Historic hangar gets recognition
A mammoth structure that once overlooked the southern tip of San Francisco Bay is Fort Sill's newest entry on the National Register of Historic Places.
It also has the potential to become the first entry in what would be Fort Sill's second historic district. The first was the area around the Old Post Quadrangle, designated the Fort Sill National Historic Landmark in 1963.
"Henry Post Airfield and (the) Balloon/Blimp Hangar are part of Fort Sill's aviation legacy," Fort Sill Director of Museum Services Frank Siltman said. "The 1st Aero Squadron was activated here at Fort Sill in 1915, and with the beginning of World War I, Henry Post Airfield was activated and became an active part of Fort Sill's mission. During World War I and World War II, training for aerial observation from aircraft and balloons was an integral part of Fort Sill's mission."
The Oklahoma Historical Society and the State Historic Preservation Office (SHPO) recently announced the National Register listing of the balloon hangar. The hangar was originally at Moffett Field in Mountain View, Calif., and it was disassembled and moved here in 1934-35, Siltman said. The first powered dirigibles arrived here in 1937, but left in 1941. The Army Aviation School was at Fort Sill until 1956, when it moved to its present location at Fort Rucker, Ala.
Four wooden balloon hangars were built for Fort Sill in 1917, but all of them burned in the 1920s. Building 5037 on Tucker Road is the only balloon hangar extant on Fort Sill and the only one at Sill ever constructed of metal. It is one of nine metal balloon hangars of a similar design constructed at military installations across the United States during the interwar years of the 1920s and '30s. It is 103 feet tall roughly eight stories high and measures 126 feet wide by 220 feet long for a total of 27,270 square feet.
As the low bidder, Manhattan Construction Company of Oklahoma City was awarded the contract to pour the foundation and a concrete apron in front of the building. A labor dispute delayed the project as local unions objected to the hiring of non-union workers and Manhattan continued to hire both union and non-union labor. Manhattan was also awarded the contract for assembly of the hangar, which was completed by Jan. 22, 1935. By March 1935 it housed three "free" and three "captive" balloons.
"Free" balloons are so called because they go with the prevailing winds, though it is possible to maneuver them by going up and down to catch wind currents. Sausage balloons were huge in comparison to the "free" balloons. They were called "captive" balloons because they were tethered to the ground and used for observation purposes. They were cumbersome to move from place to place because they had to avoid power lines and other obstructions.
According to SHPO's nomination packet, the balloon hangar was made of large sheets of corrugated iron fastened to structural steel girders and support beams. The corrugated iron panels were coated with tar, asbestos and lead-based paint. Due to environmental concerns, Fort Sill in consultation with SHPO replaced all of the original panels with matching zinc-coated panels in 1994.
"The balloon hangar nevertheless retains sufficient integrity to ably convey its historic significance. The majority of interior finishes, the configuration of space and the feeling remain intact," the registration form states.
Sitting at an angle to the road and facing northeast, the balloon hangar is surrounded by buildings of a similar vintage. To the east is a row of officers' housing built in 1933-34. To the south and west are several administrative buildings constructed in the 1934-35 time frame. They include a large barracks, a dispensary, a fire station, a quartermaster garage and a large airplane hangar built in 1932. The hangar is Building 4908, which temporarily housed the Air Defense Artillery (ADA) Learning Center in 2013 while a new climate control system was being installed in the learning center's two stone warehouses on Bateman Road.
The area above has been identified as the Post Field Historic District. On April 23, 2008, SHPO concurred with Fort Sill's determination that the Post Field Historic District is eligible for the National Register. The balloon hangar is a contributing resource to this district, but according to the registration form "it is also individually eligible as a highly distinctive building at Fort Sill that represents a significant trend in early 20th century military aviation and possesses significant architectural and engineering value."
Balloons continued to be used in artillery observation after the hangar was built. The 1st Balloon Squadron at Fort Sill was entrusted with experimental testing on the C-6 motorized observation balloon. That was the oldest balloon squadron in the Army and one of three still in service in the late 1930s. In contrast to the old C-3, the C-6 had a detachable basket that could be replaced by a motorized car. It could then be flown to a new artillery observation point or behind allied lines at night. That cut the size of the ground crew from 63 to 20.
The balloon hangar was also used in the testing of the D2A model barrage balloon in the spring of 1939. Barrage balloons are essentially captive balloons used for passive defense purposes, rather than observation. Because they were cheaper than first-line fighter aircraft, the Army assigned the 1st Balloon Squadron to test a high-altitude D2A as part of a pre-World War II study of the applicability of barrage balloons. Basically, barrage balloons caused incoming airplanes to fly lower, which put them in closer range to anti-aircraft guns. The balloons' cables and other mooring equipment, as well as small explosives in some cases, also created a physical risk to enemy aircraft.