AMERICAN BRIDGE BUILDING

New Zealand Times, Volume LXXI, Issue 4407, 13 July 1901, Page 5 (Supplement)

AMERICAN BRIDGE BUILDING

Americans are twenty years in advance of other nations (except Canada) in the art of bridge, design and construetion. The steel of which a bridge is made represents about half of its cost. Steel is now made in the United States at much less cost than in any other country. In Britain, labour is so much hampered by trades-unionism that it is admitted by one of the leaders that the cost of labour in making steel in the United States is not one-half of what it is in Britain. This can b e said also of the labour employed iu manufacturing. The market for bridges is far greater in the United States than elsewhere. The States hav© now 190,000 miles of railways, and it has been estimated that there is an average of one span of metallic bridge for every three miles of railway. This gives 63,000 bridges on existing lines, without including those required for new lines. The increase in the United States of the weight of cars and engines has resulted in wonderful economic changes. The average rate of frights on American railways was in 1867 a little over five dollars per ton. Now it averages 95 cents. Any one can figure the saving on 976 millions of tons of freight moved in 1900. Thes 0 larger cars carry double the paying load of the old ones that they have superseded, and more powerful engines draw more cars in a train. This increase of weight of rolling stock has led to the renewal of the 63,000 eld bridges by stronger and heavier ones. This demand has brought into existence many bridge-building companies, and they can well afford to equip themselves with tho best labour-saving and accurate working machinery, regardless of first cost, as they know it would seldom if ever lie idle. European bridge builders are not in this position. Trains have not increased in weight as they have in America. Tho old bridges answer their purpose, and the demand has been chiefly confined to new ones. Bridge building is merely an adjunct to other business, and possibly the owners are wise in not investing much capital in special tools.—T. C. Clarke in “The Engineering Magazine.”