Hangar One (Mountain View, California)

Hangar One is one of the world's largest freestanding structures, covering 8 acre, and has long been one of the most recognizable landmarks of California's Silicon Valley. An early example of mid-century modern architecture, it was built in the 1930s as a naval airship station for the USS Macon.

Design and construction
Designed by German air ship and structural engineer Dr. Karl Arnstein, Vice President and Director of Engineering for the Goodyear Zeppelin Corporation of Akron, Ohio, in collaboration with Wilbur Watson Associates Architects and Engineers of Cleveland, Ohio, Hangar One is constructed on a network of steel girders sheathed with galvanized steel. It rests firmly upon a reinforced pad anchored to concrete pilings. The floor covers 8 acres and can accommodate six (6) (360 feet x 160 feet) American football fields. The airship hangar measures 1133 ft long and 308 ft wide. The building has an aerodynamic architecture. Its walls curve inward to form an elongated approximate catenary form 198 feet (60 m) high. The clam-shell doors were designed to reduce turbulence when the Macon moved in and out on windy days. The "orange peel" doors, weighing 200 short tons (180 metric tons) each, are moved by their own 150 hp motors operated via an electrical control panel.

The hangar's interior is so large that fog sometimes forms near the ceiling. A person who is unaccustomed to the building's extension is susceptible to optical disorientation. Looking across its deck, planes and tractors appear like toys. Looking up, a network of catwalks for access to all parts of the structure can be seen. Two elevators meet near the top, allowing maintenance personnel to get to the top quickly and easily.

Narrow gauge tracks run through the length of the hangar. During the period of lighter-than-air dirigibles and non-rigid aircraft, the rails extended across the apron and into the fields at each end of the hangar. This tramway facilitated the transportation of an airship on the mooring mast to the hangar interior or to the flight position. During the brief period that the Macon was based at Moffett, Hangar One accommodated not only the giant airship but several smaller non-rigid lighter-than-air craft simultaneously.

Similar structures
Hangar One is similar to the Goodyear Airdock in Akron, Ohio which was built by the Goodyear Zeppelin Corporation in 1929. At the time this was built, it was the largest building in the world without interior supports, providing an unusually extensive room for the construction of "lighter-than-air" ships (later known as airships, dirigibles, or blimps). The first two airships to be constructed and launched at the Airdock were USS Akron and its sister ship, USS Macon, built in 1931 and 1933, respectively. These two airships were 785 feet (239 m) in length.

Other historic references date back to Europe. An outstanding example are the two Hangar d' Orly for dirigibles at Orly Air Base near Paris. They were designed and built in 1921–1922 by French structural and civil engineer Eugène Freyssinet, the major pioneer of prestressed concrete, and destroyed in World War II.

Another remarkable example of a similar concrete construction are the two airplane hangars for the Italian Air Force in Orvieto, Italy, by Italian architect and structural engineer Pier Luigi Nervi, designed in 1935 and built in 1938. They were destroyed during World War II.

Renovation and future
There has been an ongoing debate over the future of Hangar One. As the 21st century began, maintenance shops, inspection laboratories and offices along its length helped to keep the hangar busy, and plans to convert it to a space and science center were proposed. These were put on hold with the discovery in 2003 that the structure was leaking toxic chemicals into the sediment in wetlands bordering San Francisco Bay. The chemicals originated in the lead paint and toxic materials, including polychlorinated biphenyls (PCBs), used to coat the hangar. Proposed options included tearing down the hangar and reusing the land, or cleaning the toxic waste from the site and refurbishing the hangar for future preservation.

The US Navy evaluated options for remediating the PCBs, lead and asbestos, as NASA considered options for reuse of the hangar. Some historic and nonprofit groups advocated designating the hangar as a historic landmark.

In 2006, an offer to clean the hangar and coat its outsides with solar panels to recoup the costs of cleaning was proposed by a private company, but the plan never saw fruition due to its cost.

In 2008, the Navy proposed simply stripping the toxic covering from the hangar and leaving the skeleton, after spraying it with a preservative. The Navy claimed that to reclad the structure would cost another $15 million, which would be NASA's responsibility. This was regarded as a partial victory by campaigners. NASA indicated that it was still urging the Navy to restore the hangar, but that it was willing to help save the structure; in particular, NASA was in favor of re-covering the structure at the same time as it was stripped.

After months of planning and preparation, work to remove the exterior panels began in April 2011, requiring "the biggest scaffolding job in the history of the West Coast." The work was completed in mid-2012.

In September 2011, Google top executives Larry Page, Sergey Brin and Eric Schmidt proposed paying the full $33 million cost of revamping Hangar One, in exchange for being able to use up to two-thirds of the floor space to shelter eight of their private jets.

In September 2012, it was reported that proposals to restore the hangar had been rejected by NASA administration, and that the government would instead direct its efforts toward selling the Moffett facility.

Legacy
Hangar One is listed in the Santa Clara County Heritage Resource Inventory. Hangar One is also a designated Naval Historical Monument and a pivotal contributing property to the U.S. Naval Air Station, Sunnyvale National Register Historic District—significant on the national level for its association with the expanding coastal defense capabilities of the U.S. Navy and airship technology during the country's peacetime era between 1932 and 1945. The district was listed on the National Register of Historic Places in 1994. In 2008, Hangar One was listed as one of the 11 most endangered historic places in the U.S by the National Trust for Historic Preservation.

In popular culture, Hangar One can be seen in various episodes of the Discovery Channel TV show MythBusters. For instance, the show used one of the smaller hangars to disprove the myth that it is not possible to fold a sheet of paper in half more than seven times. The sheet of paper covered nearly the full width of the airship hangar. Other episodes of Mythbusters have utilized the hangar to test myths such as "Inflating a football with helium allows longer kick distances" and "Airworthy aircraft can be constructed of concrete.".