When you hear the name Tillamook, most people think of the dairy company or the scenic Oregon coastline nearby. Fewer know the town is home to a world-class aircraft museum, and fewer still know why it’s remarkable in the timber engineering world: it is the tallest clear-span timber-built structure in the United States, standing 22 stories tall.<\/p>\n
The Tillamook Air Museum (TAM) sits just two miles south of downtown, its collection of aircraft housed inside a former military blimp hangar built in 1942. The site has been in service in some capacity for most of its 81 years, and this is where WRD was able to support the TAM team with 50+ years of wood science and timber inspection expertise.<\/p>\n
Hangar B, as it’s known, is one of two hangars that stood on the property in service from 1942 to 1948. The museum is the only one still standing, Hangar A was lost to a fire on August 22, 1992. The museum in Hangar B has been open to the public since 1994, displaying military and civilian aircraft from World War II, Vietnam, and Korea. The collection includes planes like the P-51 Mustang and helicopters such as the Huey and Cobra used during the Vietnam War, alongside interactive exhibits sourced from the museum’s own collection, historical groups, and individual enthusiasts.<\/p>\n
TAM began seeing warning signs about the condition of their building. When they inquired, other firms advised that complete reconstruction was the only viable option, at upwards of $15 million to tear down and rebuild. Wanting a second opinion and a thorough investigation, they turned to WRD.<\/p>\n
Due to its size and equipment, upkeep of the facility was difficult, as was verifying the status and health of the structure. TAM was hard-pressed to find a company whose capabilities and years of experience matched the needs of a structure this complex. The building is a massive site: 1,072 ft long and 296 ft wide, with six doors that stand 120 ft tall and weigh 30 tons each. The hangar also features two timber catwalks 137 ft above the deck and a timber bridge spanning its width. In its entirety, the structure comprises 3.2 million board feet of timber, sourced completely from the Pacific Northwest.<\/p>\n
WRD sent two teams to conduct a comprehensive building inspection. Given the facility’s layout and the special equipment required, Hangar B was temporarily closed while the timber inspection was carried out. The team executed tests on the 50,000 unique timber elements in the structure. To preserve the structure, they used non-destructive test methods including compression-wave testing with stress-wave timing equipment, along with recovering small localized samples for examination in our IAS-accredited lab in Jefferson, OR. Those samples were collected to read moisture content (MC), specific gravity (SG), and wood species identification, among other things.<\/p>\n
Inspecting the structure required a telescopic aerial lift capable of reaching such great heights. The lift reached the upper areas of the main structure, but a more extensive inspection of the roof was required, carried out under proper safety protocols to ensure the team had full access to every needed area. These included the bents and bays near the roof peaks and the various truss and support areas that could exhibit severe decay from leakage or prolonged moisture infiltration.<\/p>\n
WRD inspected every timber element of the structure (trusses, rafters, ridge beams, and purlins) and took extra care with hard-to-reach areas: concealed cross bracing, connector plates and all fastener locations, and roofing materials showing any sign of weathering or damage. With the structure standing for more than 80 years, WRD was prepared to inspect every element that could have been damaged by rot, decay, and the harsh weather common to the Pacific Northwest.<\/p>\n
Once the inspection was complete, WRD provided TAM with an extensive report detailing every element inspected and its findings, along with recommendations for any necessary repairs or replacements. The inspection lasted several days and gave TAM the crucial information needed to maintain the integrity of this beloved structure. As a result, TAM was able to analyze the data and decide the best course of action for their repairs, ensuring Hangar B remains standing strong and ready to serve the community for many years to come.<\/p>\n
The experience of WRD’s timber experts was crucial in providing the data and analysis to help preserve this historically significant building, exemplifying a commitment to quality service. Pairing that expertise with equipment that can safely and efficiently access the highest points of the structure enabled WRD to deliver reliable results on an important preservation project, helping the Tillamook Air Museum continue Hangar B’s legacy and secure its place in history for many more years to come.<\/p>\n","protected":false},"excerpt":{"rendered":"
Inside WRD’s structural inspection of the landmark Tillamook Air Museum hangar.<\/p>\n","protected":false},"author":3,"featured_media":2703,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"nf_dc_page":"","site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[77],"tags":[],"class_list":["post-2607","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-inspections"],"_links":{"self":[{"href":"https:\/\/woodrandd.com\/staging\/9964\/wp-json\/wp\/v2\/posts\/2607","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/woodrandd.com\/staging\/9964\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/woodrandd.com\/staging\/9964\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/woodrandd.com\/staging\/9964\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/woodrandd.com\/staging\/9964\/wp-json\/wp\/v2\/comments?post=2607"}],"version-history":[{"count":2,"href":"https:\/\/woodrandd.com\/staging\/9964\/wp-json\/wp\/v2\/posts\/2607\/revisions"}],"predecessor-version":[{"id":2637,"href":"https:\/\/woodrandd.com\/staging\/9964\/wp-json\/wp\/v2\/posts\/2607\/revisions\/2637"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/woodrandd.com\/staging\/9964\/wp-json\/wp\/v2\/media\/2703"}],"wp:attachment":[{"href":"https:\/\/woodrandd.com\/staging\/9964\/wp-json\/wp\/v2\/media?parent=2607"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/woodrandd.com\/staging\/9964\/wp-json\/wp\/v2\/categories?post=2607"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/woodrandd.com\/staging\/9964\/wp-json\/wp\/v2\/tags?post=2607"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}