The Railway Conquest of the World

by Frederick Arthur Ambrose Talbot

THE WONDERFUL WASSEN LOOP ON THE ST. GOTTHARD RAILWAY, SHOWING THREE TIERS OF TRACK

The path of the tunnel through the heart of the mountain was plotted by Mr. M. O. Gelpke, C.E., and this in itself was a great achievement. Fifteen stations were scattered over the mountain slopes for the manipulation of the survey instruments, and many of these were situated unavoidably in positions very difficult, and often impossible, of access. Borings were made to ascertain the rock strata which would have to be pierced by Professor Fritsch of Frankfort, and from the result of these essential investigations it was computed that the work, including the necessary railway line on either side of the great tunnel, could be completed for a sum of £7,480,000, or $37,400,000. The money was raised by guarantees of £1,800,000 ($9,000,000) from Italy, £800,000 ($4,000,000) from both Germany and Switzerland, and by the issue of shares and mortgage bonds to the extent of £2,720,000, or $13,600,000. As a further contribution to the task, the Swiss Government undertook to supervise actual construction.

The financial arrangements completed, the company had to search for a man to bore the tunnel. For this purpose tenders were sought for the whole contract. The terms of the latter were severe, as were also the technical conditions. The tunnel was to carry a double track, to have a height of 19.68 feet to the crown of the arch, and a maximum width of 26.24 feet, with a minimum width of 24.93 feet. The tunnel was to be quite straight, with the exception of a slight curve at the southern end, where, for a distance of 474 feet from the entrance, a curve of 984 feet radius was to be introduced to gain Airolo station. The rise from the northern entrance was to be about 1 in 172 to the summit level 3,781 feet above the sea, followed by a drop of 1 in 1000 to the southern end. These gradients falling on either side from the centre were necessary for drainage, and were estimated to be just sufficient to ensure the water flowing to the portals.

Seven tenders were submitted for the enterprise, the lowest being that of L. Favre, a well-known engineer of Geneva, who had completed many notable railway works in Europe. He undertook to complete the tunnel for £2,000,000 ($10,000,000) within eight years. His nearest competitor, an Italian company, wanted twenty-five per cent. more, but would not guarantee completion within less than nine years. Monsieur Favre was supported by a body of influential capitalists, and the contract was awarded to him.

Having sanctioned the project, the Government was determined that it should be completed, and resolved that the engineer should be held to his self-appointed time limit. The penalty it stipulated was exacting. For every day over the ninth year Favre was to forfeit £200, or $1000, for six months, and then double that penalty per day until completion. A year was thus allowed over and above what he demanded to cope with any unforeseen contingencies that might arise during the progress of the task. Similarly, M. Favre was to receive a premium of £200, or $1000, a day for every day he was in advance of the stipulated period. His Italian competitor, while agreeable to the forfeit, stipulated that it should not be enforced until after the eleventh year, which terms the authorities refused to entertain. To ensure securing the forfeit money should the engineer be late, Favre was compelled to deposit a sum of £320,000 ($1,600,000) with the Government before a stone was moved.

No undertaking of such a magnitude as this tunnel, although protected adequately by severe restrictions, ever has been carried out in the face of so many vicissitudes; no engineer ever has been so harassed as was M. Favre. From the moment the tender was signed and sealed troubles commenced, some incidental to the task, others purposely thrown in his way by jealous outside interests. In the first place, the Government undertook, according to the terms of the contract, to have the approaches to the tunnel completed so that he could commence operations without delay. This was not done. Further opposition was then encountered from another and unexpected quarter, which assumed such proportions as to jeopardise the whole scheme. Italy, having contributed about a sixth of the cost, and who therefore had an important voice in the matter, demanded that half the work should be granted to the Italian engineers who had been engaged upon the Mont Cenis tunnel. This was a bitter question, and it took M. Favre two weary months to adjust it.

These hindrances at last settled satisfactorily, work was commenced on the northern side of the Alps at Göschenen on June 4, 1872, and at Airolo, the southern portal, on July 2 of the following year. The preliminary preparations were of a gigantic character. Though M. Favre had sublet the constructional contract for the tunnel itself, he was primarily responsible and nursed it as the engineer-in-chief. Huge plants had to be installed at either end for supplying the various demands for power for a thousand-and-one purposes. At the northern end water turbines were laid down, driven from the river Reuss, a head of water of 279 feet being available. At the Airolo end a similar installation was established and operated under a water head of 541 feet from the Tremola. Subsequently, it was found that this latter supply was inadequate. But M. Favre was a man of infinite resource. He promptly built a viaduct 12,000 feet in length, tapping the Tessin River, and thus overcame the water power difficulty. Small towns sprang up at either end around the respective portals to house the machinery, the workmen, and innumerable other details.

As tunnel-boring operations upon such a scale as this were in their infancy, this engineer-in-chief perforcedly had to break a great deal of new ground; to carry out considerable pioneer work. Hitherto, the usual tools at the service of the excavators were the pick-axe, shovel, chisel, and sledge-hammer; but such implements as these in a work of this magnitude were akin to forging a mighty crank shaft with a blacksmith’s hammer. New forces had to be created. The Mont Cenis had demonstrated this fact, and in the course of its realisation a new tool appeared. This was the mechanical percussion rock drill, operated by compressed air at a pressure of 112 pounds and upwards per square inch. To furnish the requisite energy to the tools elaborate air-compressing plants had to be laid down. These were designed by Professor Colladon, and they were capable of compressing 1,596 cubic yards of air to a pressure of eight atmospheres every minute, the power being stored in huge cylindrical reservoirs, not unlike mammoth steam boilers, from which the conduits extending to the working faces on either side were charged.

The scene in the tunnel was impressive in the extreme. At the working face a little gallery was bored, about eight feet wide by the same in height, at the roof of the tunnel. The drilling machines were mounted on travelling carriages, with their perforating chisels jutting ugly and business-like from the front. With the pent-up force of eight atmospheres behind them, they rapped against the solid rock and slowly but surely made a perforation. At frequent intervals there was a slight stop, the chisel point was withdrawn and a jet of water, drawn from a tender hauled up in the rear, was directed into the hole, when the chisel instantly resumed its monotonous round. At intervals, a chisel, with its cutting edge blunted from continual hammering at the iron-like mass, was taken out, thrown on one side, and another inserted in its place, to continue the attack on the rock. Progress was laboriously slow, or comparatively rapid, according to the nature of the material encountered. When the rock was of a granitic nature, then advance was only at the rate of an inch or two per hour; on the other hand, when soft, clayey material was tapped, then the chisels bored their way at the rate of as many feet in the same time.