The Channel Tunnel, (French: le tunnel sous la Manche; often nicknamed the Chunnel) is a rail tunnel beneath the English Channel at the Straits of Dover, connecting Cheriton in Kent, England and Sangatte in northern France. A long-standing and hugely expensive project that saw several false starts, it was finally completed in 1994. It is the second longest rail tunnel in the world, second to the Seikan Tunnel in Japan. It is operated by Eurotunnel.
A link between Britain and France had been proposed on many occasions, but it was not until the 20th century that engineers came to believe that the necessary technical ability was available. Various French and British engineers put forward proposals and works on a tunnel were briefly undertaken in 1880 (but soon abandoned due to flooding). The British government was, however, firmly opposed to a link, fearing that it could serve the French as an invasion route. It was not until after World War II that the concept began to receive serious attention.
The current tunnel
In 1957 the Channel Tunnel Study Group was formed. It reported in 1960 and recommended a railway tunnel of two main tunnels and a smaller service tunnel. The project was launched in 1973 but folded due to financial problems in 1975 after the construction of a 250 m test tunnel.
In 1984 the idea was relaunched with a Anglo-French government request for proposals to build a privately funded link. Of the four submissions received the one most closely resembling the 1973 plan was chosen and announced on January 20, 1986. The Fixed Link Treaty was signed by the two governments in Canterbury, Kent on February 12, 1986 and ratified in 1987.
The planned route of the tunnel took it from Calais to Folkestone (a route rather longer than the shortest possible crossing) and the tunnel was to follow a single chalk stratum (which meant the tunnel was deeper than the previous attempt). For much of its route, the tunnel is nearly 40 m under the seafloor, with the southern section being deeper than the northern.
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, a consortium of construction companies. 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 liner. After the British and French TBMs had met near the middle, the French TBM was dismantled while the British one was diverted into the rock and abandoned. Almost 4 million cubic metres of chalk were excavated on the English side, much of which was dumped below Shakespeare Cliff near Folkestone to reclaim 90 acres (360,000 m²) of land from the sea.
The Channel Tunnel consists of three parallel tunnels: two primary rail tunnels, which carry trains north and south, and a smaller access tunnel. This access tunnel (which is served by narrow wheeled vehicles) is interconnected, by means of transverse passages, to the main tunnels at regular intervals. It allows maintenance workers access to the tunnel complex, provides a safe route for escape during emergencies, and dissipates the aerodynamic shockwave that would otherwise accumulate in front of a train travelling through a main tunnel at full speed.
When the two tunnels met 40 m beneath the English Channel seabed on December 1, 1990 (in what was to become one of the "crossover halls" that allow diversion of trains from one main tunnel to the other), it became possible to walk on dry land from Britain to mainland Europe for the first time since the end of the last glaciation, over 13,000 years ago. The British and French efforts, which had been guided by laser surveying methods, met with less than 2 cm of error.
It is 50 km long, of which 39 km are undersea. The average depth is 45 m (150 ft) underneath the seabed. It opened for travel later in 1994 and its rail service carries vehicles as well as passengers. Nearly 7 million passengers take the 35 minute journey through the tunnel every year. At completion, it was estimated that the whole project cost around £10billion.
The tunnel is operated by Eurotunnel plc. Four types of train services operate:
- Eurostar, a high speed passenger service. This connects London's Waterloo station (incidentally, named for the Napoleonic battle between the UK and France) with the Gare du Nord station in Paris and with Brussels Midi/Zuid station, with stops at Ashford, Calais-Frethun and Lille.
- Le Shuttle , which carries cars, coaches and vans across the channel similarly to the ferries: these run from Sangatte (Calais/Coquelles) to Folkestone.
- Freight shuttle trains, which carry lorries on open railcars, with the lorry drivers travelling in separate passenger coaches.
- Freight trains carrying conventional rail freight or container loads.
Although Eurostar trains travel at high speeds in France (where the tracks are modern and custom-made for the standard TGV cruising speed of 300 km/h (186 mph), and within the tunnel at up to 160 km/h (100 mph), their speed in Kent is limited by the relatively low-speed tracks over which they must run. The British government has instituted the Channel Tunnel Rail Link project, a partly government-funded scheme to build a dedicated high-speed line from London to the tunnel entrance. As of late 2003, around half the distance had been completed (the section from north Kent to Cheriton).
There have been proposals for local passenger rail services linking Kent with towns in the Pas de Calais, along the lines of the local trains that run between Zealand and southern Sweden across the Oresund Bridge, but the likelihood of such a service remains very uncertain.
The tunnel has become a popular means by which asylum seekers, hoping that their chances of receiving asylum are better in the UK than in France, illegally enter the UK. A few attempt to walk through the tunnel or to cling to the trains themselves, but most try to hide in freight containers or trucks using the tunnel. In 2002, British immigration authorities added sophisticated listening and imaging equipment to their post in Kent, hoping to hear the heartbeats or sense the breathing of such stowaways. In early 2003 the British government persuaded French authorities to close the controversial center for asylum seekers at Sangatte , which they felt encouraged such clandestine travel. In an unusual move, the British and French governments agreed to provide immigration staff at opposite ends of the tunnel; thus the French immigration control posts are located in England while the British ones are in France.
Appearances in film
Given its status as one of the 20th century's most significant feats of engineering, it is perhaps surprising that the Channel Tunnel has not become more of a cultural icon (although admittedly other "modern wonders of the world" such as the Golden Gate Bridge and Empire State Building are more photogenic).
The Channel Tunnel features in the climax of the film Mission: Impossible (Brian De Palma, 1996), in which Tom Cruise, clinging on to a high-speed train, is chased by a helicopter into what is supposedly the Channel Tunnel. The largely CGI sequence contains many factual errors in addition to the physical impossibility of such a flight. Two of the most significant errors are the apparent use of standard French TGVs in the Channel Tunnel - SNCF passenger trains do not operate in the tunnel - and showing a single rectangular twin-track tunnel. In fact, the Channel Tunnel uses two physically separated single-track tunnels for the two directions of travel. The sequence showing the train going into the Channel Tunnel was reportedly filmed in the Upper Nithsdale valley on the Kilmarnock to Dumfries railway line in Scotland.
- Channel Tunnel History
- Channel Tunnel Facts - a selection of historical and geological facts about the tunnel
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Channel Tunnel Rail Link | Channel Tunnel