The Wheeling daily intelligencer. [volume] (Wheeling, W. Va.) 1865-1903, 1883-05-24
THE CONNrRuCrION.
How the CaissoSns We're Buiit-Towers
aud SupeIst ructure.

How the Caissons Were Built-Towers
aud SupeIst ructure.
So far as the public are concerned allthat
is apparent is the structure-two huge
stone towers, behind which hangs the
bridge, leadinginto Brooklyn beyond, an
coming into New York. By the aid Of a
cassion, a huge wooden diving bell, on
which we're laid the solid walls oil masonry,
little by little the vast foundation on the
New York side was sunk so feet below the
surface Of the rushing waters, resting on
the bedrocks there. The caisson top was
lo2 feet by 172 feet and 90 feet thick, OF
tough Southern pine, fastened by bolts and
Joints, aggregating $50 tons in weight The
sides ct the top were s feet thick, and
tapered down to s inches thick.
The reader may not appreciate the innu-
merable difficulties OF a technical nature
which conironts the workmen atevery step,
but II Is easy to understand that on this
great, strong box huge layers OF masonry
were laid, and that little by little its "
weight sank 1t to the level carefully prepar.
| ed BY men inside the box or ~caisson, who,
aided by prepared machinery, hauled up
the stone and dirt at the bottom, so that
the final rest was exactly as 1t should be.
The Brooklyn caisson was not ready until
MAY, 1870, at which time 1t was towed into
lis berth near the Fulton ferry slip. After
1t was thoroughly ready the granite blocks,
averaging five tons each, were gradually
laid until the middle Of July OF that
year when compressed air was let in
and workmen began to excavate.
Having finished the foundations in this
extraordinary name the upward pro.
gress Of the great towers was the second
step. Obviously there was nothing about
this oil startling nature. 1t was q tremen.
dous job, for the towers are 276i feet high,
but aside from the necessity for accurate
elevation and the many loopholes and sub.
diyiaions needed for the steel bands and
traces and wire ropes Of the bridge and its
connections with the anchoragee, the
building ofthe masonary there was pre-.
cisely like that Of any other.
THE su~PERsTRucrURE.
The bridge may be said to begin at Chat
ham square in New York and end at the
corner OF Sands and Washington streets in
Brooklyn, but the bridge proper, the single
span which constitutes the marvel OF en-
gineering skill, stretches 1881 feet from
tower to tower and 8 1890 from anchorage to
anchorage. At the towers the bridge is lis
feet above high water mark and the centre
1855 feet. Clearly the first thing to be done
before stretching a single wire across was
the establishment Of an anchorage on each
side OF the river. These anchorages hold
The wires, and are located $50 feet inland
from the towers on each side. There they
stand, vast ag~gregations Of stone, ITO feet
by l3S feet at the base, 90 feet above high
water mark, and weighing 60, 900 tons each.
The bridge is held up by cables-iour
huge punches Of wires, laid parallel and
bound together by an unbroken wrapping,
also Of wire. Each wire Is an eighth OF an
inch thick, and, as there are 5000 Of them
in each cable, making q bunch or bundle
about sixteen inches thick, the physical
difficulty OF binding them to either may
be readily imagined. To do this 1t was
necessary to arrange the wires in small
parcels, 10 to a cable, and each holdine27S
single wires. These parcels or bundles
formed q continuous wire rope 200 miles
long, which was carried from anchorage 10
anchorage, back and forth, 27s times.