blockbuster bomb
{{Short description|Large conventional bombs used in World War II by the Royal Air Force}}
{{lead too short|date=November 2020}}
File:Lancaster I NG128 Dropping Load - Duisburg - Oct 14 - 1944.jpg drops "window" (chaff) to disrupt enemy radar, then a 4,000 pound blockbuster bomb and incendiary bombs during Operation Hurricane against Duisburg on 14/15 October 1944]]
A blockbuster bomb or cookie was one of several of the largest conventional bombs used in World War II by the Royal Air Force (RAF). The term blockbuster was originally a name coined by the press and referred to a bomb which had enough explosive power to destroy an entire street or large building through the effects of blast in conjunction with incendiary bombs.
Design
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 bombs, termed medium capacity (MC) by the RAF, contained 50% explosive by weight, the remainder comprised 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.Ordnance Pamphlet 1665 (1946) pp.36–37 Subsequent Mark II and Mark III HC bombs differed in detail; the conical nose was replaced with a domed nose and the number of fuzes 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.Ordnance Pamphlet 1665 (1946) pp.39
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.{{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 }} A {{convert|12000|lb|abbr=on}} version was created by adding a third 4000 lb section{{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 }}Air Publication AP1661B Vol I and should not be confused with the 12,000lb 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 tiles off, so that the following barrage of small {{convert|4|lb|abbr=on}} incendiary bombs 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 bays 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".{{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|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}} The local newspaper referred to him as "Blockbuster Brooks".{{citation needed|date=March 2014}}
Operational use
File:Royal Air Force Bomber Command, 1942-1945. CH18371.jpg Avro Lancaster with the "Usual" area bombing load of a {{convert|4,000|lb|t|abbr=on}} bomb and 12 Small Bomb Containers, each filled with {{convert|4|lb|kg|abbr=on}} incendiary bombs]]
The first type of aircraft to carry {{convert|4,000|lb|t|abbr=on}} bombs operationally was the Wellington during a strike on Emden in April 1941;{{cite book | last1=Polmar | first1=N. | last2=Allen | first2=T.B. | title=World War II: the Encyclopedia of the War Years, 1941-1945 | publisher=Dover Publications | series=Dover Books on Military History | year=2012 | isbn=978-0-486-47962-0 | url=https://books.google.com/books?id=30gRAGjXrIIC&pg=PA166 | access-date=2020-03-13 | page=166}} carriage of the bomb required the bomb beam to be removed from the bomb bay and a slot cut in the bomb doors - the bomb protruded slightly through this and, on release, simply fell out through the hole.{{cite book | last1=Murray | first1=Iain | title=Vickers Wellington Manual | publisher=Haynes | year=2012 | isbn=978-0-85733-230-1 | page=100}} The bomb later became part of the standard bomb load of the RAF's heavy night bombers and Mosquitoes of the Light Night Strike Force, whose aircraft would sometimes bomb Berlin twice in one night, flown by two different crews.
The 2,000 lb HC was used until the end of the war, its usage peaking in 1944 with over 16,000 dropped.
The {{convert|8,000|lb|t|abbr=on|adj=on}} and the {{convert|12,000|lb|t|abbr=on|adj=on}} could be carried only by the Avro Lancaster which needed to be slightly modified with bulged bomb-bay doors.
File:RAF Bomber Command HU95286.jpg ]]
The first use of the {{convert|8,000|lb|t|abbr=on|adj=on}} HC was by 15 Squadron Lancasters against Berlin on 2 December 1943. Bad weather and other factors meant their effectiveness was not noted.Maynard, John Bennett and the Pathfinders 1956 Arms and Armour Press. p148
The {{convert|4,000|lb|t|abbr=on}} "cookie" was regarded as a particularly dangerous load to carry. Due to the airflow over the detonating pistols fitted in the nose, it would often explode even if dropped in a supposedly "safe" unarmed state. The safe height above ground for dropping the "cookie" was {{convert|6000|ft|m|abbr=on}}; any lower and the dropping aircraft risked being damaged by the explosion's atmospheric shock wave:
{{blockquote|We were flying at 6,000 feet which was the minimum height to drop the 4,000 pounder. We dropped it in the middle of town [Koblenz], which gave the aircraft a hell of a belt, lifted it up and blew an escape hatch from out of the top.|Jack Murray, pilot of "G for George", reporting on G for George's mission on 17th April 1943."G-for-George" by Michael Nelmes and Ian Jenkins. Banner Books, Maryborough QLD, 2002. {{ISBN|1-875593-21-7}}{{page needed|date=March 2020}}}}
617 Squadron developed a technique of dropping a 1,000 lb MC bomb just before a 12,000 lb HC bomb. The shock wave from the 1,000 lb explosion fired the pistols on the 12,000 lb bomb, causing an "air burst"; this technique was used successfully in attacks including the Michelin factory at Clermont-Ferrand in March 1944.{{cite book | last1=Murray | first1=Iain | title=Dam Busters Manual | publisher=Haynes | year=2011 | isbn=978-0-85733-015-4 | page=66}}
Post-war unexploded ordnance
File:Fundort Luftmine 04 Koblenz 2011.jpg, 4 December 2011.]]
An unusual dry period led to low river levels in the Rhine in December 2011, exposing a 4,000 lb HC bomb in the riverbed near Koblenz. A radius of {{convert|2|km}} around the bomb site (containing about 45,000 people) was evacuated while the bomb was defused.{{Cite news | title = Work to defuse WWII bomb in Rhine near Koblenz begins | url = https://www.bbc.co.uk/news/world-europe-16018659 | work = BBC News | date = 4 December 2011 | access-date = 4 December 2011 | archive-url = https://web.archive.org/web/20111203225957/http://www.bbc.co.uk/news/world-europe-16018659 | archive-date = 3 December 2011 | url-status = live }} Another unexploded blockbuster was found in Dortmund in November 2013, requiring the evacuation of more than 20,000 people from the area.{{cite news |url=https://www.cbsnews.com/news/4000-pound-world-war-ii-bomb-forces-mass-evacuation-in-germany/ |title=4,000-pound, World War II bomb forces mass evacuation in Germany |agency=Associated Press |work=CBS news |date=3 November 2013 |access-date=2017-09-03 |archive-url=https://web.archive.org/web/20170904012827/https://www.cbsnews.com/news/4000-pound-world-war-ii-bomb-forces-mass-evacuation-in-germany/ |archive-date=4 September 2017 |url-status=live }} Other bombs were found and defused in Vicenza on 29 April 2001 and 25 April 2014. In 2001, defusing operations required the evacuation of 70,000 within a radius of {{convert|3|km|abbr=on}},{{cite news | url=https://ricerca.repubblica.it/repubblica/archivio/repubblica/2001/04/05/vicenza-settantamila-evacuati-per-disinnescare-la-maxi.html | location=Vicenza | work=La Repubblica | title=Vicenza, settantamila evacuati per disinnescare la maxi bomba | date=5 April 2001 | language=it | access-date=15 May 2019 | archive-url=https://web.archive.org/web/20190515102034/https://ricerca.repubblica.it/repubblica/archivio/repubblica/2001/04/05/vicenza-settantamila-evacuati-per-disinnescare-la-maxi.html | archive-date=15 May 2019 | url-status=live }} while in 2014 defusing operations required the evacuation of 30,000 within a radius of {{convert|2.5|km|abbr=on}}.{{cite news | url=http://www.oggitreviso.it/vicenza-si-prepara-al-bomba-day-evacuazione-30-mila-84663 | location=Vicenza | work=OggiTreviso | title=Vicenza si prepara al Bomba Day. Evacuazione per 30 mila | date=22 April 2014 | language=it | access-date=22 April 2014 | archive-url=https://web.archive.org/web/20140426233505/http://www.oggitreviso.it/vicenza-si-prepara-al-bomba-day-evacuazione-30-mila-84663 | archive-date=26 April 2014 | url-status=live }}
On 19 December 2016, a British bomb identified as a 4,000 lb HC blockbuster{{cite news |title=German city evacuated after discovery of unexploded RAF bomb |url=https://www.theguardian.com/world/2016/dec/25/augsburg-germany-evacuated-unexploded-second-world-war-bomb |newspaper=The Guardian |agency=Associated Press |access-date=26 December 2016 |archive-url=https://web.archive.org/web/20161226053508/https://www.theguardian.com/world/2016/dec/25/augsburg-germany-evacuated-unexploded-second-world-war-bomb |archive-date=26 December 2016 |url-status=live }} was discovered in Augsburg, Germany. It was defused on Christmas Day, requiring evacuation of more than 54,000 people within a radius of 1.5 km.{{cite news |url=http://live.augsburger-allgemeine.de/Event/Liveticker_zur_Fliegerbombe_in_Augsburg |title=Liveticker zur Fliegerbombe in Augsburg |newspaper=Augsburger Allgemeine |date=21 December 2016 |access-date=2017-09-03 |language=de |archive-url=https://web.archive.org/web/20161223011730/http://live.augsburger-allgemeine.de/Event/Liveticker_zur_Fliegerbombe_in_Augsburg |archive-date=23 December 2016 |url-status=live }}
On 29 August 2017, another British HC 4000 lb bomb was discovered during construction work near the Goethe University in Frankfurt, requiring the evacuation of approximately 65,000 people within a radius of {{convert|1.5|km|abbr=on}}. This was the largest evacuation in Germany since the Second World War.{{cite news |url=https://www.theguardian.com/world/2017/aug/31/ww2-blockbuster-bomb-to-force-evacuation-of-70000-in-frankfurt |title=WW2 'blockbuster' bomb to force evacuation of 70,000 in Frankfurt |newspaper=The Guardian |date=31 August 2017 |agency=Agence France-Presse |access-date=31 August 2017 |archive-url=https://web.archive.org/web/20170831042532/https://www.theguardian.com/world/2017/aug/31/ww2-blockbuster-bomb-to-force-evacuation-of-70000-in-frankfurt |archive-date=31 August 2017 |url-status=live }}{{Cite news |author=Hannelore Crolly |url=https://www.welt.de/vermischtes/article168209250/Das-macht-die-Blockbuster-Bombe-so-gefaehrlich.html |title=Evakuierung in Frankfurt: Das macht die 'Blockbuster'-Bombe so gefährlich |newspaper=Die Welt |language=de |orig-year=1 September 2017 |date=2 September 2017 |access-date=1 September 2017 |archive-url=https://web.archive.org/web/20190206213545/https://www.welt.de/vermischtes/article168209250/Das-macht-die-Blockbuster-Bombe-so-gefaehrlich.html |archive-date=6 February 2019 |url-status=live }}{{cite news |url=https://www.faz.net/aktuell/rhein-main/bombenfund-in-frankfurt/bombenalarm-in-frankfurt-ganz-frankfurt-dankt-den-helden-des-tages-15182153.html |title=Bombenalarm in Frankfurt: Ganz Frankfurt dankt den Helden des Tages |newspaper=Frankfurter Allgemeine Zeitung |language=de |date=3 September 2017 |access-date=3 September 2017 |archive-url=https://web.archive.org/web/20170904054608/https://www.faz.net/aktuell/rhein-main/bombenfund-in-frankfurt/bombenalarm-in-frankfurt-ganz-frankfurt-dankt-den-helden-des-tages-15182153.html |archive-date=4 September 2017 |url-status=live }}
On 8 April 2018, an HC 4000 lb bomb was discovered during gardening jobs in Paderborn, near the local university, leading to the evacuation of 26,400 people while the bomb was defused.{{Cite news | url=http://www.westfalen-blatt.de/OWL/Bombenfund-Paderborn/3242134-Im-Garten-von-Familie-Werth-in-Paderborn-liegt-die-1800-Kilo-Bombe-Wohnen-auf-dem-Pulverfass | title=Wohnen auf dem Pulverfass | newspaper=Westfalen-Blatt | language=de | date=2018-04-03 | access-date=2018-04-12 | archive-url=https://web.archive.org/web/20180412212019/http://www.westfalen-blatt.de/OWL/Bombenfund-Paderborn/3242134-Im-Garten-von-Familie-Werth-in-Paderborn-liegt-die-1800-Kilo-Bombe-Wohnen-auf-dem-Pulverfass | archive-date=12 April 2018 | url-status=live }}{{Cite news | url=https://www.paderborn.de/rathaus-service/news/bombenentschaerfung.php | title=Bombenentschärfung am 8. April 2018 in Paderborn | language=de | access-date=2018-04-12 }}{{Dead link|date=October 2019 |bot=InternetArchiveBot |fix-attempted=yes }}{{Cite news | url=http://www.nw.de/lokal/kreis_paderborn/paderborn/22107589_So-verlief-die-Bombenentschaerfung-in-Paderborn.html | title=So verlief die Bombenentschärfung in Paderborn | newspaper=Neue Westfälische | language=de | date=2018-04-09 | access-date=2018-04-12 | archive-url=https://web.archive.org/web/20180411120009/http://www.nw.de/lokal/kreis_paderborn/paderborn/22107589_So-verlief-die-Bombenentschaerfung-in-Paderborn.html | archive-date=11 April 2018 | url-status=live }}
On 20 March 2024, a MK IV bomb was found in a construction site in Viterbo, Italy causing an evacuation of more than 30,000 people in a range of 1400m from the discover site.{{Cite web |last=Strocchia |first=Raffaele |date=2024-05-03 |title="Cinque ore per neutralizzare la bomba". Ma la fine dell'evacuazione sarà annunciata solo con il suono delle sirene |url=https://www.viterbotoday.it/cronaca/quanto-dura-evacuazione-bomba-viterbo-7-maggio-2024.html |access-date=2024-09-03 |website=ViterboToday |language=it}}
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Bombs
=2,000 lb HC=
Design of a 2,000 lb to meet requirements of similar size to existing 1900 lb GP bomb was by Vickers with parachute arrangements by the RAF; this was at the same time Woolwich was designing the 4000 lb bomb. Actual case construction was by Great Western Railway Company. Live tests began at start of 1941; a few were used operationally in late 1941 with parachute dropping and delay timer. The parachute requirement was dropped and from early 1942 they were used with conventional tail. Improved Mark II and Mark III (with different fuse positions) followed in 1943. Actual weight was {{convert|1,723|lb|abbr=on}} for Mark II and III with 71% charge to weight filling of 60/40 or 50/50 Amatol, RDX/TNT 60/40, or Torpex 2.{{cite web |url=http://www.wwiiequipment.com/index.php?option=com_content&view=article&id=106:2000lb-high-capacity-bomb&catid=43:bombs&Itemid=60 |title=2,000lb High Capacity Bomb |last=Boyd |first=David |work=WWII Equipment |access-date=21 February 2021 |date=1 January 2009 }}
=4,000 lb HC=
- Mark I: first production design
- Mark II: three nose pistols
- Mark III: no side pistol pockets
- Mark IV: no stiffening beam
- Mark V: U.S. production
- Mark VI: U.S. production
Filling was Amatol, RDX/TNT, Minol, or Torpex.
In 1943, 25,000 of these were used; this rose to 38,000 in 1944. In 1945 up to the end of the war a further 25,000 were used.
=8,000 lb HC=
=12,000 lb HC=
Other uses
=Air mines=
File:German parachute mine.jpg
During The Blitz the Germans used naval mines dropped with parachutes as improvised blockbusters. Their fuse was triggered by the shock of landing, with the bomb exploding after a 17-second delay. As the bomb was not in a crater, the force of the blast would disperse laterally, causing extensive damage.{{Cite web |url=http://fishponds.org.uk/luftbri5.html |title=The Luftwaffe over the Bristol area - Luftwaffe weapons |access-date=20 May 2006 |archive-url=https://web.archive.org/web/20060519035540/http://fishponds.org.uk/luftbri5.html |archive-date=19 May 2006 |url-status=live }}Montague Trout comment in a [http://www.bbc.co.uk/ww2peopleswar/stories/07/a1112707.shtml Collaborative Article: The Blitz by Mark E] {{Webarchive|url=https://web.archive.org/web/20090203183834/http://www.bbc.co.uk/ww2peopleswar/stories/07/a1112707.shtml |date=3 February 2009 }} The large raid on Coventry on 14–15 November 1940 included the use of 50 parachute mines, which caused extensive blast damage. The British called these devices air-mines,Taylor, Fredrick; Dresden Tuesday 13 February 1945, Pub Bloomsbury (first publication 2004, paperback 2005). {{ISBN|0-7475-7084-1}}. Page 120. a calque of the German term Luftmine. These types were used also during air raids on Malta, especially on its harbour areas.
See also
- Tallboy (bomb)
- Grand Slam (bomb)
- Firebombing
- Firestorm
- Pumpkin bomb, test Fat Man atom bomb casings filled with nearly {{convert|6|ST|t|spell=in}} of Composition B explosive
- SC 1800 Satan, the rough German equivalent of the American AN-M56 general purpose blockbuster.
- BLU-82
- MOAB
References
; Citations
{{Reflist}}
; Bibliography
- {{cite web |url=http://www.constable.ca/caah/bombs.htm |work=Canadian Aces |publisher=Constable.ca |title=English Bombs of WWII |url-status=dead |archive-url=https://web.archive.org/web/20120917143217/http://www.constable.ca/caah/bombs.htm |archive-date=17 September 2012 |df=dmy-all }}
- {{Cite report
|date=10 June 1946
|title=British Explosive Ordnance
|url=http://www.lexpev.nl/downloads/britishexplosiveordnance1946.pdf
|publisher=Department of the Navy, Ordnance Systems Command
|series=Ordnance Pamphlet
|issue=1665
|access-date=2 February 2013
|archive-url=https://web.archive.org/web/20160304185457/http://www.lexpev.nl/downloads/britishexplosiveordnance1946.pdf
|archive-date=4 March 2016
|url-status=dead
}}
External links
{{Commons category|4000 lb HC bomb}}
- [http://www.ww2aircraft.net/forum/album/showphoto.php?photo=10969 A 12,000lb HC blockbuster pictured in the factory minus-tail unit]
- [http://www.ww2aircraft.net/forum/album/showphoto.php?photo=5954 A 12,000lb HC blockbuster being dropped]
- [http://www.ww2aircraft.net/forum/album/showphoto.php?photo=6052&size=big&cat= An 8,000lb HC blockbuster about to be loaded aboard a Lancaster]
{{RAF WWII Strategic Bombing}}
{{WWIIBritishAircraftWeapons}}
{{Use dmy dates|date=February 2015}}
{{Use British English|date=February 2015}}