There are seven tunnels. The Fraser Canyon segment of Highway 1 has seven tunnels: Yale, Saddle Rock, Sailor Bar, Alexandra, Hells Gate, Ferrabee, and China Bar. The entire length of the highway in British Columbia features 42 bridges.
The first tunnel on the Fraser River Route was built by the Canadian Pacific Railway (CPR) in 1883-1884 to replace a ferry crossing that had been washed away by floods. The original tunnel is still in use by salmon migrating upriver toward their home streams. The CPR opened more tunnels along its line in BC, including one just north of Vancouver that is now part of the city's public transit system.
Fraser Canyon was named after Sir James Alexander Fraser, who led an expedition up the river in 1824-1825. He documented the native cultures living along the river at the time. In addition to being the first European to see the canyon, Fraser also became the first person to view the Rockies when he reached them from the south in August 1825. He returned the next year with another expedition and helped establish two British settlements in what is now Canada. One of these was located near the present-day town of Fort Langley, which grew around the fort established by Fraser's team.
In truth, the highway only contains three tunnels: the Harvey Tunnel, the Houma Tunnel, and the Belle Chasse Tunnel. However, since these tunnels are part of the interstate system, they must be maintained to a higher standard than other roads in Louisiana.
The Harvey Tunnel is located in Jefferson Parish near the community of Kenner. It has two 12-foot wide lanes for traffic and a center divider wall with green space behind it. The tunnel itself is an elevated structure with no vertical barriers between cars. Wind can blow debris into the roadway, so drivers should watch out for rocks and other objects that could fall from the surrounding area. The tunnel entrance is just north of the Jefferson Parish line with exit ramps leading back into Louisiana down to US 90.
The Houma Tunnel is also located in Jefferson Parish but closer to the town of Houma. The tunnel itself is an underground structure with no vertical barriers between cars. The entrance to the tunnel is just south of the parish line with exits leading back into Louisiana down to US 90.
There are more than two tunnels, but not all of them are open at the same time. The oldest part of the site is a network of mine shafts that were dug between 1580 and 1630 to drain the coal mines below Hill Top. They were later used as air raid shelters during the Second World War.
Today you can walk through these historic tunnels at Kelmarsh Hall and at Hulley's Hole under the grounds of the house. Both sites are very interesting for miners with decades of experience; others may find them frightening!
The main tunnel system at Kelmarsh was built in the early 17th century by the Carters, an important local family who were major landowners at the time. It runs for about 250 meters from near the entrance of Hill Top at the bottom of Church Street down into the hillside beneath the house to reach a point just outside the back door. Here it divides into three branches: one goes left toward the stables and the other two go right toward the cellars and the old gunpowder store.
At first glance, Kelmarsh might seem like a normal country house with its own village close by, but this is not the case.
One is the Eastern Harbour Tunnel, which is part of the Kowloon–Canton Railway. The other two are the North Island and South Island High Speed Rail Lines, which are both light rail systems.
In addition, there are several hundred miles of underground drains and sewers beneath Hong Kong.
The territory's first tunnel, the Tung Choi Wan Tunnel, was opened in 1872. It is located under Victoria Park in the Central district. The second one, the Eastern Harbour Tunnel, was opened in 1979. It connects with the Kowloon–Canton Railway at its West Rail Line terminus at Hung Hom station. The third one, the North Island and South Island High-Speed Rail Lines, began operation in December 2003. It links central Hong Kong with the New Territories town of Sha Tin.
There are also plans to build a fourth tunnel for an extension of the East Rail Line from Kwun Tong to Po Lam. The project is expected to be completed by 2029.
In addition, Hong Kong has more than 500 miles of sewer lines and over 2,000 manholes.
Only two of these tunnels are still accessible by automobile through Gold Camp Road. The third tunnel in this series of nine may be located on the walkable extension of Gold Camp Road, however it is closed owing to the risk of rock falls. There are also some closed mine shafts in this area that may or may not be connected to the main network.
The first two miles of the road between Georgetown and Ouray are paved with brick. The remaining unpaved miles are called "the canyon." They're made up of rocks of all sizes, from small pebbles to large boulders. The trail is generally easy to follow but can be difficult when it's wet. A four-wheel-drive vehicle is recommended for this trip.
There are 107 tunnels. This is one of the highest numbers per length of track among all major European rail networks.
The average depth is 12.5 m (41 ft), with a maximum depth of 42 m (137 ft). The deepest portion of the tunnel is 33 m (108 ft) long.
Tunnels were originally built without electricity or air conditioning, so they needed to be ventilated. This was usually done by opening sluices at the end of each tunnel section, allowing fresh air into the tunnel and discharging stale air out of it. These sluices could only be opened from both ends; that is why long tunnels required multiple sections which could be joined together only at certain intervals. The total number of joined sections determines the length of a single tunnel. For example, the Simla Tunnel is made up of eight sections which are joined together.
There are some portions of the tunnel where you can see stars through the window! The first section of the tunnel is under the North Indian city of Shimla, above which lies the Himalayan mountain range.
Tunnels that are lengthy According to best estimates, there are over 600 derelict railway tunnels in the United Kingdom, some of which are outstanding buildings. The majority of these were built for the main line railways which ceased to use them from around 1960. A few small branches and cross-overs still use a few of these tunnels but they are now used by freight trains only.
The number of abandoned mines is unknown but probably exceeds that of the tunnels. There are known coal and metal mines, as well as an iron mine. An aerial tunnel flyover was planned for the M6 motorway but this was rejected by the government in 2002 because it would have destroyed important habitat. Instead, a road tunnel was constructed next to it. This is called the Welsh Backbone Route and runs between South Wales and Northern England. It uses the same tunnelling technique as the M6 but instead of driving into the rock face, the walls are built up inside the tunnel.
The number of tunnels beneath roads is also high. These include gas pipes, water mains, and sewer lines. Some are large enough to drive through but most are too small. They are usually no more than two feet wide.
Finally, there are also numerous smaller footpath or cycle tunnels.