It also facilitated the transport of goods across the Hudson River, which had previously served as a barrier to shipping materials between New Jersey and New York City. Today, the Holland Tunnel is the second longest continuous underwater vehicular tunnel in North America after the 9,foot [2, m] long Brooklyn-Battery Tunnel, which opened in Bennett at the New York Plaza of the Holland Tunnel to unveil a commemorative bronze plaque mounted on a five-foot high granite pedestal.
Bennett welcomed guests to the ceremony, at which speakers included Robert A. Robert B. Today, the plaque can be viewed on the west side of Varick Street between Watts and Broome Streets, near the entrance to the north tube of the Holland Tunnel. Home Met Section. Tech Groups. Holland Tunnel. The Holland Tunnel was the longest underwater vehicular tunnel in the world when it opened.
The first tunnel with a ventilation system specifically designed for exhaust fumes from motor vehicles, the Holland Tunnel has four ventilation buildings. The Hudson River Vehicular Tunnel was named in memory of chief engineer Clifford Holland, who died two days before the tunnel was holed through.
The Holland Tunnel. Tunnel construction required workers to spend large amounts of time in the caisson under high pressure of up to On exiting the tunnel, the workers had to undergo controlled decompression to avoid the bends , a condition in which nitrogen bubbles form in the blood from rapid decompression.
Fortunately, no workers died as a result of decompression sickness: the work involved ", decompressions of men coming out of the compressed air workings," which resulted in cases of the bends, none fatal. Completion of the tunnel took nearly seven years and claimed the lives of 14 workers.
The most significant design aspect of the Holland Tunnel is its pioneering ventilation system. At the time of its construction, underwater tunnels were a well-established part of civil engineering, but no long vehicular tunnel had been built: the technical hurdle was the ventilation required to evacuate the carbon monoxide emissions, which would otherwise asphyxiate the drivers.
There are four ventilation towers serving the two tubes of the tunnel, designed by Norwegian architect Erling Owre. Thomas Edison had contended it was impossible to ventilate a tunnel with the volume of traffic envisioned for the Holland Tunnel. Previously, tunnels had been ventilated longitudinally. Engineer Ole Singstad pioneered a system of ventilating the tunnel transversely. Working with Yale University and the United States Bureau of Mines, Singstad built a test tunnel in the bureau's experimental mine at Bruceton, Pennsylvania , over feet m long—where cars were lined up with engines running.
Volunteer students were supervised as they breathed the exhaust in order to confirm air flows and tolerable carbon-monoxide levels by simulating different traffic conditions, including backups. Singstad confirmed the feasibility of a tri-level tunnel with the large middle section accommodating vehicles and two plenums, a lower and upper plenum each respectively supplying fresh air and exhausting fumes at regular intervals—solving the ventilation problem.
On opening day the average carbon monoxide content in both tunnels was 0. The highest was 1. The permissible standard was 4 parts per 10, parts of air. The public and the press proclaimed air conditions were better in the tube than in some streets of New York City. The tunnel opened at pm on November 13, , with President Coolidge ceremonially opening the tunnel from his yacht by turning the same key that had "opened" the Panama Canal in , Time magazine called it "the golden lever of the Presidential telegraphic instrument"—which rang a giant brass bell at the tunnel's entrances that triggered American flags on both sides of the tunnel to separate.
Vehicles were allowed to pass through the tunnel at one minute after midnight, with the widows of Chief Engineers Holland and Freeman in the second toll-paying vehicle. The tunnel was an immediate success. In , control but not real property title of the tunnel was passed to the Port Authority of New York and New Jersey, which continues to operate it today. Horsedrawn vehicles have always been banned from the tunnel. Because it was considered an exceptional engineering accomplishment, it was named after its first chief engineer, Clifford M.
Holland unfortunately died before the tunnel was completed and the tunnel was finally completed under the leadership of Ole Singstad. The Holland tunnel consists of two tubes, each providing two lanes of traffic, located in the bedrock beneath the river.
The lowest point of the tunnel is approximately 93 feet below mean high water. One of the biggest challenges of the tunnel was how to ventilate it and properly remove the automobile exhaust fumes. After thirteen years of discussion, the young civil engineer Clifford Holland was given the job of drilling a highway tunnel under the Hudson River.
He began drilling two parallel thirty-foot-diameter tunnels, almost two miles long, under the Hudson River. But now such a tunnel faced a problem no earlier tunnel had ever faced. The automobile had come into its own. This tunnel would have to carry forty thousand trucks and cars each day. Huge quantities of carbon monoxide gas had to be cleared out. Holland's great contribution would necessarily be a wholly new ventilation system to flush out exhaust gases.
His system was gargantuan. Forty-two fans, each eighty feet in diameter, replaced four million cubic feet of fresh air per minute. If all that air had been pumped in from the ends, it would've blasted through the tunnel at seventy-five miles per hour. To get around that problem, Holland pumped fresh air down a service tube below the tunnel. He scavenged bad air out through a second tube paralleling the tunnel from above.
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