Building NY’s Lincoln Tunnel – An Underwater Marvel

How do you build a transportation project that has to support more than 150,000 trips per day, all under water and be operating 100% effectively through New York’s harsh winters and brutal summers with no loss of efficiency or increased risk to the people using it? Slowly and with a team of committed experts. That’s how New York’s Holland Tunnel was built.

Soon after the Port Authority of NY & NJ acquired the Holland Tunnel in 1930, New York and New Jersey authorized the agency to build what was then called the Midtown Hudson Tunnel. The planned called for building the tunnel 100 feet below the Hudson River and was estimated to take four years to complete.

The city engaged the best architects to design the tunnel. Then they brought in the top geotechnical engineers to test all of the soil and rock, underground water, site and structural conditions, in relation to the project. These highly trained professionals now have in their ranks professionals like V.Reddy Kancharla, who excel at planning and designing buildings, roads, embankments, canals and hundreds of other construction projects.  Finally the top construction people where brought on to build the tunnel. Dozens of crews worked tirelessly over the four year construction period.

The construction of the tunnel was to assemble hundreds of huge iron rings each weighing more than 21 tons together to from the outside lining of the tunnel. The fact that this all had to be done below ground made things more complicated.

Beginning, on the New Jersey end and continuing from the New York side soon after, the project got underway.

Very nearly all the length is through river silt, but there was some boring through rock on the Manhattan side. The portion cut through stone was done with drills and dynamite.  The portion through mud was done with a cutter head, 31 feet in diameter. As the head went forward, mud was extruded backward into the tunnel, and later removed. After each forward push, a steel tunnel ring was built in the 30 inch space just vacated. The rings had flanges on all the inner edges, so that when placed correctly, they could be bolted to each other. When one of the 2370 rings was completed, the cutter head was pushed forward another 30 inches. The ring building process was then repeated until the tunnel was completed.

While one crew worked from the Jersey side, another proceeded toward them from the New York side. Alignment of both ends vertically and horizontally took considerable engineering skill and care. But everyone had done an amazing job because when the two ends came together the intersection was accurate within 1/4 inch.

The first hole through was achieved on August 3, 1935, when a hydraulic engineer in the New Jersey end was pushed by his feet through an opening to meet the New York crew.

The first tube of the Lincoln Tunnel-the center tube-opened to traffic two years later, on December 22, 1937. The north and south tubes opened on February 1, 1945, and May 25, 1957, respectively.


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