The railway system of the Argentine Republic is separated from the Chilian system by the chain of the Andes. The English contractors, Messrs. Clark & Co., have undertaken to connect them by a line which starts from Mendoza, the terminus of the Argentine system, and ends at Santa Rosa in Chili, with a total length of 144 miles. The distance from Buenos Ayres to Valparaiso will thus be reduced to 816 miles. The Argentine lines are of 5.4 foot gauge, and those of Chili of 4.6 foot.

The line in course of construction traverses an extremely hilly region. The starting and terminal points are at the levels of 2,338 feet (Mendoza) and 2,706 feet (Santa Rosa) above the sea; the lowest neck of the chain is at the level of 11,287 feet.

Study having shown that a direction line without tunnels, and even with the steepest gradients for traction by adhesion, would lead to a considerable lengthening of the line, and would expose it to avalanches and to obstructions by snow, there was adopted upon a certain length a rack track of the Abt system, with gradients of 8 per cent., and the neck is traversed by a tunnel 3 miles in length and 1,968 feet beneath the surface. The number and length of the tunnels upon the two declivities, moreover, are considerable. They are all provided with rack tracks. The first 80 miles, starting from Mendoza, are exploited by adhesion, with maximum gradients of 2½ per cent. Upon the remaining 64 miles, traction can be effected either by adhesion or racks.

FIG. 1.   REGION TRAVERSED BY THE RAILWAY THROUGH THE ANDES.
FIG. 1. - REGION TRAVERSED BY THE RAILWAY THROUGH THE ANDES.

The track is of 3.28 foot gauge, and this will necessitate trans-shipments upon the two systems. The rails weigh 19 pounds to the running foot in the parts where the exploitation can be effected either through adhesion or racks, and 17 pounds in those in which adhesion alone will be employed.

FIG. 2.   DIRECTION LINE OF THE RAILWAY THROUGH THE ANDES.
FIG. 2. - DIRECTION LINE OF THE RAILWAY THROUGH THE ANDES.

The special locomotives for use on the rack sections will weigh 45 tons in service and will haul 70 ton trains over gradients of 8 percent. Those that are to be employed upon the parts where traction will be by adhesion will be locomotives with five pairs of wheels, three of them coupled. The weight distributed over these latter will be 28 tons. These engines will haul 140 ton trains over gradients of 2 per cent.

The earthwork is now finished over two-thirds of the length, and the track has been laid for a length of 58 miles from Mendoza. It is hoped that it will be possible to open the line to traffic as far as to the summit tunnels in 1891, and to finish the tunnels in 1893. These tunnels will have to be excavated through hard rock. To this effect, it is intended to use drills actuated by electricity through dynamos driven by waterfalls. The Ferroux system seems preferable to the Brandt and other hydraulic systems, seeing the danger of the water being frozen in the conduits placed outside of the tunnels. - Le Genie Civil.