The tunnel called for even greater amounts of earth moving than the Kenney Dam. The deadline for completion was October 1953 with aluminum production set to begin in mid-1954. Never before was so much rock moved so quickly. Tunnel crews broke world records as they tore out the side of DuBose Mountain and moved closer to the generators at Kemano. When completed the tunnel would be 10 miles long, drop 2,600 feet, and be wide enough for four cars side by side to drive through.
American-based Morrison-Knudsen (MK) was one of the few construction companies in the world that had the experience necessary for a project as large and as difficult as the tunnel and powerhouse. The construction miners, a highly trained and skilled building group, used moles, and hydraulic and pneumatic drills. However, safety was often compromised for production. Sixteen died between November 1951 and May 1952. Dangerous conditions included lack of ventilation, working in knee-deep water, and falling loose rock.
The tunnel was driven from four headings. Miners were in Kemano Camp 5, Horetzky Creek, and West Tahtsa Camp 3, and two smaller camps - “1,600” and “2,600” - so called for their elevation. Camps had minimal comforts for the worker. Accommodation consisted of canvas-covered structures and “quonsets”, tunnel-shaped huts of corrugated iron with cement floors.