Engineering Wonders of the World
Volume I

6 ENGINEERING WONDERS OF THE WORLD Fig. 12.—BRICKLAYERS AT WORK ON NEW TERMINAL BUILDING, NEW YORK. Observe the suspended scaffolds. {Photo, Illustrations Bureau.) underground work is, from an engineering point of view, of exceptional interest. When the foundations are ready to carry their load, the steelwork is begun. First come The Cage. the columns, whose section has been cal- culated carefully to carry the stresses due to “ dead load,” “ live load,” and wind pressure. The corner col- umns of the Metropolitan Life Assurance Building are required to bear each a maxi- mum load of about 5,000 tons. As the New York building laws place the limit of weight on foundations at 15 tons to the square foot, the engineer or architect has to distribute the pressure of the columns over the piers by a grillage of girders. Moreover, the column feet must be anchored firmly to the piers to resist the lifting efforts of the wind. When once are fairly- started, erec- tion goes a- head very rapidly. Great jib cranes rise at the top of all the columns The Men who do the Work. and filling them with concrete. On top of each pier is a steel grillage to distribute the pressure of the columns. The Terminal Build- ing of the Hudson Companies rests on a coffer- dam of concrete with 8-foot walls extending from 80 to 95 feet below the surface. For the Singer Building thirty-four caissons were sunk 200 feet; whereas for the Metropolitan Life Assurance Building the engineers made arti- ficial foundations. Though out of sight, this to lift the steelwork members into place. As fast as these last reach, their respective positions they are workmen and spiked temporarily, ready for the riv- eters, who, armed with sledges and pneumatic tools, soon make every- seized by nimble-footed Fig. 13.—TYPICAL COLUMN FOUNDATION, RITZ HOTEL.