how was channel tunnel made?
The long tunnel is 250 metres below sea level.
The Channel Tunnel, the so-called \"tunnel\", is one of the longest tunnels in the world.
There are actually three tunnels.
There are two tracks, and the third is a service channel that is not commonly used by small vehicles.
The idea of building the tunnel was put forward at least a few hundred years before it was built.
Even the construction of the tunnel began at that time, but it was later stopped because of concerns that it was used as a medium to invade the UK.
On 1970, the construction work resumed again and was finally completed on 1994.
The tunnel is fifty kilometers long.
All three were drilled from the rocks under the English Channel.
The construction process began with the excavation of two main tunnels from both sides of the English Channel.
To achieve this spectacular feat of engineering, a total of ten contractors worked at the same time.
Various types of machines are used to drill solid rock under channels.
The diameter of the two main tunnels is 25 feet each and the diameter of the service tunnel is 11 feet.
The boring machine used is a rig that can be chewed and stored by breaking broken rocks and deposits into small pieces.
Most of these exercises are powered exercises that move on a predetermined path.
As the drilling machines dig the rocks forward, they spray high-density concrete on the newly dug tunnel walls to prevent seawater from infiltrating.
The excess rubble in the broken tunnel was sent back to the land and outside the tunnel using a conveyor belt system.
The tunnel is dug in a pre-planned manner of the system and tilted down from both sides.
Service channels also drill in the same way, connecting the two side tunnels once they are fully drilled.
There are fixed railway lines in the tunnels on both sides.
Rail lines are used by Eurostar passenger trains and many freight trains.
Using the tunnel, the train can complete the journey between Britain and France is 20-35 minutes.
The service tunnel in the middle is basically an emergency escape passage that can be used in the event of a fire or other similar accident.
In addition, there are many cross channels in the middle, allowing the train to change the track.
The approximate speed of these trains is hundreds of miles per hour.
The total cost of the tunnel is about $12 billion.
Tunnels can also be used for heavy vehicles, but only through special shuttles.
In addition, air is provided in all three tunnels through a special ventilation system.
On 1996, a major fire broke out in a shuttle and 31 people were trapped.
However, everyone escaped due to specially designed service tunnels.
The Channel Tunnel is the lifeline of Britain and France.
It was one of the most successful engineering feats that was considered almost impossible at first.
However, through the perfect and precise planning of tunnel engineers, as well as the use of incredible civil engineering skills, this impossible task has played a role in the vital connecting medium between the two most important countries in the world.