From Auspoint, which is at an altitude of 1,563 feet, the line makes one continual climb, climb, to the Selzthal terminus, nearly 40 miles distant. The average rise ranges from 70 to 132 feet per mile to overcome the Pyrhn Pass, beneath which a tunnel nearly 3 miles in length was bored. This tunnel, however, is only one of many, for there are numerous short burrows through shoulders and crags. Nor are the bridges a whit less majestic. The Steyr River is crossed by a lofty single masonry arch, and again lower down by an iron suspension structure, while the Teichl is spanned by a single-span lattice steel bridge. The loftiness of these structures is an outstanding characteristic. The rivers at the points in question have cut their beds at a great depth below the banks which constitute the railway level. Swerving bends are also conspicuous, for the railway continually swings from one side of the valley to the other.
The construction of the Pyrhn railway, however, was simple in comparison with the other links of this chain of communication. At Klagenfurt, south-east of Vienna, commences the Karawanken railway, so named because it pierces the difficult mountain range of that name. The stretch is only 19 miles in length, but the country proved to be so broken that only 4 miles of level track could be introduced, and those in the vicinity of the stations! Throughout the remaining 15 miles the railway is really a gigantic switchback.
The line hugs the hill-sides, and has to make the rough descent of the broken Hollenburger in order to gain the level of the Drave River, to pass between the Stattnitz on the northern and the Karawanken chains on the southern side of the depression. The mountain-side is steep and broken in the extreme. In all directions gullies extended, where the soft earth had been washed away by the violence of the snow freshets. These had to be filled in with solid, heavy embankments, the debris for which was torn from deep cuttings through projecting humps of rock. Some of the gaps were too wide and deep to be overcome in this summary manner, and had to be bridged. The Hollenburger viaduct stands out prominently among works of this kind. From end to end it measures 262½ feet in length, and in the centre the rift is 92 feet below the level of the rails. The mountains sheer up precipitously on the one, and the beautiful valley of the Rosenbach falls away on the other, side of the track.
Gaining the river-bank, the line sweeps across the waterway by a majestic lofty iron bridge 656 feet in length. Gaining the opposite bank, it plunges among the well-wooded slopes of the Karawanken belt of mountains, effecting a good climb up and down towards the Rosenbach valley, which is crossed by means of a long viaduct, consisting of four arched masonry spans each 24 feet and three steel spans of 177 feet apiece, at a height of 170 feet.
The ascent is heavy, as the objective is the northern entrance to the Karawanken tunnel, which burrows through the range for a distance of five miles. The piercing of this subterranean passage excited considerable attention. The Austrian engineers who had achieved such a triumph in the rapid boring of the Arlberg upheld their reputation as accomplished masters in this phase of railway-building, notwithstanding the fact that the rocky mass was found to be of such unstable character that the tunnel had to be lined from end to end.
The task was taken in hand shortly after the Austrian Government sanctioned these railways in 1901. Boring was carried out simultaneously from each end. The ground around each portal was quickly cleared, and when the work was in full swing 6000 men found employment. The first step was to secure power to furnish the energy to operate the variety of mechanical appliances that were necessary to dislodge and transport the rock, as well as to dispel the Cimmerian gloom in the heart of the mountain. There was a small waterfall six miles from the proposed southern mouth of the tunnel, with a drop of 35 feet, and capable of furnishing some 900 horse-power. This picturesque Alpine cascade was harnessed and compelled to drive turbines and dynamos to generate electricity, which was transmitted by overhead wires for six miles to the boring works at the tunnel entrance. Here the current was pressed into a multitude of services, not the least important of which was the driving of the huge fans, whereby a great volume of clean, pure, cool air was swept in a steady stream through the shaft to strike against the wall of rock upon which the drillers were concentrating their energies, displacing the atmosphere contaminated by the fumes of the dynamite blasting, grime and dust. Moreover, the temperature, which rapidly rose as the heart of the mountain was penetrated, was tempered pleasantly by the incoming currents, so that the fatigue of toiling in the blackness and confined space was reduced.
THE TAUERN RAILWAY, SHOWING WINDING CHARACTER OF THE LINE
THE ENTRANCE TO THE TAUERN TUNNEL,