Channel tunnel

The Eurotunnel or Channel Tunnel (French: Tunnel sous la Manche; English: Channel Tunnel or Chunnel) is a railway tunnel, opened on May 6, 1994, which crosses the English Channel, joining France with the United Kingdom. It is an important infrastructure work of the international transport. The journey can be made by private car (boarding the shuttle train "Shuttle"), or as a passenger on the Eurostar train, on a journey that lasts approximately 35 minutes between Coquelles (city of Calais) in France and Folkestone in the United Kingdom. It is the third longest tunnel in the world, only surpassed by the Seikan tunnel and the Gotthard tunnel, and the one with the longest underwater section in the world, with an average depth of 50 meters.

The tunnel is operated by the Franco-British company Eurotunnel. In 2013 it reached a turnover of 1,090 million euros, exceeding the figure of 1,000 million for the first time.

Technical characteristics

View in cross section of the tunnel at the level of intercom tunnels. These tunnels (C) exist every 375 m. Air pressure relief ducts (D), present every 250 m, allow air to circulate. The middle tunnel (B) is a service tunnel. Tunnels A are where normal trains circulate.

The rail service through the Eurotunnel has two variants: the Eurostar train, for passengers, and the Shuttle train, which transports trucks, cars and motorcycles. The tunnel is 50.5 km long, 39 of them underwater, making it the second longest underwater tunnel in the world, with an average depth of 40 meters, behind the Seikan Tunnel, whose length is 53 km, a 240m deep.

The Channel Tunnel is made up of three galleries:

• Two 7.6 m diameter tunnels reserved for rail transport, one way and the other back (A).
• A 4.8 m service gallery, prepared for the circulation of electric vehicles (B).

These three galleries are linked every 375 m by other auxiliary and maintenance cross galleries (C) and (D), which allow an air current to reduce pressure, thus also preventing the spread of smoke in case of fire, as well as the shock due to the aerodynamic resistance when crossing the trains that circulate at 140 km/h.

Advantages

• The Eurostar high-speed train takes 2 hours and 20 minutes to get from London to Paris, and 1 hour and 57 minutes from London to Brussels.
• The goods are transported on a train instead of trucks or ferris through the Channel of La Mancha, which is subject to possible adverse weather conditions or other factors.
• The motorists enter the shuttle trains and can stay in their vehicles or stroll while the train crosses the tunnel. Truckers put the truck in the cars, and a minibus moves them to the club carriage, where they have seats and a food service.

Inside of a carportacoches.

There are doors between each wagon that are removed to allow the loading and circulation of cars, from the tail to the beginning of the trains, at two heights. These doors are closed when the train is loaded and reopened for unloading.

Construction

Geological profile along the tunnel as it was built. In most of its length, the tunnels cross a layer of ridge

The works began in April 1988 on both banks and on December 1, 1990 the tunnel boring machines were found.

The tunnel boring machines used to excavate the tunnel were built by the French and British. Cylindrical in shape, the tunnel boring machine has several blades ('teeth') mounted on its front. The teeth are made of extremely hard metal and as they rotate they dig into the ground, creating space for the machine to continue moving forward. The drill used in the Eurotunnel was 8.78 m in diameter and 200 m long, with a total weight of 11,000 tons. It is capable of penetrating many types of terrain, from soft to rocky, advancing 20 km without interruption.

Tunneling requires a solid understanding of geology and selecting the best rock strata through which to tunnel. Features of the Channel Tunnel include:

• Crete on the cliffs on both sides of the Canal, without major flaws.

• Four geological strata, formed by marine sediments between 90 and 100 million years old. The two upper strata are formed by permeable ridges, above a third layer of slightly permeable ridge and a fourth coat of waterproof clay (from the lower Cretaceous period). Among these last two strata, there is a thin layer of calcareous and gluconic sand.

• The blue crest layer (in French: "craie bleue") of between 25 and 30 m of thickness located in the lower third of this material, was a priori the most appropriate stratum of the Canal bed to dig a tunnel. It is a relatively easy to drill material, which requires minimal support, and with a clay content of 30-40 % that provides waterproof to groundwater.

The average depth of the channel bed is 54 m, with a maximum of 180 m. from the sea is 107.3 meters.

Concessionaire company

Location and connections

Eurotúnel
Legend
High Speed 1 towards Ashford International South Eastern main line towards Ashford International Step at Dollands Moor level CC deCA current change Dollands Moor cargo tracks Viaducto de Balancing Ponds (120 m) Grange Alders Viaduct (526 m) Dover Line Viaduct (116 m) South Eastern main line towards Dover Priory Viaducto Autopista M20 (309 m) High Speed 1 / Network Rail Getlink -1.659 km Cheriton artificial tunnel (1010 m) Folkestone Shuttle Terminal - 4,436 km Folkestone Shuttle Sidings Cheriton Junction Service road Tunnel Mouth in Castle Hill 0 km British cruise 0.478 km Holywell artificial tunnel 0,882 km Shakespeare Cliff Shaft (Adits A1 " A2) English Channel British submarine cruise 17,062 km United Kingdom France 26,988 km French submarine cruise 34.688 km Manche Sangatte Shaft Tunnel boot in Beussingues 50.459 km Beussingues trench French cruise Service road Autopista A16 LGV Nord towards Calais-Fréthun " Lille Europe SNCF SGetlink Do Fréthun's cargo tracks Cocktails Eurotunnel Lille-Fontinettes railway towards Les Fontinettes Calais Shuttle Terminal Eurotunnel Shuttle 57.795 km
Distances from the entrance to the tunnel in Castle Hill Distances to the connections of the terminals

The construction of the tunnel was financed by private companies, without state intervention, in exchange for the concession to operate it until 2052. A study carried out in 1984 by French and British banks considered the project viable. The British government, led by Margaret Thatcher, opposed public funding for the project, a position agreed with the French government in the Treaty of Canterbury.

The cost was €16 billion. Coordination difficulties between contracted and subcontracted companies and the technical difficulty of the project raised costs considerably.

Eurotunnel is a private concessionaire for the project. It manages rail transport, collecting tolls from the railway companies that use the tunnel and using its own means to exploit the traffic of goods and passengers. Demand has been lower than expected, mainly due to low-cost airlines. Based on a forecast of 30 million passengers and 15 million tons of merchandise per year, in 2013 18.8 million passengers and 19 million tons of merchandise were transported, including trains (10.1 and 1.3, respectively) and the ferries.

Input from other operators

After the change in safety regulations by the Channel Tunnel Safety Authority (CTSA) for passenger trains in the Eurotunnel, discussed (11/16/2009) with the manufacturers and operators, it granted in June 2013 to the German operator DB Part B of the Safety Certificate, which recognizes that there is a Safety Management System that satisfies Community regulations for this section, that is, that it complies with the safety and organization procedures, which authorizes DB to provide services through the Eurotunnel with any approved material. This has nothing to do with the supposed homologation of the Velaro D trains since, in addition, the Eurotunnel evacuation tests, carried out in October 2010, were carried out with a 3M ICE, the same one that was exhibited at the London St. Pancras station. Part A of the certificate confirms that the Railway Undertaking has a Safety Management System that satisfies European and national standards and requirements, in a harmonized manner throughout the European railway system; while Part B confirms the application of said Safety Management System to circulate through a certain infrastructure (a point-to-point route along a line). The Certificate is valid for five years, renewable for successive equal periods, provided that the regulatory conditions required for its granting are met.

Subsequently, the UKBA (The UK Border Agency) explained that there will be no checks outside of the current ones (Lille, Paris and Brussels), and that they do not like DB's suggestion that checks be done on board the trains. For its part, SNCF is doubling the capacity of the passport control area at Lille-Europe station. After these news, in addition to the difficulties to homologate the Velaro D even in Germany, DB has parked its plans to reach London, at least in this decade.

Eurostar announced a service to Marseille for 2015 that will require a 1h 43m stop in Lille (London direction) for baggage and passport control.

Traffic volume

Figure showing the evolution of different types of traffic.

Source: Eurotunnel

The first column represents the number of passengers on Eurostar trains, the sixth and seventh columns represent an official estimate on transport by shuttle trains.

Fire incidents

There are several incidents of this nature that have occurred in the Channel Tunnel. Since its inauguration there have been four fires:

• The first occurred in November 1996, when a truck lit up causing the tunnel cut for several months.
• The second took place in August 2006, for the same reason, but this time without causing any harm.
• Another occurred on 11 September 2008, by a burning cargo train, disrupting all traffic and passenger service.
• Finally, the last of the fires known so far occurred on January 17, 2015, when a truck lit at the French end of the tunnel. The accident forced the Eurotunel to close all day.