The sun. [volume] (New York [N.Y.]) 1833-1916, 1915-09-26

bridge instead of a Cantiloyer h,t1..
was decided upon. \ Cautileycr bride.
in some particulars would laye n,
fered fewer difficulties, hut in o,bs-
ways IL would have had serious draw.
backs. A cantilever bridge may 10
popularity described as a succession n,
seesaws pivoted upon towers but VIII
neighboring ends Joined. this union
OF the counterbalanCing weight OF tho
extended arms serving to helm ON. IN
the support of the intermediate ioined
arms when sustaining a live load.
"The He'll Gate arch. on the Other
hand. depends upon its own dead
weight ana the firmncss Of the toyt
foundations TO anchor ii and To het
the shifting burden of moving tran,
But of course the principal diilcul'l
of such a structure is that encour.
tered during building. when section
by section the arch grows and rise,
as IL reaches out from each side =
the river while tho union. which u''..
mately means strength. has not been
effected. How have We been an'c p.
hold increasing hundreds of tons u.
steel aloft and make 1t safe for 'rar.
cling derricks to work ont on tie
very ends Of the growing arch a,l
from that apparently pcrilous pom
To raise great Orders. &c. high mo
the air for assembling?
Here is where We have tcmpurur.
lily had TO the can,ilcvcI rr..
ciple in assembling the elem"u', =
each half section Of the span. and -
this purpose "e have employee o.,
nomically material which will ,a'.r .r
be used for the immediate s,lr""
Of the tracks destined to traVcisr '.
piers Of the approaches on either .a
of the East River. These hcu,' ape.
ders have been just the thing r,ins.
for the temporary backs;ayS. tu, I'D
anchorages needed for the Suipo' .
the span while banging in mida.r It.
gradually grouing across Hell C
and its dangerous waters.
This temporary countcrhalau., ..
cantilever is something Xix" % titan A.,
letter A lyirN on n leg W.. re
other in the n =. from which r.. 4.
be carried to each half are go 81.
points from either bank. The luN.'
leg rests in n deep trench VIA "'
foot firmly planted against the r".-
face of the neighboring tower and I,
apex is anchored by n hONlike arrange
ment Of other Girders filled with mary
hundreds of tons of earth.
with our backstay iusta. t'!'r ui
| at the rear OF each tower, On" 't';
| panel of the span was hois,ed 30 place
resting at the bottom on tNl gre
slanting pedestals with pivotcd yu.He.'
tons and secured At Tn" top .m1l''
! diately above the unfir.>l"! store.
work by means Of Girdcrs Used '
temporary ties TO carry the ';t'
stress rearward to the upper ."sS p
the cantilevers. When, from a..
shore, the arch had reached waterfall.
for six panels the outer cni~ hJ. 8
sag of quite eight inches ami . Na'
necessary To correct this dc''rmt''
Therefore. from tho top Of o." cant
lever we spread two moro ties Wln.
Joined tho upper chord at the Top .,
the sixth panel OF each ha'' arch 70
either side of the river,
THE ultimate union N, r'
take place until the w"|...r .
favorable. | mean ol tN' We
must wait until the E,trp 90 90
sun il lessened and until tNc 'cm
perature of the air and the ''mper'
ture OF the steel are Identical JUS
before the middle panel is !ns'I''.
each half of the then incomp.o'" are.
will weigh fully $500 ons, The MIC
die panel will weigh 500 to,,s and '-
suspended traCkway with is ro'n'.'
lions to the We sides ~ the lower
chord will bring the total acn1 N".-.
to 10000 IONS of steel alone WE.
that union at the centre las h"~
made, then We shall o. ADJ" 90 ''
move all OF the temporal" Ca''ia'''
structure, and the arch "th SIAM
rigidly and fast upon IN" Era".'' i"'.
holds provided on the river .'1n'' .
each tower.
"We are using in the Wu'a ''' long
est and biggest rivetS lh1' .''' 'l'
been employed within MY N."".,,
upon an undertakinE of l..s s"'
largest of them ARE AN ''. '"'
quarter in diameter and '..-
steel plates which, Com.''' .''
inches thick. ON the pr' |''
bridge the heaviest rlNoie '
and an eighth IN diamc'''
the day before that fatal .''
heads hogan popping oft 4
shots, and when enough eff ."
failed then the suspended r..''
crashed into the rlNcr.
"The Little He'll Gate hn.u
decidedly %intcrosttng. ana "' W"
overshadowing ueighhor r''.
River would he commons
n structure of Importance .
ton has Il length Of l''' geo ,,
made up Of four inverted ...,
truss spans To ~" ',-'.
these howstrin- uu--"- d'
ing affairs, and Vet '.'N ' .rI
of linked eychars - m''.. '."'
more than two inches '"...