An undersea tunnel
is a tunnel
which is partly or wholly constructed under a body of water. They are often used where building a bridge or operating a ferry link is impossible, or to provide competition (or relief) for existing bridges or ferry links. There are many reasons for building an undersea tunnel as opposed to the construction of a bridge or establishment of a ferry link.Sullivan, Walter. , New York Times
, June 24, 1986. Retrieved 15 August 2010.
Compared to bridges
One such advantage would be that a tunnel would still allow shipping to pass. A low bridge would need to be an opening or swing bridge to allow shipping to pass, which can cause traffic congestion. Conversely, a higher bridge that does allow shipping may be unsightly and opposed by the public. Bridges can also be closed due to harsh weather such as high winds. Another possible advantage is space: the downward ramp leading to a tunnel leaves a smaller footprint compared to the upward ramps required by most bridges.
Tunneling will generate soil that has been excavated and this can be used to create new land, as was done with the soil of the Channel Tunnel
- Further information: Tunnel –Choice of tunnels vs. bridges
Compared to ferry links
As with bridges, albeit with more chance, ferry links will also be closed during adverse weather. Strong winds, or the tidal limits may also affect the... Read More