The Holland Tunnel, which was the first underwater passageway for vehicles, is equipped with a ventilation system that blows fresh air through ducts in the roadway while exhaust ducts above the roadway remove fumes. It was built from 1920 to 1927 under the Hudson River to connect New York City and Jersey City, New Jersey. The Holland Tunnel's ventilation system of 84 fans makes it possible for all of the air inside the tunnel to be completely replaced with clean air within 90 seconds. Until this ventilation system was devised, underwater vehicular crossings were too dangerous to implement because of carbon monoxide buildup.
More about the Holland Tunnel:
- During the construction of the tunnel, chief engineer Clifford Holland is said to have had a nervous breakdown because of the stress and work involved with the project. He was hospitalized until his death in 1924, three years before the tunnel's completion.
- At 8,558 feet (2,608.5 m) on its westbound tube, the Holland Tunnel is the second-longest underwater crossing for vehicles in North America, behind New York City’s Brooklyn-Battery Tunnel, which is 9,117 feet (2,799 m) long.
- More than 16 million vehicles traveled through the New York-bound tube of the Holland Tunnel in 2012.