BIG NEW YORK TUNNEL.

New Zealand Herald, Volume LXV, Issue 19940, 8 May 1928, Page 6

BIG NEW YORK TUNNEL.

UNDER THE HUDSON RIVER. OUTLAY OF £9,600,000. [FROM OtTE OWN COBBBSPONDINT. ] NEW YOKE, April 4. The Holland tunnel, providing vehicular communication under the Hudson River between New York and New Jersey, was opened for traffic recently, and 52,000 vehicles now pass through it daily. The tunnel consists of two tubes, the north accommodating west-bound traffic from the New York entrance, and the south tube serving east-bound traffic from the western ontrance at New Jersey. On each side of the river the entrances are located two blocks apart, to prevent traffic congestion in the city streets. The roadway in each tube averages 20ft. in width, permitting of two lines of traffic. The maximum speed ia 30 miles an hour and vehicles must keep 75ft. apart. Almost 2000 vehicles an hour can pass through each tube. Among the novel engineering problems involved in the construction and operation of this underground passage were those of ventilating and lighting. Extensive /experiments were performed to determine the amount and composition of exhaust gase3 from automobiles and their effect on human beings. As a consequence, the ventilation system has been established by which the air in the entire tunnel can be changed in a little less than one and a-balf minutes. Fresh air is supplied along the roadway, and the foul air is carried off through the ceiling. It is believed that the failure of the air supply is impossible under any conceivable condition. From the first it was recognised that the successful operation of the tubes would depend on lighting the interior to approximate daylight. There must be no Budden strain upon the eyes of the driver coming suddenly from full daylight into the subterranean passage and no glare upon leaving it. Similarlv the eye of the driver must be protected against bright lights when in transit. Artificial daylight has been attained by lights that will not go out. The essential part of the scheme is the white tiling of the walls that line the tunnel The total '"X* of the ooastroction wm £0,600,000.