Yorkville enquirer. [volume] (Yorkville, S.C.) 1855-2006, 1905-04-04
A GREAT. ENGINEERING FEAT.
How the Two Ends Of The simpIon
Tunnel Mere Brought Together.

How the Two Ends of the simpion
Tunnel Mere Brought Together.
The joining Of the two enis Of the
simplon tunnel marked the completion
of one of the greatest engineering
feats Of the time. The boring OF
tunnel twelve and quarter miles long
Is in itself a large undertaking, but the
engineers FRI charge of this work have
had to contend with many extremely
difficult problems, among the worst
being the spring Of hot wafer. which
finally became 30 troublesome as to
necessitate the abandonment Of one
end Of the work. Now the tunnel is
complete; In a few months trains win
be running through It and most I'M
portant link furnished In tie line of
communication between Italy and Gen.
trail Europe.
The Simplon tunnel pierces Mont
Leone, In the Alps, making a straight
line from Brig, In Switzerland. to
Iselle, in Italy. The boring was car
ried on from both sides of the noun
tain, the work beginning ir August,
1898. The work consists Of two tun-
nels, q main and an auxiliary, paral-
lei, with fifty feet from axis to axis,
and at one point the borings are one
and half miles below the surface, 80
that great heat had to be contended
with. The tunnels are, heavily arched
from end to end. to prevent the block
ing of the way by fragments OF rock
From the Swiss side the borings rise
at a grade Of one metre In 500, ana
from the italian side in 14s. The
summit is 9.572 kilometres from the
Swiss portal and 10.197 from the Ital-
ian end. by last November the main
Swiss boring was carried over the
summit, and when 1t had reached q
point about 800 yards from the Italian
end 1t had to be stopped because OF
the difficulty encountered In the
springs of hot water.
The Swiss boring was carried to the
summit without much trouble, as the
grade naturally carried of the fitra-
ton of water, which amounted to over
700 gallons minute. When the turn
was made the trouble began. In a dis
tance of 1000 yards between the sum-
NIT and the face Of the boring. the IN
flow of water was 1908 gallons per
minute and with the water brought In
artificially for refrigeratng. rock
boring and other appliances the inflow
was 3,s72 gallons minute, which had
of course, to be carried of by the
pumps. Then, in the last 600 feet OF
the main Swiss bore, thirteen springs
of hot water were encountered, vary
ing in temperature from 1OS degrees
to 1T. In the Italian heading, there
was a grade to carry away the water
and no hot springs were being en-
countered, though the men worked In
water proofs, knee deep In water, with
cascades playing over them. The hot
rock and water made the temperature
unbearable for the workers. 1t was
necessary to cool the water Issuing
from the hot springs by playing jets
of cold water into them, and also 10
keep up a continual spraying of the
hot rocks. This water had ID be piped
into the tunnel a great distance TO the
workings, and to keep 1t cool the pipes
had to be covered with broken char
coal and cased In sheet metal. AS the
face Of the heading was carried on, the
problem of getting cold water became
more difficult, and naturally there
came a time when the capacity or the
boring became insufficient for the pip
ing needed to carry on the work. Last
May the engineers in the Swiss bor-
ing opened two hot springs yielding
48O gallons a minute. At the same
time an Alpine storm and landslide
cut off the water supply at the en-
trance. The Swiss boring was stopped
after heavy iron gates had been erect
ed at the lowest point Of the work
on the Italian slope to confine the wa
ter and protect the tunnels approach
ing from Iselle.
The Italian borings, having the ad-
vantage Of gravitational drainage
continued rapidly without special difn-
Guilty until they reached last fall
point about 800 yards from the aban-
doned Swiss workings. Here the hot
springs were encountered. The first OF
these discharged $50 gallons a minute
and had temperature Of ia degrees.
The drainage problem was not so diffi-
cult as in the last part Of the Swiss
work, bat the same system Of cooling
the rock, water and air had to be In
troduced. and consequently. the boring
proceeded very slowly.
When a thin diaphragm Of rock re-
mained between the two main tun-
nels, the great volume Of hot water
which had accumulated In the aban-
doned Swiss workings between the
summit and the italian headway was
drained of the mountain was pierced.
The dispatches show that the last blast
that Joined the two was followed by
rush of hot water In which several
workmen lost their lives.-New York
Evening Sun.