The Channel Tunnel, (French: le tunnel sous la Manche; popularly nicknamed the Chunnel in English) is a 50-km-long (~31 imperial miles) rail tunnel beneath the English Channel at the Straits of Dover, connecting Cheriton in Kent, United Kingdom, and Coquelles near Calais 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, surpassed only by the Seikan Tunnel in Japan. It is operated by Eurotunnel plc.
Historical attempts or proposals for a tunnel
A link between Great Britain and France had been proposed on many occasions.
- 1802 Albert Matthieu-Favier, a French engineer, put forward a proposal for a tunnel. Passengers would travel through the tunnel in horse-drawn coaches; the road would be lit by oil-lamps; and a mid-tunnel island would have provided a fresh-air respite for the horses. The cost would have been one million pounds even then.
- 1875 Peter Barlow, builder of London's first Underground railway, suggested a floating steel tube across the Channel. The idea was rejected.
- French & British Parliamentary bills passed to build the tunnel. Insufficient funds raised and the concession ran out a year later.
- 1876 Extensive geological survey carried out; French sink two shafts.
- 1880 The South Eastern Railway (SER) arranges trial borings on the British side.
- 1881 Patented (Beaumont) boring machine drives a tunnel 897 yards (820 m) parallel to cliffs on the British side.
- Work begins by (SER) on Channel Tunnel; again insufficient funds. Submarine Continental Railway Company set up.
- 1882 Rival Channel Tunnel Company causes a rift in proceedings; adverse comments by media and an influential group (including Robert Browning and Alfred Lord Tennyson). Eventually work was halted by the Board of Trade because of military objections: the ease with which invaders could attack from the Continent was cited.
- 1922 Workers started boring a tunnel from Folkestone: after 400 ft (128 m) of tunnel had been completed, political objections again brought the project to an end.
The current tunnel
In 1957 le Tunnel sous la Manche Study Group was formed. It reported in 1960 and recommended two main railway 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 joint British and 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 20 January 1986. The Fixed Link Treaty was signed by the two governments in Canterbury, Kent on 12 February 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 (130 ft) 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 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 liner. After the British and French TBMs met near the middle, the French TBM was dismantled while the British one was diverted into the rock and abandoned. Almost 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 (360,000 m²) of land from the sea. In all, 8 million m³ of spoil were removed, at an average rate of 2400 tonnes/hour.
The Channel Tunnel consists of three parallel tunnels: two primary rail tunnels, which carry trains north and south, and a smaller access tunnel. The access tunnel, served by narrow rubber-tyred vehicles, is connected by transverse passages to the main tunnels at regular intervals. It allows maintenance workers access to the tunnels and provides a safe route for escape during emergencies.
The British and French efforts, which had been guided by laser surveying methods, met with less than 20 mm of error. When the two tunnels met 40 m beneath the English Channel seabed on 1 December 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 Great Britain to mainland Europe for the first time since the end of the last ice age 8,500 years ago. The tunnel was officially opened by Queen Elizabeth II and French President François Mitterrand in a ceremony held in Calais on 6 May 1994.
The Channel Tunnel is 50 km (31 miles) long, of which 39 km (24 miles) are undersea. The average depth is 45 m (150 ft) underneath the seabed. It opened for business in late 1994, offering two principal services: a shuttle run for vehicles, and Eurostar passenger service linking London with Paris and Brussels.
In 2004, 7,276,675 passengers travelled through the tunnel on Eurostar while in the same year Eurotunnel carried 2,101,323 cars, 1,281,207 trucks, and 63,467 coaches on its shuttle trains.
Rail freight carried through the Channel Tunnel increased by 8% to 1,889,175 t in 2004.
A journey through the tunnel lasts about 20 minutes; from start to end, including a large loop to turn the train round, a shuttle train journey totals about 35 minutes. Eurostar trains travel considerably more slowly than their top speed while going through the tunnel, in part to fit in with the shuttle trains.
At completion, it was estimated that the whole project cost around £10 billion.
The tunnel is operated by Eurotunnel plc.
Four types of train services operate:
- Eurostar, high speed passenger trains. These connect London's Waterloo station (named for the Napoleonic battle between the UK and France) with the Gare du Nord station in Paris and Brussels Midi/Zuid station, with stops at Ashford, Calais-Frethun and Lille. Eurostar services will switch from Waterloo to St Pancras railway station when the new Channel Tunnel Rail Link railway line is completed between the tunnel and London in 2007.
- Eurotunnel Shuttle, passenger shuttle trains. These carry cars, coaches and vans between Sangatte (Calais/Coquelles) and Folkestone. Enclosed rail wagons with minor amenities, some double-deck, permit drive-on and drive-off operation; passengers stay with their vehicle. Formerly marketed as Le Shuttle.
- Eurotunnel freight shuttle trains. These carry lorries on open rail wagons, with the lorry drivers travelling in separate passenger coaches.
- Rail freight trains. These trains carry conventional rail freight or container loads between Europe and Britain.
Eurostar trains travel at high speeds in France and upon the Channel Tunnel Rail Link, 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). The first section of the Channel Tunnel Rail Link, between the tunnel & Ebbsfleet in North Kent, opened in 2003. Until the second section between Ebbsfleet and St Pancras opens in 2007 Eurostar trains use 'traditional' lines for the final part of the journey into Waterloo, running at much lower speeds.
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 such a service remains unlikely.
The Channel Tunnel's only serious operational incident was the 18 November 1996 fire aboard a shuttle train carrying trucks and trailers. With rescue crews already alerted, the Folkestone-bound train came to an emergency stop halfway through the tunnel. Amid acrid smoke, truck drivers were evacuated to a train headed the other way. Fire crews managed to extinguish the superheated fire in a number of hours, battling low water pressure, high-velocity wind from the emergency actions of the ventilation fans, and intense heat. 650 ft (200 m)0 of the tunnel lining was seriously damaged, and another 650 ft was significantly damaged. In some areas the concrete liner was thinned due to spalling from the heat to only 50 mm of its original 450 mm thickness. The rear wagons and rear locomotive of the train were destroyed. No lives were lost, due in large part to the safety of the tunnel design and the response of safety crews from France and the UK.
The tunnel was re-opened for limited use on 21 November 1996, only three days after the fire. With only one main tunnel in operation, safety rules prohibited passenger services from using the tunnel. Freight services operated in half-duplex fashion until the tunnel was repaired. Passenger services resumed on 4 December 1996, and full service was restored on 6 January 1997.
The tunnel's operators faced criticism for mishandling the incident. The train had been observed to be on fire when entering the tunnel, and much of the incident's complexity could have been avoided if the train had stayed above ground. Once it was decided to have the train proceed to Folkestone, much of the trouble could again have been avoided if this plan had been completed, but the train driver decided to stop in the tunnel due to concern about a possible derailment. There were also miscommunications in the fire-fighting response. 
As one of the first international rail tunnels, the Channel Tunnel required an inventive approach to border controls. The official border between France and the United Kingdom is a painted line roughly halfway through the tunnel (there is more tunnel on the UK side). The British half is part of the District of Dover and the English county of Kent. As a practical matter border controls are handled at boarding or on the train. A detailed three-way treaty between the United Kingdom, France, and Belgium governs border controls, with the establishment of control zones wherein the officers of the other nation may exercise limited customs and law enforcement powers. For most purposes these are at either end of the tunnel; for certain city-to-city trains the train itself represents a control zone.
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 the United Kingdom, while the British ones are in France.
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, enter the UK. A few attempt to walk through the tunnel or to cling to the trains, 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 the French authorities to close the controversial centre for asylum seekers at Sangatte, which they felt encouraged such clandestine travel, and to surround the portal with fearsome barbed-wire fencing.
Eurotunnel, the company who built and funded the project, and currently run the 'Le Shuttle' services, have been in financial difficulties almost from the start. Attempts at remedying the problems have included cutting the number of trains per hour on a normal day from four to two, reducing staff and streamlining the business.
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 feat. In the film the tunnel is shown as a single rectangular twin-track tunnel, and the trains shown are standard French TGVs but without overhead wires. In reality the Channel Tunnel uses two separate single-track tunnels for the two directions of travel, while SNCF passenger trains do not operate in the tunnel. The sequence showing the train going into the tunnel was reportedly filmed in the Upper Nithsdale valley on the Kilmarnock to Dumfries railway line in Scotland.
- Information on both le shuttle and Eurostar
- Channel Tunnel History
- Channel Tunnel Facts - a selection of historical and geological facts about the tunnel
- Channel Tunnel Fire - detailed technical summary of the emergency response
- Engineering specifications
- Another page with history of Channel Tunnel
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