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 Crozet ...
–
* 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 Crozet ...
replacement – - 1944
* the
Lötschberg Base Tunnel
, line = Lötschberg Line
, location = Traversing the Bernese Alps in Switzerland
, coordinates = –
, system = BLS, SBB CFF FFS
, status =
, start = Frutigen, canton of Bern,
, end = Raro ...
– 10 cm
*the
Holland Tunnel
The Holland Tunnel is a vehicular tunnel under the Hudson River that connects the New York City neighborhood of Hudson Square in Lower Manhattan to the east with Jersey City in New Jersey to the west. The tunnel is operated by the Port Author ...
- 1 cm
See also
*
Cascade Tunnel
The Cascade Tunnel refers to two railroad tunnels (original 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 Everett, wit ...
References
External links
*
Gautrain tunnel breakthrough*
*
*
- 10 cm
Tunnel construction
{{Rail-transport-stub