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
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
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,
"Cornish Pumping Engine Fact Sheet."
The Hi-Line and the Yellowstone Trail: To Glacier Park and Back Again.
1 Sept. 2004.
26 May. 2022
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