Northern Wisconsin advertiser. [volume] (Wabeno, Wis.) 1898-1925, 1900-12-27

" ~ VI - tOho aPlCNNs thN PAObAClu
of supporting the structure while re
moving the material is a rather com
pEoated one 1t is met by placing two
pains of massive I-bears, two feet in
depth and about 35 feet in length
parallel with the tracks and spanning
the section to be excavated, and sup
porting beneath them series OF
transverse IL by II timbers, the tim
bers being secured to the longitudinal
steel I-beams by bolts, each timber
bearing against the base of the track
yokes. With the track thus securely
supported, it was possible to excavate
beneath the structure without inter.
fering with the traffic. After the ex-
cavation has been carried out down
to subgrade, the footings for the steel
columns are laid, the columns erected,
and the l-beams which form the
framework of the walls and roof of
the subway are laid in place. The
temporary timber false work is then
removed, and the concrete arches are
turned between the steel framing.
Following this, four layers of felt and
tar waterproofing are laid completely
around the concrete, and an outer pro-
jecting sheath of concrete and brick
is placed over the whole subway. The
loose material is then filled in and the
street restored to its original surface.
This framing, by the way, is spaced
about five feet apart, and answers in
some sense to the framing or ribs of
modern steamship. During the ex-
cavation, provision has to be made for
supporting the water and gas mains
and cable condults, and this is done by
singing them by chains from IL by
IL timbers, which are temporarily
supported on timber struts.
The particular piece of work to
which we have just referred is, in
respect of the difficulties of excava-
ton, one Of the easiest on the whole
route of the subway, the material be
ing loose, sandy soil, easily removable
by pick and shovel. Over a great por-
ton of the line, however, the excava-
ton will be through solid rock, and
blasting will be necessary. Drilling
will be carried out almost exclusively
by pneumatic drills, and to provide the
power for operating these, two out OF
several power stations have already
and the other at One Hundred and
Sixty-fifth street and the Hudson river
The compressed air is led from the
station by and 10-inch mains of stee
pipe, the mains being laid parallel t.
the route Of the tunnel throughout the
sections which they are intended t.
serve. The air is led from the mains
to the drills by flexible piping.
Although not much of the rapid tran
sit road will lie in tunnel proper
where it does pass beneath the sur
face it will, in places, lie at a very
considerable depth, particularly be
meath Washington Heights. In the
stretch of about IA miles, from One
Hundred and Ninety-fifth street, the
road will be at an average depth OF
about 120 feet below the surface oil
Broadway, and in that distance there
will be two subterranean stations, one
at One Hundred and Sixty-ninth street
100 feet below the street, and another
at One Hundred and Eighty-fi rst
street, at depth of 120 feet. The yer
tical excavation for the shaft will con
tain two large elevators and a stair
way, the stairway being provided in
case of breakdown at any time in
the elevator service. The station will
consist of large chamber excavated
in the solid rock, the roof being in
the form of an elliptical arch. There
will be two elevator landings at the
bottom of the shaft, the upper one oil
which will discharge it's passengers al
the level of a bridge, which will ex
tend across the tracks and enable the
passengers to reach the downtown
tracks. During the morning hours the
elevators will stop at this level, fol
the reason that almost all of the
travel at that time will be in the
downtown direction. During the even
ing hours, when business men are re
turning from the city, the elevators
will run to the lower level, so as to
save passengers the necessity for
climbing any stairways. The eleva
tor cars will be unusually large, with
sufficient capacity to remove all the
passengers unloaded from one train
before the next train enters the sta
ton. The excavation for the One Hun
dred and Sixty-ninth-street station is
so far advanced that the vertical
shaft and the transverse tunnel lead
ing from the shaft to beneath Broad
way are completed, and about rs feet
of drifting has already been completed
north and south beneath Broadway or
the line of the tunnel itself