Saturday, June 23, 2007

Channel Tunnel - England and France

England and France

The English Channel, known, to the French as la Manche (the Sleeve), is a narrow strip of the Atlantic Ocean that separates England from the rest of Europe. It is at its narrowest at the hazardous Dover Strait, notorious for its strong tides, dense fogs, and frequent gale-force winds. The Channel Tunnel— popularly called “the Chunnel”—provides a railroad connection between Britain and France under the Dover Strait and is one of the most ambitious infrastructure projects ever undertaken in Europe, among the great engineering feats of the twentieth century. The complicated, visionary project was dogged by financial, logistical, and safety problems, exacerbated by two languages, two governments, two sets of legal requirements, ten contractors, and 220 financial backers in twenty-six countries.

The idea of the fixed link has a long history, the earliest recorded proposal, by a French engineer named Nicolas Desmaret, dating from 1751. About fifty years later Albert Mathieu Favier suggested a horse-drawn railroad under the Channel; his scheme included an artificial island that would serve as a staging post. Another French engineer, Aimé Thomé de Gamond, worked on several plans for almost forty years from 1830, making careful geological surveys of the seabed. In 1856 he proposed a railroad tunnel between Folkestone in the southern English county of Kent and Cap Gris-Nez on the French coast. A modified version was supported by the British engineers William Low and Sir John Clarke Hawkshaw in 1867, and a report was published the following year. For several reasons, largely political, the project went no further.

In the meantime the development of a pneumatic boring machine revolutionized tunneling techniques. In the mid-1870s Channel Tunnel companies were formed in England and France. In 1881 the South Eastern Railway acquired land near Folkestone, and the Submarine Railway Company bored 2,100 yards (2,000 meters) of pilot tunnel under the English Channel at Shakespeare Cliff. In France, 1,800 yards (1,600 meters) were drilled at Sangatte, southwest of Calais. Work stopped in May 1882 when the security-conscious British Parliament, afraid of undersea invasion, opposed the project. It remained in abeyance until after the Great War.

Work on a trial bore at Folkestone Warren in 1922 was aborted after only 140 yards (128 meters), again because of political antagonism in England. Despite support from eminent politicians, the Channel Tunnel was shelved until the Great Depression and another World War had passed. In 1948 the South Eastern Railway (by then Southern Railways) assigned its plans on to the nationalized British Railways, but it was not until 1956 that the French/British Channel Tunnel Study Group was formed to investigate the economic and engineering aspects of a fixed link. Four years later, it recommended a tunnel—in fact, two single-track railway tunnels and a service tunnel—between Folkestone and Sangatte. The two governments agreed to proceed with the project.

Years of surveys and research yielded a scheme the cost of which would be divided equally between Britain and France, and work began on both sides of the Channel in 1974. Only a year later Britain withdrew from the project when the estimated cost was increased by 200 percent. A pilot tunnel at Shakespeare Cliff was abandoned, and the project again lapsed. In 1984 it was once more agreed to in principle at an Anglo-French summit, and applications were invited from the private sector to build the tunnel. The successful tenderer for the design, planning, and construction, announced in January 1986, was Transmanche Link (TML), a consortium

of British and French corporations. The British Channel Tunnel Group (Balfour Beatty Construction, Costain UK, George Wimpey International, Taylor Woodrow Construction, Tarmac Construction, Midland Bank, and National Westminster Bank) was to build the English terminal and 14 miles (22.3 kilometers) of tunnels from Shakespeare Cliff. France-Manche, the French group (Bouygues, Dumez, Societé Auxiliaire d’Enterprises, Societé Generale d'Enterprises Sainrapt et Brice, Spie Batignolles, Banque Nationale de Paris, Credit Lyonnais, and Banque Indosuez) was responsible for the French terminal and the remainder of the tunnels from Sangatte. In order to finance the work, a private Anglo-French organization, Eurotunnel, was established and given a fifty-five year concession agreement to build and operate the link. Construction was under way, with three tunnel-boring machines at Shakespeare Cliff and three more at Sangatte by November 1987. The excavators met on 1 December 1990.

The 31-mile-long (50-kilometer) Channel Tunnel connects the terminals at Folkestone, England, and Coquelles, near Calais, France. The submarine section is nearly 24 miles (38 kilometers) long. The two concrete-lined, single-track railroad tunnels, 25 feet (7.6 meters) in diameter, are spaced 98 feet (30 meters) apart, and a 16-foot-diameter (4.8-meter) tunnel between them is used for maintenance and ventilation. Two huge crossover chambers allow trains to switch tunnels. Maintenance-access cross passages every 1,230 feet (375 meters) link the central service tunnel and the rail tunnels. At 820-foot (250-meter) intervals, piston ducts arch above the service tunnel to link the others and relieve the pressure created by speeding trains. The tunnels are drilled through the rock at an average of 150 feet (45 meters) beneath the seabed. Electrical power for drainage pumps, lighting, and trains is fed from the national supply grids in England and France.

The Chunnel was officially opened on 10 December 1993, and Eurotunnel commenced its commercial operations six months later. At the time of completion, the project had cost U.S.$13.5 billion. Four different services pass through the tunnel: Le Shuttle carries tourist vehicles: Le Shuttle Freight handles commercial vehicles such as vans, trucks, and semitrailers; Eurostar transports pedestrian passengers; and other freight trains travel between Britain and mainland Europe. The journey between Paris and London takes just three and a half hours; the actual Channel crossing only thirty-five minutes. The Channel Tunnel is only one element of the European Community’s plan for a 12,500-mile (20,000-kilometer) high-speed rail network linking cities across the continent.

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