The new Northwest. [volume] (Portland, Or.) 1871-1887, 1872-05-24
The Proposed Bridge,

Accompanying the plans and specifi-
cations of the proposed bridge across the
Willamette at this point submitted to
the Council recently, Colonel Chap
man, as President of the Portland, Dalles
and Salt Lake Railroad Company, read
the following communications: The
Portland, Dalles and Salt Lake Railroad
Company submit for your approval
maps of the plan of the bridge across the
Willamette river at Portland. Una
voidable delay has occurred in present.
ing the plans, OccasiOned mainly in pros
ecuting the enterprise of the Portland,
Dalles and Salt Lake Railroad, of which
the bridge is a part. As will be seen,
the plan only embraces the bridge across
the Willamette river from abutment to
abutment. Not having secured q loca-
ton when the plan was made, Madison
street was taken as given point, and
the length of bridge and height of piers
adjusted to the width and depth of the
river at that locality. The plan shows
the draw to be of the full width of the
bridge, embracing three heavy trusses,
and, therefore, very pOnderous and un-
wieldy. But in the bridges of this char
acter, as in case of the new Long Bridge
at Washington, constructed by the Key
stone Bridge Company, the width of the
roadway of the draw is contracted TO
thirteen feet in the clear, and CARRYING
both railroad and roadway travel on
two trusses, with partition, fence or
screen between the railroad and road
way, and so contracting the dimensions
of the pivot pier. The abutments are
to be of stone. From the scale, the
height and dimensions of piers are
easily ascertained. The pivot and
seat piers are designed to be of stone.
They will be founded upon piles and
timber grillages, on timber cribs we'll
banded together, forming bins or cells
to be filled with stone; otherwise they
will be timber cribs, with suitable foun-
datiOns of piles or timber grillages, the /
cribs to be well banded together, FORM
ing bins or cells, to resist the force of
water and shocks of timberand ice. The
other piers, extending over the sand bar
from the draw to the East Portland
shore, are to be timber, founded upon
cribs well banded together, forming bins
or cells, to be filled with stone. On the
top of these cribs will be bolted the sills
of the timbered piers, which are securely
fastened to the cribs by long bolts, pass
ing up through the crib walls. These
cribs may be more thoroughly secured
by means of piles. The plan of these
piers appear on one of the accompanying
maps. If, however, in the progress of
the work, under the eye of skillful en-
gineer, it be deemed advisable, timber
piers will be omitted, and the crib piers
carried to full height. In all cases where
practicable the cribs are to be secured
in their position by piles. The map of
the fender to the draw explains itself.
Ii Is to be timber cribs, with bins or
cells, to be filled with stone, and secured
i'm ifs FAnafffnr, kr- MI
ture for the railroad or roadway can
only be available in this instance where
the street is sufficiently elevated to al
low one or the other below and between
the street and high water This is not
the case either at Main, Madison or JEFF
fersOn. l have selected Madison and
Asylum streets in East Portland to fill
the requirements of the ordinance and
agreement, hoping that the Council will
allow an opportunity to secure q perma-
nent location. Should q location be Sc
cured where the streets are more ele-
waited, so that the railway may rest upon
the superstructure, the plan of the
bridge will be contracted in width to
fourteen feet for the roadway, and sus-
tanned only by two trusses, instead of
three, and the piers reduced accordingly.
The size of timbers, iron, &c, are
IudIheu on Tile maps ITOlu WHICH, can
readily be determined the strength and
capacity of the bridge. 1 am informed
by competent judges that it is ample
for the heaviest railroad, and roadway
travel; and will be secure if railroad and
roadway and net walk are used stimuli
taneOusly. The bridge is estimated to
carry 5000 pounds per lineal foot on the
railroad side, and ], 800 pounds per lineal
foot on the roadway side. The hracas
and rods to be proportioned to sustain
the bridge when swung open; and the
travelling load when closed. The pivot
bridge will rotate on the patent anti
friction cones, and turn-table as shown
on the accompanying lithOgraphic plan:
the same now in use on the Long Bridge
at Washington.
Let prudence always attend your
Pleasures it is the way to enjoy the