Rugged winter weather has caused many headaches in the construction industry in Canada down through the years. Sustained temperatures of 35 degrees below zero, however, failed to halt construction of Manitoba Hydro's Kettle Rapids Dam. With the aid of the shelter and modern building techniques, Hydro spokesman say the project has stayed on schedule. The temporary framework covering a large portion of the project during the first winter was 580 feet long, 120 feet wide and 13 feet high, and was heated by an oil-fired steam generator. It enveloped almost half the length of the 1,200 foot long concrete intake structure near the south end of the 3,800 foot long, 130 foot high concrete and earth-fill dam. This heated enclosure enabled the builders to hit a target of close to 4,000 cubic yards of concrete per week in the building of some of the world's first dikes over permafrost. The supply and control of heat inside the structure held the key to the operation. A boiler plant located at the south dam abutment within the cofferdam consumed up to 4,000 gallons of fuel oil daily. The total heating plant capacity, never fully demanded, was 1,200 boiler horsepower or over 40 million Btu per hour. Another critical factor in the success of the unusual operation was heat retention in the structure. A cladding was bolted to the steel frame erected in early winter. The cladding was 24 by 3 foot, galvanized, corrugated steel panels, with every fourth panel replaced with a similarly sized strip of translucent fiberglass to permit daylight to enter.