Cornish Pumping Engine Fact Sheet

The famed Chapin Mine in Iron Mountain, discovered in 1879, was one of the wettest iron mines ever to be worked. During its first ten years of production, ground pumps were able to take care of the constant accumulation of seeping water, but when mining was attempted at deeper levels, the problem became impossible for the ground pumps to handle.

The kind of extensive dewatering required was known to be done only in the deep tin mines of Cornwall, England. The Cornish Pumping Engine was so named because it was patterned after the engines used in Cornwall's mines.

Edwin Reynolds, chief engineer for the E. P. Allis Company (now the Allis-Chalmers company) of Milwaukee, Wisconsin, designed the steeple compound condensing steam engine in 1890.

The engine's high pressure cylinder has a 50-inch bore, and the low pressure cylinder is 100 inches in diameter. The stroke of the pistons is 10 feet. The flywheel alone is 40 feet in diameter and weighs 160 tons. It had an average normal speed of only ten revolutions per minute.

The "slot" for the flywheel is about 20 feet below the bed of the engine, and the big shaft which drove the wheel is 24 inches in diameter. The engine itself extends 54 feet above the floor of the engine room. The designers estimated the weight to be 725 tons overall.

The engine had been placed on the surface close to the boilers so that there was comparatively little loss of steam by condensation. If the engine had been placed down in the mine, flooding might have damaged or stopped it. In an emergency, the mine could be completely shut down and allowed to fill with water. The engine's boilers consumed 11 thousand tons of coal annually.

The pumping equipment used a reciprocating motion applied to a line of steel rods extending 1,500 feet down into the mine with eight pumps attached at intervals of 170 to 192 feet along the rods. Each forced the water to the next higher pump and finally out at the surface of the mine.

As the engine was designed to run slowly, the pumps had a capacity of over 300 gallons per stroke of the pistons. At ten revolutions per minute, this meant that over three thousand gallons of water poured out every minute through the pipe line, which was 28 inches in diameter. A total of five million gallons of water could be removed from the mines each day.

The engine began operation at "D" shaft of the Chapin Mine on January 4, 1893. The engine alone cost $82,500 in 1890. The portion of the pumping system located in the shaft cost much more, and the installation added brought the total expenditure to an estimated $250 thousand for the entire pumping plant. Some estimates are much higher.

A crew of 60 divided into three shifts operated the plant, including the men in the boiler house, engine house, and shaft.

The pump worked well at "D" shaft until underground conditions caused it to shift, and the equipment was forced out of alignment. In 1896 it was dismantled and stored at a site known as the Sandbanks, which was halfway between its original location and its present site at Ludington "C" shaft. The pumping engine went back into operation in 1908 at "C" shaft, where it dewatered the combined Chapin, Ludington, and Hamilton mines, each of which had been operating in close proximity to the others.

The Cornish Pumping Engine and equipment were highly efficient at this site, but in 1914 the Oliver Mining Company put into operation at the Chapin the largest electrically driven centrifugal pumps in mine service in America at the time. Unable to adapt to the drive of the electric motors beneath her, the magnificent Cornish Pumping Engine, world famous as one of the wonders of the mechanical and steam age, stood idle and was kept only for use in case of accident to the other pumps.

[Blomquist, Beatrice. Cornish Pumping Engine Fact Sheet. Iron Mountain, MI: Menominee Range Historical Foundation, n.d.]
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