Ores obtained from the Mesaba and other Lake ranges usually average slightly more than 50 per cent. in iron. There is an enormous amount of ore in this region, however, which runs less than 40 per cent. in metallic content, and further, is too rich in silicon, which factors make it unavailable for steel making without previous treatment, but this ore is too valuable and too much needed to be allowed to go to waste. The Corporation solved the problem by erecting at Coleraine a “concentrator,” which is really nothing but a great washing plant for ore, and by this means crude ore containing 37 per cent. or thereabout, in iron, after treatment in which water and gravity are the principal factors, is brought up to an average of about 56 per cent. metal. In one day this concentrator has treated 50,000 tons of crude ore, producing 32,000 tons of concentrates.
Let us leave the mining regions and follow the ore on its journey to the furnaces. The journey is begun in either of the two railroad systems owned by the Corporation, and radiating over the ranges—the Duluth, Missabe & Northern, at the head of which is William A. McGonagle, which serves the Mesaba range principally, and the Duluth & Iron Range, of which F. E. House is president, which serves the Vermilion section.
We shall soon arrive at Duluth, or near-by Two Harbors, where these roads terminate. Here the ore trains run out on the huge Corporation docks, some of which project half a mile into the lake, and dump their cargo into enormous pockets in these docks. This ends the first stage of the journey.
But our travels have hardly begun. The next stage of the journey is made by boat. The Corporation, through the Pittsburgh Steamship Co., owns no less than seventy-eight large steamers, many of them capable of carrying 12,000 tons of cargo, and all built specially for ore transportation. To and fro between Duluth and Two Harbors on Lake Superior, and Gary, Chicago, Cleveland, Ashtabula, Conneaut, Fairport, and other points in the lower Lake, this great fleet goes constantly except when winter freezes up transportation.
Arrived at the ore docks, the boat makes fast alongside, and the work of putting in its ore cargo begins immediately. This is a rapid-fire operation. A touch of an electric lever and from each of the three-hundred-ton “pockets” on the dock descends a great chute into the maw of the ship, and through these chutes the ore, impelled by gravity, comes cascading.
In a few hours at most the work is done, and the ship is ready for her return trip. The average time taken to load a thousand tons of ore is half an hour, but on one occasion 12,817 tons were put into a vessel in thirty-five minutes. In one day twenty-four boats were loaded with 211,887 tons. From a single dock 10,921,107 tons have been put on ship-board in one season.
A sail of three or four days and we arrive at one of the lower Lake ports. Here the boats are unloaded by methods even more impressive than those connected with the loading operation, and so efficient that a twelve-thousand-ton steamer has been emptied to the last spadeful in three short hours.
Of the various unloading devices employed the Hulett machines are the most modern and impressive. Notwithstanding their weight, which runs into hundreds of tons, these gigantic affairs are moved up and down the dock and perform all their operations by the touch of a light lever. Almost “a child can handle them.” The mighty arms of these machines give them somewhat the appearance of gargantuan grasshoppers. The operator sits in comfort in what corresponds to the wrist of one of these great arms, and, at his will, the clamshell bucket hand dips down into the bowels of the vessel and, opening its metal fingers wide, to a span of 22 feet in the largest sizes, closes with irresistible might on everything within its grasp.
The Hulett machine is the very embodiment of power, power chained and subservient to the will of man. The incalculable force of those mighty fingers would crush a steel railroad car as one might squeeze a sponge. A miscalculation by the operator, and the steel ribs of the unloading steamer would be torn away, gnarled and twisted. And each lift of that hand brings with it a load worthy of its might, some seventeen tons of ore.
Before following the ore farther on its trip to the furnaces we can find time to devote a minute to a related operation, the shipment of coal to the mining regions to supply the power for the operations there. This is marked by the same big-scale, time-saving methods. Arriving at the docks at the lower Lakes, the coal train is run out beside the now empty vessel, and another great machine picks up car after car, and swinging it out over the hold of the ship, overturns it and empties it in a few seconds.