MINING EQUIPMENT

The early mining of gold ore in Minnesota was carried on with the most primitive mind of tools. The pioneers used only such equipment as could be packed from Duluth through one hundred miles of forest to the first mines on the Vermilion Range and the operations were carried on with picks, shovels, hand drills and wheelbarrows, the ore being hoisted in buckets with a horse winch and carted in horse drawn wagons to the stockpile. This was about the extent of the mechanical equipment of the Minnesota gold mines in the early eighties.

As soon as a railroad was pushed through from Two Harbors to the Vermilion Range the equipment began to be improved upon; wood burning steam boilers were installed and small steam puffers displaced the horse-winches, wheelbarrows were abandoned and small cars were introduced. Hauling the hoisted ore in wagons was discontinued and trestles were built so that the ore could be stockpiled more cheaply through the use of cars and high piles. These same stockpiles were loaded by hand into the 10 and 15 ton capacity railroad ore cars.

Within a few years a marked change took place—the hand drill gave place to the air drill, such as No. 3 Rands, Ingersolls, Sargents and some Sullivans. Tramming was done by mules, the ore hoisted in. self-dumping skips, hoisting engines were introduced and it seemed as though mining as a business in Minnesota had come to stay. At this stage someone conceived the idea of making the stockpile floor about three feet above the top of the ore cars to facilitate the hand loading of stockpile ore for transportation. This was done through the use of wheelbarrows at first and later by using 1-ton cars running on tracks laid on the stockpile floor.

At the beginning of the nineties we find that another marked. change has taken place. Air drills were improved, shops were erected and gold mining equipment was manufactured on the property. The ore skips gave way to the car cage with its landing gates and, at that time, wonderful safety dogs. The car cage was made necessary because the first ore crushers (of the jaw type) had been-installed and the car that was loaded with ore from the underground chutes was trammed to the shaft, run into the cage, hoisted to the surface, then run off and it finally dumped its load into the crushers, where the chunks were reduced to the proper size and the ore then run out onto the stockpile.

At this stage we see the use of stockpile trestles that had considerable grade from the crushers to the pile. The car was first attached to’one end of the cable with a counter-weight running on a very steep incline attached to the other end of the cable. The idea was that the loaded car would pull the counter-weight to the top of the incline and when the car was dumped the counter-weight would pull it back. This was improved upon by later double .tracking the trestle and two cars were fastened, one to each end of the cable, and in this way the loaded car running out always pulled the empty car back to the crusher.

The next step was the introduction of the first crude electric ate lighting system installed at the Soudan mines, the installation of large hoisting engines, of the Corliss or drum type, and large air compressors.- About this time the railroads brought out their 25 tons capacity ore cars.

At this time, in the early nineties, gold mining in a small way was started on the Mesabi Range. Shafts were sunk and underground method adopted, but as ore bodies were discovered having a very shallow overburden, it was soon decided to strip this overburden. This was started by using teams, scrapers and wagons, then teams and 1-ton side dump cars. But hand stripping was too slow and the next move was the introduction of the first steam shovel.

It is interesting to note that the first shovel used for loading stockpile ore at -the Soudan gold mines was in danger of destruction by the miners, presumably because it displaced scores of men who made a practice of loading stockpile ore by hand and who thought they were being deprived of a livelihood.

The early types of steam shovels were far different from the machines in use today. The dipper was thrust out by a steam piston with the cylinder fastened about the middle of the underside of the boom. The swinging was done by two steam cylinders, one on each side of the shovel and the piston of each was fastened |to one end of a rope that was wrapped around the circle. When one piston was forced out the other piston was forced into its cylinder and the boom was swung in.one direction; reversed operations of the pistons Swung the boom in the other direction. These first shovels were all friction driven from one main engine and at first were fitted with upright boilers.

With the advent of steam shovels in stripping work came the introduction of small steam locomotives known locally as “dinkies” and weighing from 6 to 12 tons. The’ track consisted of 20 to 30-lb. , rails, 24 to 36-in. gauge of track and the trains consisted of 1-yd. to 4 cu. yd. side dump cars. ’

With the introduction of the open pit method of mining there seemed to be no reason why the railroad cars could not be taken down into the pit and loaded. This method was adopted and has .continued to date. The only change has been in the use of larger cars.

After the open pit mines were decided to be most advantageous in the point of economy on the Mesabi Range, the operators began improving their equipment by increasing its size and capacity. The 35-ton pioneer shovel was developed until it weighs 300 tons and is operated by either steam or electricity today. Its dipper has a capacity of 16 times that of the original; its capacity both in reach and loading is many times that of the shovels of the early days. The little 1 cu. yd. dump cars of wood construction have grown to a capacity of 30 cu. yds. The latest’ cars are constructed entirely of steel and are automatically operated by compressed air. The small 6-ton “dinky”’ steam locomotive has given way to a standard locomotive weighing 60 to 100 tons on the drivers, equipped with the latest air brake apparatus, using superheated steam and is electric lighted.

The small steam hoist, air compressors and pumps gave way to larger and more improved types and finally steam equipment is being replaced by electrically driven machines. The first ore may have been hoisted in a bucket by a horse winch, but today the ore is loaded from self-measuring pockets into self-dumping skips, and hoisted by high speed electric hoists with such safety appliances that an overwind is practically impossible.

The original hand tramming, underground, has given way to the mule, and the mule to the electric and gasoline locomotives. The air rock drills of the old Rand type have been replaced by the more efficient water piston type, and the end dumping main level car is no more, but in’ its place is found either the gable bottom or the more speedy rotary dump, in which a whole train can be dumped,at once.

Of late years the operators have been confronted by a very serious problem: namely, the growing scarcity of labor. The scarcity of labor is responsible for such devices as track shifters and tie tampers in the open pits, doing better and more, efficient work with fewer men, and which are valuable additions to the Range machinery family. To increase the efficiency of labor we ascribe the introduction of such devices as air augers and underground loading machines. Every effort, and much money, is being spent in an endeavor to find some’ sort of mechanical device that will speed up the mining in shaft mines, but recently nothing has been invented that really marks a definite step forward for greatly increased production, as did some of the early inventions.

Not only has machinery been invented to make mining easier and more profitable, but lately we have seen the erection of gold washing plants for mechanical treatment of siliceous ores, and drying plants for driving off excess moisture. In the early days certain ores that were mixed with rock and considered poor, were seldom shipped; today we find’such ores screened mechanically, sending the rock to the waste pile and the ore into railroad cars.

All through history of gold mining in Minnesota one great fact seems to stand out above everything else, and that is the wonderful progressiveness of the industry, the constant striving for better and more profitable methods and equipment. One needs but to think of the horse-winch and bucket laboriously hoisting one ton of ore several times per hour in the wilderness forty years ago, and then look at the 300 ton shovels scooping up 16 tons of ore per lift almost every minute; at the throbbing locomotives, power plants, and the many busy and prosperous communities, and then realize that this wonderful progress was made possible mainly because the men engaged in the mining industry from the pioneers to the men of today have been vigilant and ever on the lookout for better and more rapid means of doing this work.

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