PERIODICALLY, the question of the Channel Tunnel is raised before public opinion. It's a way of testing the waters, of realizing whether the long-matured project is approaching the time of its realization.

However, there is no longer any doubt: not only are all the Chambers of Commerce in France, all the associations, even all individuals, demanding this tunnel, which is essential to the economic development of the two countries; but in England, where the irreducible oppositions have come from until now, we now share the same opinion, we are eager to see this new link created between the British Isles and the continent.

The English objections were of a military and moral nature. On the other side of the strait, there was fear of an invasion of England by an army appearing unexpectedly from the tunnel. But, perhaps even more, national pride was touched by the idea that the United Kingdom, so proud of its splendid isolation, would no longer be quite an island.

These two reasons, both as incomprehensible as the other to our French eyes, were nevertheless strong enough to put an obstacle to the enterprise. But, in recent years, a new development has occurred which has disrupted the living conditions of peoples: the admirable progress of aviation.

The English no longer have to fear the invasion of their territory by an army moving along a tunnel... since transport planes could fulfill this task much better. They no longer have to defend the insularity of their country, since these same planes connect it to the continent every day.

Thus, by a strange irony, if soon the railway can go directly from Paris to London, it is to the plane that we will owe it.

The first idea for the Channel Tunnel dates back to 1875. It was initially received as favorably in England as in France. A Franco-English commission was created to study the enterprise and the first work began on both sides.

In 1882, there was already, at the foot of the cliff of Dover, a gallery of two kilometers, of which more than 1,500 meters sank under the sea, and, on the French side, a gallery of 1,800 meters. But English opinion was suddenly moved, and it was then that the military and moral objections that I have mentioned intervened so imperiously that everything was abandoned.

Fortunately, the two study societies, one French, the other British, have survived to this day. They jointly continued their projects. They are ready to spring into action.

At present, the plans and specifications for the route, last modified in 1919, are finalized. The technical implementation will be very easy, thanks to the powerful means available to the art of engineering today: freezing of aquifers, compressed air boxes, high-performance electric drills, enormous flow pumps, injection machines. cement or pouring concrete; finally, for operation, use of electric traction.

The final project is due to Mr. Sartiaux, the eminent chief engineer of the Chemins de fer du Nord, who, for many years, devoted all his attention to it with his collaborator, the engineer L. Breton. Death prevented Mr. Sartiaux from seeing his work come to fruition. He was replaced at the head of the French Tunnel Company by Mr. Javary, the current director of the Compagnie des Chemins de fer du Nord.

Here are some details about the work to be undertaken.

Two parallel tracks will detach themselves from the Boulogne-Calais line, 6 kilometers from Marquise, in Pas-de-Calais, and will sink under the sea, south of Escalles, through two parallel cylindrical tunnels, 5 m long. 50 radius.

After having reached a gentle slope of 95 meters below sea level, or 45 meters lower than the maximum depth of the Channel, the two tracks will go up to exit on the English coast, at Shakespeare-Cliff and join , via a large loop, the Dover-London line.

The tunnel will have a total length of 54 kilometers. It will only take 40 minutes for a passenger train to cross it.

From distance to distance, the two tunnels will be linked together by galleries. To allow the evacuation of water and debris, a lateral tunnel will be established below the tracks, leading to two access shafts 125 meters deep opening on each bank.

This tunnel, smaller than the others - it will be three meters in diameter - will be the first built. It will be used to launch a certain number of branches towards the route of the final tunnels which will be points of attack and construction sites. A small electric railway, with 0 m gauge. 60 will operate in this temporary gallery throughout the duration of the work, ensuring a daily traffic of four thousand tons of materials and twelve hundred workers.

Thanks to the modern means used and the multiplicity of construction sites, the time required for the main perforation work is estimated at two years and five years for completion of the tunnel. As for the cost price, it is estimated, according to the latest estimate, at 1 billion 670 million francs.

Claude FRANCUEIL.