Although Thomé de Gamond's revised plan of 1867 came to nothing in itself, it did cause renewed talk about a Channel tunnel. The new spirit of free trade was favorable to it among Europeans, and everybody was being greatly impressed with reports of the striking progress on various great European engineering projects of the time that promised closer communication between nations—the successful cutting of the Isthmus of Suez, the near completion of the 8.1-mile-long Mount Cenis rail tunnel, and the opening, only a few years previously, of the 9.3-mile-long St. Gotthard Tunnel, for example. Hardly any great natural physical barriers between neighboring nations seemed beyond the ability of the great nineteenth-century engineers to bridge or breach, and to many people it appeared logical enough that the barrier of the Dover Strait should have its place on the engineers' list of conquests. In this generally propitious atmosphere, an Englishman named William Low took up where Thomé de Gamond left off. Shortly after the Universal Exhibition, Low came up with a Channel tunnel scheme based principally upon his own considerable experience as an engineer in charge of coal mines in Wales. Low proposed the creation of a pair of twin tunnels, each containing a single railway track, and interconnected at intervals by short cross-passages. The idea was a technically striking one, for it aimed at making the tunnels, in effect, self-ventilating by making use of the action of a train entering a tunnel to push air in front of it and draw fresh air in behind itself. According to Low's scheme, this sort of piston action, repeated on a big scale by the constant passage of trains bound in opposite directions in the two tunnels, was supposed to keep air moving along each of the tunnels and between them through the cross-passages in such a way as to allow for its steady replenishment through the length of the tunnels. With modifications, Low's concept of a double self-ventilating tunnel forms the basis for the plan most seriously advanced by the Channel Tunnel Study Group in 1960.
After showing his plans to Thomé de Gamond, who approved of them, Low obtained the collaboration of two other Victorian engineers—Sir John Hawkshaw, who in 1865 and 1866 had had a number of test borings made by a geologist named Hartsink Day in the bed of the Channel in the areas between St. Margaret's Bay, just east of Dover, and Sangatte, just north-east of Calais, and had become convinced that a Channel tunnel was a practical possibility in geological terms; and Sir James Brunlees, an engineer who had helped build the Suez Canal. In 1867, an Anglo-French committee of Channel-tunnel promoters submitted a scheme for a Channel tunnel based on Low's plan to a commission of engineers under Napoleon III, and the promoters asked for an official concession to build the tunnel. The members of the commission were unanimous in regarding the scheme as a workable one, although they balked at an accompanying request of the promoters that the British and French Governments each guarantee interest on a million sterling, which would be raised privately, to help get the project under way, and took no action. But apart from the question of money the promoters were encouraged. In 1870 they persuaded the French Government officially to ask the British Government what support it would be willing to give to the proposed construction of a Channel railway tunnel. Consideration of the question in Whitehall got sidetracked for a while by the outbreak of the Franco-Prussian war in the same year, but in 1872, after further diplomatic enquiries by the French Government, the British Government eventually replied that it found no objection "in principle" to a Channel tunnel, provided it was not asked to put up money or guarantee of any kind in connection with it and provided that ownership of the tunnel would not be a perpetual private monopoly. In the same year, a Channel Tunnel Company was chartered in England, with Lord Richard Grosvenor, chairman of the London, Chatham & Dover Railway, at its head, and with Hawkshaw, Low, and Brunlees as its engineers. The tunnel envisioned by the company would stretch from Dover to Sangatte, and its cost, including thirty-three miles of railway that would connect on the English side with the London, Chatham & Dover and the South-Eastern Railways, and on the French side with the Chemin de Fer du Nord, would be £10,000,000. Three years later, the English company sought and obtained from Parliament temporary powers to buy up private land at St. Margaret's Bay, in Kent, for the purpose of going ahead with experimental tunneling work there. At the same time, a newly formed French Channel Tunnel Company backed by the House of Rothschild and headed by an engineer named Michel Chevalier obtained by act of the French legislature permission from the French Government to start work on a tunnel from the French side at an undetermined point between Boulogne and Calais, and a concession to operate the French section of the tunnel for ninety-nine years. The cahier des charges of the French tunnel bill dealt in considerable detail with the terms under which the completed tunnel was to be run, down to providing a full table of tariffs for the under-Channel railroad. Thus, a first-class passenger riding through the tunnel in an enclosed carriage furnished with windows would be charged fifty centimes per kilometre. Freight rates were established for such categories as furniture, silks, wine, oysters, fresh fish, oxen, cows, pigs, goats, and horse-drawn carriages with or without passengers inside.
The greatest uncertainty facing the two companies, now that they had the power to start digging toward each other's working sites, consisted of their lack of foreknowledge of geological obstacles they might encounter in the rock masses lying between the two shores at the neck of the Channel. However, the companies' engineers had substantial reasons for believing that, in general, the region and stratum into which they planned to take the tunnel were peculiarly suited to their purpose. Their belief was based on a rough reconstruction—a far more detailed reconstruction is available nowadays, of course—of various geological events occurring in the area before there ever was a Channel. A hundred million years ago, in the Upper Cretaceous period of the Mesozoic era, a great part of southern England, which had been connected at its easterly end with the Continental land mass, was inundated, along with much of Western Europe, by the ancient Southern Sea. As it lay submerged, this sea-washed land accumulated on its surface, over a period of ten million years, layers of white or whitish mud about nine hundred feet thick and composed principally of the microscopic skeletons of plankton and tiny shells. Eventually the mud converted itself into rock. Then, for another forty million years, at just the point where the neck of the Dover Strait now is, very gentle earth movements raised the level of this rock to form a bar-shaped island some forty miles long. By Eocene times this Wealden Island, stretching westward across the Calais-Dover area, actually seems to have been the only bit of solid ground standing out in a seascape of a Western Europe inundated by the Eocene sea. When most of France and southern England reappeared above the surface, in Miocene times, this island welded them together; later, in the ice age, the Channel isthmus disappeared and emerged again four times with the rise and fall of the sea caused by the alternate thawing and refreezing of the northern icecap. When each sequence of the ice age ended, the land bridge remained, high and dry as ever, and it was over this isthmus that paleolithic man shambled across from the Continent, in the trail of rhinoceroses, hippopotamuses, giant boars, and other great beasts whose fossilized bones have been found in the Wealden area.
Encroaching seas made a channel through the isthmus and cut the Bronze Age descendants of this breed of men off from the Continent about six thousand years ago. Then fierce tidal currents coursing between the North Sea and the Atlantic widened the breach still further until, as recently as four thousand years ago (or only about a couple of thousand years before Caesar's legions invaded Britain by boat), the sea wore away the rock of the isthmus to approximately the present width of the Strait, leaving exposed high at each side the eroded rock walls, formerly the whitish mudbank of Cretaceous times—now the white chalk cliffs of the Dover and Calais areas. Providentially for the later purposes of Channel tunnelers, however, the seas that divided England from the Continent also left behind them a thin remnant of the old land connection in the form of certain chalk layers that still stretched in gentle folds across the bottom of the Strait, and it was through this area of remaining chalk that the Victorian engineers planned to drive their tunnel headings. Even more providentially, they had the opportunity of extending their headings under the Channel through a substratum of chalk almost ideal for tunneling purposes, known as the Lower Chalk. Unlike the two layers of cretaceous rock that lie above it—the white Upper Chalk and the whitish Middle Chalk, both of which are flint-laden, heavily fissured, and water-bearing, and consequently almost impossible to tunnel in for any distance—the Lower Chalk (it is grayish in color) is virtually flint-free and nearly impermeable to water, especially in the lower parts of the stratum, where it is mixed with clay; at the same time it is stable, generally free of fissures, and easy to work. From the coastline between Folkestone and South Foreland, north-east of Dover, where its upper level is visible in the cliffs, the Lower Chalk dips gently down into the Strait in a north-easterly direction and disappears under an outcropping Middle Chalk, and emerges again on the French side between Calais and Cap Blanc-Nez. Given this knowledge and their knowledge of the state of Lower Chalk beds on land areas, the Victorian engineers were confident that the ribbon of Lower Chalk extending under the Strait would turn out to be a continuous one. To put this view to a further test, the French Channel Tunnel Company, in 1875, commissioned a team of eminent geologists and hydrographers to make a more detailed survey of the area than had yet been attempted. In 1875 and 1876 the surveyors made 7,700 soundings and took 3,267 geological samples from the bed of the Strait and concluded from their studies that, except for a couple of localities near each shoreline, which a tunnel could avoid, the Lower Chalk indeed showed every sign of stretching without interruption or fault from shore to shore. However, when these studies were completed, Lord Grosvenor's Channel Tunnel Company did not find itself in a position to do much about them. The company was having trouble raising money, and its temporary power to acquire land at St. Margaret's Bay for experimental workings had lapsed without the promoters ever having used it. William Low, who had left the company in 1873 after disagreements with Hawkshaw on technical matters—Low had come to believe, for one thing, that the terrain around St. Margaret's Bay was unsuitable as a starting place for a channel tunnel—had become the chief engineering consultant of a rival Channel-tunnel outfit that called itself the Anglo-French Submarine Railway Company. But the Anglo-French Submarine Railway Company wasn't getting anywhere, either. It remained for a third English company, headed by a railway magnate named Sir Edward Watkin, to push the Channel-tunnel scheme into its next phase, which turned out to be the most tumultuous one in all its history.
M.P.'s Bride. "Oh! William dear—if you are—a Liberal—
do bring in a Bill—next Session—for that Underground Tunnel!!"
This cartoon depicting the horrors of the Channel crossing originally
appeared in Punch in 1869. In 1961, 92 years later, Punch found it
as timely as ever.
THE GREAT
TUNNEL SCHEMERS