The Westside LRT tunnel through the West Hills in Portland, OR includes two 31 ft. I.D. vertical elevator/stair shafts that provide high speed elevator access to the Tri-Met LRT tunnel station from the Washington Park Zoo parking lot some 260 ft. above the tunnel. Both the East Shaft and the West Shaft used precast box sections with integral stairs as a value engineering alternative to cast-in-place stair shafts and stairs. The stair box units are stacked vertically and have matching curbs and blockouts on the top and bottom of each corner to facilitate horizontal alignment during installation.
