torpedo”. He proposed that a bomb could bounce over the water surface, avoiding torpedo nets, and sink directly next to a battleship or dam wall. The surrounding water would concentrate the force of the explosion on the target.
The key trick was to spin the bomb so that it would bounce over the water. Another Vickers designer, George Edwards, who was a keen cricketer and knew something about spin bowling, suggested that backspin on the bomb would be more effective than topspin. Backspin would cause the bomb to travel more slowly than the aircraft which dropped it so that the plane could escape the bomb blast. The Royal Air Force chiefs were initially sceptical of the idea of a bouncing bomb but to their credit they authorised experiments to go ahead. When these were successful the RAF Command planned a major bombing raid on the Möhne, Eder and Sorpe dams in the Ruhr region of Germany. These dams were important strategic targets which provided hydroelectric power and pure water for steel-making and industry, as well as drinking water and water for the canal transport system. The dams had proved impossible to bomb with conventional bombs and they were protected from torpedoes by underwater nets.
The raid on the dams was carried out on the night of 16/17 May 1943 by 19 specially modified Lancaster bombers of RAF 617 Squadron, led by Guy Gibson. The squadron was later called the Dam Busters. The squadron leaders were briefed by Barnes Wallis. It was an extremely challenging assignment. The planes had to release their bombs at an altitude of just 60 ft (18 m), at a precise distance from the dams while flying at night at a speed of 240 mph (390 km/h). Expert crews were given intensive training.
The Möhne and Edersee dams were breached, causing catastrophic flooding of the Ruhr valley and of villages in the Eder valley; the Sorpe Dam sustained only minor damage. Two hydroelectric power stations were destroyed and several more damaged. Factories and mines were also damaged and destroyed. An estimated 1,600 civilians were killed by the flooding. Despite rapid repairs by the Germans, production did not return to normal until September. The raid was a success but came at a heavy price. The RAF lost 53 aircrew killed and 3 captured, with 8 aircraft destroyed.
Wallis became a Fellow of the Royal Society in 1945 and was knighted in 1968. He was awarded £10,000 for his war work from the Royal Commission on Awards to Inventors. His grief at the loss of so many airmen in the dam’s raid was such that Wallis donated the entire sum to his old school, Christ’s Hospital School in 1951 to allow them to set up a trust, allowing the children of RAF personnel killed or injured in action to attend the school. He continued to carry out advanced research and development on aircraft design into his old age. He died in 1979.
When everyone else was thinking vertically, he thought horizontally.