New-York tribune., 1867-09-11


the railroad tracks annually without confusion and with
1ut crowdng The central fifth division Of the bridge
will allow people OF leisure and old and young nyalids 20
over the bridge on fine days IN order 10 ENJOY
that m crowded commercial city such promenade Wll
be of ncaiclabc value. Every stranger who visits the
city WILL at least, take two walks on this prom
enade and the receipts OF the Bridge Company from THIS
alone VIII be quite large At each terminus, where
IS 10 feet wide and it, level with
the floors of the railway Beyond this, where the an
of central trsses represented the section
of the suspended structure At each tower the promen'
and is divided INTO two walks, which pass around the
central pier high enough to allow the railway cars TO
have detection Of 1913 feet. which l25 OF the span
The best quality OF iron wre Il suspended over chas
feet will only be exposed to Onethrd Of lis breaking
strain Reducing the width of the chasm to 5000 feet the
plain therefore that the central span of The East River
Bridge which only C0O feet from center TO center OF
of 600 feet more can be made just as SAFE ana as
strong in proportion as span OF 100 rect Inc larger
ton of cost But as the span increases does its cost in.
crease The weight OF superstrucure OF the East RIVER
ana including me weght n pbe 81 oIa naximnm trans
on The bridge by crowds of people the road and foot
ways and the railway trains fully loaded Wlil ne Nv
ton the ma ximum weight the road and i0Otways
assumed pounds per superficial foot whcn is % we
and nromscuonsiy More weight be placed upon the
That The snperscture is suspended four cables of II
inches diameter each made OF the pest quu9 vi ssoct
rltmate strength of 100 tuns neat. The aggregate
strength of the cable stays Will be equal 10 SIX tihe Ie
tension that will result from the above maximum WelS
The question whether iron wire steel wire should be
used iii the cables need not be decided now III iron WIRE
is employed the cables will have to be nearly 80 hohes n
diameter in place of III inches of steel TO guard against
vertical and horizontal oscillations and to insure that de-
gree of stiffness in the flooring which Is a0soey neces
sary the effects of violent gales in such an eAOsed
situation have provided six lines OF o qodI sseS oS
anohOrwal to anchorwall The iron moor beams winch
are spaced In pairs, feet inches apart d ' no
longitudinal trusses at right angles ana are tVeea 70
the middle chords and to the upright posts Ine sn Oh
each truss feet the floor being laid above the center
the upper part OF the truss frames answers ior
protection well as DIVISION III place or ralngs; iuUSc
parts the longitudinal russes which extend below the
1OOrbeams afford an eXceIieht means IoI M,iu
bracing. most effective framing - thus optleu
the greatest emergency. not disposed Ia under
rate the great force OF gale when directedt0wa
the suspCnded work and also fully aware that herein
lies the great danger to all suspension bridges OF Ordinary
design. But my system OF constructor ON ~
d"sfrncye fnrces N is for te same reason that in my
calculation of the requisite supporting strength 30 aise
proportion has been assigned 10 stays ia pace o ee
The East River Bridge viii form huge truss OF l6 feet
span and depth of 100 feet The towers form one
supporting element, the framing OF the moor forms we
second and the extensive system OF stays lOinS Ihc
third The stays arranged in four distinct pans
connected by the floor The latter IN connection Tn
the stays. will support itself without the aSiahee 9i % ,
cables If the structure is viewed III TINS hght II VIII
make different impression upon those WHO are M inc
habit of asSocatng with the idea OF suspension nIaeS
the picture OF free swinging pendulum Ihc Wcg, oi
the superstructure, without eanes WIZ oH a,OU iii h
$1,000 tunS ample to hold up the Moor II the cabes We
po s m % bod the center Of the bridge to provide
for greater strength and security, ana 10 MAINTAIN thc
r1d economy was 10 be exercised for want OF capital,
less strength and stiffness might answer By reduction
of weight and strength great deal OF expensive ma
teTa and Tgrk h @ nes % Of the Work be- also Decreased
ifsg sfofV in he
sred The great features of the work Will be the two
towers The base of each tower at the water line
nred i'm the direction Of the river is J feet long and it,
extreme width will be 80 feet. Below the upper coIce
at the top the tower these dimensions are reduced 10
100 feet by 40 feet This reduction is not effected by
gradual drawing in or Slopng but by soped Offsets at
intervals which leave the intermediate portions 0i
the masonry plumb face The elevation OF the moor Is Us
above high water the hight ot the r0ohg above me
floor is $50 feet making toaI hght Oh zoo zee. s
water to top of roof not including tne Dhustlaue ana
ornamental blocks This large body noes does nor i3im one
solid mass but Is built hollow. TWO large opehnss OF
wehOles each 1 feet by 20 feet wide are LEFT oren IN
tnued 1901 feet above the floor in the form of pointed
arches. The shafts provided with protecting butresses
for the purpose OF saviug masonry 10 gain strength ana
TO improve their architectural appearance III WORK 0
such magnitude and located as IT is between tWo great
No expensive cutting, however, will he required m this
rockwofk below the floor Above the floor draft VIII be
cut around the margin OF each stone ana the face be
tween will be simply cut down to uniform but projecting
level The impression Of the whole Will be that OF mas
81 S ode nq T dmdhsd6 rs sohe Of 20 an
| the inside. or backing Will be rnbbe ana con
|
the Cubical quantity in TIE two towers VIII be b2A
cubic yards u cubic feet each The foundations for
support of these large of masonry must be I'M
yielding Solid rock bottom u preierabe 10 any otncI
hut if such cannot he found at reasonable dph theh
cure. The cubic contents OF one tower Is 3l1l cubic
yards. equal sis124 cubic feet which at lGO weigh
weight of supcrscturc and load OF 4,7j3 tuns, and we
have total OF ~ COS uns neat Now the area OF base at
line is superficial feet and therefore tie pres
upon each superficial foot will be 1888 uns IL is
important that great pressure should he spread IA much
| l4 dane
the base of the masonry Itself either by solid stone or
by concrete But neither of these methods is as good and
Trustworthy a heavy. solid timber foundation.
therefore propose to lay down solid timber platform.
with its lower base enlarged 10 ia feet IN length by &C
feet in width and of depth Of about 20 feet The
area of the lower base will therefore he 1904 superficial
feet and the superintendent pressure will be reduced
from l53 tuns ii tuns per superficial foot Now pres
sure OF to Al tnDs per superficial foot OF foundation is
ordinary and unusual weight imposed upon railroad
bridge foundations with piers of 90 to co feet high and
such pressure will always be considered safe and Sc
bed OF compact gravel sand provided there
is danger Of undermining spreading sideways. The
location Of the anchorage ON the NewYork side VIII he
side facing the latter The Brooklyn anchorage will
he located in James-st and part OF adjoining block
| The anchorage VIII not form one sold mass, pu,
there Will be two large open spaces left in each wall
will add here few remarks explaining Low these spaces
can be improved ana utzed 20 an excellent purpose so
as 10 bring high rate OF rent BY arching and iron floor
ing eight be formed III each anchorage each
over 20 deep feet wide and about high
BY being converted into treasury vaults for the safe
vaults will possess unequaed claims not only for the
City of New-York but for the whole country and the
whole continent. No city the world wOCld possess
treasury vaults OF equal strength. safety, and security
| against fire well AS burglary BY small additional
| expenditure absolute safety may he obtained in every
respect Although the cost OF this masonry will be about
$GOOO0O feel satisfied that If my suggestions carried
out the eventual of safes will pay than per
cent the above cost for these vaults established
and placed under good management, would soon be filed
with threefOurths OF all the investments and secur
ties held in this country. No rock Will be found
available for anchoriDg the suspension cables either
side OF the Each OF the four cables
ohorwas at an elevation of nearly 50 feet above tide
and passes through the sonry distance Of 20 feet
which point a connection is formed with the anchor
| chains. These composed Of 10 sinks the first
is Is feet long the Others are ~ feet inches long
| each, measured from center to center of eye
! Each chain has a total length Of 100 feet
4 m nd n of "A