Rambles on Railways

by Sir Cusack P. Roney

Albano is the first halting station of the day express train from Rome to Naples; close to it is the Alba lake seven miles round, at an elevation of 700 feet above the level of the sea. 2,000 years ago the Romans constructed a duct to carry off its superfluous water into the Tiber; part of the duct is through a tunnel, which, in consequence of modern repairs, is still in a state of perfect preservation. It is a little more than a mile long, and its dimensions are 6 feet high and 4 feet wide; it was completed in a year.

But the grandest tunnel of ancient Italy is the underground canal constructed by the orders of the Emperor Claudius to draw off the waters of the lake then called Fucinus, now Celano, into the River Siris. This stupendous work, three miles long, and nowhere less than twenty feet high, required the labour of 30,000 men for eleven years to accomplish. It has several shafts as in modern tunnels; it is now in a sound state, having been solidly repaired only a few years ago.

In the second volume of La Vie de Cæsar, by the Emperor Napoleon III., pages 412, et seq., (English edition) will be found the account of the siege of Uxellodum (Puy d’Issolu, near Vayrac), the capture of which by Julius Cæsar, U.C., 703, put him in complete possession of Gaul. The town, surrounded on all sides by steep rocks, was, even without being defended, difficult of access to armed men. It was also well provisioned, but, as its water supply was derived from an abundant spring which arose at the foot of the wall of the town, 300 feet from the channel of the River Tourmente, “Cæsar resolved,” says his Imperial historian, “to drain this spring, and for this purpose he did not hesitate to attempt a laborious undertaking. Opposite to the point where the spring rose, he ordered covered galleries to be pushed forward against the mountain, and, under protection of them, a terrace to be raised. Although these works were attended with great danger and fatigue, they were vigorously persevered in. At the same time, a subterranean excavation on a lower plane than the fountain, and running from the galleries, was made. This work, carried on, free from all danger, was executed without being perceived by the Gauls; the terrace attained a height of sixty feet, and was surmounted by a tower of ten stories, which, without equalling the elevation of the wall of the town, a result it was impossible to attain, still commanded the fountain. Its approaches, battered by engines from the top of the tower, became inaccessible; in consequence of this, many men and animals in the place died of thirst. Nevertheless, the Gauls did not yield. At last, the subterranean gallery having reached the veins of the spring, they were taken and turned aside. The besieged seeing the fountain all at once dried up, believed, in their despair, that it was an intervention of the gods: they submitted to necessity, and surrendered.” Researches made for the purposes of the Vie de Cæsar, by M. J. B. Cessac, assisted subsequently by the Permanent Commission of the Department du Lot, have brought this tunnel fully into view. It was carried through the marl; and the proof that the Roman soldiers had not boring tools suited for penetrating rock is afforded by the fact that, when they came upon it, they deviated in the expectation that they would come upon the tufas which, formed by the waters, would necessarily lead towards the spring. The Roman soldiers were right in their expectations.

The galleries and tunnel, as well as the siege-works, are illustrated by two plates, No. 31 and 32 of the Appendix. The tunnel was about 550 yards long. During M. Cessac’s investigation the timber which supported part of it still existed.

The earliest mention that we have of tunnelling in connection with the Alps dates back more than 400 years. Anne,[125] Duchess of Savoy, conceived the grand project of piercing the Col di Tenda, then, and for nearly two centuries and a-half afterwards, the best and easiest pass available between France and north-western Italy, with a tunnel at about one-third of its height from the summit. It appears, beyond doubt, that the works were begun, but at the death of Anne they were abandoned; after a lapse of three centuries they were resumed in 1782 by order of Victor Amadeus III., King of Savoy. The excavation of the mountain was continued, although not vigorously, until 1794, when it was abandoned, in consequence of the invasion of Savoy by the French. The total length of the tunnel would have been about 3,000 yards, and by means of it a precipitous sugar-loaf ascent of 1,300 feet to the top of the pass would have been avoided. At the present time the idea of the tunnel is revived, it being proposed to construct to it a railway on the Fell system,[126] from Cuneo at the foot of the pass, which place is now connected with Turin and the whole system of Italian railways by a line fifty-four miles long. The Cuneo district is one of the most productive of the fertile plains that fringe the southern slopes of the Alps, and extend for a width of from fifty to sixty miles beyond them.

We did not begin either to make canals or to tunnel in Great Britain until a little more than a century ago. Now we have 2,200 miles of inland navigation, of which 213 are in Scotland and 297 in Ireland. Brindley, the engineer of the Duke of Bridgewater, commenced the Harecastle Tunnel on the Trent and Mersey Canal in 1765, but it took him eleven years to finish it. It was not until 1776 that the first boat was able to go through it. The tunnel is 2,880 yards long, 12 feet wide and 9 feet high. Although Brindley was much troubled with quicksands, the work was completed for the marvellously small sum of £3. 10s. 8d. a yard forward. Some years afterwards, in consequence of the immense increase of the business of the canal, Telford constructed another Harecastle Canal alongside the first, the dimensions of which are—length, 2,936 yards; width, 14 feet; height, 16 feet.

The longest canal tunnel—indeed, the longest tunnel, whether railway or canal—in England is the Marsden, on the Huddersfield Canal, 5,450 yards (3 miles and 170 yards), thus exceeding the longest railway tunnel by 154 yards. The lengths in yards of some of the principal canal tunnels of England are as follows:—Sapperton (Thames and Severn), 4,180; Lapal (Dudley), 3,776; Blisworth (Grand Junction), 3,080; Tipton Green, 2,926; Oxenhall, 2,192; Foulbridge (Leeds and Liverpool), 1,640; Asperton (Hereford and Gloucester), 1,320; Fenny Compton (Oxford), 1,188. From this list we exclude the Old Thames and Medway Canal Tunnel, near Rochester, because the South-Eastern Railway Company, when it purchased the canal, converted the tunnel into one suitable for a railway; its length is 3,740 yards.

The most recently constructed canal tunnel in England is the Netherton Tunnel, on a branch of the Birmingham Canal, having only been completed in 1858. It is 3,036 yards long, 27 feet wide, and 24 feet 4 inches high in the clear. Seventeen shafts altogether were sunk during its construction, of which ten were closed on being used for traffic. The greatest depth of any of the shafts is 344 feet 6 inches, the least 65 feet 9 inches. The time occupied for completing this tunnel was only two years. For full and minute description of this tunnel see proceedings of the “Institution of Civil Engineers,” Vol. XIX.

The village of Highgate, situated on one of the two northern hills in the immediate vicinity of London, was to have had a tunnel 301 feet long, 24 feet wide, and 13 feet high, for the purpose of avoiding the steep and dangerous hill on the great road which led, and still leads from London, towards the North. An Act of Incorporation was obtained, and the undertaking was prosecuted for a time with great energy; but unfortunately, after 130 yards of the work had been accomplished, the whole fell in on the 13th of April, 1812. The accident created an intense sensation, and it was the subject of a drama: “The Highgate Tunnel, or the Secret Arch,” which for a time was a source of attraction at one of the minor theatres at the East end of London. The disaster put an end to the desire for a tunnel, and the present road was constructed through a deep cutting, by means of which much of the steepness of the hill was done away with. Hornsey Lane crosses this cutting, on a noble bridge, which is called the Highgate Arch.

The late Mr. Robert Stephenson, M.P., in his address to the Institution of Civil Engineers, on his election as President in January 1856, stated, that “tunnels for railways had traversed hills and penetrated mountains to the extent of nearly 70 miles,” the miles of railways opened in the United Kingdom at that time being 8,054.