Cement Plant
Monday morning we strike camp at 9:00 a. m. We drive into Rapid City,
get our snapshots of the Badlands which had been finished there, again
shop a bit, and drive out to the cement plant.
First, however, a word about Rapid City. It is a thriving little city on
the eastern entrance to the Hills. The streets have a modern air to
them, with occasional reminders of the days of the “West.” During the
tourist season the city fairly teems with life. Prices are reasonable
and the people are courteous. The city resembles those farther east for
the most part, not being without the familiar Woolworth and Penny
stores. But the relics of cowboy days are still in evidence, and
specimens of fish and game, alive or mounted, are shown with no little
pride.
The high school, where President Coolidge had his summer Capitol in
1927, is a place worth stopping to see.
The State cement plant is run by the State of South Dakota. It employs
about 150 people. The plant consists of the quarries, the sheds for raw
rock, chutes, power house, crushers, the hydrating and baking plant, the
furnaces, the drying tanks, the sacking department, and the offices.
Each of the buildings is very large. The raw rock shed holds thousands
of tons of rock. Each of the ten storage or drying tanks holds 15,000
barrels of cement. The plant can turn out twenty car loads a day, with
eight hundred to a thousand sacks to each car.
The men work nine hours each day and sometimes ten. The plant closed
five months the first year, three the second, and this last year it
closed but one month. When we visit it, it has more orders than it can
fill. The South Dakota cement is a superior quality and is much in
demand.
To the person interested in machinery the huge turbines and generators
are very interesting. These powerful affairs taking up but little room,
generate enough electrical power to run the whole enormous plant.
In going through the plant one starts at the raw rock sheds. Here the
loading devices carry the stone over a conveyor into the crushers. From
there the material goes, by various processes to be soaked and made into
mud, mixed, dried in blast tubes by very intense heat and flame, crushed
again, run into drying tanks, and finally sacked and loaded into
boxcars.
There are two men, known as sackers who, with the use of machinery, can
fill 15,000 to 20,000 sacks a day. They receive the empty sacks, tied by
wire at the top, and only open in one toe. This open toe is slipped over
a nozzle through which the cement pours into the sack suspended upside
down, resting on a small scale. When the proper weight of cement has
entered, the scale lets the bag down upon a conveyor belt and at the
same time shuts off the cement in the nozzle.
[Illustration: South Dakota State Cement Plant, Rapid City]
The flap inside the toe of the sack pulls across the hole closing the
sack. Each man has four sacks filling at once, and he has just barely
time to put on a sack and re-adjust his machinery before the next sack
is ready. The conveyor belts carry the filled bags to a chute which
deposits them in the box car, one on either side of the sacker. Each of
the many machines throughout the plant is driven by a small but powerful
electric motor.
[Illustration: A visitor in the forests of the Black Hills]
The cement plant is not one of nature’s wonders, but one of the products
of God’s masterpiece, man. It and other mechanical achievements are
hardly less to be marvelled at than the natural wonders, themselves.