• Undersea Tunnel Channel Tunnel, 1994
  

The tunnel carries high-speed Eurostar passenger trains, Eurotunnel Shuttle roll - on / roll - off vehicle transport — the largest in the world — and international rail freight trains. The tunnel connects end - to - end with the LGV Nord and High Speed 1 high speed railway lines.

Ideas for a cross Channel fixed link appeared as early as 1802, but British political and press pressure over compromised national security stalled attempts to construct a tunnel. The eventual successful project, organized by Eurotunnel, began construction in 1988 and opened in 1994. The project came in 80% over its predicted budget. Since its construction, the tunnel has faced several problems. Fires have disrupted operation of the tunnel. Illegal immigrants and asylum seekers have attempted to use the tunnel to enter the UK, causing a minor diplomatic disagreement over the siting of the Sangatte refugee camp, which was eventually closed in 2002.

In 1802, French mining engineer Albert Mathieu put forward a proposal to tunnel under the English Channel, with illumination from oil lamps, horse drawn coaches, and an artificial island mid Channel for changing horses.

In the 1830s, Frenchman Aimé Thomé de Gamond performed the first geological and hydrographical surveys on the Channel, between Calais and Dover. Thomé de Gamond explored several schemes and, in 1856, he presented a proposal to Napoleon III for a mined railway tunnel from Cap Gris - Nez to Eastwater Point with a port / airshaft on the Varne sandbank at a cost of 170 million francs, or less than £7 million.

In 1865, a deputation led by George Ward Hunt proposed the idea of a tunnel to the Chancellor of the Exchequer of the day, William Ewart Gladstone.

After 1867, William Low and Sir John Clarke Hawkshaw promoted ideas, but none were implemented. An official Anglo - French protocol was established in 1876 for a cross - Channel railway tunnel. In 1881, British railway entrepreneur Sir Edward Watkin and French Suez Canal contractor Alexandre Lavalley were in the Anglo - French Submarine Railway Company that conducted exploratory work on both sides of the Channel. On the English side a 2.13-meter (7 ft) diameter Beaumont - English boring machine dug a 1,893 - meter (6,211 ft) pilot tunnel from Shakespeare Cliff. On the French side, a similar machine dug 1,669 m (5,476 ft) from Sangatte. The project was abandoned in May 1882, owing to British political and press campaigns advocating that a tunnel would compromise Britain's national defenses. These early works were encountered more than a century later during the TML project.

In 1919, during the Paris Peace Conference, British Prime Minister David Lloyd George repeatedly brought up the idea of a Channel tunnel as a way of reassuring France about British willingness to defend against another German attack. The French did not take the idea seriously and nothing came of Lloyd George's proposal.

In 1929 there was another proposal for the building of a channel tunnel, but nothing came of this discussion and the idea was shelved. Proponents estimated construction to be about US$150 million. The engineers had addressed the concerns of both nations' military leaders by designing two sumps — one near the coast of each country — that could be flooded at will to block the tunnel. This design feature did not override the concerns of both nations' military leaders, and other concerns about hordes of undesirable tourists who would disrupt English habits of living. Military fears continued during World War II. After the fall of France, as Britain prepared for an expected German invasion, a Royal Navy officer in the Directorate of Miscellaneous Weapons Development calculated that Hitler could use slave labor to build two Channel tunnels in 18 months. The estimate caused rumors that Germany had already begun digging.

In 1955, defense arguments were accepted to be irrelevant because of the dominance of air power; thus, both the British and French governments supported technical and geological surveys. A detailed geological survey was carried out in 1964-65. Construction work commenced on both sides of the Channel in 1974, a government funded project using twin tunnels on either side of a service tunnel, with capability for car shuttle wagons. In January 1975, to the dismay of the French partners, the British government cancelled the project. The government had changed to the Labour Party and there was uncertainty about EEC membership, cost estimates had ballooned to 200% and the national economy was troubled. By this time the British tunnel boring machine was ready and the Ministry of Transport was able to do a 300 m (980 ft) experimental drive. This short tunnel was reused as the starting and access point for tunneling operations from the British side.

In 1979, the "Mouse - hole Project" was suggested when the Conservatives came to power in Britain. The concept was a single - track rail tunnel with a service tunnel, but without shuttle terminals. The British government took no interest in funding the project, but Prime Minister Margaret Thatcher said she had no objection to a privately funded project. In 1981 British and French leaders Margaret Thatcher and François Mitterrand agreed to set up a working group to look into a privately funded project, and in April 1985 promoters were formally invited to submit scheme proposals. Four submissions were shortlisted:

• A rail proposal based on the 1975 scheme presented by Channel Tunnel Group / France – Manche (CTG / F–M);
• Eurobridge: a 4.5 km (2.8 mi) span suspension bridge with a roadway in an enclosed tube;
• Euroroute: a 21 km (13 mi) tunnel between artificial islands approached by bridges; and
• Channel Expressway: large diameter road tunnels with mid - channel ventilation towers.

The cross Channel ferry industry protested under the name "Flexilink". In 1975 there was no campaign protesting against a fixed link, with one of the largest ferry operators (Sealink) being state owned. Flexilink continued rousing opposition throughout 1986 and 1987. Public opinion strongly favored a drive - through tunnel, but ventilation issues, concerns about accident management, and fear of driver mesmerization led to the only shortlisted rail submission, CTG / F-M, being awarded the project.

The British Channel Tunnel Group consisted of two banks and five construction companies, while their French counterparts, France – Manche, consisted of three banks and five construction companies. The role of the banks was to advise on financing and secure loan commitments. On 2 July 1985, the groups formed Channel Tunnel Group / France – Manche (CTG / F–M). Their submission to the British and French governments was drawn from the 1975 project, including 11 volumes and a substantial environmental impact statement.

The design and construction was done by the ten construction companies in the CTG / F-M group. The French terminal and boring from Sangatte was undertaken by the five French construction companies in the joint venture group GIE Transmanche Construction. The English Terminal and boring from Shakespeare Cliff was undertaken by the five British construction companies in the Translink Joint Venture. The two partnerships were linked by TransManche Link (TML), a bi-national project organization. The Maître d'Oeuvre was a supervisory engineering body employed by Eurotunnel under the terms of the concession that monitored project activity and reported back to the governments and banks.

In France, with its long tradition of infrastructure investment, the project garnered widespread approval. In April the French National Assembly gave unanimous support and, in June 1987, after a public inquiry, the Senate gave unanimous support. In Britain, select committees examined the proposal, making history by holding hearings outside of Westminster, in Kent. In February 1987, the third reading of the Channel Tunnel Bill took place in the House of Commons, and was carried by 94 votes to 22. The Channel Tunnel Act gained Royal assent and passed into English law in July. Parliamentary support for the project came partly from provincial members of Parliament on the basis of promises of regional Eurostar through train services that have never materialized; the promises were repeated in 1996 when the contract for construction of the Channel Tunnel Rail Link was awarded.

The Channel Tunnel is a build - own - operate - transfer (BOOT) project with a concession. TML would design and build the tunnel, but financing was through a separate legal entity: Eurotunnel. Eurotunnel absorbed CTG / F-M and signed a construction contract with TML; however, the British and French governments controlled final engineering and safety decisions, which are now in the hands of the Channel Tunnel Safety Authority. The British and French governments gave Eurotunnel a 55- (later 65-) year operating concession to repay loans and pay dividends. A Railway Usage Agreement was signed between Eurotunnel, British Rail and the Société Nationale des Chemins de fer Français guaranteeing future revenue in exchange for the railways obtaining half of the tunnel's capacity.

Private funding for such a complex infrastructure project was of unprecedented scale. An initial equity of £45 million was raised by CTG / F-M, increased by £206 million private institutional placement, £770 million was raised in a public share offer that included press and television advertisements, a syndicated bank loan and letter of credit arranged £5 billion. Privately financed, the total investment costs at 1985 prices were £2600 million. At the 1994 completion actual costs were, in 1985 prices, £4650 million: an 80% cost overrun. The cost overrun was partly due to enhanced safety, security, and environmental demands. Financing costs were 140% higher than forecast.

Working from both the English side and the French side of the Channel, eleven tunnel boring machines cut through chalk marl to construct two rail tunnels and a service tunnel. The vehicle shuttle terminals are at Cheriton (part of Folkestone) and Coquelles, and are connected to the English and French motorways (M20 and A16 respectively).

Tunneling commenced in 1988, and the tunnel began operating in 1994. In 1985 prices, the total construction cost was £4.650 billion (equivalent to £11 billion today), an 80% cost overrun. At the peak of construction 15,000 people were employed with daily expenditure over £3 million. Ten workers, eight of them British, were killed during construction between 1987 and 1993, most in the first few months of boring.

A small, two inch (50 mm) diameter pilot hole allowed the service tunnel to break through without ceremony on 30 October 1990. On 1 December 1990, Englishman Graham Fagg and Frenchman Phillippe Cozette broke through the service tunnel with the media watching. Eurotunnel completed the tunnel on time, and the tunnel was officially opened one year later than originally planned by British Queen Elizabeth II and French President François Mitterrand in a ceremony held in Calais on 6 May 1994. The Queen traveled through the tunnel to Calais on a Eurostar train, which stopped nose to nose with the train that carried President Mitterrand from Paris. Following the ceremony President Mitterrand and the Queen traveled on Le Shuttle to a similar ceremony in Folkestone. A full public service did not start for several months.

The Channel Tunnel Rail Link (CTRL), now called High Speed 1, runs 69 miles (111 km) from St Pancras railway station in London to the Channel Tunnel portal at Folkestone in Kent. It cost £5.8 billion. On 16 September 2003 UK Prime Minister Tony Blair opened the first section of High Speed 1, from Folkestone to north Kent. On 6 November 2007 the Queen officially opened High Speed 1 and St Pancras International station, replacing the original slower link to Waterloo International railway station. On High Speed 1 trains traveling at speeds up to 300 km/h (186 mph), the journey from London to Paris takes 2 hours 15 minutes and London to Brussels takes 1 hour 51 minutes.

In 1994, the American Society of Civil Engineers elected the Channel Tunnel as one of the seven modern Wonders of the World. In 1995, the American magazine Popular Mechanics published the results.

Surveying undertaken in the twenty years before tunnel construction confirmed earlier speculations that a tunnel route could be bored through a chalk marl stratum. The chalk marl was conducive to tunneling, with impermeability, ease of excavation and strength. While on the English side the chalk marl ran along the entire length of the tunnel, on the French side a length of 5 kilometers (3 mi) had variable and difficult geology. The Channel Tunnel consists of three bores: two 7.6-metre (25 ft) diameter rail tunnels, 30 meters (98 ft) apart, 50 kilometers (31 mi) in length with a 4.8-meter (16 ft) diameter service tunnel in between. There are also cross passages and piston relief ducts. The service tunnel was used as a pilot tunnel, boring ahead of the main tunnels to determine the conditions. English access was provided at Shakespeare Cliff, while French access came from a shaft at Sangatte. The French side used five tunnel boring machines (TBMs); the English side used six. The service tunnel uses Service Tunnel Transport System (STTS) and Light Service Tunnel Vehicles (LADOGS). Fire safety was a critical design issue.

Between the portals at Beussingue and Castle Hill the tunnel is 50.5 kilometers (31 mi) long, with 3.3 kilometers (2 mi) under land on the French side, 9.3 kilometers (6 mi) under land on the UK side and 37.9 kilometers (24 mi) under sea. This makes the Channel Tunnel the second longest rail tunnel in the world, behind the Seikan Tunnel in Japan, but with the longest under - sea section. The average depth is 45 meters (148 ft) below the seabed. On the UK side, of the expected 5 million cubic meters (6.5×10⁶ cu yd) of spoil approximately 1 million cubic meters (1.3×10⁶ cu yd) was used for fill at the terminal site, and the remainder was deposited at Lower Shakespeare Cliff behind a seawall, reclaiming 74 acres (30 ha) of land. This land was then made into the Samphire Hoe Country Park. Environmental impact assessment did not identify any major risks for the project, and further studies into safety, noise, and air pollution were overall positive. However, environmental objections were raised over a high speed link to London.

Successful tunneling under the channel required a sound understanding of the topography and geology and the selection of the best rock strata through which to tunnel. The geology generally consists of northeasterly dipping Cretaceous strata, part of the northern limb of the Wealden - Boulonnais dome. Characteristics include:

• Continuous chalk on the cliffs on either side of the Channel containing no major faulting, as observed by Verstegan in 1698
• Four geological strata, marine sediments laid down 90-100 million years ago; pervious upper and middle chalk above slightly pervious lower chalk and finally impermeable Gault Clay. A sandy stratum, glauconitic marl (tortia), is in between the chalk marl and gault clay
• A 25-30-meter (82-98 ft) layer of chalk marl (French: craie bleue) in the lower third of the lower chalk appeared to present the best tunneling medium. The chalk has a clay content of 30-40% providing impermeability to groundwater yet relatively easy excavation with strength allowing minimal support. Ideally the tunnel would be bored in the bottom 15 meters (49 ft) of the chalk marl, allowing water inflow from fractures and joints to be minimized, but above the gault clay that would increase stress on the tunnel lining and swell and soften when wet.

On the English side of the channel, the strata dip less than 5°, however, on the French side, this increases to 20°. Jointing and faulting is present on both the English and French sides. On the English side, only minor faults of displacement less than 2 meters (7 ft) exist. On the French side, displacements of up to 15 meters (49 ft) are present owing to the Quenocs anticlinal fold. The faults are of limited width, filled with calcite, pyrite and remolded clay. The increased dip and faulting restricted the selection of route on the French side. To avoid confusion, micro-fossil assemblages were used to classify the chalk marl. On the French side, particularly near the coast, the chalk was harder, and more brittle, and more fractured than on the English side. This led to the adoption of different tunneling techniques on the French and English sides.

The Quaternary undersea valley Fosse Dangaered, and Castle Hill landslip, located at the English portal, caused concerns. Identified by the 1964-65 geophysical survey, the Fosse Dangaered is an infilled valley system extending 80 meters (262 ft) below the seabed, 500 meters (1,640 ft) south of the tunnel route, located mid-channel. A 1986 survey showed that a tributary crossed the path of the tunnel, and so the tunnel route was made as far north and deep as possible. The English terminal had to be located in the Castle Hill landslip, which consists of displaced and tipping blocks of lower chalk, glauconitic marl and gault debris. Thus the area was stabilized by buttressing and inserting drainage adits. The service tunnels were pilot tunnels preceding the main tunnels, so that the geology, areas of crushed rock, and zones of high water inflow could be predicted. Exploratory probing took place in the service tunnels, in the form of extensive forward probing, vertical downward probes and sideways probing.

Marine soundings and samplings by Thomé de Gamond were carried out during 1833-1867, establishing the seabed depth at a maximum of 55 meters (180 ft) and the continuity of geological strata (layers). Surveying continued over many years, with 166 marine and 70 land-deep boreholes being drilled and over 4,000 - line - kilometers of marine geophysical survey completed. Surveys were undertaken in 1958-1959, 1964-1965, 1972-1974 and 1986-1988.

The surveying in 1958-1959 catered for immersed tube and bridge designs as well as a bored tunnel, and thus a wide area was investigated. At this time marine geophysics surveying for engineering projects was in its infancy, with poor positioning and resolution from seismic profiling. The 1964-1965 surveys concentrated on a northerly route that left the English coast at Dover harbor; using 70 boreholes, an area of deeply weathered rock with high permeability was located just south of Dover harbor.

Given the previous survey results and access constraints, a more southerly route was investigated in the 1972-1973 survey and the route was confirmed to be feasible. Information for the tunneling project also came from work before the 1975 cancellation. On the French side at Sangatte a deep shaft with adits was made. On the English side at Shakespeare Cliff, the government allowed 250 meters (820 ft) of 4.5-meter (15 ft) diameter tunnel to be driven. The actual tunnel alignment, method of excavation and support were essentially the same as the 1975 attempt. In the 1986-1997 survey, previous findings were reinforced and the nature of the gault clay and the tunneling medium (chalk marl that made up 85% of the route) were investigated. Geophysical techniques from the oil industry were employed.

Tunneling between England and France was a major engineering challenge, with the only precedent being the undersea Seikan Tunnel in Japan. A serious risk with underwater tunnels is major water inflow due to the water pressure from the sea above under weak ground conditions. The Channel Tunnel also had the challenge of time - being privately funded, early financial return was paramount.

The objective was to construct: two 7.6-meter (25 ft) diameter rail tunnels, 30 meters (98 ft) apart, 50 kilometers (31 mi) in length; a 4.8-meter (16 ft) diameter service tunnel between the two main tunnels; pairs of 3.3-meter (11 ft) diameter cross - passages linking the rail tunnels to the service tunnel at 375-meter (1,230 ft) spacing; piston relief ducts 2-meter (7 ft) diameter connecting the rail tunnels at 250-meter (820 ft) spacing; two undersea crossover caverns to connect the rail tunnels. The service tunnel always preceded the main tunnels by at least 1 kilometer (0.6 mi) to ascertain the ground conditions. There was plenty of experience with tunneling through chalk in the mining industry. The undersea crossover caverns were a complex engineering problem. The French cavern was based on the Mount Baker Ridge freeway tunnel in the US. The UK cavern was dug from the service tunnel ahead of the main tunnels to avoid delay.

Precast segmental linings in the main TBM drives were used, but different solutions were used on the English and French sides. On the French side, neoprene and grout sealed bolted linings made of cast iron or high strength reinforced concrete were used. On the English side, the main requirement was for speed and bolting of cast iron lining segments was only carried out in areas of poor geology. In the UK rail tunnels, eight lining segments plus a key segment were used; on the French side, five segments plus a key segment. On the French side, a 55-meter (180 ft) diameter 75-meter (246 ft) deep grout-curtained shaft at Sangatte was used for access. On the English side, a marshaling area was 140 meters (459 ft) below the top of Shakespeare Cliff, and the New Austrian Tunneling method (NATM) was first applied in the chalk marl here. On the English side, the land tunnels were driven from Shakespeare Cliff, the same place as the marine tunnels, not from Folkestone. The platform at the base of the cliff was not large enough for all of the drives and, despite environmental objections, tunnel spoil was placed behind a reinforced concrete seawall, on condition of placing the chalk in an enclosed lagoon to avoid wide dispersal of chalk fines. Owing to limited space, the precast lining factory was on the Isle of Grain in the Thames estuary.

On the French side, owing to the greater permeability to water, earth pressure balance TBMs with open and closed modes were used. The TBMs were of a closed nature during the initial 5 kilometers (3 mi), but then operated as open, boring through the chalk marl stratum. This minimized the impact to the ground and allowed high water pressures to be withstood, and it also alleviated the need to grout ahead of the tunnel. The French effort required five TBMs: two main marine machines, one main land machine (the short land drives of 3 km allowed one TBM to complete the first drive then reverse direction and complete the other), and two service tunnel machines. On the English side, the simpler geology allowed faster open - faced TBMs. Six machines were used, all commenced digging from Shakespeare Cliff, three marine - bound and three for the land tunnels. Towards the completion of the undersea drives, the UK TBMs were driven steeply downwards and buried clear of the tunnel. These buried TBMs were then used to provide an electrical earth. The French TBMs then completed the tunnel and were dismantled. A 900 mm gauge railway was used on the English side during construction.

In contrast to the English machines, which were simply given alphanumeric names, the French tunneling machines were all named after women: Brigitte, Europa, Catherine, Virginie, Pascaline, Séverine.

There are three communication systems in the tunnel: concession radio (CR) for mobile vehicles and personnel within Eurotunnel's Concession (terminals, tunnels, coastal shafts); track - to - train radio (TTR) for secure speech and data between trains and the railway control center; Shuttle internal radio (SIR) for communication between shuttle crew and to passengers over car radios. This service was discontinued within one year of opening because of drivers difficulty setting their radios to the correct frequency (88.8 MHz).

All tunnel services run on electricity, shared equally from English and French sources. Power is delivered to the locomotives via an overhead line (catenary) at 25 kV 50 Hz.

A large proportion of the railway south of London uses a 750 V DC third rail to deliver electrical power, but since the opening of High Speed 1 there is no need to use the third rail system for any part of the Eurostar journey. High Speed 1, the tunnel itself and the route to Paris has power provided via overhead catenary at 25 kV 50 Hz. The railways on "classic" lines in Belgium are also electrified by overhead catenaries, but at 3000 V DC.

A cab signalling system is used that gives information directly to train drivers on a display. There is Automatic Train Protection (ATP) that stops the train if the speed differs from that indicated on the in-cab display. TVM430, as used on LGV Nord, is used in the tunnel. The TVM signalling is interconnected with the signalling on the high - speed lines either side, allowing trains to enter and exit the tunnel system without stopping. The maximum allowed speed is 160 km/h.

The American Sonneville International Corporation track system was chosen, consisting of UIC60 rails on 900A grade resting on microcellular EVA pads, bolted into concrete. The Channel Tunnel network and terminal areas use a very large loading gauge to allow drive-in shuttle rolling stock. Through freight traffic is allowed up to European GC loading gauge if onward travel is via High Speed 1. to either St Pancras (for passenger traffic) or as far as Barking in east London (for freight traffic). Ballasted track was ruled out owing to maintenance constraints and a need for geometric stability.

Initially 38 Le Shuttle locomotives were commissioned, working in pairs with one at each end of a shuttle train. The shuttles have two separate halves: single and double deck. Each half has two loading / unloading wagons and twelve carrier wagons. Eurotunnel's original order was for nine tourist shuttles.

HGV shuttles also have two halves, with each half containing one loading wagon, one unloading wagon and 14 carrier wagons. There is a club car behind the leading locomotive. Eurotunnel originally ordered six HGV shuttles rakes.

Forty - six Class 92 locomotives for hauling freight trains and overnight passenger trains (the Nightstar project, which was abandoned) were commissioned, which can run on both overhead AC and third - rail DC power. However, RFF does not let these run on French railways, so there are plans to certify Alstom Prima II locomotives for use in the tunnel.

Thirty - one Eurostar trains — based on the French TGV — built to UK loading gauge, and with many modifications for safety within the tunnel, were commissioned, with split ownership between British Rail, French National Railway Company (SNCF) and National Railway Company of Belgium. British Rail ordered seven more for services north of London.

At the end of 2009, extensive fire - proofing requirements were dropped and Deutsche Bahn received permission to run German Intercity - Express (ICE) trains through the Channel Tunnel in the future. On 19 October 2010 Deutsche Bahn ran the first ICE train through the Channel Tunnel arriving in St. Pancras after evacuation tests in the tunnel were a success.

Diesel locomotives for rescue and shunting work are Eurotunnel Class 0001 and Eurotunnel Class 0031.

Services offered by the tunnel are:

• Eurotunnel Shuttle (formerly Le Shuttle) roll - on roll - off shuttle service for road vehicles,
• Eurostar passenger trains,
• Through freight trains.

Both the freight and passenger traffic forecasts that led to the construction of the tunnel were largely and universally overestimated. Particularly, Eurotunnel's commissioned forecasts were over - predictions. Although the captured share of Channel crossings (competing with air and sea) was forecast correctly, high competition and reduced tariffs has led to low revenue. Overall cross - Channel traffic was overestimated.

With the EU's liberalization of international rail services, the tunnel and High Speed 1 have been open to competition since 2010. There have been a number of operators interested in running services including Deutsche Bahn, through the tunnel and along High Speed 1 to London.

Total cross - tunnel passenger traffic volumes peaked at 18.4 million in 1998, then dropped to 14.9 million in 2003, from then rising again to 17.0 million in 2010.

At the time of the decision about building the tunnel, 15.9 million passengers were predicted for Eurostar trains in the opening year. In 1995, the first full year, actual numbers were a little over 2.9 million, growing to 7.1 million in 2000, then dropping again to 6.3 million in 2003. Eurostar was also limited by the lack of a high speed connection on the British side. After the completion of High Speed 1 (formerly CTRL) to London in two stages in 2003 and 2007, traffic increased. In 2008, Eurostar carried 9,113,371 passengers in cross - Channel - Tunnel traffic, a 10% increase over the previous year, despite traffic limitations due to the 2008 Channel Tunnel fire. Eurostar passenger numbers continued to increase, reaching 9,528,558 in 2010.

Cross - tunnel freight traffic volumes have been erratic, with a decrease during 1997 due to a closure caused by a fire in a freight shuttle. The total freight crossings increased over the period, indicating the substitutability of the tunnel by sea crossings. The tunnel has achieved a cross - Channel freight traffic market share close to or above Eurotunnel's 1980s predictions but Eurotunnel's 1990 and 1994 predictions were overestimates.

For freight transported on through freight trains, the first year freight prediction was 7.2 million gross tonnes; the actual 1995 figure was 1.3 million gross tonnes. Through freight volumes peaked in 1998 at 3.1 million tonnes. This figure fell back to 1.21 million tonnes in 2007, increasing again slightly to 1.24 million tonnes in 2008. Together with that carried on freight shuttles, freight traffic growth has occurred since opening, with 6.4 million tonnes carried in 1995, 18.4 million tonnes recorded in 2003 and 19.6 million tonnes in 2007. Numbers fell back in the wake of the 2008 fire.

Eurotunnel's freight subsidiary is Europorte 2. In September 2006 EWS, the UK's largest rail freight operator, announced that owing to cessation of UK - French government subsidies of £52 million per annum to cover the Channel Tunnel "Minimum User Charge" (a subsidy of around £13,000 per train, at a traffic level of 4,000 trains per annum), freight trains would stop running after 30 November.

Shares in Eurotunnel were issued at £3.50 per share on 9 December 1987. By mid 1989 the price had risen to £11.00. Delays and cost overruns led to the share price dropping; during demonstration runs in October 1994 the share price reached an all - time low value. Eurotunnel suspended payment on its debt in September 1995 to avoid bankruptcy. In December 1997 the British and French governments extended Eurotunnel's operating concession by 34 years to 2086. Financial restructuring of Eurotunnel occurred in mid 1998, reducing debt and financial charges. Despite the restructuring, The Economist reported in 1998 that to break even Eurotunnel would have to increase fares, traffic and market share for sustainability. A cost benefit analysis of the Channel Tunnel indicated that there were few impacts on the wider economy and few developments associated with the project, and that the British economy would have been better off if the tunnel had not been constructed.

Under the terms of the Concession, Eurotunnel was obliged to investigate a cross-Channel road tunnel. In December 1999 road and rail tunnel proposals were presented to the British and French governments, but it was stressed that there was not enough demand for a second tunnel. A 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, with the French border controls on the UK side of the tunnel and vice versa. For certain city - to - city trains, the train itself represents a control zone. A binational emergency plan coordinates UK and French emergency activities.

In 1999 Eurostar posted its first ever net profits, having previously made a loss of £925m in 1995.

The terminals sites are at Cheriton (Folkestone in the United Kingdom) and Coquelles (Calais in France). The terminals are unique facilities designed to transfer vehicles from the motorway onto trains at a rate of 700 cars and 113 heavy vehicles per hour. The UK site uses the M20 motorway. The terminals are organized with the frontier controls juxtaposed with the entry to the system to allow travelers to go onto the motorway at the destination country immediately after leaving the shuttle. The area of the UK site was severely constrained and the design was challenging. The French layout was achieved more easily. To achieve design output, the shuttles accept cars on double decks; for flexibility, ramps were placed inside the shuttles to provide access to the top decks. At Folkestone there are 20 kilometers (12 mi) of mainline track and 45 turnouts with eight platforms. At Calais there are 30 kilometers (19 mi) of track with 44 turnouts. At the terminals the shuttle trains traverse a figure eight to reduce uneven wear on the wheels. There is a freight marshaling yard west of Cheriton at Dollands Moor Freight Yard.

A 1996 report from the European Commission predicted that Kent and Nord-Pas de Calais had to face increased traffic volumes due to general growth of cross - Channel traffic and traffic attracted by the tunnel. In Kent, a high speed rail line to London would transfer traffic from road to rail. Kent's regional development would benefit from the tunnel, but being so close to London restricts the benefits. Gains are in the traditional industries and are largely dependent on the development of Ashford International passenger station, without which Kent would be totally dependent on London's expansion. Nord - Pas - de - Calais enjoys a strong internal symbolic effect of the Tunnel which results in significant gains in manufacturing.

The removal of a bottleneck by means like the Channel Tunnel does not necessarily induce economic gains in all adjacent regions. The image of a region being connected to the European high speed transport and active political response are more important for regional economic development. Some small - medium enterprises located in the immediate vicinity of the terminal have used the opportunity to re-brand the profile of their business with positive effect, such as The New Inn at Etchinghill which was able to commercially exploit its unique selling point as being 'the closest pub to the Channel Tunnel'. Tunnel induced regional development is small compared to general economic growth. The South East of England is likely to benefit developmentally and socially from faster and cheaper transport to continental Europe, but the benefits are unlikely to be equally distributed throughout the region. The overall environmental impact is almost certainly negative.

Since the opening of the tunnel, small positive impacts on the wider economy have been felt, but it is difficult to identify major economic successes directly attributed to the tunnel. The Eurotunnel does operate profitably, offering an alternative transportation mode unaffected by poor weather. High costs of construction did delay profitability, however, and companies involved in the Channel Tunnel's construction and operation early in operation relied on government aid to deal with debts amounted. Eurotunnel has been described as being in a serious situation.

There have been three fires in the Channel Tunnel, all on the heavy goods vehicle (HGV) shuttles, that were significant enough to close the tunnel, and other more minor incidents.

During an "invitation only" testing phase on 9 December 1994, a fire broke out in a Ford Escort car whilst its owner was loading it on to the upper deck of a tourist shuttle. The fire started at approximately 10:00 with the shuttle train stationary in the Folkestone terminal and was extinguished around 40 minutes later with no passenger injuries.

On 18 November 1996, a fire broke out on a heavy goods vehicle shuttle wagon in the tunnel but nobody was seriously hurt. The exact cause is unknown, although it was not a Eurotunnel equipment or rolling stock problem; it may have been due to arson of a heavy goods vehicle. It is estimated that the heart of the fire reached 1,000 °C (1,800 °F), with the tunnel severely damaged over 46 meters (151 ft), with some 500 meters (1,640 ft) affected to some extent. Full operation recommenced six months after the fire.

The tunnel was closed for several hours on 21 August 2006, when a truck on an HGV shuttle train caught fire. On 11 September 2008, a fire occurred in the Channel Tunnel at 13:57 GMT. The incident started on a freight carrying vehicle train traveling towards France. The event occurred 11 kilometers (6.8 mi) from the French entrance to the tunnel. No one was killed but several people were taken to hospitals suffering from smoke inhalation, and minor cuts and bruises. The tunnel was closed to all traffic, with the undamaged South Tunnel reopening for limited services two days later. Full service resumed on 9 February 2009 after repairs costing €60 million.

On the night of 19/20 February 1996, approximately 1,000 passengers became trapped in the Channel Tunnel when two British Rail Class 373 trains on continent bound Eurostar service broke down owing to failures of electronic circuits caused by snow and ice being deposited and then melting on the circuit boards.

On 3 August 2007, an electrical failure lasting six hours caused passengers to be trapped in the tunnel on a Eurotunnel shuttle crossing.

On the evening of 18 December 2009, during the December 2009 European snowfall, five London bound Eurostar trains failed inside the tunnel, trapping 2,000 passengers, during the coldest temperatures for eight years. A Eurotunnel spokesperson explained that snow had evaded the train's winterization shields, and that the transition from cold air outside to the tunnel's warm atmosphere had melted the snow, resulting in electrical failures. One train was turned back before reaching the tunnel; two trains were hauled out of the tunnel by Eurotunnel Class 0001 diesel locomotives. The blocking of the Channel Tunnel led to the implementation of Operation Stack, the transformation of the M20 motorway into a linear car park.

The occasion was the first time that a Eurostar train was evacuated inside the tunnel; the failing of four at once was described as "unprecedented". The Channel Tunnel reopened the following morning. Nirj Deva, Member of the European Parliament for South East England, had called for Eurostar chief executive Richard Brown to resign over the incidents. An independent report by Christopher Garnett (former CEO of Great North Eastern Railway) and Claude Gressier (a French transport expert) on the 18/19 December 2009 incidents was issued in February 2010, making 21 recommendations.

A Brussels – London Eurostar broke down in the tunnel on 7 January 2010. The train had 236 passengers on board and was towed to Ashford; other trains that had not yet reached the tunnel were turned back.

Immigrants and would-be asylum seekers have been known to use the tunnel to attempt to enter Britain. By 1997 the problem had attracted international press attention, and the French Red Cross opened a refugee center at Sangatte in 1999, using a warehouse once used for tunnel construction; by 2002 it housed up to 1500 persons at a time, most of them trying to get to the UK. In 2001, most came from Afghanistan, Iraq and Iran, but African and Eastern European countries are also represented.

Most migrants who got into Britain found some way to ride a freight train, but others used Eurostar. Though the facilities were fenced, airtight security was deemed impossible; refugees would even jump from bridges onto moving trains. In several incidents people were injured during the crossing; others tampered with railway equipment, causing delays and requiring repairs. Eurotunnel said it was losing £5m per month because of the problem. A dozen refugees have died in crossing attempts.

In 2001 and 2002, several riots broke out at Sangatte and groups of refugees (up to 550 in a December 2001 incident) stormed the fences and attempted to enter en masse. Immigrants have also arrived as legitimate Eurostar passengers without proper entry papers.

Local authorities in both France and the UK called for the closure of Sangatte, and Eurotunnel twice sought an injunction against the center. The United Kingdom blamed France for allowing Sangatte to open, and France blamed the UK for its lax asylum rules and the EU for not having a uniform immigration policy. The cause célèbre nature of the problem even included journalists detained as they followed refugees onto railway property.

In 2002, after the European Commission told France that it was in breach of European Union rules on the free transfer of goods because of the delays and closures as a result of its poor security, a double fence was built at a cost of £5 million, reducing the numbers of refugees detected each week reaching Britain on goods trains from 250 to almost none. Other measures included CCTV cameras and increased police patrols. At the end of 2002, the Sangatte center was closed after the UK agreed to take some of its refugees.

The Channel Tunnel Safety Authority is responsible for some aspects of safety regulation in the tunnel; it reports to the IGC.

The service tunnel is used for access to technical equipment in cross passages and equipment rooms, to provide fresh air ventilation, and for emergency evacuation. The Service Tunnel Transport System (STTS) allows fast access to all areas of the tunnel. The service vehicles are rubber - tyred with a buried wire guidance system. Twenty - four STTS vehicles were made, and are used mainly for maintenance but also for firefighting and in emergencies. "Pods" with different purposes, up to a payload of 2.5-5 t (2.8-5.5 tons), are inserted into the side of the vehicles. The STTS vehicles cannot turn around within the tunnel, and are driven from either end. The maximum speed is 80 km/h (50 mph) when the steering is locked. A smaller fleet of fifteen Light Service Tunnel Vehicles (LADOGS) were introduced to supplement the STTSs. The LADOGS have a short wheelbase with a 3.4 m (11 ft) turning circle allowing two - point turns within the service tunnel. Steering cannot be locked like the STTS vehicles, and maximum speed is 50 km/h (31 mph). Pods up to 1 tonne can be loaded onto the rear of the vehicles. Drivers in the tunnel sit on the right, and the vehicles drive on the left. Owing to the risk of French personnel driving on their native right side of the road, sensors in the road vehicles alert the driver if the vehicle strays to the right side of the tunnel.

The three tunnels contain 6,000 tonnes (6,600 tons) of air that needs to be conditioned for comfort and safety. Air is supplied from ventilation buildings at Shakespeare Cliff and Sangatte, with each building capable of full duty providing 100% standby capacity. Supplementary ventilation also exists on either side of the tunnel. In the event of a fire, ventilation is used to keep smoke out of the service tunnel and move smoke in one direction in the main tunnel to give passengers clean air. The Channel Tunnel was the first mainline railway tunnel to have special cooling equipment. Heat is generated from traction equipment and drag. The design limit was set at 30 °C (86 °F), using a mechanical cooling system with refrigeration plants on both the English and French sides that run chilled water circulating in pipes within the tunnel.

Trains traveling at high speed create piston - effect pressure changes that can affect passenger comfort, ventilation systems, tunnel doors, fans and the structure of the trains, and drag on the trains. Piston relief ducts of 2 - meter (7 ft) diameter were chosen to solve the problem, with 4 ducts per kilometer to give close to optimum results. Unfortunately this design led to unacceptable lateral forces on the trains so a reduction in train speed was required and restrictors were installed in the ducts.

The safety issue of a fire on a passenger-vehicle shuttle garnered much attention, with Eurotunnel itself noting that fire was the risk gathering the most attention in a 1994 Safety Case for three reasons: ferry companies opposed to passengers being allowed to remain with their cars; Home Office statistics indicating that car fires had doubled in ten years; and the long length of the tunnel. Eurotunnel commissioned the UK Fire Research Station to give reports of vehicle fires, as well as liaising with Kent Fire Brigade to gather vehicle fire statistics over one year. Fire tests took place at the French Mines Research Establishment with a mock wagon used to investigate how cars burned. The wagon door systems are designed to withstand fire inside the wagon for 30 minutes, longer than the transit time of 27 minutes. Wagon air conditioning units help to purge dangerous fumes from inside the wagon before travel. Each wagon has a fire detection and extinguishing system, with sensing of ions or ultraviolet radiation, smoke and gases that can trigger halon gas to quench a fire. Since the Heavy Goods Vehicle (HGV) wagons are not covered, fire sensors are located on the loading wagon and in the tunnel itself. A 10-inch (250 mm) water main in the service tunnel provides water to the main tunnels at 125-meter (410 ft) intervals. The ventilation system can control smoke movement. Special arrival sidings exist to accept a train that is on fire, as the train is not allowed to stop whilst on fire in the tunnel. Eurotunnel has banned a wide range of hazardous goods from traveling in the tunnel. Two STTS (Service Tunnel Transportation System) vehicles with firefighting pods are on duty at all times, with a maximum delay of 10 minutes before they reach a burning train.