Engineering Wonders of the World
Volume I

THE NEW YORK SUBWAY. 349 excavation was to be made was supported by two steel girders, drawn in through a narrow excavation and supported on trestles set in deep pits. With this support the earth below the overhang could safely be removed and the Subway built (see Fig. 9). At present stone piers on its roof carry the overhang of the monument’s foundation. These are only a few out of the scores of special problems which, arose during the Sub- way building. A new difficulty was en- countered at every step. Most of them are unrecorded, but the completed Subway is the monument of those who achieved them. Fig. 9.—SKETCH OF WORK UNDER THE COLUMBUS MONUMENT, AT INTERSECTION OF EIGHTH AVENUE, BROADWAY, AND 59TH STREET. methods described above. For a proper com- prehension of their importance, we may note that the outer or “local” tracks have stations Fig. 10. —INTERLACING STEEL FRAMEWORK WHERE THE SUBWAY PASSES THROUGH THE FOUNDATIONS OF THE “ TIMES ” BUILDING, BROADWAY AND 42nd STREET. The columns at the left belong to the Times building structure. The subway occupies the spaces shown in the upper central part of the picture. (Photo, Pierre P. Pull is.) The stations form part of the Subway about every quarter mile; while the middle structure itself, and were built with it by the or “ express ” tracks have stations at one to