The Dallas weekly herald. [volume] (Dallas, Tex.) 1873-1885, 1883-11-29
TUNNEL TALK.
Subterranean Routes OF Considerable
Length and Cost.
Mountains but Mole Hills In Sciences
Hands.


Hands.
Tunnels Completed and Contemplated.
The Arberg tunnel ranks only after the
Mont Gem and Mount St Gothard tunnels
among great modern engineering works of
its class in Europe. The object of the new
line is to shorten the distance between
western Austria and eastern Switzerland,
create direct traffic between the two
countries and render them independent of
the south German railways over which 1t
has heretofore been conducted. The new
line is DIVIDED into two sections-the first
running from Innsbruck to Lsndeck,
the second from Landeck to Bludenz.
The former, which is forty-tive
miles in length, passes along the
right bank of the Inn. Its construction
presents no extraordinary engineering
difficulties. The construction of the stretch
between Landeck and Bludenz has been
muLh more difficult and costly. 1t is a
mountain line from first to last. In the
valley Of Rosanna the erandient is one in
forty. The road crosses the valley OF Pam
znau on viaduct of three arches each hav-
ing a span of 1877 feet. The length Of this
stretch is thirty.five miles, and the total
estimated cost II, $4,000 hoiins, or So.
S92, 900.
At St. Antoine, l ,721 feet above Landeck,
is the beginning of the great tunnel on
which work has just been com pleted. The
point fixed upon by the Austrian govern
ment for commencing this work 10 not the
one that was chosen by General Nordling,
who first surveyed the ground. The tun-
mel, had his scheme been adopted, would
have been higher up the mountain, shorter,
wide enough only for single rails, and,
therefore, less expensive than the one
finally fixed upon. But the government.
believing that the Arlberg line will some
day be one of the most important in Eu.
rope, decided that 1t was expedient to pro-
vide every facility for q great traffic. The
gradients were made as easy as possible,
even though the tunnel should be little
longer. and the line will be double.railed
throughout its length.
The work OF boring the tunnel began on
the Austrian side iii June, 1880 and in Sep
TENDER operations were begun on the Swiss
side OF the mountain. The work proceeded
at a speed which affords striking illustra-
ton of the Improvements that have lately
been effected in the art OF mountain tun,
neiing. The Mont Gents tunnel WAS bored
at the rate of 8 637 feet year, the st. Goth
ard at the rate of 5,474 ieet, and the Arl-
berg was pierced at the rate OF 1859 feet q
year. The Arlberg engineers also p-ohted
BY the experience of their predecessors in
the matter of cost, for while the outlay Oh
the Mont Gents tunnel was So coo per run
ming meter-39 IL inches-and on the st.
Gothard 81 $50, the expenses of making the
Arlberg did not exceed $3.50 the meter.
In this regard, however, the tunnel last
named benefited by its shortness, since the
| longer the tunnel other things being equal
| the greater the relative cost.
An interesting experiment was made in
| the Arberg tunnel with new sort OF per-
forator. The perforator used in the Mont
Cents and st. Gothard tunnels consisted OF
series of chisels mot diamond pointed, as
has sometimes been stately driven with q
quick, hammer-like action by compressed
air, the machines for the production of
which were actuated by turbines at the two
ends of the galleries. This system was the
one in use on the eastern or Austrian side
of The Arlberg, The chisels cover space
of seven square meters, and make twenty
to twenty-five holes at one time, each from
one and half TO two meters deep. These
are then filled with dynamite and the
mine exploded. Every blast lengthens
the DRIFT by about one and a quarter
meters. The pertorators move forward on
wheels, and the air, compressed to q pres
sure of five atmOspheres, is supplied
through flexible tubes. On the west side
drills are employed of a diameter ofseventy
millimeters, 70 which, hy means of wster
pressure of from sixty TO one hundred at
M ospheres, a rotary movement is commu
nicated. Six or eight of these drills are as
effective as twenty or twenty-five Of the at.
mospheric perforator, md ihe holes they
make are so much wider that equal results
are produced with lighter charges of dyns-
mite.
The greatest difficulty in Alpine tunnel
ing consists less in quarfying out passage
than in getting rid of rubbish. After every
blast the outcome of 1t, in the shape OF loose
material, must be removed before boring
operations can be resumed; and when an at
mosphere already close and impure Is still
further fouled by the smoke of an explol
sion the labor Of removal becomes danger.
ous as well as difficult. Fatal &C.
cidents sometime happen. The leading
miners in the Arlberg tunnel, when en-.
gagged in this work, cover their mouths and
nostrils with sponges which have been
stepped In vinegar, an expedient which
has been found singularly eflicscious In
neutralizing the bad effects of the poison.
Gus air they a. e often compelled TO breathe.
An important part which the removal offs
rubbish plays In these undertakings is
shown 10 the fact that Of the time required
for the making Of the Arlberg tunnel fully
one-haifwas devoted to the carrying away
of loose material.
At times the contractors were unable 10
gil the exsct terms Of their contract,
which stipulated that they we're TO exca-
yAte something like ten feet per diem. For
pest months their progress was not so
crest 90 this, especially on the western
sope OF the mountain, where the rocks
were tougher than those on the
,hs,srn slope. The york was further inn
peosi oy the inrush Of immense quantities
~ gsier. bot this enemy Of the engineer
having be n subdusd the undertaking pro-
ceeded At an even more rapid rate than
that presor.btd 10 the bond. II must, how
pvsrbe q long time before it can be utilized
tor traffic purposes; for even after the main
tast il campisted the approaches have still
N he made AID 3 hu gdrri difiicultiis over.
cor,e such ~ those which interferred with
the utii z.ti0h Of the s.. GothArd boring
Onoe c0npirted hOreysr It will sff0rd q
q1irk rnu nom suitzsrlaBd and France
u fbe wrstern provinces Of Ausriz- The
frst rsgion 70 e beusf-tsd By Toe railway
running under the AriBsrg viii, II course,
be ID. NorsTibzrg but Sslzhs ., 5iyris
utlper and loser Austria fyrUi esd lstris
VII be iapped by ".
Tss Aribsrg isaiis 4 ibnss Aiuire ps sss
Of ehirh the loot T. letter known thsn the
summit The iron horse hss not yet
reached lie bsse, hDd ihJuFh TIE rosd-
blsst-d 10 places through The AlfetE hsl
on Of the sol d rock-is sun .isr.lg piciu-
rp-cuf. most trnvelsrs brund fof TIE Tyr0l
hsve hitherto prsfsrrd the rB1ndab0ut
railway journey b. way Of G4nich and
IrnsbrUck % having their bOIies shaker
in fbs difigsnces that ply between B 'udsuz
sud the pleasant town or The Ion. But IN
rnary rsspecs this spat. which has D0S
ben pierced, i geographically far more
impurtsut than some CHER u more his
t1riral ucts- II 4 the Eaterbed a The tHo
Ersstest rivers Of Eur1pr, and rnsT thus b.
iairly entitled - TIE cist1nction o. boldinr
= h usrs. TIE bEisncs between the rO-th-
81 ard srutherr Gerrnaric s,a'es. To the
one t.lrngs IRE watefrUF which. 49,
crursinr fh-r1Eh ne .l.rag arr r- l-
r-r.s. r-.srs be--t url tars "a l-'rr
slric-L ne TIE elEar uct-f-