The New York Rapid-transit Subway

106 DISCUSSION ON NEW YORK SUBWAY. [Minutes of Mr. Rend, rusting. Some years ago Mr. Read was carrying out the foundations for the Seamen’s Hospital at the Albert Docks in reinforced concrete, and the question arose whether the rods should be cleaned or coated. After the work was done, he had a block made with some of the rustiest bars procurable embedded in it. He had quite forgotten the block, which had been lying in his garden, half in the ground and half out, since 1903. When the Paper was read, a fortnight ago, he unearthed the block, which was then in the snow, and broke it open; and he had laid it on the table. He found that the rusty bars were perfectly clean. He had held for some time the opinion that steel rods which had been thoroughly embedded in concrete would not rust if taken out and exposed. He left the clean bars taken out of the concrete exposed to the atmosphere, the snow, and the rain, in order to see what the effect on the bars would be. He had also placed with them on the table some steel test-bars, and it would be seen that, as the result of the fortnight’s exposure, the steel test-bars had rusted considerably more than the bar which had been taken out of the concrete. He had been very much interested in the account of the construction of the tunnel under the Harlem River. A few months ago he had an opportunity of seeing the construction of the Metropolitan railway in Paris, where they were sinking into the river in much the same way as had been done in New York. Alongside of the river, in water-logged ground, they were sinking a whole station from the street. The steel skeleton of the station was built above-ground, the street was excavated, and the framework was let down and concreted. Then air-locks were placed in it and it was sunk deepei. W hen he saw it the top was about level with the surface of the street, and the air-locks were in. Mr Haigh. Mr. Arthur H. Haigh remarked that the question of cost o construction had loomed large in the discussion, and he would like to compare the cost of a shallow subway with that of a deep tube. He had recently had the privilege of going through the New York Subway, and had examined the tunnel just being completed near the Brooklyn Bridge ; and he had been especially struck with the reinforced-concrete work for the ordinary length of the subway, a matter he would like to refer to later on. With regard to cost, the information given in the Paper was meagre, and it was not very clear what was implied. It had to be remembered, in comparing the work, that the line had not been made on one system; it was really a combination of a shallow subway with an elevated railway. The small amount of tunnelling was only such as would be requisite under any system to meet the topography of the district. As a matter