Tillamook Air Museum

Believed to be the largest clear-span structure in the world built entirely of wood, Tillamook U.S. Naval Air Station’s Hangar B was built in 1942–1943 to house a squadron of K-class blimps or non-rigid airships, which were used for anti-submarine coastal defense. Planning for ten of these naval blimp stations began in the summer of 1941 (before the Pearl Harbor attack), with construction of two initiated the following year at the Tillamook station, ideally situated in the protected coastal plain at the southern end of the Tillamook estuary, about 4,000 feet from the Pacific Ocean and about 82 miles south of the Columbia River and Fort Stevens.

The two identical blimp hangars initially built at Tillamook were capable of housing a total of eight airships. The hangars were built of wood rather than steel, due to restrictions during World War II. Because each of the airships were around 216 feet long, 69 feet wide, and 79 feet wide (for comparison, today the average Goodyear Blimp measures 190 feet in length), each airship hangar measured 1,072 feet in length and 296 feet in width. The height of the 51 catenary arch wood trusses measured 192 feet (15 stories). At the end of each hangar were tall, hollow enclosures accommodating three sliding doors on each side, providing for a total opening measuring 120 feet high and 220 feet wide; the six 30-ton door segments move on rails into hollow pocket enclosures. Aside from the two enormous hangars, Naval Air Station Tillamook (as it was officially known) also contained administration buildings, barracks, mess halls, and other support facilities.

Hangar B was the first hangar erected by the U.S. Bureau of Yards and Docks with the Sound Construction and Engineering Company; its construction lasted from October 1942 to mid-August 1943. Meanwhile, the first airship arrived in February 1943, but, with no hangar to protect it, the blimp was shredded in a late March coastal storm. The second structure, Hangar A, was built much more rapidly, in just 27 days (July to August 1943) since the engineering challenges had been sorted out in the construction of Hangar B. The hangars each required 2 million board feet of lumber, most of it from Oregon, which was supplied by 50 local lumber mills. Even the gutters and downspouts were wood, and as a result more than 2,000 tons of steel were conserved per hangar.

The K-class blimps were used for extended coastal submarine patrol and convoy escort. Enclosing 425,000 cubic feet of helium gas, each airship had a lift capacity of 7,700 pounds, and could carry a crew of ten aloft for two to three days. Cruising at 50 to 67 knots, the airships could range 500 miles from their base, and could cover 13,000 square miles each day. Each K-class airship was armed with four depth charges and two machine guns mounted in front.

Following the end of World War II, the airship station was put on reduced functional status and was ultimately decommissioned in 1948. At that point, the property became Tillamook Airport. Three local lumber companies—Rosenberg, Angel Lumber, and Diamond Lumber—housed their operations in the hangars from 1949 to 1982. Local dairy farmers then began using Hangar A to store 300 truckloads of hay, which caused its destruction by fire in 1992. Two years later, the Port of Tillamook created the Tillamook Air Museum in Hangar B, displaying more than 30 war planes. A portion of the voluminous space was also leased to American Blimp Corporation, the country’s largest manufacturer of blimps.