The Minneapolis journal. [volume] (Minneapolis, Minn.) 1888-1939, 1905-04-15
PUSHING ALONG ]
AMAZING TUNNEL
THE ENGINEERING MIRACLE UN-
DER THE HUDSON.
A Method Of Boring that Not Only
crawls Into Hole and Pulls the Hole
In After It, but Pushes the Hole on
Ahead The Romantic Up and Down
History Of a Great Enterprise.

Ii <1L0I IL, Out EuSneS the Hole on |
Ahead-The Romantic Up and Down
History Of Great Enterprise.
Boston Transcript.
The rapid progress made in the con- !
Of the trolley tunnel under the |
Hudson river at New York IL exciting the
wonder and admiration Of engineers. The i
records of fast tunnel-driving have not
only been broken. but left out of sight.
And yet the chief feature Of the work is
its extreme simplicity--the ease with
but impossible is being pushed ahead at
so great speed Says Engineering News
in an editorial:
Everyone has heard of the person who,
for the purpose Of escaping from the OBJ
servation OF his fellowmen, crawled into a
hole and pulled the hole in after him.
That mythical feat is now equaled by the
achievement Of well-known New York
engineer who is driving a tunnel under
the Hudson river and actually pushing the
hole ahead Of him. The work on the
south tube for the Hudson river tunnel,
represents a method of tunnel driving
which, we risk little in saying, has never
been carried on or attempted before in
the world. That 1t is successful is at
tested by the rate at which the tunnel is
being driven, which far exceeds all rec
ords Of fast tunnel driving ever made.
What is being done is to push the ny
sdraulic shield right into the soft mud,
which is forced to either side and up
ward into the bed Of the river. The tun-
mel is thus not being excayated at all,
but it is actually bored In the same man
ner that an awl bores hole in wood or
leather. OF course. in driving tunnel
in this manner, nearly all the difficulties
and dangers usually attendant upon sub
marine tunnelling are eliminated. The
workmen are protected by the iron-walled
tunnel around them and the shield III
front. So long as the shield can shove
its way ahead Without encountering boul-
ders or other obstacle, necessitating the
opening of the bulkhead doors and work
In front Of the shield, the workmen are as
safe as II they were in the open air.
Moreover, when the shield Is pushed for
ward In this manner, there Is actually no
tunnelling work to be done, All the work.
men have to do is to place ring after ring
Of the cast Iron lining as the shield moves
ahead. Hydraulic power makes the hole
that Is ordinarily dug by pick and shovel
and dynamite.
1T will be evident Of course. that this
method Of working is only made possible
by the exceeding softness OF the semi
thru which the tunnel is being driven.
| This semifluid silt has defeated every
engineer who has hitherto attempted to
penetrate It by ordinary tunnelling meth
DDS. De Witt IIaskins spent years OF
| time and a large slice Of Trenor w.
Parks fortune in driving 1000 feet Of the
north tunnel, and the enterprise was then
! abandoned by both engineers and CAPT
! talists. After lying idle for half q dozen
| Z, Itch, ND o0G
4 to complete it with the famous firm OF
i s. Pearson & Son as the contractor and
i the distinguished Sir Benjamin Baker as
/ consulting engineer. But the million and
| q half Of money which was raised proved
] insufficient to complete even the one
1 river tunnel, and again the work was
4 abandoned and lay untouched for thir-
4 teen years y
sIt was in November, 1874, that worl
( on the Hudson river tunnel was begun
I SO that thirty years have now elapsed
! since Mr. Haskins first undertook tn,
4 work. It had come to be universally re-
4 garded by engineers and contractors az
4 the most difficult work ever attempted
4 And now comes forward Charles M. ia
cobs, and. by simply putting force enough
to push his shield right thru the soft silt
discovers that, instead Of being the mos
} difficult tunnelling proposition ever un
H.,
drives his south tunnel along at the as
tonishing rate Of nearly fifty feet a day.
ut is doubtless true that the condition
under the Hudson river are extremely un
usual. Probably in no other submarin
tunnel ever attempted has the materia
. penetrated been soft enough to do wit
!. it what is being done now under the Hud
{ son. There is, however, another piece Q
? tunnel work in connection with tn
: same enterprise which represents condi
tons only too common. The engineer
often asked to drive q tunnel beneath
street surface thru soft material loade
overhead by buildings. often Of grea
8 value. II he judges by the records {
e past experience, he will probably advis
: that the probabilities are exceedin
!. strong that settlement of the buildin
. foundations will occur. In driving tn
2 Howard street tunnel In Baltimore, f.
. example, building after building alon
the line Of the tunnel was injured {
s ruined In Brooklyn. numerous cases {
4 settlement have occurred along tt
= streets where sewer tunnels have bee
e driven; and other instances might easil
/, be cited.
a '.But the approach. to the north TUX
. Of the Hudson river tunnel is being bui
thru a coarse, easily-moved sand, loade
a above by high brick buildings, and II
work is being done with such care as
n corlflne the excapated material to the e,
p act section cut out by the shield. and :
it far the buildings above are intact.
= more noteworthy achievement in sof
ground tunnel-driving it would be hal
!, to find anywhere"