A MONSTER MAGNET.

Star (Christchurch), Issue 9318, 19 August 1908, Page 2

A MONSTER MAGNET.

CAPABLE OP LIFTING TEN TONS. (By W. F. McCLURE, in the " Workers' Magazine.'') One of the meet interesting industrial achievements of the present day in America is the lifting and transporting of everything in iron and steel, from small scrap material to weights oi 20,000 pounds each, by means of electrically operated magnets. During the last year or co especially the uses ol the iifting magnet have been multiplied, specially designed magnets ot widely different types being perfected for the different shapes in metal they aro to handle. The sight of a concave block connected with electric Avires descending into a vast pile of scrap iron and returning in midair with a largo load clinging to it is indeed novel. Likewise when another block descends upon a huge iron casting and the casting jumps from the ground to meet it, one etaxide in wonderment before it. Great sheets of steel also may be handled by the earn© unseen power, and not only this but three or four men may stand upon the sheet and with it bo carried high above the ground. NO CHAINS OR HOOKS NEEDED. That such an invention should revolutionise the method of handling v large variety of metal materials is at one© apparent. There is by this method no equipment in tho way of chains, filings, or hoisting hooks to be fitted about the articles to be lifted, and, therefore, as a rule, no men on tho giound are necessary in its operation. When the magnet descends upon the object there is nothing more to do but to begin the return trip. One interesting use to which one type of magnet is put is the lifting and dropping of what are known as "skull cracker balls." These balls weigh no much as 20,000 pounds. They are used at the furnaces and steel mills in breaking up injperfect metal castings and the like, which must always be broken before they can be molted again. This magnet is 'first U6ed to pile the metal which is to be broken in the desired heap or place. It next lifts the " cracker ball high above the pile and the operator at the proper time breaks the current of electricity and releases it to fall with all its weight i upon the metal beneath. Finally tiu» broken castings are lifted by the same magnetic power and loaded into cam or other receptacles. MAGNET LIFTS 20,000 POUNDS. Another interesting sight is the lifting by magnet power of a complete "<sow and pigs" out of the sand floor of a furnaco casting house. A different j type of magnet is required for this. Tne tonnage which a magnet will lift p.leo depends to some extent upon the; object to bo lifted. / j On© type of magnet which is fifty- j one inches in diameter and weighs 5100 pounds will, besides lifting the 20.000 pound cracker balk, lift 6000 pounds of billets or slabs or two ingots of 6000 pounds each. It will unload machine cast pig iron from care at tho rate ofl2oO pounds each lift, or from stock piles at the rate of 1350 pounds, and sand pig iron at the rate of 115U pounds from cars or 1200 pounds from stock piles. ' , ■ ' . i Descending into a pile of scrap iron-, j pieces of harvesting machinery, plow points, and the like, it returns vrihh 900 pounds or more clinging to it. It ■will return f rom a fine wire scrap pilo with 500 poundfe or will carry the samp amount of loose tin. . In junk dealers' scrap it will lift 800 pounds or more, and these are but a part of the articles which this one type will Jiandle. SWEEPS CLEAN AS GIGANTIC BROOM. One of the principal uses of this magnet is in loading the charging, boxes at open hearth furnaces, A little of the material spills alongside tho boxes, but this easily is picked up and loaded into them by lowering the magnet and allowing it to sweep noar tht> ground. Also in cars tho magnet is often brought close to the floor and will clean up all the small chips and even the metal dust that conies within its reach, thus adding to the amount of metal which can bo used in re" melting. The sand of a blast furnace casthouse with use becomes full of small particles of iron known as "shot" and occasionally must be riddled to remove tins shot unless a magnet is available, when the fihot can be removed by sweeping the magnet over the bed of sand. j In the case of billets and ingots the load depends to some extent upon their being piled evenly, and this is one of the instances where a man upon the ground comes in handy. HANDLES 600 TONS A DAY. This olin magnet will handle easily from 400 to 600 tons per day, and as a rule has displaced seven labourers per turn, so that where a plant such as an open hearth furnace runs day and night one of these magnets will displace fourteen labourers, which will effect a big saving in the handling cost. Special fast cranes also will increase the amount handled by the magnet in a day. . Storage piles of scrap iron can be made much higher, it is claimed, by the use of the magnet than it would be practical to' attempt otherwise. Some of these piles rise to a height of 25ft. The work of storing is done rapidly. One load which required two men four hours to place in a waggon was lifted by a magnet from the waggon in just two and a half minutes and placed on a storage pile. Lifting magnets usually are operated from an electric overhead travelling crane, although they may be operated from a locomotive crane. The magnet used in picking up all small scrap material as well as most of the larger articles, and described in foregoing paraprraolis, is concave and therefore may shelter considerable, of /its load out of sight: SAVES LABOUR. INCREASES CAPACITY. . The magnetised coils with which tho electric wires connect also ar© enclosed within. There is a difference in the shape and construction of the magnet used in lifting long, thin metal sheets. Th« improvement in methods of handling tho finished iron and steel is in keeping with the progress which also is being made in the handling of the raw material for these metals. Iji nothing bars there been more marked development than in rapid iron ore handling at both the upper and lower lake pov+s. The introduction of automatic ore unloaders, ear>h one with pix operators, taking the place of tw^nt^-fiVe under fho old rp«ime. revolutionised the industry. Also the old nne-ton buckets have (riven place to tl^se which lift fiv" and even up +o twelvo tons each. It has been only a few years pfr»ce the magnet was reeardod as a toy. Now it is one cf*t.He pri^nt forces of the inrJusfvipl wnrld. Tho Herculean work that it does, however, may be t»Ve7i «s a mere suggestion of the possibilities of the. rnaenet iv the. y><v>r fn+nre. MAY BE USED IN BUILDING SKYSCRAPERS. The immense derricks and cranes, familiar to Chicago, which lift the huge structural iron beams and cross pieces in their place in the skyscraper may soon become obsolete. If the power that it- takes to lift them can be electrically applied by means of the magnet, we may see tons of steel; rising to the twentieth story of a building in the clutch of invisible fingers.' There can be no greater industrial miracle than this.\ Tho unseen^ but titanic forces of nature thus developed soon may be used in a hundredVways — ■ ■. IP

in building bridges, in laying railroad tracks, in loading and unloading metal objects and machinery at the wharves. One can imagine the magnet at work *at the iron mines of the world, carrying the ore without buckets, saving more than half the labour of handling, cheapening the cost of man's most useful metal in this "iron age." At the present development of the magnet it may be only a flight of fancy to conceive this giant force applied in warfare to the enemy's ironclad battleships — yet granting the miracle of the magnet, nothing else seems impossible. It is estimated that this might save nearly half in the cost of handling the structural iron used in buildings, if the magnet really is an economy in point of power units as hae been claimed for it. It would pick up an iron beam without recourse to grappling hooks or chains as easily as the toy horseshoe magnet will pick up a needle or a shingle nail. When the beam was in place the throwing of a switch would break the connection, and the magnet would release its hold.