The Cairo bulletin. [volume] (Cairo, Ill.) 1872-1878, 1878-02-03
NOTICE TO CONTRACTORS.
OFFICE OF CITY CLERK,

cairo, U.s., Jan, o, 1915, J
Sealed proposals " ill be received at this
office, directed TO the city council of Cairo,
Illinois, until O'Clock Tuesday evening,
February 9th. A. d. 1878, for the construc-
ton OF q one span iron bridge, together
with The approaches or abutments and
foundation, across Cache river, about one
and one ali miles from Mound City rail-
road depot, and four miles north of the city
OF Cairo, in the counties Of Alexander and
Pulaski, state OF Illinois, according TO the
plans and specifications prepared by John
L. Hely, ESD, Z. E., now on file and sub
ject to examination IN this Office, the spesi-
liCstions of which are O. follows, Wig:
Said bridge and trestle work o be made
up of eighteen (is) OPP, nings OF eight en- (iS)
feet from centre to centre OF po IL. and one
span OF one hun ired (lOO) feet a.ross the
river bed.
The one hundred (iOO) feet span to be OF
iron, and SO propOrtloned that load OF ten
QO) tons dist buted over twepty (20) lineal
tect at the centre OF the span, shall not
strain the iron over twelve thousand
| az 0O0) POUNDS per square inch tensile, or
over seven thousand i've hundred e 5N0)
pounds per square inch shearing strain
the strain in compression to be IN at,
leat in the proportion to the ratio Of
| length to diameter, by Gord0n'6 formula.
The span OF said bridge to be one num-
| dred 400 feet in the clear and the roadway
twelve (l2) feet wide.
The floor to be OF white oak plank two
and oue-hali (2i) inches thick and not over
twelve (i2) inches wide.
| The floor beams to be Of white oak and in
| proportion TO the balanc, of the one hun.
dreG lC0) feet span structure, and also to
be provided with a suitable axle guard.
The alb we to rest upon iron columns pro-
portioned TO the structure to be supported,
the columns at each end OF the bent or iron
span to be placed on mud sill 2Xl2, twen-
~ t20) feet long morticed and tenoned to a
sufficient number of white oak piles, firm.
ly driven into the river bank.
1REsTLE WORK.
The bents to be formed oftour posts 10Xl0
inches square, the Two inner parts to stand
perpe and the two outer parts to
he framed and stand at batter Of one in
| eight. The cap and sill OF the bents to be
l2Xl2 inca square timber, tao caps to be
twenty (21) feet long, and the stills to pro-
jeot on each end two teat past tho outer
edge OF the outside posts. The posts to be
mOrticed and tenoned into the caps and stills,
and each tenon to be pinned with two
tbree-quarter % inch square iron pirs, and
each bent to he brsced by two diagonal
spiked on caps, posts and stills.
The bents to rest or stand upon four mud
sills l2X12 inches and eight ~ feet long set
In the ground and placed on the alignment
of the work.
The carriage way of the 'trestlework to
be sixteen Q6) feet wide, the floor plank
10 be three (3) inches and not over twelve
Q2) inches wide, and to be well spiked on
TO the stripgers and floor beams.
The floor beams to he made up as follows
two (2) stringers of SNl2 inches set on the
caps and sixteen (l6) feet apart from out.
side to outside. The space between said
siringers to be equslly divided for seven
(7) beams of 3Xl2 inches each, and each sci
OF floor beams or spans to have three (S) set:
OF herfingbone bridging OF INA inch scant.
ling.
The stringers and floor beams to rest Of
least Fix (6) inches on the caps.
The stIiDgers to connect by half JOINTS
and 10 be fastened to the caps by one inch
round spikes or bolts eighteen QS) inches
long.
A railing or ballasters four az feet high
to be constructed on each side OF above dis.
cribed trestlework. The posts to be Axe
inch clees and braced on the caps and fasten.
ed on to the sttingers by two (2) one.hali
inch bolts. The parts to be six Coy feet
apart; the hand rail IN inches, and an
axle guard OF 2Xl2 inches, all well fastened
on to the posts.
All OF the above timbers to be OF white
or burr oak of best qua lity, and
the work done In a thorough and work
manlike III inner, and under the supervision
of such person as the committee on streets,
or the city council OF the city OF Cairo may
designate.
The approaches to above trestlework and
bridge to be of earth and with slope oil
not more than one in ten and not les than
sixteen (l6) feet wide on top, with q slope
TO the base Of one in two. Separate bids
will be received for iron span, including
abutments and foundation, for The woode n
trestle portion of said bridge, and for the
earthen approaches, or for the entire
work.
9he right to reject any or all blds, Is re
served. j, b. PHILLTs,
dtd. City Clerk.