Hangar 1831 is the only steel vaulted-roof hangar at the base. Built specifically to house the new B-29 aircraft, it measures 200 feet by 228 feet and contains 53,400 square feet total, including offices in the side wooden lean-to buildings. A small rectangular door above the sliding hangar doors opened to accommodate the height of the B-29’s vertical tail. Often called the Enola Gay hangar, it was utilized by the 393rd Bombardment Squadron of the 509th Composite Group for operations and maintenance.