The Mineral argus., 1884-01-03
openinc Of the Can,lIever bridge.

LoCKPoRT, N. Y, Special Telegram, Dec. 20.
AT sn early hour this morning special trains
from New York and Chicago, bearing the
officers and guests of the New
York Central and Micbigane Central
railroad from Buffalo, Rochester, Syracuse
depot here, where they unloadod their
to Witness the formal opening Of
the great cantilever bridge over the Niagara
river. At IL o'clock the bridge was tested
by placing a number of Mogul engines,
whose aggregate weight was 1000 tons, upon
the center of the bridge, and a large number
of engineers, members of the American society,
made a careful examination Of every part
of the structure. Every part was declared
firm. The DETECTION was trifiing and the bridge
was pronounced q success. Following this test
two trains of palace cars, III which we're the
1000 invited guests were run upon the
bridge and there photographed. The first
crossing of the bridge was made Dec. 9TH last,
when Division superintendent Burrows, of the
New York Central, accompanied by a number
of civil engineers and experts, member of the
press and one or two ladies crossed on his pony
engine No. 513.
The bridge is located about 500 feet above the
old railroad suspension bridge. spanning a chasm
$40 feet wide between the bluffs and over 200
feet deep. As the foaming rapids ct this point
rendered 1t impossible to build pleas in the river or
erect temporary supports, II was necessary to de-
sign a structure which could be erected without
such is lse work: TO a tain this end a bridge of the
cantilever type was adopted which would be self
supporting during erection. The principle OF tho
c%autilever is that OF q beam supported at or near
its center, with arms extending both ways, one arm
being held down by an anchorage or counter
weight so that the load on tho overhanging arm
produces an uplifting force in the opposite end
which Is resisted By the co~unterweight- The
structure consists Of two immense steel
towers. 1872 feet 6p inches high.
resting on stone piers thirty-nine feet
hiUb Each Of ithaca fnrrara ns.vnr q aaraffawru
800 feet 2 Sic inches long. One end of each
tower rests upon an abutment at the edge Of the
bluff, while tho other end extends out over the
river. The shore ends of the cantilevers are
anchored to the abutment masonry or anchorage
piers, and both river arms are connected by an in
spap of 100 feet, which is suspended
from the extreme ends Of the river arms. The total
length of the bridge proper is 9IO feet As inches
between the centers of the anchorage piers; the
clear span between towers being 470 feet, The
height from surface OF water to base Of rail is 239
feet. The towers are braced steel structures, con-
tanning four columns each. which are made up Of
plates and angles riyeted together, braced
with horizontal struts and tie rods. The
batter Of the columns at right angles
to the center line of the bridge is 1 in s. and 3aral-
lei to the center line i In "a. The trusses are two
ia number. 2S feet apart between ~centers: the va
rious members being connected with steel pins rs
inches, ga inches, and 5as inches in diameter,
turned accurately SO as to fit the bored pin holes
within i-64 of an inch. The depth Of the canti-
lever trusses over the towers Is 56 feet, and at the
shore ends 81 feet. and at tho river ends 20 feet.
- 4ONtA @AoAhS auu teHtNlpOhtS ~ udu6 OF
plates and angles rivited together ard latticed, the
posts being of 12by 15-iuch chan
nels' latticed. The upper chords Of tho eantileYers
are s-inch bars, the shore arms having a
compression member is inches deep COM
posed Of plates and angles packed between the
chord bars. The shore ends Of tho cantileyers are
attached to short links, oscilating on nirs anchored
to the abuiment masonry, which serve as anchor
ages and also rs rockers to allow for expansion aud
contraction of the shore arms produced by changes
Of temperature. EXPANSION joints are also pro-
Yided for at the connection Of the intermediate
span with the river ends Of the two cantileyers.
The structure is proportional to carry, in addition
TO its own weight, a freight train on each track at
the same time, Weighing one ton per lneal foot,
with each train headed by two 76-ton consolidation
engines, with a factor Of safety Of ). The wind
bracing has been proportional for a pressure Of 3 o
pounds per square foot, on a surface twice the area
Of one face Of the truss, plus area Of floor system,
plus the area Of side Of train taken as 10 feet YER
tical height.