How was the tunnel under the English Channel built?

Question

It seems like it was quite a feat. Is there more than one?

Answer 1

Digging the tunnel took 15,000 workers over seven years, with tunnelling operations conducted simultaneously from both ends. The prime contractor for the construction was the Anglo-French TransManche Link (TML), a consortium of ten construction companies and five banks of the two countries. Engineers used large tunnel boring machines (TBMs, mobile excavation factories that combined drilling, material removal, and the process of shoring up the soft and permeable tunnel walls with a concrete lining).

In all, eleven TBMs were used on the Channel Tunnel:

three French TBMs driving from Sangatte to under the Channel,
one French TBM driving the service tunnel from Sangatte cofferdam to the French portal,
one French TBM driving one running tunnel from Sangatte cofferdam to the French portal, then the other running tunnel from the French portal back to Sangatte cofferdam,
three British TBMs driving from Shakespeare Cliff to the British portal,
three British TBMs driving from Shakespeare Cliff to under the Channel.
Construction on the service tunnel began on December 1, 1987 from both the UK and French shores, and on December 1, 1990 the service tunnels broke through at the halfway point. TML carefully staged the break through for maximum effect: TML tunnellers Phillipe Cozette and Graham Fagg cut a heading between the two drives under the watchful eye of the media.

The main rail tunnels met on May 22, 1991 and on June 28, 1991, each accompanied by a breakthrough ceremony. When each pair of TBMs met, the French TBM was dismantled while the British one was diverted into the rock, concreted in place, and abandoned.

The next few years were spent refining, equipping, and finishing the tunnels. In 1994 the Channel Tunnel was considered completed.

In the end, almost 5 million cubic yards (4 million m³) of chalk were excavated on the British side, much of which was dumped below Shakespeare Cliff near Folkestone to reclaim 90 acres (0.36 km²) of land from the sea. Called Samphire Hoe, the area is now a popular park. In all, 10.5 million cubic yards (8 million m³) of soil were removed, at an average rate of 2,400 tonnes/hour.

Answer 2

It was doug with a boreing machine. They dig a huge hole, lays some tracks in it, then build a huge boring machine on the tracks. This thing is round - about 20 ft in diameter and has huge cutting bits on the face of it. It spins around counter clockwise (or anti-clockwise for those in the U.K.) and scrapes off the soil and rock. It drops the debris on to a conveyor belt in frint of the bit and the debris is carried out under the machine to train cars that haul it away.

As this thing is turning and digging it is slowly inched forward. As more and more debris is removed, gigantic pre-fab concrete rings an installed behind the machine, thus making the tunnel.

The remarkable thing about the Chunnel (Channel Tunnel) is that they had one of these things at both ends heading towards each other. When they met at the middle they were only a few inches off, left and right of each other. They did this twice - one from France to England, one from England to France.

NYC subways, storm drainage tunnels, the Big Dig in Boston, and many many others are build this way.

Check the link below. Be sure to click on the TBM and SBU links for pics. See how big these things really are.

Answer 3

Digging the tunnel took 15,000 workers over seven years, with tunnelling operations conducted simultaneously from both ends. The prime contractor for the construction was the Anglo-French TransManche Link (TML), a consortium of ten construction companies and five banks of the two countries. Engineers used large tunnel boring machines (TBMs, mobile excavation factories that combined drilling, material removal, and the process of shoring up the soft and permeable tunnel walls with a concrete lining).

In all, eleven TBMs were used on the Channel Tunnel:

three French TBMs driving from Sangatte to under the Channel,
one French TBM driving the service tunnel from Sangatte cofferdam to the French portal,
one French TBM driving one running tunnel from Sangatte cofferdam to the French portal, then the other running tunnel from the French portal back to Sangatte cofferdam,
three British TBMs driving from Shakespeare Cliff to the British portal,
three British TBMs driving from Shakespeare Cliff to under the Channel.
Construction on the service tunnel began on December 1, 1987 from both the UK and French shores, and on December 1, 1990 the service tunnels broke through at the halfway point. TML carefully staged the break through for maximum effect: TML tunnellers Phillipe Cozette and Graham Fagg cut a heading between the two drives under the watchful eye of the media.

The main rail tunnels met on May 22, 1991 and on June 28, 1991, each accompanied by a breakthrough ceremony. When each pair of TBMs met, the French TBM was dismantled while the British one was diverted into the rock, concreted in place, and abandoned.

The next few years were spent refining, equipping, and finishing the tunnels. In 1994 the Channel Tunnel was considered completed.

In the end, almost 5 million cubic yards (4 million m³) of chalk were excavated on the British side, much of which was dumped below Shakespeare Cliff near Folkestone to reclaim 90 acres (0.36 km²) of land from the sea. Called Samphire Hoe, the area is now a popular park. In all, 10.5 million cubic yards (8 million m³) of soil were removed, at an average rate of 2,400 tonnes/hour.

Answer 4

It was digged starting from both sides at the same time, and meeting each other in the mid point.
It is digged under the bottom of the sea ( that means "no water", only rock)
It have 1 tunnel for each direction and 2 more for emergency and service and maintenance.

Answer 5

There are actually three tunnels. 2 rail and one emergency access tunnel in between them. For more info look at this site which gives the complete history.
http://www.theotherside.co.uk/tm-heritage/background/tunnel.htm

Answer 6

It was a boring procedure.

There are three tunnels: one for each direction, plus a service tunnel.

Answer 7

it was built like a channel tunnel,
as for the number, i can not tell you, sorry

Answer 8

A marvel of a civil engineering and hydrography achievement!

Answer 9

by people

Answer 10

With diggers and lots of workmen lol..........