The Portland daily press. [volume] (Portland, Me.) 1862-1921, 1878-04-24
The Longest Suspension Bridge in the
World.

To the Editor of the Press:
For the following stat istics in regard to the
great East r Yer bridge connecting New York
and Brooklyn l am indebted to the poiteness
of Mr.. e f Harrington, who was formerly
citizen of Portland. Mr.. Harrington has built
two suspension bridges across the Delaware
river, was superintendent of wood work in the
construction of the Cincinnati bridge across
the Ohio, was superintendent of the construc-
ton of the new bridge at Niagara, and now
hills the responsible position of master mech inic
10 charge of cable making for the East River
bridge of which the construction was begun
Jan 2, 1870 The foundations of the towers
sustaining The structure are, ia New York, rs
feet 6 10 below high water; in Brooklyn, "A feet
inches: masonry in New York tower. 46 945
cubic yards; in Brooklyn tower, 1924 cuuic
yards; weight in New YORK; 1874 1O5 tons;
weight In Brooklyn, 5000 tons; size of towers
at high water line 140 feet by SO feet; height of
hoor at towers above high water 119 feet, height
OF trdge in centre of river with atmospheric
temperature of 500 F., 1856 feet; height of
towers above roadway 157 feet inches;
total height of towers above high water 97 f.et
8 inches over all wi 18th of bridge So feet:
length of river span 1895 feet SIX inches; length
of each land span $50 feet; length of Brook
Ign approach 81 feet; length of New YORK
approach 1850 feet six inches; length of whole
bridge 5,9S7.
The first wire was run out May 30, 1877. The
wire first used weighed at the rate of II feet to
the pound. The wire now used is II feet to the
pound. The wire is of cast steel galvanized
and has been tested to the extent of $500
pounds strain on single wire. No wire is
accepted which will not bear a strain of
1900 pounds. Iron wire of the same size
has tension power of only about 1000
pounds Each strand contains 2S6 wires.
These wires are not fastened separately at the
apcborages, but as the wire is run out the
"bight' is passed around an iron attachment of
sufficient diameter to allow the wires to "ren-
der or slip so as to distribute the strain equally
upon each individual wire This of course in
wolves the splicing together of many of the
COTS 10 which the wire arrives from the factory.
This is done by coupling of special cons,ruc.
ton. The two ends of wire which are to be
joined are cut obliquely, right screw thread
Is cut ON one and q left thread on the other :
the ends are inserted 10 long double nut with
corresponding threads aud the nut is turned on
until the beveled ends of the wires are brought
to bear against each other in the centre of the
nut The uuscreWlng of the coupling by a
rotary motion OF the wire is thus prevented
The wires are run out by machine known as
the travelling sbeave invented by Mr. r Iebling
and modified for this service which requires
unusual strength of machinery account of
the great length of wire, The sheave consists
essentially, of a revolving wheel attached
to an eDsless wire rope by which it is
carried across from one anchorage to the
other. The motive power aud the coils
OF wire are 10 Brooklyn. A loop of wire-one
part OF which IS an Incomplete strand and the
other part wound on druo-is passed around
the wheel which is started for the N-w York
sds and as it goes it uuwinds the wire from the
drum Arrived at the New York anchorage
the loop or blight of wire is passed over a heavy
iron shoe aud the sheave returns empty Mean
while the wire on the Brooklyn side is passed
over similar shoe aud the sheaf goes over
with another loop Nineteen strands compose
cable. There are to be- four cables. The
strength of each cable is to be II 200 tons. The
wires are not twisted tOsether-tne 5,434 wires
In each cable are laid parallel and straight ex-
cept the long vertical curves of the cable
Uoder favorable Circumstance sixty-seys u (67)
miles OF wire are run out in nine hours and
half 1t IS anticipated that ali the wires will
be laid by about the first of Dacembsr next
Inc WORK is now thoroughly systematized and
progresses with great reg ularity.
No accident requiring medical or surgical
care has occurred TO any mao employed on the
cable work. Other items L reserve for future
letter. g. RR
Brooklyn, April 49, 1873.