Editing T-12 Cloudmaker (section)

== Development ==
The T-12 was a further development of the concept initiated with the United Kingdom's [[Tallboy bomb|Tallboy]] and [[Grand Slam (bomb)|Grand Slam]] weapons developed by British aeronautical engineer [[Barnes Wallis]] during the [[World War II|Second World War]]: a hardened, highly aerodynamic bomb of the greatest possible weight designed to be dropped from the highest possible altitude. Penetrating deeply in the earth before exploding, the resulting shock wave was transmitted through the earth into targets. The resulting [[camouflet|underground cavity]] and [[ground motion]]<ref name="EUROCK2010">{{cite book|last1=Li|first1=J.C.|last2=Ma|first2=G.W.|editor1-last=Zhao|editor1-first=Jian|editor2-last=Labiouse|editor2-first=Vincent|editor3-last=Dudt|editor3-first=Jean-Paul|editor4-last=Mathier|editor4-first=Jean-Francois|title=Rock Mechanics in Civil and Environmental Engineering|chapter=An analytical study to predict underground explosion-induced ground motion|chapter-url=https://books.google.com/books?id=IdbKBQAAQBAJ&pg=PA305|accessdate=27 April 2017|date=19 May 2010|publisher=CRC Press|isbn=978-0-203-84069-6|page=305}}</ref> could also undermine structures. The bomb could also be used against hardened targets. These types of bombs can reach [[supersonic speed]]s and have tail fins designed to spin the bomb for greater accuracy.

Originally designed to meet a {{convert|42000|lb|kg|abbr=on}} target weight (one half of the maximum payload for the  [[Convair B-36|Convair B-36 "Peacemaker"]] bomber), with its hardened case was slightly less than {{convert|43000|lb|kg|sigfig=3|abbr=on}}. The final T-12 weighed {{convert|43600|lb|kg|abbr=on}}. This was twice the size of the United States' previous largest bomb, the {{convert|22000|lb|kg|abbr=on}} M110 (T-14), the American-built version of the British Grand Slam. The T-12 was not a simple scale up of the M110, but incorporated modifications based on testing and calculations. The B-36 was redesigned so it could carry the T-12, although a converted [[B-29 Superfortress]] was used for testing.