Sacramento daily record-union. [volume] (Sacramento [Calif.]) 1875-1891, 1883-12-08
THE NEW NIAGARA BRIDGE.

Niagara river is at length spanned in
full view of the mighty cataract by the
Michigan Central's cantilever bridge. On
the llth of last April contract was en-
tered into. The excavations for the found
atoms were begun April 10Th. The pits
for the piers were finished, and the intro
duction of the Beton cement begun June
OH. The foundations were completed June
Doth on the American side, and seven days
later on the Canada side. The first stone
for the piers on the American side was laid
June 26th, and on the Canada side July
18th. The American piers were capped
August 2Odh, and the Canadian September
Sd. On August 29ih the first column OF
steel for the tower was lowered on the
American side, and on the Canada side
September 10Th. The last section Of the
American tower had been laid two days
previous, and on the Canadian tower 1t was
put down September 18Th. On the oath
the first iron for the centilever was run
out, and both centilevers were completed
on the 18th instant. Last Tuesday heavy
beam of timber was thrown across, and the
Canadian and American gangs of builders
were able to clasp hands. One of them,
Jack Mccoy, found the temptation to be
the first man to cross on the beam toe
strong for resistance, and over he went on
keen jump, in violation of the orders Of
his foreman. His eagerness to be the
first man" therefore secured for him
what the workmen designate to be a red
ticket" In other words, he received an
immediate dismissal from the service of the
contractors. Yesterday the work of put
ting in the fixed span begun early, and
when the hour of noon arrived the sections
had been connected and the bridge prac.
tically completed.
The principle of the cantilever plan is
that of trussed beam supported at or neal
it's center, with the arms extending each
way, and one end anchored or counter
weighed to provide for unequal loading.
In practice it is entirely new, this being
the only bridge completed upon this prin'
ciple. The Firth of Forth bridge in Scot.
land, with clear span of 1000 feet, is
being built upon this plan, and also IN this
country the Fraser river bridge, 3l5 feet
clear span, en- the Canadian Pacific. These
are the only examples of this design yet
undertaken.
The total weight of the iron and steeI
entering into the construction of the mas
sive structure is $500 tons. The bridge /;
of sufficient width for double track, and
is built to carry upon each track at the
same time freight train of the heaviest
kind extending the entire length Of the
bridge, headed by two consolidation
engines, and side pressure of thirty
pounds per square foot, which pressure Is
produced by wind having velocity Of
seventy.five miles per hour. Under these
loads the structure is strained only to one.
quarter of it's ultimate strength. The totaI
length of the bridge proper is 900 feet and
inches, divided into two cantilevers oil
S95 feet on the Canadian and 355 feet on
the American side, supported on steel tow.
ers arising from the waters edge. A fixed
span of Il9 feet and inches is suspended
from and connects the river arms of can't.
levers. The clear span across the river is
494 feet and inches, being the broadcast
double track truss span ever yet built. The
bridge spans chasm of $50 feet from bluff
to bluff. The total weight resting on each
OF the towers under a maximum condition
of strain is in round numbers 3. 200 tons
The total uplifting force that can be
exerted on each of the shore arms Of the
cantilever is $40 tons, and the weight Of
each shore anchorage is 500 tons. 1t will
be seen that every single piece of materia
is five times as strong as it actually need
be, 80 that the bridge can be strained tC
only one-fifth of its ultimate strength
Buffalo Courier.