COURTESY BROWN HOISTING MACHINERY CO. CLEVELAND, O.
COAL CAR DUMPER IN OPERATION
THE STORY OF COAL
Handling Coal
THREE
In times gone by coal was carried out of the mines on the shoulders of men and women, and then transferred in wheelbarrows to the sailing-vessels or wagons in which it was taken to market. In progressive mines of today the coal is loaded in the mine into small mine cars, which are hauled and hoisted to the surface by electricity or steam. The mine cars are dumped on an elevated platform called the “tipple,” and the coal passes through chutes or conveyors to the railway cars waiting underneath to receive it. On its way downward it undergoes a more or less elaborate process of screening, breaking, picking, washing, etc., according to the kind of coal and the purpose for which it is to be used.
The coal reaches the market by three general methods of transportation: (1) All-rail; (2) rail to the seaports, where it is used for bunkering steamers or carried by vessels to other ports, foreign and domestic; (3) rail to the Great Lakes, especially Lake Erie ports, from which it is carried to ports on the upper lakes, and from the latter again by rail to markets in the interior. The railroads themselves use about one-fourth of all the coal mined in this country. The coastwise coal-carrying trade is mainly by wooden barges towed by steamers, though much coal is also carried by schooners, some of which can carry a cargo of 5,000 tons or more. About four per cent. of the bituminous coal output goes to foreign countries.
“The consumption of coal,” says the United States Geological Survey, “is a measure of the industrial activity of a people, for as yet coal is the main source of mechanical energy. In this respect the United States is the foremost nation, its average annual consumption of coal for all purposes being about five tons per capita. Prior to the present war in Europe the consumption of coal per capita in England, Belgium and Germany was about four tons, in Russia a quarter of a ton, and in France about 1.6 tons.”
Marvelous forms of labor-saving machinery have been introduced to facilitate the loading and unloading of coal. The principal form of apparatus for transferring coal either to or from a vessel is the “bridge tramway plant,” which consists of long steel bridges mounted side by side on suitable rails so that they can be moved into place over the hatchway of a vessel. Huge buckets, which load and unload themselves, are carried on a “trolley,” suspended from the bridge, and transfer coal at high speed from the vessel to the stock pile or railway cars, or vice versa. The cost of loading coal by this method is only a cent or two a ton.
Another ingenious device is the “car-dumper.” This powerful machine picks up bodily from the railway track a car loaded with a hundred tons of coal, overturns it, and discharges its contents into the hold of a vessel; after which it returns the car to the track. It is capable of handling fifty cars an hour. It is equipped with special apparatus to prevent the coal from being discharged too violently, and thus being badly broken up.