The Columbian. [volume] (Bloomsburg, Pa.) 1866-1910, 1905-06-22
GREAT TEST OF ENGINEERING.
SimpIon Tunnel Twelve and a Halt
Miles lonq-Lives Lost In Work.

ing feats OF the time. The boring OF
tunnel 12A miles long is in itself a
large undertaking, but the engineers
in charge of this work have had to
contend with many extremely diff
cult problems, among the worst be-
ing the springs of hot water, which
finally became so troublesome as TO
necesstate the abandonment of one
end of the work. Now the tunnel is
cCmplete in few months trains Will
he running through il, and a most i'm
portant link furnished in the line of
communication between Italy and
Central Europe.
The Simplon tunnel pierces Mont
Leone, in the Alps, making 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 in August,
1898. The work consists of two tun-
nels, a main and an auxiliary, paral-
lei, with 90 feet from axis to axis, and
ot one point the borings are one and
4 half miles below the surface, so
that great heat had to be contended
with The tunnels are heavily arcned
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, and
from the Italian side / in 143. 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 it had reached a
point about 300 yards from the Italian
end it 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 off the
filtration of water, which amounted to
ever 700 gallons a minute. When the
turn was made the trouble began. In
a distance of 1000 yards between the
summit and the face of the boring,
the inflow of water was 1,G0S gallons
per minute, and with the water
brought in artiicially for refrigerat-
ing, rock boring and other appliances
me inflow was 3,672 gallons a minute,
which had. of course to be carried
off by pumps. Then, in the last 600
feet of the main Swiss bore, thirteen
springs of hot water were encoun.
tered, varying in temperature from
los degrees to III In the Italian
heading there was a grade to carry
away the water and no hot springs
were being encountered, though the
men worked In waterproofs, knee
deep in water, with cascades playing
over them. The Swiss had hard
problem. 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 to keep up a contin-
ual spraying of the hot rocks. This
water had to be piped into the tun-
mel great distance to the workings,
and to keep it cool the pipes had to
I've covered with broken charcoal and
cased in sheet metal AS the face OF
tho heading was carried on, the prob
lem Of getting cold water pecame
more difficult, and naturally there
came time when the capacity of the
boring became insufficient for the pip
ing needed to carry on the work. Last
May the engineers in the Swiss bor-
Inc opened two hot springs yielding
4S0 gallons a minute. At the same
time an Alpine storm and landslide
cat 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 water
and protect the tunnels approaching
from Iselle.
The Italian borings, having the ad-
vantage Of gravitational drainage
continued rapidly without special diff
Guilty until they reached last fall a
point about 300 yards from the aban-
doned Swiss workings. Here the hot
springs were encountered. The first
Of these discharged $50 gallons q
minute and had temperature OF ia
degrees. The drainage problem was
hot so difficult as in the last part of
the Swiss work. but the same system
OF cooling the rock, water and air had
TO be introduced, 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 off and the mountain was
pierced. The dispatches show that
the last blast that Joined the two was
followed by a rush of hot water In
which several workmen lost their
lives.-New York Sun