Vermont watchman and State journal. [volume] (Montpelier, Vt.) 1836-1883, 1849-12-20
VOL. Xiv, NO. 6.---wHoLE NO. 1858.
Suspension Bridge.

The magnitude of the immense Wire
Bridge in the progress of construction over
the Ohio river at Wheeling, will be under
stood from the following description of it,
the items of which are derived from the re-
port of the Engineer, Mr.. Chas. Ellet, Jr.
"The span of the bridge is / ,0l0 feet
flom centre to centre of the supporting tow
ers, being l52 feet longer than the celebrd-
ted Friebourg bridge, which is the greatest
span heretofore constructed The height
of the flooring at its greatest elevation is
81 feet above the low water level The Ohio
giving an elevation of So feet above the
great flood of 1892 and SO above any 9th
CIR known rise OF the stream stage of
water, by the way, that is seldom attained
and when attained is never nayigated in con.
sequence of the overflow Of the banks, the
submerging of the bottoms, and the gener-
al sweeping off Of wood-pilcs, &c. so that
all reference to and comparisons with it are
matters rather of curiosity than OF practical
utility. On rise of twenty feet above low
water there will be an elevation Of II feet
from the surface Of the water to the floor of
the bridge.
: The summit to the eastern tower is l52
SO feet above low water, and 90 feet above
the abutment by which it is supported. The
flooring is "a foot wide, with two foot ways,
each 3 l.2 feet, and an intermediate car
riage way II wide. The flooring is sup
ported by - cables of iron wire, four inch
es in diameter and | $50 feet long. These
cables rest on IRON rollers, placed on the
SUBMITS Of the towers, the movements of
which will relieve the towers of the strain
which would be occasioned by the contrac-
ZION and elongatlon of tie wires, conse-
quent on variations of temperature, or the
transtory loads that may pass over. The
cables are anchored into the heavy masonry
Of the wing walls at each end ofthe bridge.
The length Of the wood work which rests
on the cables is go feet its weight SAG
pounds per lincal foot, or 52l 100 pounds,
or ;!62 tons in the whole Each cable is
composed of $50 strands of No. 10 wire
The weight of each lineal foot of the IL
cables, composed Of $500 strands is $50
pounds, making, with the weight of timber,
bolts, castings, suspenders, &c, $40 pounds
per lineal foot, or A tons as the perma-
nent weight of the bridge itself
Now, Independent ofthis, its own weight,
the bridge is constructed to support the
greatest transitory weight that is ever like
y to be, or l may say, can possibly be
brought upon it. A column of sixteen of
the siX-horse wagons used on the National
read would fill the length of the span from
one abutment to the other The flooring is
wide enough to receive two such columns,
and therefore capable of containing 30 such
teams at a time; and assuming the average
weight of each horse at 700 pounds, and of
each loaded wagon at $4,000 pounds, and
allowing 500 men OF the average weight of
l20 pounds each at the same time, we have
an aggregate of 593 400 pounds or 297
tons as test OF any transitory weight ever
likely to be brought upon it. This is about
equal to the weight of 700 cattle, or 1000
men. Now the aggregate strength of 5000
strands OF wire comprising the cables, at | :
800 pounds tension for each, (and this is as
certaned by machine for the purpose) is
5000, 900 pounds, or 1850 tons. In the
ordinary state of the bridge, therefore, they
will be capable of supporting fve ,timeS the
tension which actually has place, and when
the platform is covered with - loaded teams
they will be capable OF resisting three times
the tension prOduced by the peigM of the
bridge iseJf and three times the adtlitiOnat
tension produced by the load upon tie .fOOr-
I ing. Thus it would seem that the strength
of the cables is more than sufficient for all
practical purposes; and all other parts of
the structure are in the same proportions.
1t is confidently expected, no untoward
event occurring in the meantime, that the
bridge will! be ready for service by the first
of November next. Then may Wheeling
be proud of her great achievement, then
will she have distinguished herself as hav-
ing erected one of the nobcst and one of
the most useful works Of the aye"