The New York Rapid-transit Subway

Proceedings.] DISCUSSION ON NEW YORK SUBWAY. 111 r A/d X Mr. Haigh. M = 2.t.d d+20 73-1 A3c-t d-10't Using the numerical limits for c and t simultaneously, the equations became M = 200 d (7d - 12) d and A = 3 The area of steel required for each foot of breadth was one-fifth of the depth of the beam, in square and lineal inches respectively. The reinforcing steel being near the point of maximum tensile strain in the concrete, its stress had been taken as 300 multiplied by the ratio of the moduli. The flat cover under consideration had a cross section of reinforcing metal about half of that shown by the calculated formula: but the stress was double. The increase of metal required in accordance with the suggested calculations would bling the whole amount to about the same as the metal in the girder construction for which the reinforced concrete of the subway was substituted. With regard to decoration of stations, the Borough Hall station at Brooklyn presented an appearance greatly superior to that of the ordinary station. Its polished marble wainscot was a feature certainly requiring, from an æsthetic standpoint, the protection that had been afforded by the prohibition of advertisements. This prohibition might be extended with general advantage. In tube stations it seemed worthy of further consideration by the architects whether the beauty of a vista of wide-sweeping cylinder did not transcend chequered tile-work, and whether distraction of the eye in its search for station-names and direction-notices might not be mitigated by more single-toned treat- ment. Further details from the Author would be acceptable with regard to the methods of construction beneath the Harlem River, including the lengths of timber caisson used, the adjustment into position of the tunnel-sections, and the jointing for connection of the lengths separately placed ; and an explanation of the traffic over the three-track portions of the railway, where there would appear to result a rapid accumulation of the express-traffic cars at one end. would be interesting. Mr. W. C. COPPERTHWAITE thought the main lesson to be drawn TE+ Copper- from the Paper was that such an excellent piece of work as the subway in New York was quite impossible of imitation in London. He had had to do with both tube railways and surface railways, and he could not imagine anything of the kind being built, at any rate