The construction of Mill No. 3 at Britannia Mine began after Mill No. 2 was destroyed by fire in 1921. Rebuilding was essential for the Britannia Mining and Smelting Company, as the mine could not operate profitably without a mill to process its ore.
Construction Begins
Preparing the site proved more difficult than expected. The schist bedrock intended to support the foundations fractured easily, requiring workers to remove considerably more rock than originally planned.
Site clearing began shortly after the fire and continued until March 1922. Concrete foundations were poured in April, and construction of the main building began in July.
The Mill’s structural frame required approximately 1,426 tonnes of steel, while its exterior was covered with corrugated galvanized iron.
An Impressive Gravity-Fed Mill
Mill No. 3 was completed on January 26, 1923. At the time, it was considered one of the most impressive gravity-fed mills in North America.
Its location on the mountainside was an important part of the design. Ore entered near the top of the building and moved downward through different processing stages using gravity, with the resulting mineral concentrate emerging near the bottom.
This approach reduced the need for a complicated system of conveyors to move material between levels.
The Scale of the Concentrator
The completed Mill was enormous. It stood approximately 270 feet high and 209 feet across, with a total internal volume of more than three million cubic feet.
Natural light entered through nearly 1,200 windows containing 18,792 individual panes of glass, giving the industrial building its distinctive appearance.
An Industrial Engineering Landmark
Construction of the Mill, including its machinery and materials, cost $953,484.59 at the time. More importantly, its innovative design attracted the attention of mining and construction professionals.
Engineers travelled to Britannia to study the Concentrator, which became a remarkable example of early 20th-century mining engineering, industrial architecture and gravity-fed ore processing.
More than a century after its completion, Mill No. 3 remains the defining structure of Britannia Mine’s industrial heritage.