Editing Bouncing bomb (section)

===Highball===<!--this section linked from [[Skip bombing]]-->
In April 1942, Wallis himself had described his proposed bomb as "essentially a weapon for the [[Fleet Air Arm]]".{{cn|date=May 2022}} This naval aspect was later to be pressed by a [[Minutes|minute]] issued by British prime minister [[Winston Churchill]], in February 1943, asking "Have you given up all plans for doing anything to {{ship|German battleship|Tirpitz||2}} while she is in [[Trondheimsfjord|Trondheim]]? ... It is a terrible thing that this prize should be waiting and no one be able to think of a way of winning it."<ref>Sweetman (2002), Part 1, p. 106.</ref> However, Highball was ultimately developed as an RAF weapon for use against various targets, including ''Tirpitz''.{{citation needed|date=May 2021}}

From November 1942, development and testing for Highball continued alongside that of Upkeep, including the dropping of prototypes at both Chesil Beach and Reculver. While early prototypes dropped at Chesil Beach in December 1942 were forerunners for both versions of the bomb, those dropped at Chesil Beach in January and February 1943 and at Reculver in April 1943 included Highball prototypes.<ref>Sweetman (2002), Part 1, pp. 112, 118.</ref> They were dropped by the modified Wellington bomber and at Reculver by a modified [[de Havilland Mosquito|de Havilland Mosquito B Mk IV]], one of two assigned to Vickers Armstrong for the purpose.<ref>Sweetman (2002), Part 1, pp. 114, 118.</ref> By early February 1943, Wallis envisaged Highball as "comprising a {{convert|500|lb|kg|abbr=on}} charge in a cylinder contained in a {{convert|35|in|cm|abbr=on}} sphere with (an overall weight) of {{convert|950|lb|kg|abbr=on}}"; a modified Mosquito could carry two such weapons.<ref>Sweetman (2002), Part 1, p. 113.</ref>

[[File:Highball Bouncing Bomb at Abbotsbury Swannery Dorset UK.JPG|thumb|''Highball'' bouncing bomb prototype, now on display at [[Abbotsbury Swannery]] in [[Dorset]]]]
In tests at Reculver in the middle of April 1943, it was found that Highball's spherical casing suffered similar damage to that of Upkeep. A prototype with an altered design of casing strengthened by steel plate, but empty of inert filling or explosive, was dropped on 30 April and emerged "quite undamaged".<ref>Sweetman (2002), Part 1, p. 118.</ref> In further testing on 2 May, two examples of this prototype with inert filling, bounced across the surface of the water as intended, though both were found to be dented.<ref>Sweetman (2002), Part 1, p. 119.</ref>

Further testing was carried out by three modified Mosquitoes flying from [[RAF Turnberry]], north of [[Girvan]], on the west coast of Scotland, against a target ship, the former French battleship {{ship|French battleship|Courbet|1911|2}}, which had been moored for the purpose in [[Loch Striven]].<ref>Sweetman (2002), Part 2, p. 52. RAF Turnberry occupied the site of [[Turnberry (golf course)|Turnberry golf resort]].</ref> This series of tests, on 9 and 10 May, was hampered by a number of errors: [[buoy]]s intended to mark a point {{convert|1200|yd|m|0}} from ''Courbet'', where the prototypes were to be dropped, were found to be too close to the ship by {{convert|400|yd|m|0}}, and, according to Wallis, other errors were due to "Variations in dimensions of [prototypes] after filling and [dimensionally incorrect] jigs for setting up the [caliper] arms".<ref>Sweetman (2002), Part 2, pp. 52–53.</ref> Because of these errors, the prototypes hit the target too fast and too hard. Two aircraft failed to release their prototypes, one of which then fell off while the aircraft was turning for a second attempt.{{citation needed|date=May 2021}}

It was under such circumstances that Upkeep came to be deployed independently of Highball. In addition to continuing problems in testing Highball, it had been observed at the end of March 1943 that "At best [aircrews] would need two months' special training".<ref>Sweetman (2002), Part 1, p. 115.</ref> With this in mind, [[No. 618 Squadron RAF|618 Squadron]] had been formed on 1 April 1943 at [[RAF Skitten]], near [[Wick, Highland|Wick]], in northeastern Scotland, to undertake "Operation Servant", in which ''Tirpitz'' would be attacked with Highball bouncing bombs.<ref>Sweetman (2002), Part 2, pp. 48–49.</ref> On 18 April it was recommended that Operation Servant should be undertaken before the end of June, since 618 Squadron could not be held back for this purpose indefinitely. It was not until early September 1943 that, in view of continuing problems with both Highball and its release mechanism, most of 618 Squadron was "released for other duties". This in practice meant the abandonment of Operation Servant.<ref>Sweetman (2002), Part 2, pp. 54, 57.</ref> Core personnel of 618 Squadron were retained and these continued work on the development of Highball.<ref>Flower (2002), p. 78.</ref>

Testing between 15 and 17 May 1944 showed progress with Highball. By this time ''Courbet'' had been designated for use as a [[Mulberry harbour#Corncobs and Gooseberries (breakwater ships)|Gooseberry breakwater]] for the [[invasion of Normandy]], so the old battleship {{HMS|Malaya}}, then in reserve, was used instead (also moored in Loch Striven). With crew on board ''Malaya'', bombers dropped inert Highball prototypes fitted with hydrostatic pistols, aiming at the ship. They struck the ship, and at least two punched a hole in the ship's side. On 17 May, for the first time, Highball prototypes were released in pairs, only one second apart.<ref>Flower (2002), pp. 78–79.</ref>

By the end of May 1944, problems with releasing Highball had been resolved as had problems with aiming. Aiming Highball required a different method from Upkeep; the problem was solved by Wallis's design of a ring aperture sight fixed to a flying helmet.<ref>Flower (2002), pp. 78–80.</ref> Highball was now a sphere with flattened [[wikt:pole#Noun 2|poles]], and the explosive charge was Torpex, enclosed in a cylinder, as in Upkeep; detonation was by a single hydrostatic pistol, set to fire at a depth of {{convert|27|ft|m|0}}, and its weight was {{convert|1280|lb|kg|0}}, of which {{convert|600|lb|kg|0}} was Torpex.{{citation needed|date=May 2021}}

Highball was never used operationally: on 12 November 1944, in [[Operation Catechism]], Lancasters with [[Tallboy bomb]]s sank its primary target, ''Tirpitz''. Other potential targets had been considered during Highball's development and later. These included the ships of the [[Regia Marina|Italian navy]], canals, dry docks, [[submarine pen]]s, and railway tunnels (for which testing took place in 1943). But Italy surrendered in September 1943, and the other target ideas were dismissed as impracticable.<ref>Flower (2002), e.g. pp. 66–67, 72–76. On 3 September 1943, an [[Armistice between Italy and Allied armed forces|armistice]] was signed between Italy and the Allies.</ref>

In January 1945, at the Vickers experimental facility at [[Cobham Bus Museum|Foxwarren]], near [[Cobham, Surrey]], a [[Douglas A-26 Invader]] medium bomber of the [[United States Army Air Forces|USAAF]] was adapted to carry two Highballs almost completely enclosed in the bomb bay, using parts from a Mosquito conversion. After brief flight testing in the UK, the kit was sent to [[Wright Field]], Ohio, and installed in a A-26C Invader. Twenty-five inert Highballs, renamed "Speedee" bombs, were also sent for use in the USAAF trials. Drop tests were carried out over [[Choctawhatchee Bay]] near [[Eglin Air Force Base|Eglin Field]], Florida, but the programme was abandoned after the bomb bounced back in a drop on Water Range 60, causing loss of the rear fuselage and a [[List of accidents and incidents involving military aircraft (1945–1949)#1945|fatal crash on 28 April 1945]].<ref>Flower (2002), pp. 87–88. Also Gardner (2006), Johnsen (1999), and [https://www.youtube.com/watch?v=PCGpzRzY7fY Douglas A-26C breaks apart in mid-air testing a bouncing bomb] at YouTube. Retrieved 11 December 2010.</ref>