4. The First East River Tunnel Was Built in 1892
Photograph of the metal lined section of the tunnel. From “A General Report Upon the Initiation and Construction of the Tunnel Under the East River. In Public Domain.
We take tunnels for granted these days, but prior to the 20th century, only one tunnel existed; a small tube built in 1892 by the East River Gas Company to supply gas to Manhattan, which is still in use today. As the first company to ever attempt such an engineering feat, it needed to know what type of material they would be tunneling through as they crossed under the East River from East 71st Street to Ravenswood in Long Island City.
Since the East River reverses its flow between ebb and flood tides, the engineers would only have about 15 minutes of “still water” between the tides to drill holes into the floor of the river to get the information they needed. Ultimately, they calculated that the tunnel would need to be 111 feet below the surface of the river. To be precise, it would be 135 feet below the surface on the Manhattan end and 147 feet below on the Long Island City end.
Construction progressed from each end of the tunnel simultaneously; when the two headings finally joined together underground, the shaft centerlines were within ½ inch in each direction and less than two inches difference in depth, an engineering feat that’s still marveled today for its burrowing accuracy without modern-day computers and GPS.
One hundred and twenty years later, the tunnel is still very much utilized. It currently carries two gas supply pipelines, a fuel oil pipeline, a steam distribution pipeline, multiple electric feeders, and several telecommunication cables.
Read more about the first East River tunnel here.