THE WONDERS OF THE TYROL
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.
[Illustration: THE WORKMEN CUTTING AND BLASTING A NARROW PATH ON THE
STEEP MOUNTAIN SLOPES FOR THE KARAWANKEN RAILWAY]
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.
[Illustration: THE MASSIVE STEEL BRIDGE WHICH CARRIES THE RAILWAY
ACROSS THE DRAVE RIVER TO APPROACH THE TUNNEL THROUGH THE KARAWANKEN
RANGE IN THE BACKGROUND.]
[Illustration: THE NORTHERN ENTRANCE TO THE KARAWANKEN TUNNEL.
Five miles in length, through the Karawanken mountain chain.]
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.
[Illustration: THE TAUERN RAILWAY, SHOWING WINDING CHARACTER OF THE
LINE]
[Illustration: THE ENTRANCE TO THE TAUERN TUNNEL,
Five and a quarter miles in length, which occupied five years to bore
through the range
RAILWAY BUILDING IN THE TYROL]
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.
[Illustration: ONE OF THE HUGE LOOPS ON THE TAUERN RAILWAY
Showing heavy character of earth cutting and masonry work.]
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.