As these arrangements were taking place, a new subgroup of the Manhattan Project at Los Alamos was being organized. Titled the Z Division for its chief, Dr. Jerrold Zacharias, a Los Alamos scientist from the Massachusetts Institute of Technology (MIT), the new group's mission was to manage the engineering design, production, assembly, and field-testing of the non-nuclear components associated with nuclear bombs. Construction began on guard, storage, administrative, and laboratory facilities for the Z Division. Because the airfield was still receiving surplus warplanes, the U.S. Army constructed a fenced area for classified activities. They employed security measures including tanks, guard towers, and watch dogs to protect the small stockpile of atomic weapons parts. In the years after the war, Sandia Base boundaries would vastly expand to include the thousands of acres owned by the NMPG, which occupied much of the East Mesa.