Hangar bay shell section (UFO Crash Site and Recovery Facility)

A 6 m deep section of an 18 m span hangar bay: a segmental arch shell with real wall thickness, a 0.15 m floor slab, three internal portal frames, cladding ribs, a glazed clerestory each side, three roof lights and four high bay lamps. Sections butt on a 6 m pitch.