Probably there is no country in Europe wherein are compressed so many and such varied marvels of engineering executed in connection with the building of the iron road as in Austria. As is well known, the country is a sea of towering rugged mountains, with steep slopes, knotted by crags and scarred by deep gullies, intersected by broad sylvan valleys.

Such topographical conditions impose a severe tax upon the skill and resources of the engineer. Consequently this territory has been the scene of many grim grapples with Nature—some in which the odds have been overwhelmingly against the engineers, and in which success has been achieved only by dogged perseverance. Conspicuous in this direction are the wonderful tunnels.

It was the successful piercing of the Mont Cenis and St. Gotthard tunnels that first spurred the Austrian engineers to work of this character. Their first attempt, the boring of the Arlberg, was such a conspicuous success that they did not hesitate afterwards to have recourse to such methods when all other means appeared impracticable. To-day the country can point to four huge Alpine tunnels which stand among the foremost achievements of their class in the world. Such ways and means for forcing the iron road from one point to another are highly expensive, but in each instance the ends have justified the means. By their provision, points only a few miles apart as the crow flies, and which with surface railways could have been connected only by wearying, devious routes, have been brought into close communication.

When the Arlberg chain was taken in hand, the preliminary surveys showed that it would approximate seven miles in length, and that about the centre of the tunnel a solid mass of rock, 1,600 feet in thickness, would extend from the roof and track to the storm-swept mountain pass overhead.

At this time the two previous projects of this character had proved so costly, had occupied such a long time, and had entailed the grappling with technical difficulties such as never had been encountered before, that the idea of tunnelling the Arlberg was entertained with mixed feelings. But Julius Lott, the engineer-in-chief, was not to be dissuaded from his enterprise. He maintained that it could be accomplished far more quickly and cheaply than had been the Cenis or Gotthard works. True, it was not to be quite so long as either of the latter undertakings, but similar difficulties, if not others more perplexing, might lurk buried there in the heart of the crest. The engineer was urged in his decision by the perfection of a new boring implement which had been evolved during the final stages of the Gotthard tunnel. Although the circumstances there did not enable the new invention to demonstrate its possibilities to the full, yet what had been done sufficed to show that the new tool was destined to revolutionise the methods adopted in such huge boring operations.

This was the Brandt rock-drill, a wonderful appliance which in one stroke displaced incalculable manual labour. The tool is operated by water pressure, and the drill ploughs its way into the rock under a rotary movement in much the same manner as an auger forces its way through a piece of wood. The water pressure brought to bear upon the drill is tremendous, ranging from 1,400 to 1,680 pounds per square inch, and even the hardest rock scarcely can resist its attack.

But, as may be supposed, at times the hard texture of the rock played sad havoc with the cutting edge of the drill. Occasionally three or four drills were put out of service with every yard of advance, and even then progress was painfully slow. When, however, soft rock was encountered the tool cleaved its way through very rapidly, the cutter biting half-an-inch or more into the material with every revolution. Then it was found possible to speed up the rotations to as many as seven or eight per minute, with proportionate increase of life for the cutting edge.

Precisely what this Brandt drill signified to the engineers in connection with this tunnel may be gathered from the fact that from the time drilling commenced, in 1880, only four years elapsed before communication was established between Bluden on the one and Innsbruck on the other side of the range. In this short period a passage 26 feet high by 23 feet wide was cut through solid rock for a distance of 6⅜ miles at a total cost of £1,500,000, or $7,500,000. In comparison with the two previous enterprises of the same character this was a magnificent achievement. The Cenis tunnel, 7½ miles in length, occupied some 13 years to complete, while some 8 years were required to drive 9¼ miles through the St. Gotthard. This was an achievement of which those engaged in the task were justly proud. Indeed, the Austrians hold a unique position in the rapidity with which they can drive these gigantic undertakings through the most formidable mountain chains.

The section of railway upon which this tunnel is situated sorely tried the ingenuity of the engineers up to the Paznaun valley. The line clings to the mountain-side, which is broken up by precipitous crags, and these either had to be pierced or blasted right away to provide a path for the railway. Gushing torrents pour madly down these slopes, and had to be spanned by noble and lofty viaducts or bridges. At some places the boiling waters are deflected from their bed into an artificial channel built of concrete; at others there are massive retaining walls to prevent the waterways from breaking bounds and sweeping the embankment away. One wide gorge is bridged by a single iron span 393 feet 8 inches in length. This is the Trisanna viaduct, below which the glacial brook tumbles over the boulders at a depth of some 262 feet. Elaborate precautions also had to be adopted to protect the line from the ravages of avalanches and landslides.

Years before the Arlberg line was contemplated, however, some distinctly noteworthy achievements in engineering had been placed on record by the establishment of railway communication between Vienna and Trieste on the Adriatic Sea. Certainly the line did not follow the shortest route between these two points, but it must be borne in mind that it was undertaken in the early ’forties, when Great Britain, “the home of the railway,” only possessed some 840 miles of line, and railway engineering was quite in its infancy. It is little wonder, therefore, that the engineers of the project in this wild corner of Europe followed a circuitous path, to avoid fearsome obstacles as far as practicable. They resorted to sharp curves and heavy banks, and the line doubled and redoubled in the most amazing manner. Bridges and tunnels were introduced very freely, some of the viaducts spanning deep clefts on the mountain flanks being very lofty.

By the most direct route of this system the journey from the Austrian capital to Trieste occupies nine hours. In that journey, comparatively no longer than that entailed in speeding over the greater distance separating London from Edinburgh, one passes through four distinct expanses of scenery. Vienna nestles in a broad valley flanked on all sides by the towering snow-topped Alps. The line, upon leaving the capital, first traverses the undulating foot-hills, then wends its way through the mountains to gain the richly wooded, verdant and beautiful country of Styria, and finally passes over a vast stretch of wilderness to descend abruptly to the coast.

In forging this link in the railway chain the engineers had to overcome the Semmering range, which is amongst the most tumbled in the whole of the Austrian Alps. How did they do it? By following the natural facilities open to them: a ledge here, a gallery there; passing from this slope to that by a viaduct or bridge; zigzagging up the mountain slopes; tunnelling through rocky eminences; following winding paths for miles merely to gain points only a mile or two apart in a straight line. No doubt if that line were built to-day it would have its length cut in half, for railway engineering has advanced by leaps and bounds since 1848, when this pioneer project was taken in hand.

In carrying their scheme to fulfilment these early engineers unconsciously achieved one notable distinction: they built the first mountain railway. What matter if banks did assume a rise of 132 feet or so per mile, and the line did wander in apparent aimlessness among the peaks? Speed then was not the vital consideration it is to-day, while traffic was comparatively light, so that the haulage facilities were not taxed severely.

This mountain climb on the main line occurs between Gloggnitz and Murzzuschlag, the famous winter sporting centre in the Tyrol. The mountain crest is 4,577 feet above the sea-level, but the railway does not rise to that height; its summit is at 2,940 feet in the middle of a tunnel three-quarters of a mile in length beneath the Semmering Pass. But to gain that altitude from either side of the mountain entailed prodigious work. Pick, shovel, and gunpowder made heavy cuttings through projecting spurs, raised lofty embankments, filled gaping fissures, and cleaved galleries out of the solid rock. The two points on either side of the mountain are only fourteen miles apart in a straight line; by the railway it is more than twice the distance, the outstanding features which were necessary to render the undertaking un fait accompli being fifteen tunnels, and a score of viaducts and bridges. To construct the thirty miles over the Semmering cost a round £2,000,000, or $10,000,000, in money, and occupied between three and four years to complete.

With the march of time, however, the traffic over this railway increased, hand in hand with the expansion of Trieste, to such an extent that it proved inadequate. A more direct route between the capital and the port, as well as accelerated communication with the great centres of Europe, was demanded by the commercial community. This agitation became so insistent that at last the government was compelled to move, and the engineer of the Imperial Railways was commissioned to survey the country for the purpose of devising some scheme which would satisfy the public outcry.

This was no easy task. Innumerable knots of mountains break up the country between Vienna and the Adriatic, and they are compressed so tightly together that the narrow valleys between offered but slight assistance towards the solution of the problem. Then, again, those three well-known mountain ranges, the Tauern, Karawanken, and Julian Alps, stood right in the way, disputing any possibly shorter route than that already in existence.

The prospect before the surveyors was not very promising. However, they braved the elements among the inhospitable peaks, suffered extreme privations and fatigue as they toiled up and down the rugged, wild mountain slopes with their instruments, for month after month. At last they succeeded in formulating a project which was submitted to Parliament. In this it was proposed to make avail of any favourable stretches of existing railways which intersected the valleys in all directions, and to connect them together, so that in the end a tolerably direct route might be obtained. At any rate this proposal would reduce the journey between the Adriatic and Munich by at least eleven hours. The scheme was divided into four broad sections. It was discussed thoroughly in Parliament, but in the end it was decided to carry out in the first instance the most essential parts of the project, because embarkation upon the undertakings as set forth by the engineers would have entailed the expenditure of a gigantic sum of money. Even that which was sanctioned represented a total financial commitment of about £30,000,000, or $150,000,000, for 211¼ miles of line.

The accepted enterprise was memorable because it entailed the piercing of three mountain ranges by tunnels 5¼, 5, and 4 miles in length respectively. Of the total mileage only 41¼ miles were to be level! The remaining 170 miles represented banks, with grades running as high as 132 feet to the mile.

The project as sanctioned was divided into three sections for constructional purposes. The first section is that known as the Pyrhn railway, which connects the main line between Vienna and Switzerland via the Arlberg tunnel at Linz. From this point a short branch line ran directly southwards through the Krems valley to Klaus, having been built for tourist purposes. It was decided to overhaul this spur to bring it into conformity with the conditions of a main line, and to build the new line onwards from Klaus.

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.

On the northern side of the tunnel similar arrangements were laid down. In this instance, however, the electricity, obtained by harnessing two small waterfalls, had to operate wonderful electric drills which were used at this end for boring into the rock—on the southern side hydraulic and pneumatic drills were employed. The working face in the tunnel was illuminated brilliantly by electric light, so that the drillers laboured under conditions vastly dissimilar to those which prevailed when the first Alpine tunnel was driven. As the top of the tunnel was cut out the roof was shored up with heavy timbering, and hard on the tracks of the excavators came the stonemasons, cutting, trimming, and setting the masonry lining into position. The work was so planned that the actual progress per day should be thirteen lineal feet, and although at times the calculations were somewhat upset by something unforeseen being encountered, yet, taken on the whole, the average was well maintained. Commenced in June 1902, the mountain chain was pierced and ready for the double line of rails by November 1905, so that the work had been carried out very smartly indeed.

Emerging from the tunnel, the line once more becomes a single track, and issues into the Wurzner Save valley, the descent continuing until Assling, the terminus of the Karawanken railway, is reached, this point being 151 feet below the southern mouth of the tunnel. Here a connection is formed with the next link in the chain, this being the “Wochenier” section, which runs to the shores of the Adriatic at Trieste.

But before the latter terminal is gained another mountain mass has to be penetrated—the Julian Alps. It is a meandering line in very truth, for the configuration of the country prevented more than short pieces of straight track being sandwiched here and there between sweeping curves, elaborate winds, stiff ascents and descents—in fact, the longest piece of straight line is only of 6,600 feet in the first 55 miles. In running from Assling to the seaboard 28 tunnels are threaded, exclusive of the Wochenier, which is 4 miles long, 15 bridges and 30 viaducts are crossed, while the cuttings and embankments are innumerable. The railway traverses some of the most romantic and wildest scenery in the whole Alpine chain, especially as it approaches the southernmost clump of these mountains.

On this section the engineers accomplished an unparalleled engineering feat. The narrow Isonzo gorge had to be crossed, and it was effected by throwing a single span from one bank to the other, a matter of 733 feet. This is the longest single-arch masonry bridge in the world, and the rail-level is 120 feet above the level of the water. As the coast is approached the windings of the line become more tortuous, while the bridging, owing to the numerous rivers, is terrific. When at last Opcina tunnel is penetrated, the Adriatic is seen spread out in a vast panorama 1000 feet below.

To descend the mountain slopes with an easy grade for a distance of ten miles was a stiff problem. In order to do so the engineers had to carry the track in the form of elaborate saw-like loops. Heavy gradients could not be avoided, and this part of the line is one of the steepest and most trying to the locomotives.

Though these sections of the railway had proved difficult to carry out, it was the Tauern link in the chain that tried the energy and ingenuity of the engineers to the supreme degree, for on this stretch of railway the mighty Tauern group of mountains had to be negotiated. Surveys showed that to pierce this clump involved the boring of a tunnel for a distance of five miles at least. They proved the hardest five miles in the whole undertaking; the piercing of the Karawanken and Wochenier tunnels sank into insignificance by comparison, for this knot of the Alps was found to be formed of much sterner rock. Granite gneiss, one of the hardest substances against which it is possible to bring the edge of a drill, made progress provokingly slow. At times, when the hand drills had to be used, an advance of two feet in the course of twenty-four hours was considered excellent. The Brandt hydraulic drills, however, with the enormous energy behind them, made the task somewhat lighter, for they moved through the hardest rock at a rate of about seventeen feet every day, with occasional spurts of a foot per hour.

In this undertaking, however, many misfortunes served to delay progress. The task had barely commenced, when a flood destroyed part of the works at the northern end. The river whose water had been harnessed had been deviated from its accustomed path, because it flowed over the roof of the tunnel. As the engineers had no desire to invite an inundation by tapping the bed of the river waterway, they had provided it with a new channel. Heavy snows and rains, however, so swelled the volume of the diverted river that it broke through its artificial bonds to resume its original course. The result was that, owing to the crust of earth between the old bed and the roof of the tunnel being so thin, the water crashed through, and poured into the tunnel in an immense cascade.

The men abandoned everything hurriedly, and rushed madly for their lives from the incoming avalanche of water. For days the tunnel was absolutely inaccessible. Not content with flooding the workings, the impetuous torrent completed its devastation by sweeping away many of the supports to the line conveying the water to the drills under a pressure of 1,500 pounds per square inch, leaving the slender conduit of this great force hanging in graceful festoons in mid-air. Some of these gaps were as much as 260 feet in width, and had a break in the pipe occurred widespread damage would have been caused. But the engineers set to work, and reconstructed the temporary dam that had thus been torn roughly away and rebuilt the river’s new channel. At the same time they adopted such precautions as would preclude the possibility of the waterway again inundating the tunnel in times of the most severe floods.

Such incidents, however, are inherent to works of this character. The inundation was but one means adopted by Nature to thwart the advance of the iron road. Work had scarcely been resumed, when another disaster occurred. The drills were whirring merrily against the rock face in the tunnel, and the drillers were light-heartedly conversing with one another as they fed the boring giant in its rock-penetrating task. Suddenly there was a cry of alarm. Water was trickling rapidly from a bore-hole; it rapidly increased in volume. The drillers hurriedly withdrew their tools and backed down the cavern. There was a roar, and a limpid stream burst from the rock face. The drillers stampeded; they had tapped a subterranean spring, and it was now rushing forth with fiendish violence. The engineers hastened to the front. Such a contingency had been expected, for such incidents are inseparable from tunnelling tasks of this magnitude. The rushing stream was turned into one of the conduits at the side to carry it to the tunnel mouth, where it expended its energy harmlessly by tumbling wildly among the rocks. When pockets of water and springs are tapped in this manner, the question is to control the water so encountered in such a manner that it does not interfere with the drilling work or flood the workings. As a matter of fact, when the Simplon tunnel was in progress these underground springs were harnessed and compelled to perform useful work; they were thrown against the rock face to keep down the internal temperature.

Work continued incessantly day and night; but it was hard and exhausting the farther the men advanced. The drills scarcely could bite into the rock, as it was so tough. At one time the question became so acute that the engineers brought up the electric drills used in the Karawanken undertaking in order to see if matters could not be expedited, but they failed to make as much headway as the hydraulic tools. Another handicapping factor was the heat, which rose very rapidly, and although it did not attain that degree experienced in the boring of the Simplon, yet it caused considerable fatigue among the workmen engaged in such a confined space. The elaborate ventilating system sufficed to keep the air as sweet and cool as possible, but it did not solve the problem completely. The workmen, cramped as they were in the confined space—the area available for manipulating the tools only measured a few feet in each direction—often betrayed painful signs of physical distress.

But at last there was a wild cheer, which echoed and re-echoed through the caverns to the tunnel’s mouths. Those outside realised that something untoward had occurred, and in a few seconds the news came through the gloomy depths that the drills had pierced the last 72 inches of rock separating the two headings, and that the Tauern was conquered. That was on July 21, 1907, some five years after the first boulder was torn from the mountain-side. Once this last barrier was broken down the finishing touches were soon applied, and the double track laid from end to end.

Though the Tauern tunnel constitutes the outstanding features on the section stretching from Schwarzach St. Veit to Villach, there are innumerable other subsidiary works which in themselves are of importance. One of more than passing interest is a clever piece of construction in order to overcome a difference of 2,975 feet in level between the Tauern tunnel and Ober Villach by means of a huge “S” loop four and a half miles in length.

The fulfilment of this undertaking constitutes one of the most remarkable railway engineering feats in Europe. Certainly it ranks among the most expensive enterprises that ever have been attempted west of the Urals. To the travelling and commercial community its value is incalculable, for Munich, which was formerly a tedious journey of twenty-three hours from Trieste, is now within twelve hours’ run, while the other great centres of Europe have been brought proportionately nearer the Adriatic by this new and more direct route.