page_title: Disney bomb
section_title: Development and testing
hierarchical_section_title: Disney bomb / Development and testing
caption_attribution_description: English: Still from a World War 2 movie produced by the US Army Pictorial Service. Showing a Disney bomb being loaded onto a B-17 bomber.
context_page_description: The Disney bomb, also known as the Disney Swish, officially the 4500 lb Concrete Piercing/Rocket Assisted bomb was a rocket-assisted bunker buster bomb developed during the Second World War by the British Royal Navy to penetrate hardened concrete targets, such as submarine pens, which could resist conventional free-fall bombs.
  Devised by Royal Navy Captain Edward Terrell, the bomb was fitted with solid-fuel rockets to accelerate its descent, giving it an impact speed of 990 mph — substantially beyond the 750 mph free-fall impact velocity of the 5 tonne Tallboy "earthquake" bomb for comparable purposes.
  The Disney could penetrate 16 ft of solid concrete before detonating. The name is attributed to a propaganda film, Victory Through Air Power, produced by the Walt Disney Studios, that provided the inspiration for the design.
  The Disney bomb saw limited use by the United States Army Air Forces in Europe from February to April 1945. Although technically successful, it initially was insufficiently accurate for bunker targets. It was deployed late in the war and had little effect on the Allied bombing campaign against Germany.
context_section_description: According to an anecdote, the idea arose after a group of Royal Navy officers saw a similar, but fictional, bomb depicted in the 1943 Walt Disney animated propaganda film Victory Through Air Power, and the name Disney was consequently given to the weapon. The Royal Navy developed the bomb even though the Fleet Air Arm operated no aircraft capable of carrying it. The navy was interested in a concrete-penetrating weapon due to the German navy's extensive use of fortified submarine pens to protect their U-boats and E-boats from air attack while docked.
  The Disney Bomb was devised by a British naval officer, Captain Edward Terrell of the Royal Naval Volunteer Reserve, who served in the Directorate of Miscellaneous Weapons Development. Before the war, he had been a lawyer and the Recorder of Newbury. However, he was also an enthusiastic inventor and had filed several patents pre-war, including ones for a vegetable peeling knife and a bottle for fountain pen ink.
  The bomb's development began in September 1943. Although there was support for the idea at the highest levels within the Admiralty, production of the weapon would have to come under the Ministry of Aircraft Production (MAP). The Road Research Laboratory provided theoretical formula for penetration from US data on the performance of 15-inch (381 mm) shells against reinforced concrete, and the Chief Engineer of Armament Development at Fort Halstead prepared a preliminary design to present to the MAP. 
  In the face of opposition, the First Sea Lord prepared a memorandum for the Anti-U-Boat Committee, of which Churchill was the Chairman. Terrell visited Churchill's scientific adviser Lord Cherwell to convince him that it was feasible technically. Due to the Prime Minister's absence through illness, it was not until January 1944 that Churchill expressed a desire that the bomb should be considered by the committee. Due to the number of departments involved there were meetings involving large numbers of technicians and scientists to confirm the technical feasibility.
  Terrell received support through the Air Technical Section of the USAAC, and was able to show the Admiralty a mockup under the wing of a Boeing B-17 Flying Fortress. The Air Ministry was still opposed to its development on several technical grounds, and it took a meeting of the War Cabinet in May, which Terrell attended, to decide in its favour, giving it "P plus" priority. As a side effect the meeting focused attention on the issue of the U-boat shelters, and the RAF were directed to make attacks on them, dropping 26 Tallboys in August that year.
  Despite being a British weapon, Disneys were used only by the United States Army Air Force, with the bombs becoming a joint project between the American Eighth Air Force and the British Royal Navy; they were never used by RAF Bomber Command. The 92nd Bombardment Group was initially tasked with their use. The bombs were also dropped by the 305th Bombardment Group and 306th Bombardment Group. The 94th Bombardment Group prepared to use the bombs, but flew no operations with them before the war in Europe ended. 
  The B-17 Flying Fortresses operated by these units carried the bombs in pairs; one was slung under each wing, as they were too long to be carried in the B-17's bomb bay. The Disneys were carried from the same external mounting used for the Aeronca GB-1 glide bomb. Cameras were also fitted to the aircraft so the bombs' trajectory and effect could be recorded.
  Testing of the Disney bombs began in early 1945. Bombs were initially dropped on a bombing range near Southampton to photographically record their trajectory and calibrate bombsights. This was necessary as the flight-path of a rocket-accelerated bomb differed considerably from that of a free–falling bomb. Test drops were then conducted on the Watten bunker, German codename Kraftwerk Nord West (now known as the Blockhaus d'Éperlecques), a huge German concrete bunker near Watten in northern France. This was ideal for the purpose as the area had been captured by Allied forces in September 1944, so damage to the str
caption: American ground crew loading a Disney bomb onto a B-17 bomber[4]
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