New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1883-05-21

t,tIl
the caisson at once Deg9h az" Zen n on the river
enou0h weight on top OF IL 10 P ,hes ar shaffs
90 % rooi of the caissOn through which carr, an" Ip
excavated tine inside couu DC tne caisson
"v Ven il was sunk on the river D3ta"n ' hv
wai water ws' air. and men could go in and worS
One pound of air pressure equals lwp i one nound
had 10 be added to the air pressure inside rausos AZ d
engine above INDICATED me hegnt o. we 1,a i in
the pressure OF air The highest pressure atai1~ ~,
The easson was "a pounds 10 the square men III UNA
70 gre csne Clown S out %S%G mmediaie
ignite again. Fresh water springs appeared on
%; ;nl' s,fisn wheS depth Of IS feet
reached, and the cais9on was t9 h Nil Win
broken stone and concrete until the whQe t1ns Sr
solid mass and then the work oil erecting inc 'o"0i
SOLVING A GREAT ENGINEERING PROBLEM.
Greater difficulty encountered on the New-horh
side the cissOn was made stronger ana Digger, au
had to b. sunk to depth OF seventy-eght leeI Even
at that depth solid rock not discovered But Jagged
points of stuck up here and there, amid pea OF
quicssand. TIE points OF the ledge WHICH
apDeared only under end OF the casson
were leyelled of and the auckland was connneu
within wall Of concrete. the whole area oil the CARSON
was filed with the same material, alter wmch INV
tower was erected aud finished like the one IN bfo'1n
Til re were many interesting incidents IN the WORK VI
huoino the foundations The pre- OF the compressed
air would sometimes TIT up caisson and portion o,
would escape tarowins up ,nis4 .toTnnc
N MAJ mn watcRman caused a blowout which
covered the adlo oId and injured two or three
persons. Under extreme pressure some , on tne
wnfInnp became subject to certain physical derange-
Ineuts which nave received the name OF clssqn disease
The Brooklyn cassOn caught fre feXefa tlieS anu
Jwiee had 10 be loo1cd with water In December 1870
clrtlcss llOortr placed lighted candle on shtIl 10
close proximity the oakun caulkng OF timber JOINT
way mo ile rmber and ont OF sight, As the pressure
al outward no flame or smoke coaa DC seen va. d inc
caisson ard it some tine before the re was us
covered Colonel ROeoiing was summoned ana ne en-
teIe tbe caiSs0n a, EeioSh PIN, e u +" the
hours In the compressed ar bad us enec' ana ne
was plrialy paralyzed before he reached bone TINS
the beginning of tue disease that mas 30 long pros
traicd him.
rHE TOWERS AND ANCHORAGEs.
The towers. bult of granite, brought from Mane' are
PIG feel inches above high water mark The Brooklyn
tower reached its full lei gh in May 1875, and Its New
yr, mate in july 1876. The New-York tower above
the top o. tine weighs $4,000 TONS The rmness
the founda shown i'll the fact that the tower has
not settled inches At height OF 1lS feet there are
two arched openings IN each tower through which VIII
ps the streams of travel On the top of the tower are
Saddle plates huge iron casungs' on WHICH rest 'he
weight of the cables.
Tue cables fastened in anchor ages $50 feet distant
frn Inc anehorages are built OF stone and
are l29 by iect AT the base aud 80 feet high over
tne to- Of them ran the rOadways INDEBTED Ill
tyea,y TO- each to which are fastened iron bars
formed chains, at the end Of which are the cables
vaults in the anchorages, where the cables join the
anchor eaans. aud they can he inspected at any
the Bridge consists OF granitelpproaehes which
Sands . ana il Ia 97l feet long to the anchorage The
grad feet nine ncHes IN each 100 feet. In this
iron br.ses The NewYork approach is 5t2 long
from Cha; ham-st. the anchorage The streets are
~6crs an iron bridge crosses over the
staton Of the elevated railway Beneath the the
be utilized as warehouses. AZ each end OF
the g station houses of iron and glass; from
hi WILL RI
MAKING THE CABLES.
Alter The towers were completed the next engineering
problem was get the wires over them The cables
could not be made aud then lifted into place The first
wire was carried by ascow on August Ia, 1876
nwas lifted into place the towers and fastened to
the anchorages second wire was then run acrossand
the two WI re fastened together making endless wire
running over driving wheels. 1t was then an easy mat
1crto run across other wires and cabe-makng really
began on June IL, 1877. On August %, 1876
L. f. harrington, the master mechanic, Gro 'sed
the r.ver in rgger's chair, Which,
WAS attached to the traveller" wire Afoobridge
nuEg the top o. the towers was stretched across
iSnr fee wide and was laid small cables 200 feet
hle Two Gveeisht -lneh wire ropes served as hand
the peril rip over 1t weiIe 1t was in existence $3.50.
HIM m npe H. Isl was not Completed until October
10 1873 EacI OF the four cables contains oZ9o par
closely wrapped a solid cylinder and Is 1874 inches
in diameter. many wires could not be handed at
s91ds w6sn twelve strands were flushed in each
cable of the central ones were canped INTO the
form of email cable nine inches III diameter Tbs was
made into tne centre On June a. 1873. the first
ssTo in the of ss s Fy "
swept over the top oil the tower anu INTO ne
river killing TWO men and injuring three more. Alto
grtner some twenty nave been killed during the
erection OF the Bridge
ONE OF THE BRIDGE FRAUDS.
In tho course of the delivery of the wire in the
Bridge yard il was carefully tested and what failed 10
come up TO the standard rejected 1t was after
ward found that Of the rejected wire had again
been delivered and admitted into the work just
how much Of this used can tell but the eng
neers that there is enough extra strength in the
cables TO offset auy weakness from this cause.
When the cables ready for their loads suspended
bands made of wrought iron were fastened on at inter
walls OF seven and Ohe-haf feet. To these bands
attached suspeuGer ropes made Of sheet wires These
ropes ar made hold 100 tons eaci but
ten weight will come upon one OF them The sns
pender hold up the steel structure which forms
Or tine approaches the width of the bridge
with BcgioD blocks and the footway, which is only
three feet the roadways. has asphalt pave
ment But from anchorage To anchorage the bridge Is
different. 1t Is deft combination OF steel beams,
timber except III the space reserved for the Railway
The toal weight Of steel IN the Bridge IS 6G2O
tons. The great delay in tue delivery of this Steel
according TO contract postponed the completion OF the
As now completed there are five parallel avenues one
the Bridge. The nine feet wide cach, ar
path sfieen and onc-haf feet vide On either side
this railway blackstone tor going TO Brook
lyn and for those coming 10 Ncw-York.
CAPACITY OF TUE BRIDGE FOR TRAVEL.
The promenade has capacity, il persons at the
rate OF feet per minute, of allowing $4,000 persons
to pass every hour The roadway will admit the
passage OF 44O vehicles per hour OF weight
OF 3l2 each, estimating three moving vehicles in
every 100 feet The Bridge will sustain 10000 soldiers
marching, better than ordinary bridge.
The TO be propelled by an endless chain but
when they reach the Of the main span they will
the end by theg gravity and momentum. be-
ing under the control brakes Passengers VIII get in
end and will be unable TO get out until they reach
the end 81 tho bridge 1t Is calculated that eighty
such used the elevated roads can DO kept
IN operation at once twenty OF which viii be on ne
bridge al one time. Each car can accommodate 100
passengers and 900 persons be taken across in