HOLLAND TUNNELS

Dominion, Volume 21, Issue 114, 11 February 1928, Page 24

HOLLAND TUNNELS

REMARKABLE NEW YORK DEVELOPMENT

New York City has recently celebrated the completion of one of its most remarkable engineering projects (writes the correspondent of the “Manchester Guardian”). The Holland Tunnels, connecting Manhattan with New Jersey, have at last been finished and thrown open for the public use after eight years’ work and an expenditure of £9,600,000. They are for the use of motorpropelled vehicles exclusively, and connect Spring and Canal Streets, New York Citv,'with Twelfth and Fourteenth Streets, jersey City. There are two of these tunnels, lying beneath the Hudson River, where the great ocean liners pass above them. One is for east-bound traffic, the other for west, and each has two roadwavs, for fast passenger cars and slow lorries. The tunnels are each one and three-quarter mile in length, and they will accommodate 3800 cars an hour, or 15,000,000 a year The project has been named after Clifford M. Holland,.who was the chief engineer in charge of construction from 1919 until his death, brought on by overwork, in 1924. Only 36 years of age at the time of his appointment, he was regarded as one of tlie finest minds in American engineering, and with general approval the name of the tunnels was •hanged from “New York-New Jersey Vehicular Tunnels” to be a memorial to him. He was responsible for solving many vexing questions never before faced in tunnel construction. Never have tubes of such length been constructed to carrv motor traffic exclusively and in such large volume.

The problem of caibon monoxide gas was one of the most difficult; as little as 10 parts of this gas in 10,000 parts of air, it was learned, will incapacitate a sturdy man in a few minutes’ time. This is the gas winch causes so many deaths among persons who run automobile engines in an enclosed space, such as a closed garage. It has been shown by tests that motor exhaust vapour contains from 3 to 14 per cent, of carbon monoxide, and the greatest difficulty was encountered in determining how to prevent harm from the fumes. Professor Yarndell Henderson, of Yale University, conducted an elaborate series of experiments with a group of volunteer student subjects, which confirmed the conclusions of Professor J B. S. Haldane on monoxide poisoning. An air tight upright box like a telephone booth was built, and a student, after entering it, was subjected to a given amount of carbon monoxide or other fumes of the sort likelv to be encountered in the tunnel One arm was thrust out through a. tight-fitting aperture, and blood specimens taken and heart action noted This was done many times, after which it was decided that four parts of carbon monoxide in 10,000 parts of air was as much as Was permissible.

To prevent the charging of the air with more than this amount, two wind tunnels have been constructed, one below and one above the level of the

roadways, in which 6000 horse-power motors will maintain a gale of wind at a velocity of 72 miles an hour. Fresh air comes in through grills at the floor level, and bad air passes off through the roof. Throughout the length of both tunnels there are emergency electric signs reading “Stop Engines.” When these are flashed all motors must instantly be cut off, and the traffic halts until tlie signal is given to start again. The most elaborate provisions have been made against fire or accident. Traffic officers are on duty eVery little way, the traffic beihg controlled with coloured lights in tlie fashion now universal in America. Every 125 feet there are fire extinguishers, utilising a chemical foam and also reservoirs of sand. Automobiles were set on fire in the tunnels for experimental purposes, before they were opened to the public, and tlie ventilating svstem carried off all smoke and fumes, while the extinguishers speedily put out the flames. . If a car breaks down tn the tunnel a double-ended emergency truck, operating in either direction as a ferry-boat does, will come and carry it to one entrance or the other. Anyone careless enough to run out of petrol in the tunnel may purchase a gallon from an officer for 45., which is several times the normal American price. Traffic is supposed to travel in the high-speed lanes at thirty miles an hour, and cars must remain '75 feet apart. Tolls are charged for the use of the tubes since it is not desired to cause traffic to abandon ’the ferries, but to supplement their facilities. The basic fee is 2s. for a passenger car, though the charge for the heaviest lorries ranges as high as Bs. Horse-drawn vehicles are strictly forbidden to enter the tunnels. So are intoxicated drivers, bicycles, and lorries carrying explosives or combustibles. Horns may not be sounded, and drivers and passengers are strictly forbidden to smoke No tyres may be changed en - route.

■ A visitor to the tunnel finds himself in a white-tiled cylinder, 29|ft. in diameter, with a footway on the left for the use of traffic officers, and a double set of red and green traffic lights overhead for the slow and fast-moving lanes _ of traffic. There are none of the sensations which ordinarily go with underground passage, except’the reverberation of the noise of motors; the air is changed so frequently forty-two times an hour—that it seems entirely fresh.

Expectations are that, within a few weeks, the new tubes will be in use to their utmost capacity, since the ferries have long been badly overloaded, and a wait of several hours for a chance to get" across the Hudson has not been at all uncommon Already the building of the next set of tubes is being discussed, as well as a proposal for similar construction under the East River between Manhattan and Brooklyn, which is on the mainland of Long Island