Forms for water transfer tunnels during lock construction

Photograph showing the forms used to make the tunnels through which water from the upper river enters the lock to raise a ship. View is westward.
Abstract/Description: Photograph showing the forms used to make the tunnels through which water from the upper river enters the lock to raise a ship. View is westward.
Subject(s): Boats and boating
Soo Locks (Mich.)
Date Created: 1911 (approximate)