The Republican journal. [volume] (Belfast, Me.) 1829-current, 1870-07-28

| The NEW YORK AND BROOKLYN BRIDGE
The Brooklyn Times contains some interest
ing statements in regard to the bridge now
in process of erection, which is to cross the
East river, and connect the two cities. 1t i,
| to be the most extensive work of the kind
ever projected in this country, and will be
one of the greatest mechanical trillmphs o
the age.
1t is to have an elevation of l3O feet above
high tide, SO as to allow the passage of large
vessels beneath it, with a span between the
piers of 1,GUO ieet which will be $50 feet
more than the new suspension bridge 1T
Niagara Falls. There will be secondary
spans on each side of $40 feet to the anchor
walls, at which points the height will be 81
feet above high water. The approaches
willbe supported upon iron guys, and trusseS
resting upon small piers of mason work or
iron columns. These columns, it is proposed
shall form q part Of the walls intended to
divide the space beneath the bridge into
stores, offices, &c., of which the fire and
water proof floor of the bridge shall be the
roof The entire length IF the bridge will
he 1852 feet, or q mile and one ninth, and
the maximum grade required is about 3 feet
6 inches per hundred. 1t is to be eight y-iivc
feet III width and have a broad elevated
path for pedestrians in the middle, with !,
railroad track and two roads tor vehicles on
each side. On the railroad, two passenger
trains will run back and forth alternately,
drawn by endless wire ropes, worked 10y Il
stationary engine on the Brooklyn side.
The weight Of the central span with all the
pressure that can be placed upon il, will hc
four thousand seven hundred and ilty-1hrec
tons. This span will be steadied and sup
ported hy stays from the great piers ol
towers and by four large cables which are to
bear upon the towers and be anchored under
heavy masonry; and this work, it is believed,
may be done SO perfectly that not even IN the
heaviest gale will 4 motion be perccptablc
The towers are to be l3i feet long and DC
feet wide at the water line, and to have IN
elevation above high water of PCS feet.
At present all the energy of the employees
is being expended on the Brooklyn caisson
This it is the intention of the engineers tC
sink 60 feet below the bed Of the river
Twenty feet have already been eNcavatel
The calsson is l6S feet long by l02 wide, anc
ID feet high, constructed of solid timber IT
is, to all ntents and purposes, Just a LARGE
box, turned bottom upwards and forced
down by pressure from the top OF course
the moment the edges touch the bottom o
the river and are pressed hard against it. the
inside water may be entirely displaced by ut
mospheric air. Well, that is what has beer
done with the caisson, and as the men hay,
got all the water out and are now digging
under and around it, additional pressure i
being constantly placed on the top in order
to force it down. Already eleven feet Of
solid timber have been laid on the top, and
one course of limestone blocks, and these
latter are to be piled one above another un
til the caisson is forced down to the requisite
distance, when the erection of the tower will
be commenced. The cavity in which tn,
workmen are now engaged will, when tn,
business of excavation is finished, be file,
with cement, SO that the entire structure will
be one solid mass. The caisson on tn,
Brooklyn side will be finished in about three
months, after which the machinery anc
workmen will be transferred to New York
where they will repeat the same opera
ton, with this difference, that instead of Gt
feet they will have 10 feet to dig. This l.
necesstated by the quality of the bottom on
that side of the river. The entire work will
in ull probability be finished sometime il
1873, at least, that is the expectation of Tho
chief engineer; and should it prove correct
the work will not only be the greatest of th'
kind ever performed, but the most eXpedi
tiously completed.