Butte record. (Bidwell, Butte County, Cal.) 1853-1858, 1855-03-24
SPECIFICATIONS

! SPECIFICATIONS
For a Hirs Suspension Bridge, to B
erected at Bidacell, Butte County, Cal
ifornia, for the BidrN Bridge Com
Pany-
The Bridge may have span of two hun
dred and forty feet, measured in a straigh
line from pier to pier There are TO be fou
wire cables, two a side, about two inche
apart on the same plane. Each cable to con
tain three hundred wires, size number ten
each wire in said cables to be first stretch
ed. tested, and freed from kinks, and if of tn
proper strength, to be then layed togethe
lcompactly. giving to each wire in position, tn
same tension Each wire, before they shal
have been made into the cables, shall be dip
ped several times into linseed oil, boiled will
A small portion of litherage and lamphlack -
Each cable is to raped spiraly with wire
tightly. Each cable before being placed to it.
position, is to receive a thick coating of n,
foregoing preparation of lipseed oil &c, anc
finally painted with wife lead paint Each OF
said cables when placed in its position, to have
| the same sine and Fersine. The swag OF
each cable to be not less than twelve feet
The cables at each end are to run over tow
ers, and resting on east iron saddles the same
| as hereinafter mentioned, running back with
+" 'Si oiAc W tuc to"Cis lcct, Oh 10 Inc
point, where they strike the anchorage, each
being fastened to different anchorage on the
same line, on the same plane. and making
equal versines. The anchorages are to be
wrought iron bars, imbedded securely to the
best advantage in the bed rock, so that each
anchorage Will bear a pressure or pull in the
direction of tho cables, equal to one hundred
tons, the same to be done in the best and most
durable manner. Each cable is TO be fastened
to the anchorage by an adjusting screw or
keys, in the most approved manner, having a
strength equal to, or greater than each cable
The suspension chains are to be of number
ten wire, and about three fourths of an inch
in diameter, each wire to be tested and paint
ed as those in the cables. Said chains are to
De fastened alternately to each cable They
are to be fastened at the top to their respect
i've cables, by an iron saddle casping the ca
Die securely. The saddle and suspendng
chains on each cable are to be apart alternate
ly seven feet, measuring from the centre Of
each saddle through the entire span, making
the roadway bearers three and-a half feet
apart. The saddles on each cable are to be
fastened one to the other in a suitable manner
by number seven wire tapping its respective
cable three or more times between cash saddle
The chains at the lower ends are to be fasten-
ed securely to a stirrup that shall clasp the
tranversal road bearers The gtirrups at the
Impending points to be made with an impress
sion at tbs point Of suspension, to receive the
chain. These chains from the point of sus-
pension are to have a slight and uniform obi
guilty towards the longitudinal axis of the
Bridge. as well as towords the centre Of the
curve.
ABUTMENTS OR PIERS,
There is to be one on each side of the river,
about two hundred and forty feet apart Its
foundation is to be eyeled and solid. Each
abutment might be thirty feet long, ten feet
wide, and twelve feet high, where the road
way passes above high warter mark That
particular portion of the pier which is design
ed to support the towers. if the same shall be
built of cast iron-shall be raised about one
foot above the road way These abutments
shall have groove on their face towards each
other, of the proper Dimensions and quality,
for the roadway to abut against
These abutments or piers shall be constructed
of the strongest and best quality of stone
within one half mile of the site of said Bridge
The same is to receive batter on all sides
The stone is to be layed in hydraulic cement
and grouted. The cement to be the best and
most durable The work to be dressed Rub
BILE Masonry.
There shall be four towers, cast iron or
stone They shall each be composed of four
east iron columns, inclning inwards at the
top, aud their base resting on. and fastened to
a tabular iron plate of sufficient size and
strength. Said plate thall be anchored to the
pier. The columns at the top shall be firmly
united to EACH other, and SO constructed that
the towers on the same side, can be firmly
fastened ut the top to each other by an iron
cross bar Of sufficient strength Said cross bar
to have iron bracse connecting it with the
towers. Each tower to be constructed with
view to fasten the cast iron saddles, over which
each cable is to pass. The saddles are to be
seated on rollers on the top of the towers so
that the cables can accommodate themselves.
The same to be doue securely. They are to be
sixteen feet high, and bear pressure of nine
ty tons.
If the towers should be constructed with
stone, they are to be sixteen feet high and
sufficiently strong to bear pressure Of ninety
tons, with proper batter, to be connected at
the top by cross bar of iron or timber and
braced to the towers. The tops shall receive an
iron plate. made fast and permanent to the
tower, to which shall be fastened the cast iron
saddles made as aforesaid.
The road way is to be eighteen feet in the
clear, and the timber used shall be Yellow
Pine, or other timber of equal strength and
dur ability. 1t is to be crowned at the centre
about two feet The road bearers are to be
FIVE by teninches. and not less than TWEEN
ty feet long, excepting every sixth one, which
shall not be less than twsnty I'VE and-a-halt
feet. The road bearers are fastened to the
suspending chains bp stirrups as heretofore
described, and shall at least be one for every
chain, three and half feet apart The road
way bearers shall be covered diagonally with
plank two and a-half inches thick by not less
than twenty feet l5ng, upon which flooring
there shall be a second flooring of the same
thickness and dimensions, layed in a cross di-
agonal to the first. each to be thoroughly
spiked. Inside Of the suspending chains a
piece Of timber two by eight inches shall be
layed the length of the road way. which shall
be fastened by iron bolts to every fourth road
bearer.
THE PARAPET
Shall be constructed on the principle Of
Towns Lattice. The upper cord shall be a
curve with crown of not less than five feet
above the crown of the Bridge The cords
shall be two by eight inches, with diagonal
braces, with three and -a-half feet run,
screwed together with iron rods; also, iron
straining- rods, connecting the upper cord of
the parapet with the road bearers, and the
same screwed together firmly. The circular
cords of the parpet at each end to be securely
anchored ihto the stone a5utments. The road
bearers that are twenty-five and-a half feet
long, are to be braced at each end to the para
pet, to prevent any outward pressure of the
parapet. There is to be a corresponding num-