Pouring concrete for lock

Photograph showing a movable crane hoisting a hopper of concrete preparing to dump it into the giant form on the right. The forms also travel on tracks as the wall progresses.
Abstract/Description: Photograph showing a movable crane hoisting a hopper of concrete preparing to dump it into the giant form on the right. The forms also travel on tracks as the wall progresses.
Subject(s): Boats and boating
Soo Locks (Mich.)
Date Created: 1913 (approximate)