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.
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.
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.