(Click here if drawing doesn't appear above.) 1 Duct shafts. 2 Limits of crane hook travel. 3 10 ton bridge crane. 4 Upper part of missile assembly & checkout area. 5 Upper part of receiving area. 6 Door hood. 7 Canopy roof. 8 Stairway roof. 9 Earth cover. A Environmental closure: Plan (above), Sections (below). Left: bag extended; Right: bag retracted B Neoprene coated nylon material air inflated bag with spring loaded roller. C Dock bumper. D Roll-up door. E Pipe guard. F Roof plan. G Emergency exit tunnel. H Retaining walls.