View source for M69 incendiary

{{short description|US Army Air Forces WWII incendiary bomblet}}
{{Use American English|date=October 2024}}
{{Use dmy dates|date=October 2024}}
[[File:M69 6-pound Napalm Incendiary Bomb, Niigata Prefectural Museum of History.jpg|thumb|M69 napalm incendiary bomb, that were used in [[bombing of Nagaoka]] in 1945. Exhibit at [[Niigata Prefectural Museum of History]].]]
The '''M69''' incendiary [[bomblet]] was used in [[air raids on Japan]] and China during [[World War II]], including the [[firebombing of Tokyo]] in 1945. It was created by the [[Standard Oil|Standard Oil Development Company]], whose work was funded by the [[Office of Scientific Research and Development]].<ref>{{cite web|title= Who Made That Firebomb?|last= Wellerstein |first= Alex|website= RESTRICTED DATA The Nuclear Secrecy Blog |url= http://blog.nuclearsecrecy.com/2013/08/30/who-made-that-firebomb |date=30 August 2013 |accessdate=12 September 2020}}</ref> They were nicknamed "Tokyo calling cards".<ref>[http://kuscholarworks.ku.edu/dspace/bitstream/1808/7070/1/Curatola_ku_0099D_10041_DATA_1.pdf 180 Degrees Out: The Change in U.S. Strategic Bombing Applications, 1935-1955]- Dissertation of John M. Curatola, DPhil University of Kansas (2008). Quoting "Tokyo Calling Cards", Collier's Magazine, April 1945, 44 and 58.</ref> The M69 was a plain steel pipe with a hexagonal cross section {{convert|3|in}} in diameter and {{convert|20|in}} long. It weighed about {{convert|6|lb}}.<ref name=Ross2002>{{cite book |url=https://books.google.com/books?id=6tkcduKxmOgC&pg=PA107 |pages=107–108 |title=Strategic Bombing by the United States in World War II: The Myths and the Facts |last=Ross |first=Stewart Halsey |publisher=McFarland |year=2002 |isbn=9780786414123}}</ref>
The bomblet used [[napalm]] as an [[Incendiary device|incendiary]] filler, improving on earlier designs which used thermite or magnesium fillers that burned more intensely, but were less energy- and weight-efficient, and were easier to extinguish.<ref>[https://web.archive.org/web/20110413181928/http://www.time.com/time/magazine/article/0,9171,775519,00.html Science: Incendiary Jelly], ''Time'', 2 Apr. 1945</ref> In Germany they were filled with jellied oil and dropped in clusters of 36 in the non-aerodynamic M19 bomb.<ref>{{cite book |url=https://books.google.com/books?id=7MjxBhGuCo8C&pg=PT20 |page=20 |title=Through Blue Skies to Hell: America's Bloody 100th in the Air War Over Germany |first=Edward M. |last=Sion |publisher=Casemate Publishers |year=2008 |isbn=9781935149965}}</ref> Over Japan they were used in [[cluster bomb|clusters]] of 38 as part of the finned E-46 'aimable cluster', which opened up at about {{convert|2000|ft}}. After separation, each of the 38 M69s released a 3-foot (1 m) cotton streamer to orient its fuze downward.<ref>{{cite book |url=https://books.google.com/books?id=Sr6nn47tDOUC&pg=PA33 |page=33 |title=No Strategic Targets Left |last=Bradley |first=F.J. |publisher=Turner Publishing |year=1999 |isbn=9781563114830}}</ref><ref>{{cite web|url=http://www.468thbombgroup.org/LinkClick.aspx?fileticket%3DI8gpYUK3Bhg%3D%26tabid%3D36%26mid%3D467 |title=U.S. BOMB TYPES - INCENDIARY CLUSTER BOMBS |accessdate=2011-06-14 |url-status=dead |archiveurl=https://web.archive.org/web/20110614024345/http://www.468thbombgroup.org/LinkClick.aspx?fileticket=I8gpYUK3Bhg%3D&tabid=36&mid=467 |archivedate=2011-06-14 }}</ref> Upon hitting a building or the ground, the timing fuze burned for three to five seconds and then a small explosive charge ([[black powder]] in the standard M-69 type deployed operationally during WW2, [[white phosphorus]] in a later modification, the M-69X, which did not see wide use) ignited and propelled the incendiary filling up to 100 feet (30 m) in several flaming globs, instantly starting intense fires.<ref name=Ross2002/>
It was tested against typical German and Japanese residential structures at [[Japanese Village (Dugway Proving Ground)|Japanese Village]] and [[German Village (Dugway proving ground)|German Village]], constructed at [[Dugway Proving Ground]], [[Utah]], in 1943.<ref name="dgway">{{cite web |url=http://www.dugway.army.mil/index.php/index/content/id/208 |title=Historical Testing - Dugway Proving Ground |accessdate=2011-06-14 |url-status=dead |archiveurl=https://web.archive.org/web/20100509182002/http://www.dugway.army.mil/index.php/index/content/id/208 |archivedate=2010-05-09 }}</ref> The M69 was the most successful incendiary in the tests.<ref name=Ross2002/>
Against Japan, the M69 was carried in the bomb bay of the [[Boeing B-29 Superfortress]], with a typical load containing 40 [[cluster bomb]]s, a total of 1520 M69 bomblets.<ref name=Ross2002/> As they were very useful in China at [[Hankou]],<ref> Plung, Dylan J. "[https://apjjf.org/2018/08/Plung.html The Japanese Village at Dugway Proving Ground: An Unexamined Context to the Firebombing of Japan]." The Asia-Pacific Journal: Japan Focus, 15 Apr. 2018, Volume 16, Issue 8, Number 3.</ref> the bombs were very effective in setting fire to Japanese civilian structures in mass [[firebombing]] raids starting [[Bombing of Kobe in World War II|in February 1945 against Kobe]].<ref>[https://web.archive.org/web/20111222000559/http://www.time.com/time/magazine/article/0,9171,797324,00.html World Battlefronts: BATTLE OF THE PACIFIC: Firebirds' Flight], ''Time'', 19 Mar. 1945</ref> In the first ten days of March 1945, raids with the M69 and [[M47 bomb|M47]],<ref>{{Cite web|url=http://www.ibiblio.org/hyperwar/AAF/V/AAF-V-20.html|title=HyperWar: The Army Air Forces in WWII: Vol. V--The Pacific: MATTERHORN to Nagasaki &#91;Chapter 20&#93;}}</ref> extensive [[Bombing of Tokyo (10 March 1945)|damage was done to Tokyo]], [[Bombing of Nagoya in World War II|to Nagoya]], [[Bombing of Osaka|to Osaka]], and to Kobe.<ref>[https://web.archive.org/web/20111222000745/http://www.time.com/time/magazine/article/0,9171,803479,00.html World Battlefronts: Ten-Day Wonder], ''Time'', 26 Mar. 1945</ref>
==See also==
*[[Mark 77 bomb]]
==References==
{{reflist}}
[[Category:Cluster munitions]]
[[Category:Incendiary weapons]]
[[Category:World War II aerial bombs of the United States]]