How Was the Holland Tunnel Built?

The Holland Tunnel was built (1920-1924) by pneumatically pushing cylindrical shields through the river bottom. The shields not only dug through mud but also served as the shell beneath which the actual tunnel walls (built of iron rings filled with concrete) were constructed. Two shields were used—one began on the New York shore and the other on the New Jersey shore. They met in October 1924.

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Creative: Tronvig Group