The Fargo forum and daily republican. [volume] (Fargo, N.D.) 1894-1957, 1906-09-17

neer, Greathead, in the construction
of the Waterloo & City railway tunnel
under the river Thames in 1894.
The contractors, the O'Rourke En-
gineering Construction Co., began OPP
erations in the subaqueous tunnels on
April IS, 1904, the first boring begin
ming on the Manhattan side. On
Sept l operations on the New Jersey
side were begun, a deep shaft having
been sunk on each side prior to the
beginning of the actual boring.
Quietly the work went on, and the
public heard of little that was hap
pening Accidents were remarkably
few There was only one death that
could be traced to the effects of COM
pressed air; there were inevitably
cases of the bends" Two physicians
have been in constant attendance at
the works, and everybody who enters
one of the tubes has to undergo q
rigid examination. Comfortable quar-
tiers, well heated and we'll ventilated,
are provided for the workers, and hot
coffee is given to them, as a stimu-
liant, when they emerge from COM
pressed air.
How Tunnel Is Bored.
The tube itself consists of a series
of iron rings, and the installation of
every ring means a progress Of two
and a half feet. Eleven plates and a
key piece to go at the top complete
the circumference, and an entire ring
weighs about fifteen tons. The cast
iron plates, or sections of the ring,
have flanges at right angles to the sur
/ face, and it is by these that the sue
cessive rings are held together with
bolts. Hydraulic rams, placed against
the fianges every few inches around
the tube, push the shield forward at
maximum pressure of 3,400 tons; If
! the pressure of air in the tube be ia
ken into account the pressure upon
the shield is increased to 4,400 tons.
The shield itself weighs 1914 tons. 1t
| has nine doors in 1t, and through these
comes the rock, or sand, or silt, or
whatever the material through which
: the tube must be driven. Thirty men
work in a gang, and there are three
shifts in the day of twenty-four hours.
The record progress so far is five rings
or twelve and a half feet, in eight
hours. Men of all nationalities have
built the Pennsylvania tubes under
/ the Hudson, negroes having done a
large part of the job. Laziness is
something the contractors never had
to contend with; they say there must
| be something about the compressed
air which generates energy and en-
| thusiasm, for the "muckers" vie with
each other to make the record number
of rings.
Perhaps there has never been an
engineering project in which theory
and practice were so nearly in agree
ment. The engineers calculated the
difficulties closely, and a really re-
markedly system Of reports has been
in effect from the first day. Every
morning Mr.. Jacobs has known the
progress made the day before, to the
very inch, and the amount of rock and
soil excavated, to the cubic foot. The
| Pennsylvania railroad officers and the
contractors hold this perfect system
and the thoroughness of of each days
work chiefly responsible for the
promptness of the meeting of the
/ tubes
Engineers say, too, that no project
| was ever carried out where the EN-
J phasis was so entirely upon the re-
suits, rather than upon the money II
cost to attain them. Records have
been kept with unprecedented accu-
racy and fullness, and they have been
corrected, revised and re-revised with
| bewildering frequency.