Goodyear Airdock, Ohio

The Goodyear Airdock was built in 1929 to construct the largest airships ever made in the USA. The airdock was designed by Karl Arnstein, who was hired by Goodyear from the Zeppelin Company in Germany, when it partnered with the company to create the Goodyear-Zeppelin Corporation in 1924. Arnstein also designed the first airships to be built inside the hangar, which resembled them in structure and form. The hangar is 325 feet wide, 211 feet tall, and 1,175 feet long - longer than the only other structure anything like it in the country at that time. Hangar 1 in Lakehurst, New Jersey, which was built in 1921 to construct the USS Shenandoah. Each of the four doors weighs 600 tons, and the walls are built on tracks to allow the building to expand and contract with temperature variations. In recent years the structure has been sealed in a rubber outer skin, and insulated to some degree, making the doors inoperable. The first airship built inside it was the USS Akron, in 1931, followed by the USS Macon, in 1933 - both around 785 feet long, the largest airships ever made in the USA. These were flown over the coasts and each met their fate in the sea. Smaller airships continued to be built in the hangar, especially during WWII. The last one built there was ZPG-3W, in 1960. After that the hangar housed other defense projects, mostly related to surveillance, including the photographic division of the Goodyear Aerospace Corporation. In 1987 the Goodyear Aerospace Corporation was purchased by Loral, a space and surveillance company. Loral was purchased by Lockheed Martin in 1996, and the site became part of their Tactical Defense Systems branch, building things like flight simulators for fighter jets, and their Naval Electronics and Surveillance Systems Division, which developed a high altitude surveillance blimp, to be stationed 70,000 feet above the ground (apparently it never went into production).