Most of 1947 was spent planning for a field exercise in which a bomb team would deploy to a base and assemble weapons under field conditions.[39] A 20-foot (6.1 m) by 100-foot (30 m) portable building was acquired and outfitted as field workshops that could be loaded onto a C-54 or C-97 transport aircraft.[40] In November 1947, the 38th Engineer Battalion carried out its first major field exercise, Operation Ajax. It drew bomb components, except for fissile cores, from the AEC, and deployed by air to Wendover Field, Utah. This was the home of the 509th Bombardment Group, which was the only unit operating Silverplate B-29 bombers, and therefore the only B-29 group capable of delivering nuclear weapons.