Evening public ledger. [volume] (Philadelphia [Pa.]) 1914-1942, 1919-02-01
SUBWAY
UNDER CITY HALL
Engineers, Officials and
Prominent Citizens View
Gigantic Work
ENGINEERING TRIUMPH
Visitors See How Municipal
Building Was Set Upon
New Foundations
Pictures Of the work In the subway
will he fouud on the back pageD

fpicturea Of the work III the subway
will be found on the back pageo
For the first time today the new Broad
street subway under city Han wa'
thrown open for the inspection OF
marty OF engineers, city officials and
prominent Phrladelphians.
The keystone state Construction Com.
many. which has built the great struc'
ture. acted as host TO the visitors The
,r;n was arranged by the Engineers
Club, of this city, which sent out the
Invitations.
The visiting party was invited to a
sr,ecial luncheon at the clubhouse, ai7eI
which they were taken to the subway
and shown around by officials OF the
construction company
The party viewed one Of the most
astonishing pieces of engineering WORK
OF modern times.
Dav Inv day. since work was begun
Senten,ber 10. 1915. Philadelphians have
carrisd on the ordinary business Of life
.above and around the great excavation
annroxinately 100 feet wide by 700 feet
lonR-scarcely realizing that below the
surfac, of the street hundreds Of men
were busy on job as big and as diff
fcult as It was important.
The subway structure which was
shown for the first time today 10 mem
hers of the engineering profession
n,unicipal officials and men prominent IN
The city's life, will be the heart Of the
now underground transit system. \
few years hence the big subway terminal
under city Hall will be as familiar and
as imnortant TO Philadelphiaus as Broad.
street station nearby. Then passengers
for the new subway lines will enter the
great terminal han under the Public
buildings by entrance stairways from
Citv Hall courtyard and from the plazas
outside.
Work 81 Per Cent Completed
The party which visited the subway
today saw the great structure in the
rough. Though IL is S5 per cent com
Melted. the work which remains TO he
done will greatly alter its present an
nearance. The visitors today went
through huge galleries, fauNed by pom
derous walls of concrete and rooted with
tremendous Eirders and archways OF
concrete and steel What engineers call
the core" Of the work has not vet been
removed. This GORE" consists of the
,.ibble and dirt packed tight between
the deep-sunk retaining and dividing
walls, the debris left after the con-
struction men have passed along.
This GORE" will be eNcaVated vir-
tuaIly down to the water line, giving
vastly more head-room than appears at
present from an inspection Of the sub
way.
Passing by along the plazas Of city
Hall. or through the inner courtyard
all that one sees is the covering o
heavy planks which roofs over the eX
ter'or cuts, the few necessary building
to house conveying and eXcavating ma
chinery, and the fenced-in area opposite
Broad Street Station.
Teams or motortrucks driving in an'
out. or standing at the curb while they
We're loaded with dirt brought up from
the excavation shafts show that som'
sore of work is going along there
steadily, but offer no hint Of the magni
tude Of the undertaking.
Great Difficulties Overcome
Building this subway terminal woul,
have been n comparatively simple joi
had the work been simply a matter al
eXcavating "A great pit. lining It will
concrete, and then roofing It over will
street and sidewalk.
The difficulties lay in the fact that IN,
subway makes a sort OF subcellar for &
portion of City Hall, The great marbl,
buildings under which subway traini
will roar in future years weigh 10000
tons The job was to dig under then
and yet keep them from sinking int
their foundations, How well this iOl
was done may be realized from the fac
that the maximum settlement in any
part of city Hall has not exceeded five
eighths of an inch since the work be
gan. No serious cracks have developed
in the building. despite the fact that
in the three and half years since worE
began the whole tremendous weight has
been shifted from its original founda
tiois to new ones Of steel and concrete.
The subway under city Han has beer
costly-far more so than was estimated
originally. The contract price for tn,
work was Sl,737,320 Bat when tn,
contract was let It had not been planned
10 take the subway under the build
ing. The new work necessary becaus,
of The change in the original plans prob
ably will bring the final cost up [,
approximately $3,O0O,OO0.
Huge Jnderpinning Job
The work was essentially an under
pinnlng job. Even the laymen in tn
party which viewed the structure toda,
could see that the CruX of the worl
had been the transfer of the hall'
weight to the great columns and pier
built for the purpose Merely figuring
the loads and strains, and making tn
detailed specifications for the material
which would go into construction. wer
a difficult piece OF engineering work /
had TO be absolutely right, else Their
was grave-danger Of serious damage 4
lie structure above, to say nothing o
possible loss OF life.
The job will be done I'm It's entiret
by midsummer, II the present schedule /
adj cred TO- About $50 men are at wor
on 1t now At no time have there bee
fewer than zoe men working.
Foundations Rest ON Bed Rock
To make the hall secure from sink
ing or cracking. Il was necessary TO Sc
IL ON bed rock The weight rests on wall
built In sections each section approNi
mately six feet in length, ana CARRIE
down to the water line
Below the water line, the strain
borne by great 15-inch steel pipe pile.
II ese piles were driven down thrOug
the muck and water of the lower level,
little by little, until they struck be
rock when firmly anchored there the
were cleaned out and filled with con
crete. The walls were built on top q
them.
ggOO steel plies support Building
The steel-pipe piles are designed 4
carry weight of approximately 10
tons each as a maximum. There ar
22O0 of these piles under the building So
" some places huge weights are ear
y.led nv great columns and pillars V'h