The bouncing bomb was a kind of bomb designed by Barnes Wallis of Vickers-Armstrong at Brooklands, Surrey. It was used in the famous Dambusters raid to attack major dams in Germany's industrial Ruhr Valley during World War II. Sir Barnes Neville Wallis Sir Barnes Neville Wallis, CBE, FRS, RDI, commonly known as Barnes Wallis, (September 26, 1887 – October 30, 1979) was a British scientist, engineer and inventor. ... Brooklands was a motor racing circuit built near Weybridge in Surrey, England. ... Surrey is a county in southern England, part of the South East England region and one of the Home Counties. ... Operation Chastise was the official name for the attacks on German dams on May 17, 1943 in World War II using a specially developed bouncing bomb. The attack was carried out by Royal Air Force No. ... Scrivener Dam, in Canberra, Australia, was engineered to withstand a once-in-5000-years flood event A dam is a barrier across flowing water that obstructs, directs or retards the flow, often creating a reservoir, lake or impoundment. ... Geography Map of the Ruhr Area The Ruhr Area (German Ruhrgebiet or, colloquially, Ruhrpott) is a metropolitan area in North Rhine-Westphalia, Germany, consisting of a number of large industrial cities bordered by the rivers Ruhr to the south, Rhine to the west, and Lippe to the north. ... Combatants Allies: Poland, British Commonwealth, France/Free France, Soviet Union, United States, China, and others Axis Powers: Germany, Italy, Japan, and others Casualties Military dead: 17 million Civilian dead: 33 million Total dead: 50 million Military dead: 8 million Civilian dead: 4 million Total dead: 12 million World War II...

A real Upkeep bouncing bomb at the Imperial War Museum Duxford

Barnes Wallis first began to think of producing a bouncing bomb in 1941. He was aware that in the 19th century the Royal Navy had bounced cannonballs on water to increase their range. Initially his work on the device was to attack battleships. The bomb could be released away from the ships; the bomb would skip over anti-torpedo defences, and when it struck would roll down the hull to below the waterline, where a battleship would be least protected. An additional advantage was that the bomb could contain a much greater quantity of explosive than a torpedo. This version of the bomb, which was sphere-shaped and dimpled like a golf ball, was codenamed Highball and was developed to be dropped from a modified de Havilland Mosquito that could carry two of the weapons. ImageMetadata File history File links Download high resolution version (1600x1200, 330 KB) A real bouncing bomb at Duxford Imperial War Museum Photgraphed by me Martin Richards Feb 2005 File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... ImageMetadata File history File links Download high resolution version (1600x1200, 330 KB) A real bouncing bomb at Duxford Imperial War Museum Photgraphed by me Martin Richards Feb 2005 File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Duxford houses the Imperial War Museums aircraft collection. ... Sir Barnes Neville Wallis Sir Barnes Neville Wallis, CBE, FRS, RDI, commonly known as Barnes Wallis, (September 26, 1887 – October 30, 1979) was a British scientist, engineer and inventor. ... For the movie, see 1941 (film) 1941 (MCMXLI) was a common year starting on Wednesday (the link is to a full 1941 calendar). ... Alternative meaning: Nineteenth Century (periodical) (18th century — 19th century — 20th century — more centuries) As a means of recording the passage of time, the 19th century was that century which lasted from 1801-1900 in the sense of the Gregorian calendar. ... The Royal Navy of the United Kingdom is the senior service of the British armed services being the oldest of its three branches. ... Cannonball can refer to: The ammunition for a cannon. ... HMS Victory in 1884 Battleship was the name given to the most powerfully gun-armed and most heavily armored classes of warships built between the 15th and 20th centuries. ... A torpedo in Rail terminology refers to a small explosive device strapped to the top of the rail to alert an approaching train of immediate danger ahead. ... A golf ball on a Tee with a driver ready for a drive A golf ball is a ball designed for use in the game of golf. ... de Havilland Mosquito. ...

The dam targets were largely immune to conventional attack because of their size. An immense amount of explosive would be required to breach them, and the cushioning effect of the water meant that a near miss would be ineffective. However a bomb placed right by the dam would be effective because the water would act as a natural tamping medium, directing the explosion onto the dam, instead of protecting it, and greatly reducing the explosive power required. Current techniques would not allow the placing of a large bomb with the required accuracy. Moreover, the Germans had guarded against attack by torpedo by placing heavy nets upstream of the dams. This article is concerned solely with chemical explosives. ...

Due to time constraints set by the Royal Air Force, the final version of the bomb had to be different from the initial intention. Barnes Wallis had to forgo the spherical metal shell and the "dimples". This new version was codenamed Upkeep. Referred-to as a "mine" and officially termed the "Upkeep store", it weighed 9,250 lb including 6,600 lb of Torpex explosive. The choice of Torpex was deliberate: although its brisance is lower than Composition B, the aluminium component in Torpex made the explosive pulse last longer, which was particularly destructive to underwater targets. The bomb was cylindrical in shape, 60 inches length and 56 inches in diameter. The bomb was designed to be spun backwards at high velocity (500 rpm) before being released. It then literally bounced over the water (avoiding the torpedo nets) in the same way that a spinning stone will skip. However, to achieve this effect the bomb had to be released from a very low (60 ft) and very precise height, at 240-250 mph, 400-500 yards from the target. On striking the dam the bomb would sink to a prescribed depth of 30 ft before being detonated by hydrostatic fuze. As a back-up, a chemical time fuze detonated the bomb if the hydrostatic fuze failed. The Royal Air Force (often abbreviated to RAF) is the air force branch of the British Armed Forces. ... The pound is the name of a number of units of mass, all in the range of 300 to 600 grams. ... Torpex is a secondary explosive 50% more powerful than TNT by weight. ... Torpex is a secondary explosive 50% more powerful than TNT by weight. ... Brisance is a measure of the rapidity with which an explosive develops its maximum pressure. ... Composition B is an explosive consisting of castable mixtures of RDX and TNT as well as, in some instances, additional desensitizing agents. ... Torpex is a secondary explosive 50% more powerful than TNT by weight. ... A foot (plural: feet) is a non-SI unit of distance or length, measuring around a third of a meter. ... In an explosive device, a fuse (or fuze) is the part of the device that causes it to function. ... Hydrostatics, also known as fluid statics, is the study of fluids at rest. ...

The bombs were successfully deployed using the Avro Lancasters of No. 617 Squadron RAF in Operation Chastise (the Dambusters Raid). The raid, on the night of 16/17 May 1943, was led by Wing Commander Guy Gibson, for which he won the Victoria Cross. The results of the raid were that out of the 6 intended targets, 4 were damaged and 2 were destroyed. Yet even though the mission was considered a success, the high loss of life in the raid prompted the Upkeep bomb project to be discontinued. Highball was to have been used in the Pacific Theatre but the war ended before it could be implemented. The Avro Lancaster was a four-engine World War II bomber aircraft made initially by Avro for the Royal Air Force (RAF). ... No. ... Operation Chastise was the official name for the attacks on German dams on May 17, 1943 in World War II using a specially developed bouncing bomb. The attack was carried out by Royal Air Force No. ... Wing Commander (rank) is a rank in the Royal Air Force, equivalent to a Lieutenant Colonel in most Armies, the Royal Marines and the United States Marine Corps. ... Photo from 617 Squadron The dambusters Photo submitted by Roger Shenton - (taken by John Kramer) Photo of the Dambusters Memorial at Woodhall Spa. ... Victoria Cross medal, ribbon, and bar. ... The Pacific Theater of Operations (PTO) is the term used in the United States for all military activity in the Pacific Ocean and the countries bordering it, in World War II. Pacific War is a more common name, around the world, for the broader conflict between the Allies and Japan...

A de Havilland Mosquito dropping a Highball bouncing bomb

Both Upkeep and Highball remained Official Secrets until January 1974, when (along with the documents revealing the Ultra secret) the files were released under Britain's "thirty year rule". Image File history File linksMetadata Mosquito_Dropping_Highball. ... Image File history File linksMetadata Mosquito_Dropping_Highball. ... de Havilland Mosquito. ... 1974 (MCMLXXIV) was a common year starting on Tuesday (the link is to a full 1974 calendar). ... Ultra (sometimes capitalized ULTRA) was the name used by the British for intelligence resulting from decryption of German communications in World War II. The term eventually became the standard designation in both Britain and the United States for all intelligence from high-level cryptanalytic sources. ... The thirty year rule is the popular name given to a law in the United Kingdom, the Republic of Ireland and Australia that states that the yearly cabinet papers of a government will be released publicly thirty years after they were created. ...

After the raid the Germans discovered an Upkeep bomb that had failed to explode lying in some woods and subsequently an 850 pound version of the bouncing bomb was also attempted by the Luftwaffe. Designed for use against British shipping, it was given the codename Kurt, and was built at the Luftwaffe Experimental Centre in Travemünde. In trials, dropped by an Fw 190 it proved to be dangerous to the delivering planes as the bomb matched the speed at which it was dropped. Attempts to rectify this with booster rockets were ultimately a failure, and the project was discontinued in 1944. Luftwaffe The Deutsche Luftwaffe or (German: Air Arm, IPA: [luftvafÉ™]) is the commonly used term for the German air force. ... Barque Passat in Travemünde Travemünde is a borough of Lübeck located at the mouth of river Trave into Lübeck Bay. ... Focke-Wulf Fw 190 in flight. ... 1944 (MCMXLIV) was a leap year starting on Saturday (the link is to a full 1944 calendar). ...

All combat bombs were disposed of after the war. But a number of concrete-filled Upkeep bombs that were used for testing and training have been recovered and are on display in several museums.

External links

• Memories of an apprentice who worked on the bouncing bomb prototypes
• Technical description of the bomb