The Providence news. (Providence [R.I.]) 1891-1906, 1899-11-29
DIFFICULT ENGINEERING.

The difficulties OF the task UNDER
taken by the engineers OF the New
York Central in erecting a new super
structure on the Maiden Lane bridge
without stopping traffic are recognized
by railroad men and engineers all over
the country. Since the work has begun
Il has been visited by a number of ex-
pcrts Who have wdtchel rs progress
with interest. The last number OF the
RAILROAD Gazette" contains a descrip-
ton OF the work. from which the fol-
lowing extracts are taken.
The present double-track Hudson
| river bridge now used FOR passenger
/ trains was erected In 1872 by Clark
Reeves AZ Co, and consists OF twelve
pin-connected through hXed spans ana
"a plate girder viaduct on columns, ana
one draw span. aggregating 1900 Feet
in length. The increas q weight OF To-
| comOtlves and rolling sock has ren-
dered necessary the replacing of the
OH structure with modern bridge.
| This VIII BE- located substantially upon
| the existing alignment and with the
sam span lene his but with the base
of thp rails elevated from the draw
span westerly so as 10 be I'm harmony
W IA the new conditions at the passen-
ger station. This raising of the grade
| amounts 10 about four inch-i at the
draw span and increases 10 about four
| feet az tn westerly end OF the bridge.
The new bridge will weigh approx
mately 1900 tons.
For the purpose OF avoiding crossings
al grade OF passengers and baggage az
! the new passenger station, and 90 elm
mate grade crossings at Spencer street
and Livingston avenue beyond tine sta
tion, ana also to remove the objection
able dip ia the tracks between tho
passenger station and Broadway. the
grade OF tn tracks is 10 be raised from
the draw span OF the Hudson river pas
senger bridge westerly to Broadway,
stance of 4ii0 fcCt and varying
i'm height from a few inches 60 eleven
feo,. This work necessitates the con-
struCtion OF ext nsiVe retaining walls
and abutm ants. bridges. filling ana
the rearrangements OF tracks.
The total cost OF the work viii APP
proXimatc $1,000. eco. AMI involves the
use of $4,000 cubic yards of masonry of
various classes 10000 cubic yards OF
filling, ana $500 tons Cf steel.
The first work done was the erection
of false work under all OF the fixed
spans of the Hudson river bridge con-
sisting of timber b nts resting on piles.
y Special pile DIVE was built low
enough 10 noat under the bridge. Tn
draw span was necessarily left unim-
p-ded for The plssag- of The rive.
traitlc and will not BE- rebuilt unt The
c,osc OF navigation. The two shore
spans ~ quay street ana Maiden Lane
were temporarily supported on timber
bents. After the completion OF tha
false-work the floor OF the old bri &c
was blocked and supported thereon.
and the raising OF both tracks was
started beginn ng at the west end of
lhe bridge The Maiden Lane span was
raisad first a small amount by means
" hydraulic Jacks placed under the
ma pins. raising the adjacent spans
nj shore approach simultaneously
nough 20 give Easy grades This meth-
"a was followed untn all the spans
iere raised 10 the new grade and
locked up on the fa,se-work The con
tructiOn of the false work was started |
4-sy-iAaa -i-fr- nj ths bridge |
as started July % ana finished Aug |
s, ..
The southerly end OF the passenger
lfu begins at the northerly end of the |
diu1h n Lane span, and the work of /
eNatng this yarl was begun at tbs |
ME tIlle as the work ON the bridge. |
ne tracks fanhest from the station |
ere raised first 10 the rev grade ON !
ma hlling, and each track toward the
alton was partially raised by steps
that the ent re yard was on an in
med plane. The raising Of the Plat.
rm directly In front of the station /
ID the tracks adjacent thereto was
'dart9Nen on Sunday. September 10.
g temporary platforms. steps. etc.
wing been framed in advance. in
Iding the stairways leading 10 the
It's. wa ming rooms and restaurant
i the work OF raising the tracks at
e STATION and on the bri ige was done
Ithout interruption OF traffic. With
tt the USE or temporary tracks and
ithout accid nj or delays.