Wooden forms were used in the construction of the Delaware Aqueduct to shape the concrete lining of the tunnel as it was poured. This wooden form was used to mold the gooseneck shape that connected the Rondout Reservoir effluent chamber (water leaving the reservoir), to the connecting tunnel which led to the first shaft of the Delaware Aqueduct. September 1941.
(Image DEP Archives hdq.d.5895)
From NYC water