Mountain Con Mine
From ENHLDWiki
The following is from the Montana DEQ mine narratives; please edit, improve, and expand it.
The Mountain Consolidated Mine covers a large area near the top of Butte hill in the Centerville residential area east of Main Street. Known locally as the Mountain Con, the mine has a main hoist house at the top of the site area with the headframe, storage shed, and transfer shed below it. Down the hill from the headframe are the ruins of three ore bins which were knocked over after the mine was closed.
The Anaconda Copper Mining Company erected the steel headframe between 1916 and 1927. The 129.5-foot headframe consists of I-beams riveted together with batten plates and sitting on concrete footings. It was designed for the automatic dumping of seven-ton skips. In hoisting ore, the skips were suspended beneath a single-deck cage. Four deck cages could be utilized for moving up to 32 men at a time. The Mountain Con was a three and one-half compartment shaft with three twelve-foot sheave wheels atop the structure and an ore-loading bin off the front of the headframe.
The hoist house, erected sometime between 1916 and 1927, was located on top of the brow of the hill to utilize more stable ground. The Allis Chalmers main hoist, installed in 1927, was designed to bring men and ore from the 5300-foot level. The original hoist house sat down the hill closer to the headframe.
The cooling tower for the Mountain Con shaft is located southeast of the headframe. The refrigeration system was developed the 1930s. This evaporative cooling system included an elaborate network of pipes, cooling coils, fans and a cooling tower to carry cooled water (later brine) from the surface to the underground to cool the air in the various workings. Because the Mountain Con shaft reached a depth of over 4,000 feet by the 1930s - - a mechanical ventilation system was required to make underground temperatures tolerable.
The transformer house was to the south-southeast of the headframe. Power lines brought alternating current at 2,200 volts into the mineyard to be stepped down to 440 volts DC for use underground. This structure housed the transformers for this work. A small one-story rectangular powerhouse south-southwest of the headframe.
The ice house foundation is located adjacent to the powerhouse. The Anaconda Company used large quantities of ice to cool drinking water for those working underground. Between the hoist house and the headframe stand three sets of idler towers constructed of riveted angle sections that were designed to keep the wire rope taut between the hoisting drum and the sheave wheel at the top of the headframe. Four large steel ore bins once stood below the headframe. The B.A. & P. railroad ran cars below these bins where cars were loaded with ore for the concentrator and smelter in Anaconda.
The Mountain Con was active longer than almost all other Butte mines and reached the greatest depth. One of the earliest operations of Marcus Daly's Anaconda Mining Company, work at the mine began by 1886. Three years later, with a 3-compartment shaft 550 feet deep, the mine's work force of 350 men pulled copper and silver ores from underground. The flat pitch of the large vein gave the Mountain Con the heaviest hanging wall in the district's mines. In 1892, with the main shaft 760 feet deep, a second shaft was started southwest of the first. The No. 2 shaft was enclosed in a large wooden building which also included the hoisting engine. The mineyard also included, in 1900, a large boiler house, a rope house (for repairing cables), and wooden tramways which carried the ore from the hoisting works to bins. With up to 464 men working underground and 68 more on the surface, No. 1 and No. 2 shafts reached depths of over 2,000 and 1,600 feet, respectively, by 1900 (Inspector of Mines 1890 - 1899; Sanborn 1900).
The early Twentieth century saw continued activity at the Mountain Con Mine. The No.1 shaft reached a depth of 2,200 feet in 1902 and 2,500 feet ten years later. The No. 2 shaft was closed in about 1902. The mine remained a large employer - - over 400 people worked underground and on top in 1912. In 1918 the Anaconda Company replaced the steam hoist with a Nordberg engine, which used compressed air (Inspector of Mines 1903; 1913; Sanborn 1916; Anaconda 1918).
Operating into the 1970s, the Mountain Con was one of the last active underground copper mines in Butte. By mid-century, the mineyard consisted of a steel headframe, a hoist house, a change house, large steel ore bins, and frame buildings. Southeast of the headframe, fan housings helped ventilate the deep workings. In the mid-1930s, with the main shaft about 4,000 feet deep, the Anaconda Company installed an extensive air-conditioning system at the lower levels. The Mountain Con was one of the few shaft mines to remain open when open-pit operations began in 1955. In 1964, the main shaft of the Mountain Con reached the depth of 5,293 feet. By this time, some of the ore from the Mountain Con, especially from the deep workings, was hoisted up the Kelley mine shaft. This continued until 1973, when all underground mining in Butte ceased (Sanborn 1916-54, Mines Register 1937, Anaconda 1964, Corbett 1984).
