Vermont phÅ“nix. [volume] (Brattleboro, Vt.) 1834-1955, 1872-09-06

THE GREAT EAST RIVER BRIDGE AT
New YoRK.-The Brooklyn pier of the
East river bridge is at present within eight
or ten feet of the road level, and on Satur-
day the filling in of the New York caisson
was finished. At once on the completion
of the Brooklyn pier the three towers
which are TO surmount it will be begun,
and it is hoped that they will be nearly
completed before winter. The New York
pier, although scarcely noticeable from the
Fulton ferry-boats, is about seven feet a.
bovo high water mark, but is not likely to
be finished before next year, though the
Brooklyn towers will be finished much
sooner. The next work will be the anchor
piers, on the completion of which the cable
wires will be laid. This work will require
about three years. The New York caisson
was completed and was towed into posi-
ton last September. By the end of Octo-
Der ten additional courses of timber had
been placed upon it, and by the middle of
December sufficient masonry had been
built to sink it, so that it stood on the bot
tom at high tide, when filled with air. A
cofler-dam had been previously built IL
round it to protect it from the swift tide
currents, and works within it were at once
begun. For the purpose of keeping the
casson filled with air day and night, thir-
teen pump engines were used. The site of
the taisson had been dumping-ground,
and was covered with animal matter, be-
low which were sand, gravel, quicksand,
and rock. The anchor piers are those in
which tho aahlns aft ba
river towers, are TO be secured. The dis
tance between the towers is 1900 feet and
beside the main span, there will be minor
spansat either end 9l0 feet in length. These
will be mostly over the land. The New
York anchor pier will be just north of Do
yer street, between Water uad Cherry sts.,
aud the Brooklyn pier will be in James
street, just above Garrison street. From
these there will be viaduct of arch aud
truss work ending at Chatham street, New
York, and Sands street in Brooklyn. Tho
breadth of the bridge will be S5 feet, and
that of the viaducts 100. Much ofthe prop
erty beneath the vaducts will be purchas-
ed by the company, and will be used as
sites for storehouses. The three towers on
the river piers will be arched over so rs to
make a continuous wall. The key-stones
of the arches will be l22 feet above the level
Of the bridge. The total height of the tow
ers.above. high water will be 27s feet. Over
the towers four cables, 16 inches in dame
ter, made of steel wires, sixth of an inch
thick, and bound together with wire, will
extend. The weight of the bridge between
the piers, including the cables, will be 1900
tons. The maximum of weight the bridge
will support will be llGi tons. The pres
sure on the masonry will be 26 tons per
square foot common brick will sustain
81 tons per square foot, and granite about
1000, so that the towers will pc perfectly
safe. The land spans will balance the riv-
er spans, the pressure on the towers being,
therefore, vertical and not lateral. The
cables will run over iron rollers, at the top
of the towers, in order that they may yield
a trifle should unusual pressure be placed
on any part. Although the charter only re-
quires the bridge to be 1876 feet above high
water, 1t will be l3S feet inches above it.
Variations of temperature will give it a
rise and fall of three feet and two inches;
at its lowest the bridge will be five feet a.
bove the required height, beneath which all
ordinary shipping can pass. The bridge
will be divided into five spans, the two
outer ones for driving, the two within
those for horse-cars, and the central one
for foot passengers. The latter span will
be elev ated above tho rest. One of the
driving spans will be for fast driving, and
the'other for trucks. Teams going west
ward will take the north span, and those
going eastward tho south span. The total
length of the spans and the yiaducts will be
5s62 feet. The horse-cars will be able to
rur in three minutes from Chatham street
to Sands street.