Editing Blockbuster bomb (section)

==Design==
[[File:British HC Bomb Mk1.png|thumb|Diagram of a 4,000 lb HC Mark I bomb]]
[[File:AN-M56 (ORDATA).jpg|thumb|Standard American AN-M56 {{convert|4,000|lb|t|abbr=on}} general-purpose bomb]]
Blockbuster bombs were the RAF's high capacity (HC) bombs. Their especially thin casings allowed them to contain approximately three-quarters of their weight in explosive, with a 4,000 lb bomb (nominal weight) containing about {{convert|3000|lb|abbr=on}} [[Amatol]], [[RDX]] or [[Torpex]]. Most [[general-purpose bomb]]s, termed medium capacity (MC) by the RAF, contained 50% explosive by weight; the remainder consisted primarily of the fragmentation casing. Blockbusters increased in size as the war progressed, rising from the original {{convert|4000|lb|kg|abbr=on}} version to up to {{convert|12000|lb|kg|abbr=on}}.

The 4000 lb HC Mark I bomb – actual weight around {{convert|3,930|lb|abbr=on}} – was a welded, cylindrical shell of {{convert|0.31|in|mm|adj=on|abbr=on}} thick steel. The body of the bomb was {{convert|30|in|cm|abbr=on}} in diameter and {{convert|88|in|m|sigfig=3|abbr=on}} long with a conical nose. It had a {{convert|27|in|cm|adj=on|abbr=on}} long lightweight, empty cylindrical tail onto which a closed end was fitted, amounting to a total length of {{convert|115|in|m|sigfig=3|abbr=on}}. A T-section steel beam was welded to the inner surface of the bomb to strengthen it.<ref>Ordnance Pamphlet 1665 (1946) pp.36–37</ref> Subsequent Mark II and Mark III HC bombs differed in detail; the conical nose was replaced with a domed nose and the number of [[Fuze#Munition types|fuze]]s was increased from one to three to guarantee [[detonation]]. The Mark IV bomb did not have the T-section beam and the Mark V and Mark VI bombs were versions manufactured in the United States.<ref>Ordnance Pamphlet 1665 (1946) pp.39</ref>
 
The larger {{convert|8000|lb|t|abbr=on}} bomb was constructed from two {{convert|4000|lb|t|abbr=on}} sections, of a larger {{convert|38|in|m|abbr=on}} diameter, that fitted together with bolts.<ref name=Boyd8000>{{cite web |url=http://www.wwiiequipment.com/index.php?view=article&id=108:8000lb-high-capacity-bomb |title=8,000lb High Capacity Bomb |last=Boyd |first=David |work=WWII Equipment |access-date=4 December 2011 |archive-url=https://web.archive.org/web/20120421101213/http://www.wwiiequipment.com/index.php?view=article&id=108:8000lb-high-capacity-bomb |archive-date=21 April 2012 |url-status=live }}</ref> A {{convert|12000|lb|abbr=on}} version was created by adding a third 4000 lb section<ref name=Boyd12000>{{cite web |url=http://www.wwiiequipment.com/index.php?view=article&id=109:12000lb-high-capacity-bomb |title=12,000lb High Capacity Bomb |last=Boyd |first=David |work=WWII Equipment |access-date=4 December 2011 |archive-url=https://web.archive.org/web/20120421101159/http://www.wwiiequipment.com/index.php?view=article&id=109:12000lb-high-capacity-bomb |archive-date=21 April 2012 |url-status=live }}</ref><ref>Air Publication AP1661B Vol I</ref> and should not be confused with the 12,000lb [[Tallboy (bomb)|Tallboy]] ground-penetrating "earthquake" bomb.

The 4000 lb high-capacity design was little more than a cylinder full of explosives: it was un-[[aerodynamic]] and lacked fins. The comparable American "4,000 pound LC Bomb AN-M56" was - like other US bombs - aerodynamically designed, with a sheet metal tailfin assembly and shaped nose and aft sections. When fitted with a conical nose and a drum tail, the {{convert|2|ST|kg|abbr=on|disp=flip}} blockbuster bomb would fall straight down. These bombs were designed for their blast effect, to cause damage to buildings, specifically to blow [[roof tile]]s off, so that the following barrage of small {{convert|4|lb|abbr=on}} [[incendiary bomb]]s could reach the building interiors unimpeded. In contrast to the American AN-M56 ordnance, cylindrical HC-class bombs were used only by the RAF and associated Commonwealth air forces, the only air forces whose bombers had [[bomb bay]]s large enough to hold them.

In 1947 Alfred Cecil Brooks of Stourbridge was appointed a Member of the [[Order of the British Empire]], for creating the Blockbuster, although his citation was worded "outstanding services to the King of a nature that cannot be revealed".<ref>{{cite news|url=http://trove.nla.gov.au/newspaper/article/48780576|title=Another Invention By Block-Buster Designer|date=8 January 1944|newspaper=[[The Advertiser (Adelaide)|The Advertiser]]|access-date=12 November 2016|archive-url=https://web.archive.org/web/20161113114311/http://trove.nla.gov.au/newspaper/article/48780576|archive-date=13 November 2016|url-status=live}}</ref> The local newspaper referred to him as "Blockbuster Brooks".{{citation needed|date=March 2014}}