"Atom Bombs" On Bristol -- Troops Carry away a stretcher case from an awkward position on a blitzed site.Civil and Military co-operation in Bristol was tested over the weekend Feb. 10/11 when 1,500 troops joined forces with the civil defense in tackling the damage caused by an assumed atom bomb attack."Exercise Medusa" Was the first full-scale anti-atom-bomb test ever carried out in Britain. February 12, 1951. (Photo by Associated Press Photo).