Moffett Field Hangar Temporary Shoring, Access Systems, and Jacking
The two blimp hangars at California’s Moffett Field are among the world's largest clear-span timber structures, each stretching more than 1,000 feet long, 250 feet wide, and 170 feet tall. When significant damage to the timber truss arches of one hangar began progressing along its length, the risk of collapse became a serious concern. Power Engineering Construction Company retained Liftech to design the systems needed to stabilize the structure and provide safe access for repairs.
The Challenge
The sheer scale of the hangar made it exceptionally difficult to temporarily support the damaged structure and safely access the locations requiring repair, and the damage was actively progressing, adding urgency to an already complex engineering problem.
Our Approach
Liftech designed a suite of purpose-built systems to stabilize the hangar and enable repairs. An adjustable pipe shoring system extended from the concrete floor to multiple points on the lower chord of the damaged truss arches. A massive access shoring tower — 80 feet by 80 feet and 130 feet tall — was equipped with an overhead crane, construction elevator, ladders, and stairs, and pulled through the hangar on steel channel tracks and rollers. Designed to shore and jack the roof from its upper deck, the tower could also resist large lateral loads and was engineered to tip onto one side in the event of an earthquake. Additional steel pipe systems with jacks supported the upper arches, strand jack towers enabled assembly of the access tower inside the hangar, and a jacking procedure was developed to lift and repair a 20-foot by 22-foot by 200-foot timber box beam above the 120-foot-tall hangar doors.
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