The Cairo bulletin. [volume] (Cairo, Ill.) 1872-1878, 1878-01-18
NOTICE TO CONTRACTORS.
OFFICE OF CITY CLERK,

Cairo, Ills, Jan. 3, 1878,
Sealed proposals will be received at this
office, directed to the city council Of Cairo,
Illinois, until 5 o'clock Tuesday evening,
February 10th, A. ID. 1878, for the. construc-
ton OF one span iron bridge, together
with the approaches or abutments and
foundation. across Cache river, about one
and one lali 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, Esq, Z. e., now on file and sub
lect to examination IN this office, the speci-
fcations of which are as follows, viz:
Said bridge and trestle work 10 be made
up of eighteen u.s. openings OF eighteen (lS)
feet from centre to centre OF posts, and one
span OF one hundred 900 feet across the
river bed.
The one hundred (iOO) feet span to be of
iron, and SO proportional that load OF ten
(l0) tSns distributed over twepty (1O) lineal
ieet at the centre Of the span, shall not
strain the iron over twelve thousand
az, OOO) pounds per square inch tensile, or
over seven thousand five hundred q 500
pounds per square inch Shearing strain
the strain in compression TO be In at,
least in the proportion to the ratio Of
length to diameter, by Gordon's formula.
The span OF said bridge TO be one hun
dred (l00) feet in the clear and the roadway
twelve Q2) feet wide.
The floor to be OF white oak plank two
and one-hait (2t) inches thick and not over
twelve (i2) inches wide.
The floor beams to be of white oak and In
proportion to the balance of the one hun.
dreQ (l00) feet span structure, and also to
be provided with q suitable axle guard.
Th5 above 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 l2X12, twen-
| " COY feet long mortlced and tenoned to a
sufficient number Of white oak piles, firm.
" drive" into fR shs lev w eefRAs'
The bents to be formed offour posts 10X Il
inches square, the Two inner parts to stand
perpendicular and the two outer parts to
! be framed and stand at batter Of one in
| eight. The cap aud sill OF the bents to be
l2Xl2 inch square timber, the caps to be
twenty COY feet long, and the stills to pro-
ject on each end two feet past the 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 az inch square iron pirs, ant
each bent to be braced by two diagona
braces OF l2X2l inch plank, well fitted anC
spiked on caps, posts and sills.
The bents to rest or stand u pom four muC
stills 12Xl II inches and eight (s) feet long Sc
in the ground and placed on the alignmen
of the work.
The carriage way of the .trestlework t.
be sixteen Q6) feet wide, the floor planl
10 be three az inches and not over lively,
| haa Wi nd IN ha bid
to the striDgers and floor beams.
The floor beams TO be made up as follows
two o. stringers OF SKIP inches set on tn,
caps and sixteen (IG) feet apart from out
side 10 outside. The space between sale
stringers to be equslly divided for sever
| % beams Of 3Xl2 inches each and each sc
OF floor beams or pans 10 have three (3) set
OF hergingbone bridging of 2X4 inch scant
ling.
The stringeTs and floor beams to rest q
least six (6) inches on the caps.
The strlngers to connect by half JOINT
and TO be fastened to the caps by one incl
round spikes or bolts eighteen u.s. inche
long.
A railing or ballasters four a. feet higl
to be constructed on each side OF above dis
cribed trestlework. The posts to be Ak
inch clees and braced on the caps and fasten
ed on 10 the stringers by two (2) one.hal
inch bolts. The parts to be six (8l fee
apart; the hand rail 2X4 inches, and al
axle guard Of 2Xl2 inches, all well tastene,
on to the posts.
All OF the above timbers to be OF whit
or burr oak Of best qua lily, an,
the work done in thorough and work
maMike manner, and under the SUPERVISE,
Of such person as the committee on sire ets
or the city council OF the city of Cairo ma
designate.
The approaches to above trestework an
bridge to be of earth and with slope O
not more than one in ten and not less tha
sixteen l6) feet wide on top, with O slop
TO the base Of one in two, Separate bid
viii, be received for iron span, includinI
abutments and foundation, for the woodel
trestle portion of said bridge, and for tn
earthen' approaches, or for the entir
work.
The right to reject any or all bids, is re
served. j. b. PHILLIs,
| dtd. City Clerk.