Tunnel hole-through, also called breakthrough, is the time, during the construction of a tunnel built from both ends, when the ends meet,
and the accuracy of the survey work becomes evident. Many tunnels report breakthroughs with an error of only a few inches, for example:
* the 1858
Blue Ridge Tunnel
The Blue Ridge Tunnel (also known as the Crozet Tunnel) is a historic railroad tunnel built during the construction of the Blue Ridge Railroad in the 1850s. The tunnel was the westernmost and longest of four tunnels engineered by Claudius Croz ...
–
* the 1944
Blue Ridge Tunnel
The Blue Ridge Tunnel (also known as the Crozet Tunnel) is a historic railroad tunnel built during the construction of the Blue Ridge Railroad in the 1850s. The tunnel was the westernmost and longest of four tunnels engineered by Claudius Croz ...
replacement – - 1944
* the
Lötschberg Base Tunnel
The Lötschberg Base Tunnel (LBT) is a railway base tunnel on the BLS AG's Lötschberg line cutting through the Bernese Alps of Switzerland some below the older Lötschberg Tunnel. It runs between Frutigen, Bern, and Raron, Valais.
T ...
– 10 cm
*the
Holland Tunnel
The Holland Tunnel is a vehicular tunnel under the Hudson River that connects Hudson Square and Lower Manhattan in New York City in the east to Jersey City, New Jersey, in the west. The tunnel is operated by the Port Authority of New York an ...
- 1 cm
See also
*
Cascade Tunnel
The Cascade Tunnel refers to two railroad tunnels, its original tunnel and its replacement, in the northwest United States, east of the Seattle metropolitan area in the Cascade Range of Washington, at Stevens Pass. It is approximately east of ...
*
Siloam inscription
References
External links
*
Gautrain tunnel breakthrough*
*
*
- 10 cm
Tunnel construction
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