Two Photograph of the Catwalk on the USS Akron, ca. 1933
Original Caption: Two Photograph of the Catwalk on the USS Akron, ca. 1933..U.S. National Archives’ HMS Record Entry ID: NWL-16051..Creator: U.S. Congress. Joint Committee to Investigate Dirigible Disasters...Subjects:.Dirigible.USS Akron.Joint Committee to Investigate Dirigible Disasters.Catwalk..: arcweb.archives.gov/arc/action/ExternalIdSearch?id=6708583 ( http://arcweb.archives.gov/arc/action/ExternalIdSearch?id=6708583 ) ..Repository: Still Picture Records Section, Special Media Archives Services Division (NWCS-S), National Archives at College Park, 8601 Adelphi Road, College Park, MD, 20740-6001. ..For information about ordering reproductions of photographs held by the Still Picture Unit, visit: www.archives.gov/research/order/still-pictures.html ( http://www.archives.gov/research/order/still-pictures.html ) ..Reproductions may be ordered via an independent vendor. NARA maintains a list of vendors at www.archives.gov/research/order/vendors-photos-maps-dc.html ( http://www.archives.gov/research/order/vendors-photos-maps-dc.html ) ..Access Restrictions: Unrestricted.Use Restrictions: Unrestricted
The main types of airship are non-rigid, semi-rigid, and rigid. Non-rigid airships, often called "blimps", rely on internal pressure to maintain the shape of the airship. Semi-rigid airships maintain the envelope shape by internal pressure but have a supporting structure. Rigid airships have an outer structural framework which maintains the shape and carries all structural loads, while the lifting gas is contained in internal gas bags or cells. Rigid airships were first flown by Count Zeppelin and the vast majority of rigid airships built were manufactured by the firm he founded. As a result, all rigid airships are sometimes called zeppelins. In early dirigibles, the lifting gas used was hydrogen, due to its high lifting capacity and ready availability. Helium gas has almost the same lifting capacity and is not flammable, unlike hydrogen, but is rare and relatively expensive. Airships were most commonly used before the 1940s, but their use decreased over time as their capabilities were surpassed by those of aeroplanes.
Built in 1931-1932, designed by German airship engineer Dr. Karl Arnstein for the Goodyear Zeppelin Corporation, Hangar One covers 8 acres and can accommodate six American football fields. It measures 1,133 feet (345 m) long and 308 feet (94 m) wide and 198 feet (60 m) high. The hangar's interior is so large that fog sometimes forms near the ceiling. The "orange peel" doors, weighing 200 short tons (180 metric tons) each, are moved by their own 150 horsepower (110 kW) motors. 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" airships. It was significant for U.S. Navy coastal defense capabilities during the peacetime era between 1932 and 1941 and construction of USS Akron and its sister ship, USS Macon, built in 1931 and 1933. These two airships were 785 feet (239 m) in length. In 1965, Hangar One was nominated as a US Navy Historic Site, and next year was designated as a Naval Historical Monument. In early 2000s plans to convert it to a space and science center were proposed but put on hold with the discovery that the structure was leaking lead paint and other toxic chemicals into the sediment in wetlands bordering San Francisco Bay. In 2011, work to remove the exterior panels began, requiring "the biggest scaffolding job in the history of the West Coast." The work was completed in 2012. Google top executives Larry Page, Sergey Brin and Eric Schmidt proposed paying the $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 2014 NASA selected Planetary Ventures (a subsidiary of Google) to manage Hangar One and Moffett airfield and Google paid $1.16 billion over 60 years for the lease. Hangar One can be seen in various episodes of the Discovery Channel TV show MythBusters.
The Joint Committee to Investigate Dirigible Disasters was created to investigate the cause of the USS Akron disaster and the wrecks of other Army and Navy dirigibles and to determine responsibility. These photographs were submitted to the Joint Committee during its investigation.