Waterways and Water Transport in Different Countries by J. Stephen Jeans

THE ISTHMUS OF CORINTH CANAL. One of the many schemes that have been put forward from time to time, with a view to affording a more direct communication between the Ægean and the Black Sea, appears likely to become an accomplished fact by the cutting of the Isthmus of Corinth, which at the point where the ship canal has been undertaken, is about 3¾ miles in breadth. The scheme now being carried out, is understood to have originated with General Tarr, who obtained a concession from the Greek Government for the purpose. The required capital was estimated at some 30,000,000 francs, and this sum was readily subscribed. The undertaking does not present any very considerable engineering difficulties, although it has involved a considerable amount of excavation, the earthwork requiring to be removed being estimated at 10,000,000 cubic metres. The Isthmus of Corinth obliges vessels passing from the Mediterranean and Adriatic Seas to the Archipelago and the Black Sea to make a considerable bend to the south. The idea of piercing the isthmus originated several centuries before the Christian era, and the works were actually commenced before the reign of Nero. The route across the isthmus will shorten the distance between the Piræus and Marseilles 11 per cent.; Genoa, 12·2 per cent.; Venice and Trieste, 18·4 per cent.; and Brindisi, 32·4 per cent. The probable traffic through the canal has been estimated at over 4,500,000 tons. The works were commenced in 1882, following the straight course indicated by the traces of Nero’s canal. The canal will have a depth of 26¼ feet, and a bottom width of 72 feet, like the original section of the Suez Canal; but, as the Corinth Canal has a total length of only about four miles, the transit of vessels through it will be effected without the aid of passing places. The principal mass of the excavation is concentrated within the central 2½ miles, and the greatest depth of cutting is 285 feet. Alluvial soil is mostly found for about two-thirds of a mile from each end; but the central portion consists of close chalk underlying hard calcareous conglomerate and compact sand, necessitating blasting and the use of the pick. Depths of 33 feet are reached within 550 yards of the coast, both in the Bay of Corinth and the Gulf of Egina, and the dredging required at the entrances of the canal is not large. The west entrance, at Poseidonia, is protected by two converging jetties, forming a roadstead; and the east entrance, at Isthunia, is sheltered by a single curved jetty on the northern side. These three jetties, formed with natural blocks, are nearly completed. The canal will be open throughout, as the variations in the level of the sea are very slight; and the only large work of construction is the metal bridge of 262 feet span, which crosses the canal at a height of 170 feet above the water level, and will carry the Piræus and Peloponesus Railway and the road to Corinth over the canal. It is not a little remarkable that both the Greeks and the Romans proposed to make a canal across the Isthmus of Corinth, in order to obtain a navigable passage by the Ionian Sea into the Archipelago. Demetrius Poliorcetes, Julius Cæsar, Nero, and Caligula renewed the attempt, but without success.[213] Before their time, the Cnidians had made the same endeavour, which called forth the famous reply of the Pythia—a reply that may be translated thus— “Delve not, nor towers upon the Isthmian pile: Had Jove so wished, himself had made an isle.” The Isthmus of Corinth Canal has been cut through the tongue of land which is situated between the gulfs of Athens and Lepantus and unites the classic mainland with the shores of the Morea. By its geographical position, this isthmus, as we have seen, bars the union between the Adriatic and the Archipelago, and obliges all vessels passing from the one sea to the other to round Cape Matapan. Its existence materially lengthens the voyages of all ships bound from the western parts of Europe to the Levant, Syria, Asia Minor, and Smyrna. The last-mentioned port is the emporium to which the numerous caravans from the interior of Asia, from Persia, and the Caucasian regions have long transported the rich products of oriental countries still more distant. In a similar manner it lengthens the route from Europe to the Black Sea, which is a matter of serious importance, as from the ports on the latter are shipped the enormous quantities of wheat and other cereals which supply a considerable portion of Western Europe. The junction of the waters of the Adriatic with those of the Archipelago is expected to effect a saving in time of two days in the voyage from the harbours of Brindisi, Ancona, and Trieste, to the Levant. It will also greatly facilitate the establishment of local traffic, and probably lead to the adoption of a regular system of steam communication, of which Greece is much in want. At present, the coast is not particularly well furnished with harbours, but those that do exist are said to be easily capable of extension, and there is some inducement to construct new ones, as the adjoining bays are deep, and afford a secure anchorage for vessels of heavy tonnage. The extreme points of the Isthmus of Corinth are Heapolis and Kalamakis, and supposing them, like Suez and Port Said, to represent the respective mouths of the canal, its length would not exceed three miles at most—an insignificant cutting, so far as the actual lineal dimensions are concerned. It was anticipated, and experience has now demonstrated, that the nature of the material through which the Suez Canal is excavated will constitute the principal and possibly the sole difficulty to be contended with in future. As it is, the reduction of the present batter of the side slopes is imperative. If not performed by excavation, the operation will proceed spontaneously by the gradual sliding of the sand into the water, whence it will be removed by the dredgers, which, under any circumstances, will have a busy time of it for some years to come. Fortunately this difficulty does not exist in the canal in the Morea. The earth is of a tenacious character, which will offer a better resistance to the disintegrating action of the water agitated by the passage of ships, and the motion of screws and paddles, and thus reduce the cost of maintenance and repair. It was estimated that this important work could be carried out at the moderate cost of half a million sterling. Without taking into account the number of contingent steam and sailing ships which would avail themselves of the passage _viâ_ the Corinth Canal, a regular traffic of the boats of the Messageries Impériales, of the Company of Marseilles, of those of the Austrian Lloyd’s, and of those belonging to the Italian service was looked for. With the canal completed, Kalamakis, which at present is but a village, was expected to speedily become a maritime town of importance, and numerous cities, long since abandoned, and, as it were, buried, were to be disinterred, restored to life, and ultimately to become commercial centres, from which the mineral wealth with which the country abounds may be exported. On the 19th February, 1870, the concession for the construction of the Isthmus of Corinth Canal was given to M. Maxime Chollet, on the understanding that the works should be commenced within eighteen months, and completed within six years. The Hellenic Government granted to the concessionnaires all the land required for the canal, and 12,350 acres on each side, as well as the privilege of working the mines, quarries, and forests of the State, within a distance of 19 miles of the canal.[214] It was not, however, until 12 years afterwards that the work was actually proceeded with, so that the terms of the original concession were not carried out. The canal was not formally commenced until the 23rd of April, 1882, the first mine being fired by Her Majesty Queen Olga, in the presence of His Majesty King George, the Diplomatic Corps, and the principal Greek Government officials. According to the plans ultimately adopted, the entrances to the channel will be 100 metres in breadth, diminishing to 22 metres, and the depth will be 8 metres. The nature of the ground through which this channel has to be cut is composed, according to the report of the engineers of the company, of three distinct kinds:— Firstly.—From the Gulf of Corinth, through a plain, consisting of sand and alluvial soil, for the distance of 1¼ kiloms. Secondly.—Through a mountain range, varying in height from 40 to 80 metres, of the length of 4½ kiloms. Thirdly.—Beyond the mountain range to the sea, in the Bay of Kalamaki, the canal will traverse a little plain of the length of 600 metres, composed of alluvial soil and rocks. The excavation of those parts of the canal situated in the plains presented no difficulties, but this was not the case as regards the mountainous part, where a mass of 8,000,000 metres of solid rock has had to be excavated and transported to a distance, which labour, according to the contract, had to be done within the comparatively short period of three years. The following plan of executing the works was decided on by the engineers of the company, M. Gerster and M. Kauser:—[215]