The item is an industrial film on a black and white workprint made between 1956 and 1960. It contains footage of the construction of the Mission Dam on the Bridge River project Soletanche and shows special operations (1958-59) required to seal the foundations and substrata under the site to prevent seepage. Depicts work to remove sections of old steel pilings (cut loose by divers with torches working in mud-filled pits); driving a wall of sheet pilings; manufacturing a clay/cement grout mixture and forcing it into the substrata under pressure to form an impervious curtain. This film is likely very similar to the French-language film produced for the French engineering firm (Soletanche Ltd.) which carried out the work.