Chicago : Engineering and Contracting Pub. Co. · leaf 93
ch set of collars. Concrete for liningthe tunnel was mixed by hand, mixing boardsbeing placed on the surface above the outletportal, the control tower excavation at thecenter of the tunnel, and the intake portal,and the concrete was delivered into barrowsin the tunnel through chutes, then wheeled… … Fig. 4—Sketch Plan Showing TrackSystem and Borrow Pits.
Buildings
Internet Archive · University of Illinois Urbana-Champaign · Public Domain Mark 1.0. Free to use for anything.
