Engineering Wonders of the World
Volume III

262 ENGINEERING WONDERS OF THE WORLD. MAGNET LIFTING A SOW AND PIGS OF IRON FROM THE MOULDS. the head of the furnace, on which runs a tub containing the charge of iron ore to be emptied in at the Automatic Tips. top of the blast- furnace tower. This tub has four wheels, two on each set of rails. At the top the lower set of rails, upon which the front wheels of the tub run, curve over the furnace. The upper set of rails, carrying the bottom wheels of the tub, continue upwards, and by up- setting the tub cause its charge of iron ore to be tipped auto- matically into the furnace. The tub is hauled up by a wire-rope carried over a pulley at the top, and operated by a hoisting engine or motor situated in a building at ground-level. The engine is arranged to give a “ harmonic lift,” and so brings the car to rest gradually as it reaches the top, and reverses the motion of the tub independently of the operator. Other machinery used in connection with the blast furnaces would not be of interest to any but the enthusiastic engineer, and as a description would cause a serious divergence from the subject of this article, we will leave it out of consid- eration. The iron Lifting Magnets. when smelted is run out into open sand - moulds arranged in the form of a comb directly in front of the blast furnace. (The castings are subsequently broken up into pieces called pigs, whence the term “ pig ” - iron.) For MAGNET LIFTING PLATE WITH THRFE MEN IN THE YARD OF THE WELLMAN SEAVER MORGAN COMPANY. lifting the unbroken combs out of the sand, electro-magnets of the ironclad type, and specially designed for this work, are now suc- cessfully employed. The whole of the electric wiring is enclosed within metal, and the shape is such that as many as possible of the mag- netic lines of force are concentrated on the pig-iron. This type of magnet is also useful for lifting pieces of scrap steel which are too large to be shovelled up, and for handling plates and hot billets of steel. A literally